First Aid for the USMLE Step 3

USMLE Step 3 Third Edition TAO LE, MD, MHS Assistant Clinical Professor of Medicine and Pediatrics Chief, Section of Allergy and Immunology Department of Medicine University of Louisville

VIKAS BHUSHAN, MD Diagnostic Radiologist

HERMAN SINGH BAGGA, MD Resident, Department of Urology University of California, San Francisco

New York Chicago San Francisco Lisbon London Madrid Mexico City Milan New Delhi San Juan Seoul Singapore Sydney Toronto

Copyright © 2010, 2008, 2005 by The McGraw-Hill Companies, Inc. All rights reserved. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. ISBN: 978-0-07-173603-9 MHID: 0-07-173603-4 The material in this eBook also appears in the print version of this title: ISBN: 978-0-07-171297-2, MHID: 0-07-171297-6. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. To contact a representative please e-mail us at [email protected]. NOTICE Medicine is an ever-changing science. As new research and clinical experience broaden our knowledge, changes in treatment and drug therapy are required. The authors and the publisher of this work have checked with sources believed to be reliable in their efforts to provide information that is complete and generally in accord with the standards accepted at the time of publication. However, in view of the possibility of human error or changes in medical sciences, neither the authors nor the publisher nor any other party who has been involved in the preparation or publication of this work warrants that the information contained herein is in every respect accurate or complete, and they disclaim all responsibility for any errors or omissions or for the results obtained from use of the information contained in this work. Readers are encouraged to confirm the information contained herein with other sources. For example and in particular, readers are advised to check the product information sheet included in the package of each drug they plan to administer to be certain that the information contained in this work is accurate and that changes have not been made in the recommended dose or in the contraindications for administration. This recommendation is of particular importance in connection with new or infrequently used drugs. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGrawHill”) and its licensors reserve all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior consent. You may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to use the work may be terminated if you fail to comply with these terms. THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the content of any information accessed through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise.

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DEDICATION

To the contributors to this and future editions, who took time to share their experience, advice, and humor for the benefit of students. and To our families, friends, and loved ones, who endured and assisted in the task of assembling this guide.

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Contents Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Faculty Reviewers . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ix Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi How to Contribute . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii CHAPTER 1. Guide to the USMLE Step 3 and Supplement: Guide to the CCS . . . . . . . . . . . . . . . .1 CHAPTER 2. Ambulatory Medicine. . . . . . . . . . . 15 CHAPTER 3. Cardiovascular . . . . . . . . . . . . . . . . . 31 CHAPTER 4. Emergency Medicine . . . . . . . . . . . 49 CHAPTER 5. Endocrinology . . . . . . . . . . . . . . . . . 73 CHAPTER 6. Ethics and Statistics . . . . . . . . . . . . 91 CHAPTER 7. Gastroenterology . . . . . . . . . . . . . 103 CHAPTER 8. Hematology . . . . . . . . . . . . . . . . . . 127 CHAPTER 9. Oncology . . . . . . . . . . . . . . . . . . . . . 143

CHAPTER 10. Infectious Disease . . . . . . . . . . . 165 CHAPTER 11. Musculoskeletal . . . . . . . . . . . . . 195 CHAPTER 12. Nephrology. . . . . . . . . . . . . . . . . . 213 CHAPTER 13. Neurology . . . . . . . . . . . . . . . . . . . 235 CHAPTER 14. Obstetrics . . . . . . . . . . . . . . . . . . . 257 CHAPTER 15. Gynecology. . . . . . . . . . . . . . . . . . 275 CHAPTER 16. Pediatrics . . . . . . . . . . . . . . . . . . . 289 CHAPTER 17. Psychiatry . . . . . . . . . . . . . . . . . . . 331 CHAPTER 18. Pulmonary . . . . . . . . . . . . . . . . . . 357 CHAPTER 19. High-Yield CCS Cases. . . . . . . . . 375 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467 Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 About the Authors . . . . . . . . . . . . . . . . . . . . . . . . . . 497

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vii AUTHORS K. Pallav Kolli, MD Imaging Editor Resident, Department of Radiology and Biomedical Imaging University of California, San Francisco

Clarissa Barnes, MD Resident, Department of Internal Medicine Johns Hopkins Hospital Jonathan Day, MD Resident, Department of Internal Medicine Saint Vincent Hospital

Heidi Reetz, MD Resident, Family Medicine Santa Rosa Family Medicine Residency

Amar Dhand, MD, DPhil Resident, Department of Neurology University of California, San Francisco

Sapna Shah, MD Resident, Department of Internal Medicine University Hospitals Case Medical Center

Catherine R. Harris, MD Resident, Department of Urology University of California, San Francisco

Shannon Shea, MD, MPH Resident, Department of Pediatrics University of California, San Francisco

Sandarsh Kancherla, MD Fellow, Department of Gastroenterology St. Luke’s-Roosevelt Hospital

Benjamin Silverberg, MD, MS Resident, Department of Family Medicine University of Virginia

Nilay Kavathia, MD Resident, Department of Internal Medicine Thomas Jefferson University

Alex Wu, MD Resident, Department of Urology University of California, San Francisco

FACULTY REVIEWERS Charles Angell, MD Assistant Professor of Medicine Johns Hopkins University

Gregory C. Kane, MD Professor of Medicine, Vice-Chairman, Education Jefferson Medical College

Rizwan Aslam, MD Associate Clinical Professor, Department of Radiology and Biomedical Imaging University of California, San Francisco

Armand Krikorian, MD Assistant Professor, Division of Clinical and Molecular Endocrinology Case Western Reserve University

Mitchell Conn, MD Associate Professor of Medicine, Department of Gastroenterology Thomas Jefferson University Hospital

Lowell Lo, MD Assistant Professor, Department of Medicine University of California, San Francisco

Vanja Douglas, MD Assistant Clinical Professor, Department of Neurology University of California, San Francisco Aleksandr Gorenbeyn, MD, FACEP Assistant Professor, Department of Traumatology and Emergency Medicine University of Connecticut Sharad Jain, MD Professor, Department of Clinical Medicine University of California, San Francisco Gregory S. Janis, MD Associate Director, CCU St. Luke’s-Roosevelt Hospital Center

Andrea Marmor, MD, MSEd Assistant Clinical Professor, Department of Pediatrics University of California, San Francisco Charles J. Nock, MD Assistant Professor, Department of Medical Oncology University Hospitals Case Medical Center Maria Isabel Rodriguez, MD Clinical Instructor, Department of Obstetrics and Gynecology University of California, San Francisco David Schneider, MD Faculty, Santa Rosa Family Medicine Residency Associate Clinical Professor, Department of Family and Community Medicine University of California, San Francisco

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Preface With First Aid for the USMLE Step 3, we continue our commitment to providing residents and international medical graduates with the most useful and up-to-date preparation guides for the USMLE exams. This third edition represents a thorough review in many ways and includes the following: • An updated review of hundreds of high-yield Step 3 topics with full-color images, presented in a format designed to encourage easier learning. • An exam preparation guide for the computerized USMLE Step 3 with test-taking strategies for the FRED v2 format. • A high-yield guide to the CCS that includes invaluable tips and shortcuts. • One hundred minicases with presentations and management strategies similar to those of the actual CCS cases. We invite you to share your thoughts and ideas to help us improve First Aid for the USMLE Step 3. See How to Contribute, p. xiii. Tao Le Louisville Vikas Bhushan Los Angeles Herman Singh Bagga San Francisco

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Acknowledgments This has been a collaborative project from the start. We gratefully acknowledge the thoughtful comments, corrections, and advice of the residents, international medical graduates, and faculty who have supported the authors in the development of First Aid for the USMLE Step 3. For support and encouragement throughout the process, we are grateful to Thao Pham, Selina Franklin, and Louise Petersen. Thanks to our publisher, McGraw-Hill, for the valuable assistance of their staff. For enthusiasm, support, and commitment to this challenging project, thanks to our editor, Catherine Johnson. For outstanding editorial work, we thank Andrea Fellows. A special thanks to Rainbow Graphics—especially David Hommel, Tina Castle, and Susan Cooper—for remarkable editorial and production work. Thank you to Leighton Huey, MD, for his great feedback. Tao Le Louisville Vikas Bhushan Los Angeles Herman Singh Bagga San Francisco

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How to Contribute To help us continue to produce a high-yield review source for the USMLE Step 3 exam, you are invited to submit any suggestions or corrections. We also offer paid internships in medical education and publishing ranging from three months to one year (see below for details). Please send us your suggestions for: • • • •

Study and test-taking strategies for the computerized USMLE Step 3. New facts, mnemonics, diagrams, and illustrations. CCS-style cases. Low-yield topics to remove.

For each entry incorporated into the next edition, you will receive a $10 gift certificate as well as personal acknowledgment in the next edition. Diagrams, tables, partial entries, updates, corrections, and study hints are also appreciated, and significant contributions will be compensated at the discretion of the authors. Also let us know about material in this edition that you feel is low yield and should be deleted. The preferred way to submit entries, suggestions, or corrections is via the First Aid Team’s blog at: www.firstaidteam.com. Please include name, address, school affiliation, phone number, and e-mail address (if different from the address of origin).

NOTE TO CONTRIBUTORS All entries become property of the authors and are subject to editing and reviewing. Please verify all data and spellings carefully. In the event that similar or duplicate entries are received, only the first entry received will be used. Include a reference to a standard textbook to facilitate verification of the fact. Please follow the style, punctuation, and format of this edition if possible.

INTERNSHIP OPPORTUNITIES The author team is pleased to offer part-time and full-time paid internships in medical education and publishing to motivated physicians. Internships may range from three months (eg, a summer) up to a full year. Participants will have an opportunity to author, edit, and earn academic credit on a wide variety of projects, including the popular First Aid series. Writing/editing experience, familiarity with Microsoft Word, and Internet access are desired. For more information, e-mail a résumé or a short description of your experience along with a cover letter to the authors at [email protected].

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CHAPTER 1

GUIDE TO THE USMLE STEP 3 Introduction

2

WHAT IF I NEED TO RESCHEDULE THE EXAM?

USMLE Step 3—Computer-Based Testing Basics

2

WHAT ABOUT TIME?

6

IF I LEAVE DURING THE EXAM, WHAT HAPPENS TO MY SCORE?

6

HOW LONG WILL I HAVE TO WAIT BEFORE I GET MY SCORES?

6

6

HOW IS STEP 3 STRUCTURED?

2

WHAT IS STEP 3 LIKE?

2

WHAT TYPES OF QUESTIONS ARE ASKED?

3

USMLE/NBME Resources

7

HOW ARE THE SCORES REPORTED?

4

Testing Agencies

7

HOW DO I REGISTER TO TAKE THE EXAM?

4

1

2

CHAPTER 1

GUIDE TO THE USMLE STEP 3

Introduction

KEY FACT Step 3 is not a retread of Step 2.

For house officers, the USMLE Step 3 constitutes the last step one must take toward becoming a licensed physician. For international medical graduates (IMGs) applying for residency training in the United States, it represents an opportunity to strengthen the residency application and to obtain an H1B visa. Regardless of who you are, however, do not make the mistake of assuming that the Step 3 exam is just like Step 2. Whereas Step 2 focuses on clinical diagnosis, disease pathogenesis, and basic management, Step 3 emphasizes initial and long-term management of common clinical problems in outpatient settings. Indeed, part of the exam includes computerized patient simulations in addition to the traditional multiple-choice questions. In this section, we will provide an overview of the Step 3 exam and will offer you proven approaches toward conquering the exam. For a high-yield guide to the Computer-Based Clinical Simulations (CCS), go to Section I Supplement: Guide to the CCS. For a detailed description of Step 3, visit www. usmle.org or refer to the USMLE Step 3 Content Description and Sample Test Materials booklet that you will receive upon registering for the exam.

USMLE Step 3—Computer-Based Testing Basics HO W I S S TE P 3 S TR U C TU R E D?

The Step 3 exam is a two-day computer-based test (CBT) administered by Prometric, Inc. The USMLE is now using updated testing software called FRED v2. FRED v2 allows you to highlight text and strike out test choices as well as make brief notes to yourself. Day 1 of Step 3 consists of seven 60-minute blocks of 48 multiple-choice questions for a total of 336 questions over seven hours. You get a minimum of 45 minutes of break time and 15 minutes for an optional tutorial. During the time allotted for each block, you can answer test questions in any order as well as review responses and change answers. Examinees cannot, however, go back and change answers from previous blocks. Once an examinee finishes a block, he or she must click on a screen icon to continue to the next block. Time not used during a testing block will be added to your overall break time, but it cannot be used to complete other testing blocks. Expect to spend up to nine hours at the test center. Day 2 consists of four 45-minute blocks of 36 multiple-choice questions for a total of 144 questions over three hours. This is followed by nine interactive case simulations over four hours using the Primum CCS format. There is a 15-minute CCS tutorial as well as 45 minutes of allotted break time. WH AT I S S TE P 3 LI K E ?

Even if you’re familiar with the CBT and the Prometric test centers, FRED v2 is a relatively new testing format that you should access from the USMLE CD-ROM or Web site and try out prior to the exam. In addition, the CCS format definitely requires practice.

GUIDE TO THE USMLE STEP 3

CHAPTER 1

3

If you familiarize yourself with the FRED v2 testing interface ahead of time, you can skip the 15-minute tutorial offered on exam day and add those minutes to your allotted break time of 45 minutes. For security reasons, examinees are not allowed to bring personal electronic equipment into the testing area, including watches of any kind (digital or analog), cellular telephones, and electronic paging devices. Food and beverages are also prohibited in the testing area. For note-taking purposes, examinees are given laminated writing surfaces that must be returned after the examination. The testing centers are monitored by audio and video surveillance equipment. You should become familiar with a typical question screen. A window to the left displays all the questions in the block and shows you the incomplete questions (marked with an “i”). Some questions will contain figures or color illustrations adjacent to the question. Although the contrast and brightness of the screen can be adjusted, there are no other ways to manipulate the picture (eg, zooming or panning). You can also call up a window displaying normal lab values. You may mark questions to review at a later time by clicking the check mark at the top of the screen. The annotation feature functions like the provided erasable dryboards and allows you to jot down notes during the exam. Play with the highlighting/strike-through and annotation features with the vignettes and multiple-choice questions. If you find that you are not using the marking, annotation, or highlighting tools, the available keyboard shortcuts can save you time over using the mouse. The Primum CCS software is a patient simulation in which you are completely in charge of the patient’s management regardless of the setting. You obtain a selected history and physical, develop a short differential, order diagnostics, and implement treatment and monitoring. CCS cases feature simulated time (a case can play out over hours, days, or months), different locations from outpatient to ER to ICU settings, free-text entry of orders (no multiple choice here!), and patient responses to your actions over simulated time (patients can get well, worsen, or even die depending on your actions or inaction). Please see Section I Supplement: Guide to the CCS for a practical guide to acing the CCS. The USMLE also offers an opportunity to take a simulated test, or “Practice Session,” at a Prometric center in the United States or Canada for about $50. You may register for a practice session online at the USMLE Web site. W H A T T Y PE S O F Q U E S T I O N S A RE AS K E D?

Virtually all questions on Step 3 are vignette based. A substantial amount of extraneous information may be given, or a clinical scenario may be followed by a question that could be answered without actually necessitating that you read the case. It is your job to determine which information is superfluous and which is pertinent to the case at hand. There are three question formats: ■

Single items. This is the most frequent question type. It consists of the traditional single-best-answer question with 4–5 choices.

■

Multiple-item sets. This consists of a clinical vignette followed by 2–3 questions regarding that case. These questions can be answered independently of each other. Again, there is only one best answer.

KEY FACT Keyboard shortcuts: ■ A–E—Letter choices. ■ Enter or Spacebar—Move to the next question. ■ Esc—Exit pop-up Lab and Exhibit windows. ■ Alt-T—Countdown and time-elapsed clocks for current session and overall test.

4

CHAPTER 1

KEY FACT

GUIDE TO THE USMLE STEP 3

■

For long vignettes, skip to the question stem first, and then read the case.

Cases. This is a clinical vignette followed by 2–5 questions. You actually receive additional information as you answer questions, so it is important that you answer questions sequentially without skipping. As a result, once you proceed to the next question in the case, you cannot change the answer to the previous question.

The questions are organized by clinical settings, including an outpatient clinic, an inpatient hospital, and an emergency department. According to the USMLE, the clinical care situations you will encounter in these settings include the following: ■ ■ ■

Initial Workup: 20–30%. Continued Care: 50–60%. Urgent Intervention: 15–25%.

The clinical tasks that you will be tested on are as follows: ■ ■ ■ ■ ■ ■

History and Physical: 8–12%. Diagnostic Studies: 8–12%. Diagnosis: 8–12%. Prognosis: 8–12%. Applying Basic Concepts: 8–12%. Managing Patients: 39–55%. ■ Health Maintenance: 5–9%. ■ Clinical Intervention: 18–22%. ■ Clinical Therapeutics: 12–16%. ■ Legal and Ethical Issues: 4–8%.

When approaching the vignette questions, you should keep a few things in mind: KEY FACT Remember that Step 3 tends to focus on outpatient continuing management scenarios.

■

■ ■

Note the age and race of the patient in each clinical scenario. When ethnicity is given, it is often relevant. Know these associations well (see highyield facts), especially for more common diagnoses. Be able to recognize key facts that distinguish major diagnoses. Questions often describe clinical findings rather than naming eponyms (eg, they cite “audible hip click” instead of “positive Ortolani’s sign”). HO W AR E THE S C OR E S R E P OR TE D?

KEY FACT Check the USMLE Web site for the latest passing requirements.

Like the Step 1 and 2 score reports, your Step 3 report includes your pass/ fail status, two numeric scores, and a performance profile organized by discipline and disease process. The first score is a three-digit scaled score based on a predefined proficiency standard. A three-digit score of 184 is required for passing. The second score scale, the two-digit score, defines 75 as the minimum passing score (equivalent to a score of 184 on the first scale). This score is not a percentile. A score of 82 is equivalent to a score of 200 on the first scale. Approximately 95% of graduates from U.S. and Canadian medical schools pass Step 3 on their first try (see Table 1-1). Approximately two-thirds of IMGs pass on their first attempt. HO W DO I R E G I S TE R TO TAK E THE E X AM ?

To register for the Step 3 exam in the United States and Canada, apply online at the Federation of State Medical Boards (FSMB) Web site (www.fsmb.org). A printable version of the application is also available on this site. Note that some states require you to apply for licensure when you register for Step 3. A

GUIDE TO THE USMLE STEP 3

TA B L E 1- 1 .

CHAPTER 1

5

Recent Step 3 Examination Results

2008a

2007 # TESTED

% PASSING

# TESTED

% PASSING

17,570

95

18,241

94

16,633

96

17,245

95

937

72

996

67

21

86

21

90

20

85

19

95

1

Not reported

2

Not reported

Examinees from U.S./Canadian schools MD degree First-time takers Repeaters DO degree First-time takers Repeaters Total U.S./Canadian

17,591

95

18,262

94

Examinees from non-U.S./Canadian schools First-time takers

9,384

79

9,376

78

Repeaters

3,537

60

3,293

54

12,921

73

12,669

71

Total non-U.S./Canadian a

Source: www.usmle.org/Scores_Transcripts/performance/2008.html.

list of those states can be found on the FSMB Web site. The registration fee varies and was $705 or higher in 2010. Your scheduling permit is sent via e-mail to the e-mail address provided on the application materials. Once you have received your scheduling permit, it is your responsibility to print it and decide when and where you would like to take the exam. For a list of Prometric locations nearest you, visit www.prometric.com. Call Prometric’s toll-free number or visit www.prometric.com to arrange a time to take the exam. The electronic scheduling permit you receive will contain the following important information: ■ ■ ■

■

Your USMLE identification number. The eligibility period in which you may take the exam. Your “scheduling number,” which you will need to make your exam appointment with Prometric. Your “Candidate Identification Number,” or CIN, which you must enter at your Prometric workstation in order to access the exam.

Prometric has no access to these codes or your scheduling permit and will not be able to supply these for you. You will not be allowed to take Step 3 unless you present your permit, printed by you ahead of time, along with an

KEY FACT Because the exam is scheduled on a “first-come, first-served” basis, you should contact Prometric as soon as you receive your scheduling permit!

6

CHAPTER 1

GUIDE TO THE USMLE STEP 3

unexpired, government-issued photo identification that contains your signature (eg, a driver’s license or passport). Make sure the name on your photo ID exactly matches the name that appears on your scheduling permit. WH AT I F I NE E D TO R E S C HE DU LE THE E X AM ?

You can change your date and/or center within your three-month eligibility period without charge by contacting Prometric. If space is available, you may reschedule up to five days before your test date. If you reschedule within five days of your test date, Prometric will charge a rescheduling fee. If you need to reschedule outside your initial three-month period, you can apply for a single three-month extension (e.g., April/May/June can be extended through July/August/September) after your eligibility period has begun (go to www.nbme.org for more information). For other rescheduling needs, you must submit a new application along with another application fee. WH AT ABOU T TI M E ?

KEY FACT Never, ever leave a question blank! You can always mark it and come back later.

Time is of special interest on the CBT exam. The computer will keep track of how much time has elapsed. However, the computer will show you only how much time you have remaining in a given block (unless you look at the full clock with Alt-T). Therefore, it is up to you to determine if you are pacing yourself properly. Note that on both day 1 and day 2 of testing, you have approximately 75 seconds per multiple-choice question. If you recognize that a question is not solvable in a reasonable period of time, move on after making an educated guess; there are no penalties for wrong answers. It should be noted that 45 minutes is allowed for break time. However, you can elect not to use all of your break time, or you can gain extra break time either by skipping the tutorial or by finishing a block ahead of the allotted time. The computer will not warn you if you are spending more than your allotted break time. IF I LE AVE DU R I NG THE E X AM , W HAT HAP P E NS TO MY SCOR E?

You are considered to have started the exam once you have entered your CIN onto the computer screen. In order to receive an official score, however, you must finish the entire exam. This means that you must start and either finish or run out of time for each block of the exam. If you do not complete all the blocks, your exam will be documented on your USMLE score transcript as an incomplete attempt, but no actual score will be reported. The exam ends when all blocks have been completed or time has expired. As you leave the testing center, you will receive a written test-completion notice to document your completion of the exam. HO W LONG W I LL I HAVE TO W AI T BE F OR E I G E T MY SCO RES?

The USMLE typically reports scores 3–4 weeks after the examinee’s test date. During peak periods, however, it may take up to six weeks for scores to be made available. Official information concerning the time required for score reporting is posted on the USMLE Web site.

GUIDE TO THE USMLE STEP 3

USMLE/NBME Resources We strongly encourage you to use the free materials provided by the testing agencies and to study the following NBME publications: ■

■

■

■

USMLE Bulletin of Information. This publication provides you with nuts-and-bolts details about the exam (included on the USMLE Web site; free to all examinees). USMLE Step 3 Content Description and Sample Test Materials. This is a hard copy of test questions and test content also found on the CD-ROM. NBME Test Delivery Software (FRED v2) and Tutorial. This includes 168 valuable practice questions. The questions are available on the USMLE CD-ROM and Web site. Make sure you are using the new FRED v2 version and not the older Prometric version. USMLE Web site (www.usmle.org). In addition to allowing you to become familiar with the CBT format, the sample items on the USMLE Web site provide the only questions that are available directly from the test makers. Student feedback varies as to the similarity of these questions to those on the actual exam, but they are nonetheless worthwhile to know.

Testing Agencies National Board of Medical Examiners (NBME) Department of Licensing Examination Services 3750 Market Street Philadelphia, PA 19104-3102 215-590-9500 Fax: 215-590-9457 www.nbme.org Educational Commission for Foreign Medical Graduates (ECFMG) 3624 Market Street, Fourth Floor Philadelphia, PA 19104-2685 215-386-5900 Fax: 215-386-9196 www.ecfmg.org Federation of State Medical Boards (FSMB) P.O. Box 619850 Dallas, TX 75261-9850 817-868-4000 Fax: 817-868-4099 www.fsmb.org USMLE Secretariat 3750 Market Street Philadelphia, PA 19104-3190 215-590-9700 www.usmle.org

CHAPTER 1

7

8

CHAPTER 1

GUIDE TO THE USMLE STEP 3

NO T E S

SUPPLEMENT

GUIDE TO THE CCS Introduction

10

4. CHANGE LOCATION

11

What Is the CCS Like?

10

FINISHING THE CASE

12

1. GET INTERVAL HISTORY OR PHYSICAL EXAM

10

How Is the CCS Graded?

12

2. WRITE ORDER OR REVIEW CHART

10

High-Yield Strategies for the CCS

12

3. OBTAIN RESULTS OR SEE PATIENT LATER

11

9

10

Supplement

GUIDE TO THE CCS

Introduction

KEY FACT The focus is management, management, management. You will see few diagnostic zebras in the CCS.

The Primum CCS is a computerized patient simulation that is administered on the second day of Step 3. You will be given nine cases over four hours and will have up to 25 minutes per case. As with the rest of the Step 3 exam, the CCS is meant to test your ability to properly diagnose and manage common conditions in a variety of patient-care settings. Many of these conditions are obvious or easily diagnosed. Clinical problems range from acute to chronic and from mundane to life-threatening. A case may last from a few minutes to a few months in terms of simulated time, even though you will be allotted only 25 minutes of real time per case. Cases can, and frequently do, end in less than 25 minutes. No matter where the patient is situated during the case (ie, office, ER, or ICU), you will serve as the patient’s primary physician and will bear complete responsibility for his or her care.

What Is the CCS Like? KEY FACT Do all the sample CCS cases prior to the actual exam.

For the CCS, there is no substitute for trying out the cases on the USMLE CD-ROM or downloading the software from the USMLE Web site. If you spend at least a few hours doing the sample cases and familiarizing yourself with the interface, you will do better on the actual exam, regardless of your prior computer experience. For each case, you will be presented with a chief complaint, vital signs, and the history of present illness (HPI). At that point, you will initiate patient management, continue care, and advance the case by taking one of the following four actions that are represented on the computer screen. 1. G E T I NTE R VAL HI S TOR Y OR P HYS I C AL E X AM

You can obtain a focused or full physical exam. You can also get interval history to see how a patient is doing. Getting interval history or doing a physical exam will automatically advance the clock in simulated time. Quick tips and shortcuts: ■

■

If the vital signs are unstable, you may be forced to write some orders (eg, IV fluids, oxygen, type and cross-match) even before you perform the exam. Keep the physical exam focused. A full physical and exam is often wasteful and can cost you valuable simulated time in an emergency. You can always do additional physical exam components as necessary. 2. W R I TE OR DE R OR R E VI E W C HAR T

KEY FACT The orders require free-text entry. There is no multiple choice here!

You can manage the patient by typing orders. As part of your management, for example, you can order tests, monitoring, treatments, procedures, consultations, and counseling. The order sheet format is free-text entry, so you can type whatever you choose; the computer has a 12,000-term vocabulary that can accommodate approximately 2,500 orders or actions. If you order a medication, you will also need to specify the route and frequency. If a patient comes into a case with preexisting medications, these meds will appear on the order sheet with an order time of “Day 1 @00:00.” The medications will continue unless you decide to cancel them. Unlike interval history or PE, you must manually advance simulated time to see the results of your orders (see the next page).

GUIDE TO THE CCS

Quick tips and shortcuts: ■

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As long as the computer can recognize the first three characters of your order, it can provide a list of orders from which to choose. Simply type the test, therapy, or procedure you want. Don’t type verbs such as “get,” “administer,” or “do.” Do the sample cases to get a sense of the common abbreviations the computer will recognize (eg, CBC, CXR, ECG). Familiarize yourself with routes and dosing frequencies for common medications. You do not need to know dosages or drip rates. Never assume that other health care staff or consultants will write orders for you. Even routine actions such as IV fluids, oxygen, monitoring, and diabetic diet must be ordered by you. If a patient is preop, don’t forget NPO, type and cross-match, and antibiotics. You can always change your mind and cancel an order as long as the clock has not been advanced. Review any preexisting medications on the order sheet. Sometimes the patient’s problem may be due to a preexisting medication side effect or a drug-drug interaction! 3 . O B T A I N R E S U L T S O R S E E P A TI ENT LATE R

To see how the case evolves after you have entered your orders, you must advance the clock. You can specify a time to see the patient either in the future or when the next results become available. When you advance the clock, you may receive messages from the patient, the patient’s family, or the health care staff updating you on the patient’s status prior to the specified time or result availability. If you stop a clock advance to a future time (such as a follow-up appointment) to review results from previous orders, that future appointment will be canceled. Quick tips and shortcuts: ■

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Before advancing the clock, ask yourself whether the patient will be okay during that time period. Before advancing the clock, ask yourself whether the patient is in the appropriate location or should be transferred to a new location. If you receive an update while the clock is advancing, especially if the patient is worsening, you should review your current management. 4 . C H A N G E LO C A T IO N

According to the USMLE, you have an outpatient office with admitting privileges to a 400-bed tertiary-care facility. As in real life, the patient typically presents to you in an office or ER setting. Once you’ve done all you can, you can transfer the patient to another setting to receive appropriate care. This may include the ward or the ICU. Note that in this context, the ICU represents all types of ICUs, including medical, surgical, pediatric, obstetrics, and neonatal. When appropriate, the patient may be discharged home with follow-up. Quick tips and shortcuts: ■

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Always ask yourself if the patient is in the right location to receive optimal management. Remember that you remain the primary physician wherever the patient goes.

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KEY FACT Wherever the patient goes, you go!

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When changing locations (and especially when discharging the patient), remember to discontinue any orders that are no longer needed. Remember that any patient who is discharged home will require a followup appointment. Before discharging a patient, think about whether he or she needs any health maintenance or counseling. FI NI S HI NG THE C AS E

KEY FACT The final diagnosis and reasons for consultation do not count toward your score!

The case ends when you have used your allotted 25 minutes. If the measurement objectives for the case have been met, the computer may ask you to exit early. Toward the end of a case, you will be given a warning that the case is about to conclude. You will then be given an opportunity to cancel orders as well as write some short-term orders. You will be asked for a final diagnosis before exiting.

How Is the CCS Graded? You will be graded by a scoring algorithm based on generally accepted practices of care. This algorithm allows for wide variation and recognizes that there may be more than one appropriate way to approach a case. In general, you will gain points for appropriate management actions and lose points for actions that are not indicated or that can harm your patient. These actions are worth different points such that key actions (eg, emergent needle thoracostomy for a patient with tension pneumothorax) will earn you big points, and highly inappropriate actions (eg, obtaining a liver biopsy for a patient with an ear infection) will lose you big points. Note that you may not get full credit for correct actions if you perform them out of sequence or after an inappropriate delay in simulated time. Unnecessary and excessive orders (even if they pose no risk to the patient) will cost you points as well. The bottom line is that the CCS tends to reward thorough but efficient medicine.

High-Yield Strategies for the CCS

KEY FACT A worsening patient may reflect the testing goals of the case rather than an error on your part.

As mentioned before, it is essential to do the available practice CCS cases prior to the exam. Make sure you do both outpatient and inpatient cases. Try different abbreviations to get a feel for the vocabulary when you write orders. Try using different approaches to the same case to see how the computer reacts. Read through the 100 cases in Chapter 19, High-Yield CCS Cases. They will show you how clinical conditions can present and play out as a CCS case. Remember that the computer wants you to do the right things at the right times while posing minimal waste and unnecessary risk to the patient. When taking the exam, also bear the following in mind: ■

Read through the HPI carefully. Use the HPI to develop a short differential that will direct your physical exam and initial management. The diagnosis will often become apparent to you before you even do the physical. Jot down pertinent positives and negatives so that you don’t have to come back and review the chart. Keep in mind any drug allergies the patient might have.

GUIDE TO THE CCS

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Any unstable patient needs immediate management. If a patient’s vital signs are unstable, you may want to do some basic management (eg, administering IV fluids and oxygen) before you perform your physical exam. With unstable patients, you should be ordering tests that will yield fast results in identifying and managing the underlying condition. Consultants are rarely helpful. You will get some points for calling a consultant for an indicated procedure (eg, a surgeon for an appendectomy). Otherwise, consultants will offer little in the way of diagnostic or management assistance. Don’t forget health maintenance, education, and counseling. After treating tension pneumothorax, counsel the patient about smoking cessation if the HPI mentions that he or she is an active smoker. Don’t treat the patient alone. The computer will not permit you to treat a patient’s family or sexual partner, but it will allow you to provide education or counseling. If a female patient is of childbearing age, check a pregnancy test before starting a potentially teratogenic treatment. Sometimes the patient will worsen despite good care. Conversely, some patients will improve with poor management. If a case is not going your way, reassess your approach to make sure you’re not missing anything. If you are confident about your diagnosis and management, stop secondguessing. Sometimes the computer tests your ability to handle difficult clinical situations.

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NO T E S

CHAPTER 2

AMBULATORY MEDICINE Ophthalmology

16

ROSACEA

22

GLAUCOMA

16

ERYTHEMA MULTIFORME

22

DIABETIC RETINOPATHY

16

PEMPHIGUS VULGARIS

23

Ear, Nose, and Throat

17

INFLUENZA

17

HEARING LOSS

18

ALLERGIC RHINITIS

18

BULLOUS PEMPHIGOID

23

ACNE VULGARIS (COMMON ACNE)

24

HERPES ZOSTER

24

DERMATOPHYTOSES

25

EPISTAXIS

19

Genitourinary Disorders

25

LEUKOPLAKIA

19

ERECTILE DYSFUNCTION

25

Dermatology

20

“DERM TERMS”

20

ATOPIC DERMATITIS (ECZEMA)

20

CONTACT DERMATITIS

21

PSORIASIS ERYTHEMA NODOSUM

BENIGN PROSTATIC HYPERPLASIA

26

WORKUP OF PROSTATIC NODULES AND ABNORMAL PSA

27

Health Care Maintenance

27

CANCER SCREENING

27

21

OTHER ROUTINE SCREENING

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21

IMMUNIZATIONS

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Ophthalmology G LAU C OM A

A form of optic neuropathy that is caused by elevated intraocular pressure (defined as > 20 mm Hg) and that results in loss of vision. Open-Angle Glaucoma ■

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The most common type of glaucoma. More common in African Americans. Sx/Dx: Diagnosis is made in patients who are losing peripheral vision and who have high intraocular pressures and an abnormal cup-to-disk ratio (> 50%) (see Figure 2-1). Tx: Treat with the following: ■ Nonselective topical β-blockers (eg, timolol, levobunolol). ■ Topical adrenergic agonists (eg, epinephrine). ■ Topical cholinergic agonists (eg, pilocarpine, carbachol). ■ Topical carbonic anhydrase inhibitors (eg, dorzolamide, brinzolamide).

Closed-Angle Glaucoma A 42-year-old woman presents with headache, nausea, vomiting, and a red eye that has progressively worsened since this morning. She also notes vision changes. Exam reveals conjunctival injection; moderately fixed, dilated pupils; and no focal weaknesses in the extremities. What should you do next? Use tonometry to check intraocular pressures. A pressure of ≥ 30 mm Hg confirms the diagnosis. Refer to ophthalmology. Initial treatments include timolol, acetazolamide, and topical pilocarpine.

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KEY FACT

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Do not confuse closed-angle glaucoma with a simple headache!

An emergency! A result of the anterior chamber angle impairing drainage of aqueous humor and increasing intraocular pressure. Normal pressure is 8–21 mm Hg, whereas pressures in closed-angle glaucoma can be ≥ 30 mm Hg. Anatomic predisposition is a 1° cause; 2° causes include fibrovascular membrane formation and hemorrhage. Risk factors include a family history, female gender, age > 40–50, and Asian ethnicity. Sx/Exam: Presents with eye pain, headache, nausea, conjunctival injection, halos around lights, and fixed, moderately dilated pupils. Check intraocular pressure. Tx: ■ Contact an ophthalmologist immediately! ■ Treatment consists of topical pilocarpine for pupillary constriction, timolol and acetazolamide to ↓ intraocular pressure, and laser iridotomy. Systemic treatments include acetazolamide and mannitol. DI ABE TI C R E TI NOP ATHY

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Asymptomatic, gradual vision loss in patients with diabetes. The leading cause of blindness in the United States.

AMBULATORY MEDICINE

FIGURE 2-1.

Open-angle glaucoma. Note the change in the cup-to-disk ratio. (Reproduced

with permission from USMLERx.com.)

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Sx/Exam: Funduscopic findings include neovascularization, microaneurysms, flame hemorrhages, and macular edema. Tx: Proliferative retinopathy may be treated, and progression slowed, by laser photocoagulation surgery or vitrectomy. Prevention: ■ Patients with diabetes should have a comprehensive ophthalmologic exam at least annually to screen for signs of retinopathy. ■ Progression can be slowed with tight glucose and BP control.

Ear, Nose, and Throat (ENT) INFLUENZA ■

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An acute respiratory illness that is caused by influenza A or B and occurs primarily during the winter. Sx/Exam: Generally presents following an incubation period of 1–2 days with acute-onset upper and lower respiratory tract symptoms, myalgias, fevers, and weakness. Dx: Rapid antigen tests have a sensitivity of only 40–60%. Diagnosis may be established through PCR testing or viral culture. Tx: The antiviral drugs zanamivir and oseltamivir can be used as prophylaxis against or to treat infection in at-risk individuals; these drugs are most effective when given within 48 hours of exposure or at symptom onset. Most influenza strains have become resistant to amantadine and rimantadine.

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Cx: ■ Pneumonia is the 1° complication of influenza. Those who are predisposed to it usually have an underlying condition such as diabetes mellitus (DM) or cardiopulmonary disease. Patients > 50 years of age and residents of nursing homes are also at risk. ■ 2° bacterial pneumonia, often from Streptococcus pneumoniae, is an important complication and is responsible for one-quarter of influenzarelated deaths. ■ Other complications of influenza include myositis, rhabdomyolysis, CNS involvement, myocarditis, and pericarditis. HE A R I NG LOS S

Common in the elderly. Principal causes are as follows: ■

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External canal: Cerumen impaction, foreign bodies in the ear canal, otitis externa, new growth/mass. Internal canal: Otitis media, barotrauma, perforation of the tympanic membrane.

Additional causes include the following: ■

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Presbycusis: Age-related hearing loss. High-pitched sounds are lost first, so speak loudly in a low-pitched voice. Otosclerosis: Progressive fixation of the stapes, leading to bilateral progressive conductive hearing loss. Begins in the second or third decade of life, and may advance in pregnancy. Exam is normal; surgery with stapedectomy or stapedotomy yields excellent results. Other: Drug-induced loss (eg, from aminoglycosides); noise-induced loss.

DIAGNOSIS

Distinguish conductive from sensorineural hearing loss via the Weber and Rinne tests: ■

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KEY FACT Otosclerosis is the most common cause of conductive hearing loss in young adults.

Weber test: Press a vibrating tuning fork in the middle of the patient’s forehead and ask in which ear it sounds louder. ■ Conductive hearing loss: The sound will be louder in the affected ear. ■ Sensorineural hearing loss: The sound will be louder in the normal ear. Rinne test: Place a vibrating tuning fork against the patient’s mastoid bone, and once it is no longer audible, immediately reposition it near the external meatus. ■ Conductive hearing loss: Bone conduction is audible longer than air conduction. ■ Sensorineural hearing loss: Air conduction is audible longer than bone conduction. ALL E R G I C R HI NI TI S

Affects up to 20% of the adult population. Patients may also have asthma and atopic dermatitis. SYMPTOMS/EXAM ■

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Presents with congestion, rhinorrhea, sneezing, eye irritation, and postnasal drip. Generally, one can readily identify exposure to environmental allergens such as pollens, animal dander, dust mites, and mold spores. May be seasonal.

AMBULATORY MEDICINE

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Exam reveals edematous, pale mucosa; cobblestoning in the pharynx; scleral injection; and blue, boggy turbinates.

DIAGNOSIS ■ ■

Often based on clinical impression given the signs and symptoms. Skin testing to a standard panel of antigens can be performed, or blood testing can be conducted to look for specific IgE antibodies via radioallergosorbent testing (RAST).

TREATMENT ■

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Allergen avoidance: Use dust mite–proof covers on bedding and remove carpeting. Keep the home dry and avoid pets. Drugs: ■ Antihistamines (diphenhydramine, fexofenadine): Block the effects of histamine released by mast cells. Selective antihistamines such as fexofenadine may cause less drowsiness than nonselective agents such as diphenhydramine. ■ Intranasal corticosteroids: Anti-inflammatory properties lead to excellent symptom control. ■ Sympathomimetics (pseudoephedrine): α-adrenergic agonist effects result in vasoconstriction. ■ Intranasal anticholinergics (ipratropium): ↓ mucous membrane secretions. ■ Immunotherapy (“allergy shots”): Slow to take effect, but useful for difficult-to-control symptoms. E P I S T A X IS

Bleeding from the nose or nasopharynx. Roughly 90% of cases are anterior nasal septum bleeds (at Kiesselbach’s plexus). The most common etiology is local trauma 2° to digital manipulation. Other causes include dryness of the nasal mucosa, nasal septal deviation, use of antiplatelet medications, bone abnormalities in the nares, rhinitis, and bleeding diatheses. SYMPTOMS/EXAM ■

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Posterior bleeds: More brisk and less common; blood is swallowed and may not be seen. Anterior bleeds: Usually less severe; bleeding is visible as it exits the nares.

TREATMENT ■

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Treat with prolonged and sustained direct pressure and topical nasal vasoconstrictors (phenylephrine or oxymetazoline). If bleeding does not stop, cauterize with silver nitrate or insert nasal packing (with antibiotics to prevent toxic shock syndrome, covering for S aureus). If severe, type and screen, obtain IV access, and consult an ENT surgeon. L EU K O PLA K IA

White patches or plaques in the oral mucosa that are considered precancerous and cannot be removed by rubbing the mucosal surface. However, if these white lesions are easily removed, think of Candida. Lesions can occur in response to chronic irritation and can represent either dysplasia or early invasive squamous cell carcinoma. Common among those who use chewing tobacco.

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Dermatology “DE R M TE R M S ”

The following terms describe common dermatologic lesions: ■

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Macule: A flat, circumscribed, nonpalpable lesion usually < 0.5 cm in diameter. Examples include flat nevi and café-au-lait spots. Patch: A flat, nonpalpable lesion > 0.5 cm in diameter. Examples include large café-au-lait spots and vitiligo. Papule: An elevated, palpable lesion < 0.5 cm in diameter. Examples include elevated nevi and molluscum contagiosum. Plaque: An elevated, palpable lesion > 0.5 cm in diameter. Often formed by a confluence of papules. Examples include psoriasis and lichen simplex chronicus. Nodule: A circumscribed, elevated, solid lesion measuring between 0.5 and 2.0 cm in diameter. May be in the epidermis or in deeper tissue. Examples include fibromas and xanthomas. Tumors: Larger and more deeply circumscribed, solid lesions. Examples include lipomas and various neoplastic growths. Vesicles: Circumscribed, elevated, fluid-containing lesions measuring ≤ 0.5 cm in diameter. Examples include HSV and VZV lesions. Bullae: Circumscribed, elevated, fluid-containing lesions measuring > 0.5 cm in diameter. Examples include burns, pemphigus, and epidermolysis bullosa. Pustules: Circumscribed elevations that contain purulent exudate. AT OP I C DE R M ATI TI S ( E C ZE M A)

Pruritic, lichenified eruptions that are classically found in the antecubital fossa but may also appear on the neck, face, wrists, and upper trunk. ■ ■ ■ ■

Has a chronic course with remissions. Characterized by an early age of onset (often in childhood). Associated with a ⊕ family history and a personal history of atopy. Patients tend to have ↑ serum IgE and repeated skin infections.

SYMPTOMS/EXAM

Presents with severe pruritus, with distribution generally in the face, neck, upper trunk, and bends of the elbows and knees. The skin is dry, leathery, and lichenified (see Figure 2-2). The condition usually worsens in the winter and in low-humidity environments. Often known as “the itch that rashes.” DIFFERENTIAL FIGURE 2-2.

Atopic dermatitis.

Infiltrated, erythematous facial skin with scaliness in an adolescent with atopic dermatitis. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine,

Seborrheic dermatitis, contact dermatitis, impetigo. DIAGNOSIS

Diagnosis is clinical.

7th ed. New York: McGraw-Hill, 2008, Fig. 14-6.)

TREATMENT

Keep skin moisturized. Topical steroid creams should be used sparingly and should be tapered off once flares resolve. The first-line steroid-sparing agent is tacrolimus ointment.

AMBULATORY MEDICINE

CHAPTER 2

CONTACT DERMATITIS

Caused by exposure to certain substances in the environment. Allergens may lead to acute, subacute, or chronic eczematous inflammation. SYMPTOMS

21

KEY FACT Common causes of contact dermatitis include leather, nickel (earrings, watches, necklaces), and poison ivy.

Patients present with itching, burning, and an intensely pruritic rash. EXAM ■

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Acute: Presents with papular erythematous lesions and sometimes with vesicles, weeping erosions where vesicles have ruptured, crusting, and excoriations. The pattern of lesions often reflects the mechanism of exposure (eg, a line of vesicles or lesions under a watchband; see Figure 2-3). Chronic: Characterized by hyperkeratosis and lichenification.

DIAGNOSIS ■

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Usually a clinical diagnosis that is made in the setting of a possible exposure. A detailed history for exposures is essential. In the case of leather, patch testing can be used to elicit the reaction with the exact agent that caused the dermatitis. Consider the occupation of the individual and the exposure area of the body to determine if they suggest a diagnosis.

FIGURE 2-3.

Contact dermatitis.

The erythematous, edematous base of the eruption corresponds to the posterior surface of the watch. (Courtesy of the Department of Dermatology, Wilford Hall USAF Medical Center and Brooke Army Medical Center, San Antonio, TX, as published in Knoop KJ et al. Atlas of Emergency Medicine, 2nd ed. New York: McGraw-Hill, 2002, Fig.

TREATMENT ■ ■ ■

Avoid causative agents. Cold compresses and oatmeal baths help soothe the area. Administer topical steroids. A short course of oral steroids may be needed if a large region of the body is involved.

13-56.)

KEY FACT Psoriatic arthritis characteristically involves the DIP joints.

P SO R IA S IS

An immune-mediated skin disease characterized by silver plaques with an erythematous base and sharply defined margins. The condition is common and is generally chronic with a probable genetic predisposition. SYMPTOMS/EXAM

Presents with well-demarcated, silvery, scaly plaques (the most common type) on the knees, elbows, gluteal cleft, and scalp (see Figure 2-4). Nails may show pitting and onycholysis. TREATMENT ■

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Limited disease: Topical steroids, occlusive dressings, topical vitamin D analogs, topical retinoids. Generalized disease (involving > 30% of the body): UVB light exposure three times per week; PUVA (psoralen and UVA) if UVB is not effective. Methotrexate may also be used for severe cases. ERYTHEMA NODOSUM

An inflammatory lesion that is characterized by red or violet nodules and is more common in women than in men. Although the condition is often idiopathic, it may also occur 2° to sarcoidosis, IBD, or conditions such as streptococcal infection, coccidioidomycosis, and TB.

FIGURE 2-4. Psoriasis. Note the well-demarcated, erythematous plaque with micaceous scale of the elbow. (Reproduced with permission from USMLERx.com.)

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SYMPTOMS/EXAM ■

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Lesions are painful and may be preceded by fever, malaise, and arthralgias. Recent URI or diarrheal illness may suggest a cause. Exam reveals deep-seated, poorly demarcated, painful red nodules without ulceration on the extensor surfaces of the lower legs (see Figure 2-5).

DIFFERENTIAL

Cellulitis, trauma, thrombophlebitis. TREATMENT

Treat the underlying disease. The condition is usually self-limited, but NSAIDs are helpful for pain. In more persistent cases, potassium iodide drops and systemic corticosteroids may be of benefit. FIGURE 2-5.

Erythema nodosum.

Note the bilateral erythematous nodules localized over the shins. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 68-4.)

ROS AC E A

A chronic condition that occurs in patients 30–60 years of age. Most commonly affects people with fair skin, those with light hair and eyes, and those who have frequent flushing. SYMPTOMS/EXAM ■

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Presents with erythema and with inflammatory papules that mimic acne and appear on the cheeks, forehead, nose, and chin. Open and closed comedones (whiteheads and blackheads) are not present. Recurrent flushing may be elicited by spicy foods, alcohol, or emotional reactions. Rhinophyma (thickened, lumpy skin on the nose) occurs late in the course of the disease and is a result of sebaceous gland hyperplasia (see Figure 2-6).

DIFFERENTIAL

The absence of comedones in rosacea and the patient’s age help distinguish the condition from acne vulgaris. TREATMENT ■

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FIGURE 2-6.

Rhinophyma. (Repro-

duced with permission from Wolff K et al. Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, 5th ed. New York: McGraw-Hill, 2005: 11.)

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Initial therapy: The goal is to control rather than cure the chronic disease. Use mild cleansers (Dove, Cetaphil), benzoyl peroxide, and/or metronidazole topical gel with or without oral antibiotics as initial therapy. Persistent symptoms: Treat with oral antibiotics (tetracycline, minocycline) and tretinoin cream. Maintenance therapy: ■ Topical metronidazole may be used once daily. ■ Clonidine or α-blockers may be effective in the management of flushing, and patients should avoid triggers. ■ Consider referral for surgical evaluation if rhinophyma is present and is not responding to treatment. E RY THE M A M U LTI F OR M E ( E M )

An acute inflammatory disease that is sometimes recurrent. EM is probably a distinct disease entity from Stevens-Johnson syndrome and toxic epidermal necrolysis. Many causative factors are linked with EM, such as infectious agents (especially HSV and Mycoplasma), drugs, connective tissue disorders,

AMBULATORY MEDICINE

CHAPTER 2

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physical agents, radiotherapy, pregnancy, and internal malignancies. Many cases are idiopathic and recurrent. SYMPTOMS/EXAM ■

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May be preceded by malaise, fever, or itching and burning at the site where the eruptions will occur. Presents with sudden onset of rapidly progressive, symmetrical lesions. Target lesions and papules are typically located on the back of the hands and on the palms, soles, and limbs but can be found anywhere (see Figure 2-7). Lesions recur in crops for 2–3 weeks.

DIAGNOSIS

Typically a clinical diagnosis. Biopsy can help in uncertain cases. TREATMENT ■

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Mild cases can be treated symptomatically with histamine blockers for pruritus. If many target lesions are present, patients usually respond to prednisone for 1–3 weeks. Azathioprine has been helpful in cases that are unresponsive to other treatments. Levamisole has also been successfully used in patients with chronic or recurrent oral lesions. When HSV causes recurrent EM, maintenance acyclovir or valacyclovir can ↓ recurrences of both.

FIGURE 2-7.

Erythema multiforme.

Note the typical target lesions on the palm. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 38-2.)

P EM PH IG U S V U L G A R IS

A rare autoimmune disease in which blisters are formed as autoantibodies destroy intracellular adhesions between epithelial cells in the skin. Pemphigus vulgaris is the most common subtype of pemphigus. SYMPTOMS/EXAM ■

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Presents with flaccid bullae and with erosions where bullae have been unroofed (see Figure 2-8). Oral lesions usually precede skin lesions. If it is not treated early, the disease usually generalizes and can affect the esophagus. Nikolsky’s sign is elicited when gentle lateral traction on the skin separates the epidermis from underlying tissue.

DIAGNOSIS

Skin biopsy shows acantholysis (separation of epidermal cells from each other); immunofluorescence reveals antibodies in the epidermis. TREATMENT

Corticosteroids and immunosuppressive agents. B U L L O U S PE M PH IG O I D

FIGURE 2-8.

Pemphigus vulgaris.

Note the extensive erosions due to blistering and the intact, flaccid blisters at the lower border of the eroded lesions. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York:

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An autoimmune disease characterized by antibodies against basement membrane that lead to subepidermal bullae. More common than pemphigus vulgaris, and typically occurs in those > 60 years of age (the median age at onset is 80 years). Sx/Exam: Presents as large, tense bullae with few other symptoms. DDx: Pemphigus vulgaris, dermatitis herpetiformis.

McGraw-Hill, 2008, Fig. 52-4.)

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AMBULATORY MEDICINE

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Dx: Diagnosis is made with skin biopsy, with confirmation via immunoand histopathology. Tx: Topical corticosteroids. AC NE VU LG AR I S ( C OM M ON AC NE )

A common skin disease that primarily affects adolescents. Results from ↑ pilosebaceous gland activity, Propionibacterium acnes, and plugging of follicles. SYMPTOMS/EXAM

Characterized by a variety of lesions, including closed comedones (whiteheads), open comedones (blackheads), papules, nodules, and scars. Lesions are typically seen over the face, back, and chest. DIFFERENTIAL

Rosacea, folliculitis. DIAGNOSIS

Diagnosis is clinical. TREATMENT ■

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Begin with topical antibiotics such as erythromycin, benzoyl peroxide gels, and topical retinoids. A 2° line of treatment includes addition of oral antibiotics such as minocycline and tetracycline. Isotretinoin (Accutane) can be used but is teratogenic and should be prescribed with caution in women of childbearing age. Concomitant contraception and pregnancy tests are necessary. HE R P E S ZOS TE R

A 71-year-old man presents to urgent care complaining of a lesion on his right flank. He states that the appearance of this lesion was preceded by some tingling in the same area one day ago. Exam reveals a four-inch band of painful vesicles with 2° crusting and a clear midline border. How do you evaluate this patient? The patient’s presentation is highly suspicious for herpes zoster. Although a clinical exam is typically sufficient for diagnosis, a PCR of fluid from the lesion or a Tzanck smear can be confirmatory. NSAIDs may be useful for pain control, and antiviral therapy may ↓ the likelihood of postherpetic neuralgia and speed resolution of the lesion.

A disease caused by reactivated varicella-zoster virus (VZV), which remains dormant in the dorsal roots of nerves. Risk factors include ↑ age and immunosuppression. Patients can develop postherpetic neuralgia, a painful disorder, after the eruption. SYMPTOMS/EXAM

Presents with the cutaneous finding of painful vesicles evolving into crusted lesions in a dermatomal distribution. Lesions are typically preceded by paresthesias in the area of distribution.

AMBULATORY MEDICINE

DIFFERENTIAL

Contact dermatitis. DIAGNOSIS

Diagnosis is largely clinical. Giant cells may be seen on Tzanck smear of fluid. TREATMENT ■ ■

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Pain management. If initiated within 72 hours of rash onset, antiviral treatment with acyclovir, valacyclovir, or famciclovir can ↓ the duration of illness and may also ↓ the occurrence of postherpetic neuralgia. Use of glucocorticoids is controversial and is usually not recommended. Vaccination to help prevent recurrence is becoming more popular in select patients. DERMATOPHYTOSES

Dermatophytes attach to and proliferate on the superficial layers of the epidermis, nails, and hair. Typically, they form a red and scaly lesion. Examples include the following: ■

■

■

■

■

Tinea capitis: Erythema and scaling under the scalp with thickened and broken-off hairs. Common organisms are Trichophyton tonsurans and Microsporum canis. Treatment includes griseofulvin, itraconazole, and selenium sulfide shampoo. Tinea corporis: Presents as annular, marginated plaques with a thin scale and a clear center. Common organisms include Trichophyton mentagrophytes and M canis. Treatment includes griseofulvin, itraconazole, and clotrimazole cream. Tinea pedis: Presents with red, scaly soles; maceration and fissuring and occasionally with blisters between the toes. Treatment includes griseofulvin, terbinafine, itraconazole, and antifungal foot powder. Onychomycosis: Initially presents with a loosened nail plate, yellow discoloration, and thickening of the distal nail plate. This is followed by scaling of the nail plate. Trichophyton rubrum and T mentagrophytes are the most common causes. Treatment includes terbinafine and itraconazole. Tinea versicolor: Hypopigmented macules in areas of sun-induced pigmentation. During winter, the macules appear reddish-brown. Treatment includes griseofulvin, topical selenium sulfide, and topical ketoconazole.

Genitourinary Disorders E R E CT ILE D Y S F U N CT IO N (E D )

Inability to achieve or maintain an erection sufficient to effect penetration and ejaculation. Affects 30 million men. Associated with age; some degree of ED is seen in 40% of 40-year-olds and in 70% of 70-year-olds. Etiologies are as follows: ■ Psychological: ■ Symptoms often have a sudden onset. ■ Patients are unable to sustain or sometimes even obtain an erection. ■ Patients have normal nocturnal penile tumescence (those with organic causes do not).

CHAPTER 2

25

26

CHAPTER 2

AMBULATORY MEDICINE

■

KEY FACT DM is associated with both vascular and neurologic causes of ED.

■

Organic: ■ Endocrine: DM, hypothyroidism or thyrotoxicosis, pituitary or gonadal disorders, ↑ prolactin. ■ Vascular: Atherosclerosis of penile arteries or venous leaks. ■ Neurologic: Stroke, DM, temporal lobe seizure, MS, spinal surgery, neuropathy. Exogenous: Drugs that cause ED include β-blockers, SSRIs, α-blockers, clonidine, CNS depressants, anticholinergics, chronic opioids, and TCAs.

EXAM ■

■

Look for exam findings suggesting an organic cause—eg, small testes, evidence of Peyronie’s disease, perineal sensation/cremaster reflex, evidence of peripheral neuropathy, or galactorrhea. Assess peripheral pulses; look for skin atrophy, hair loss, and low skin temperature.

DIAGNOSIS

Assess TSH, prolactin, and testosterone; order a fasting glucose to assess for diabetes. TREATMENT ■

■ ■

■

■

■

PDE-5a inhibitors (sildenafil [Viagra], tadalafil, vardenafil) inhibit cGMPspecific phosphodiesterase type 5a, thereby improving relaxation of smooth muscle in the corpora cavernosa. Side effects include flushing, headache, and ↓ BP. Patients cannot be on nitrates or α-blockers. Injectable therapies such as alprostadil are also available. An external penile pump in combination with a PDE-5a inhibitor may be useful. For those who fail medical therapy, an inflatable penile prosthesis is available. Give testosterone for hypogonadism; behavioral treatment is appropriate for depression and anxiety. A PDE-5a inhibitor may be effective for patients with psychogenic causes. Vascular surgery if indicated. BE NI G N P R OS TATI C HYP E R P LAS I A ( BP H)

Hyperplasia of the prostate that leads to bladder outlet obstruction. Incidence ↑ with age. Common in patients > 45 years of age. In patients < 45 years of age with urinary retention, consider an alternative diagnosis such as a urethral stricture or a neuropathic etiology. SYMPTOMS/EXAM ■

■

Patients complain of frequency, urgency, nocturia, ↓ force and size of the urine stream, and incomplete emptying leading to overflow incontinence. Exam reveals a firm, rubbery, smooth prostatic surface (versus the rockhard areas that suggest prostate cancer).

AMBULATORY MEDICINE

DIAGNOSIS

Diagnosed by an appropriate history and exam. Check a UA for infection or hematuria, both of which should prompt further evaluation. PSA is elevated in up to 50% of patients but is not diagnostically useful. TREATMENT ■ ■ ■

α-blockers (terazosin), 5α-reductase inhibitors (finasteride). Avoid anticholinergics, antihistamines, or narcotics. If the condition is refractory to medications, consider surgical options such as transurethral resection of the prostate (TURP). An open procedure is appropriate if gland size is > 75 g. In general, indications for TURP include recurrent UTIs, bladder stones, hematuria, episodes of acute urinary retention, and renal failure 2° to obstruction. W O R K U P O F PR O S T A T I C N O D U LE S AND ABNOR M AL P S A

■

■ ■

Significant controversy surrounds prostate cancer screening, with different groups offering varying recommendations ranging from no screening at all to a yearly rectal exam and PSA testing (see Table 2-1). If an abnormality is found on exam, proceed to prostatic biopsy. The PSA may be used as a marker to follow the response to prostate cancer treatment. With successful cancer treatments, PSA falls to undetectable levels.

Health Care Maintenance A 41-year-old woman who recently acquired health insurance comes to your primary care clinic for the first checkup in her life. She has no current complaints and no known past medical history, and she doesn’t smoke, drink, or use drugs. She has never had children. She has a stable partner with whom she has been in a monogamous relationship for 20 years. Her mother had type 2 DM. Her physical exam is within normal limits, and she is not overweight. Which screening tests might you recommend? An otherwise healthy 41-year-old woman would be well served by a Pap smear, a breast exam, and hypertension screening. Given her family history of DM, a fasting glucose test or a two-hour glucose tolerance test would be considered appropriate as well. Given her age, a screening mammogram is controversial. It is important to discuss the risks, benefits, and alternatives of screening before proceeding.

C A N C E R S CR E E N IN G

Table 2-1 outlines recommended guidelines for the screening of common forms of cancer.

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27

28

CHAPTER 2

AMBULATORY MEDICINE

TA B L E 2 - 1 .

Recommended Cancer Screening Guidelines

TYPE OF CANCER

RECOMMENDATIONS

Cervical

An annual Pap smear is recommended starting at age 21 or within three

cancer

years of onset of sexual activity. Patients should be screened annually until three consecutive normal results, after which the frequency of screening may be ↓ to every three years.

Breast cancer

Monthly self-examination and an annual exam by a physician. Mammography should be conducted every two years after age 50 (may start earlier if there is a ⊕ family history at a young age). The age at which mammographic screening should begin is the subject of controversy. The USPSTF recommends biennial screening mammography for women 50–74 years of age. For patients in their 40s, it is recommended that the decision to begin screening be thoroughly discussed with their doctors.

Colon cancer

Hemoccult annually (especially in patients > 50 years of age); flex sigmoidoscopy (every 3–5 years in those > 50) or colonoscopy (every 10 years in those > 50). If a first-degree relative has colon cancer, begin screening at age 40 or when the patient is 10 years younger than the age at which that relative was diagnosed, whichever comes first.

Prostate

Controversial. Some groups recommend no screening; others recommend

cancer

a yearly rectal exam and PSA beginning at age 45, especially for African Americans and for patients with a strong family history.

OTH E R R OU TI NE S C R E E NI NG ■

■

Hypertension: BP screening should be done at every clinic visit. For young patients (age < 50) with elevated BP, look for 2° causes of hypertension, such as chronic kidney disease, pheochromocytoma, thyroid/parathyroid disease, sleep apnea, renovascular disease, Cushing’s syndrome, coarctation of the aorta, and 1° hyperaldosteronism. Hyperlipidemia: The U.S. Preventive Services Task Force (USPSTF) strongly recommends screening men ≥ 35 years of age and women ≥ 45 years of age for lipid disorders. Treatment goals vary depending on risk factors (see Table 2-2). However, some people suggest that statins should be put in drinking water along with fluoride. Risk factors that modify LDL goals include the following: ■ Cigarette smoking. ■ Hypertension (BP ≥ 140/90 mm Hg or on antihypertensive medication). ■ Low HDL cholesterol (< 40 mg/dL). ■ A family history of premature CAD (CAD in a male first-degree relative < 55 years of age; CAD in a female first-degree relative < 65 years of age). ■ Age (men ≥ 45 years; women ≥ 55 years).

AMBULATORY MEDICINE

The Framingham risk calculator may be used to determine the 10-year risk of developing CAD and includes age, gender, total cholesterol, HDL, smoking status, and systolic BP. Diabetes: The ADA recommends testing for diabetes or prediabetes in all adults with a BMI ≥ 25 kg/m2 and one or more additional risk factors for diabetes (see below). In individuals without risk factors, testing should begin at age 45. Either fasting plasma glucose or a two-hour oral glucose tolerance test is appropriate. Additional risk factors for diabetes are as follows: ■ A family history of DM in a first-degree relative. ■ Habitual physical inactivity. ■ Belonging to a high-risk ethnic or racial group (eg, African American, Hispanic, Native American, Asian American, Pacific Islander). ■ A history of delivering a baby weighing > 4.1 kg (9 lbs) or of gestational diabetes. ■ Hypertension (BP ≥ 140/90 mm Hg). ■ Dyslipidemia. ■ Polycystic ovary syndrome. ■ A history of vascular disease. Osteoporosis: The USPSTF recommends that women ≥ 65 years of age be screened routinely for osteoporosis. Screening should begin at age 60 for women at ↑ risk for osteoporotic fractures (eg, low weight, low estrogen state). DEXA is the screening test of choice. Abdominal aortic aneurysm (AAA): The USPSTF recommends one-time screening for AAA in men 65–75 years of age who have smoked at any time. Abdominal ultrasound is the screening test of choice. ■

■

■

■

TA B L E 2 - 2 .

Treatment of Hyperlipidemia

RISK CATEGORY

LDL TREATMENT GOAL (mg/dL)

High risk (CAD or CAD equivalent)

< 100 to < 70

Moderate risk (2+ risk factors)

< 130

Low risk (< 2 risk factors)

< 160

CHAPTER 2

29

30

CHAPTER 2

AMBULATORY MEDICINE

IM M U NI ZATI ONS

Table 2-3 lists indications for adult immunizations. TA B L E 2 - 3 .

Indications for Immunization in Adults

IMMUNIZATION

INDICATION/RECOMMENDATION

Tetanus

Give 1° series in childhood, then boosters every 10 years.

Hepatitis B

Administer to all young adults and to patients at ↑ risk (eg, IV drug users, health care providers, those with chronic liver disease).

Pneumococcal

Give to those > 65 years of age or to any patient at ↑ risk (eg, splenectomy, HIV, or immunocompromised patients on chemo or posttransplant).

Influenza

Give annually to all patients > 50 years of age and to high-risk patients.

Hepatitis A

Give to those traveling to endemic areas, those with chronic liver disease (hepatitis B or C), and IV drug abusers.

Zoster

Recommended for all patients ≥ 60 years of age who have no contraindications, including those who report a previous episode of zoster or who have chronic medical conditions.

Smallpox

Currently recommended only for those working in laboratories in which they are exposed to the virus.

Meningococcal

Not recommended for routine use. Used in outbreaks. There is an ↑ risk of disease in college students, but the vaccine is only suggested and is not mandatory in this group.

CHAPTER 3

CARDIOVASCULAR Ischemic Heart Disease

32

Valvular Disease

33

Heart Failure (Congestive Heart Failure)

34

Pericardial Disease

36

PERICARDITIS

36

PERICARDIAL EFFUSION AND CARDIAC TAMPONADE

38

SYSTOLIC HEART FAILURE

34

Advanced Cardiac Evaluation

39

DIASTOLIC HEART FAILURE

35

Hypertension

40

CARDIOMYOPATHIES

35

Aortic Dissection

41

VALVULAR CAUSES OF HEART FAILURE

36

ARRHYTHMIA CAUSING HEART FAILURE

36

Peripheral Vascular Disease

43

Hypercholesterolemia

44

Infective Endocarditis

46

31

32

CHAPTER 3

CARDIOVASCULAR

Ischemic Heart Disease KEY FACT Major risk factors for ischemic heart disease: ■ Age > 65 ■ Male gender ■ Family history ■ Smoking ■ Hypertension ■ Hyperlipidemia ■ Diabetes mellitus

KEY FACT

The 1° cause of ischemic heart disease is atherosclerotic occlusion of the coronary arteries. Major risk factors include age, family history, smoking, diabetes, hypertension, and hyperlipidemia. SYMPTOMS ■ ■

■

May be asymptomatic. Stable angina presents with substernal chest tightness/pain or shortness of breath with a consistent amount of exertion; relief is obtained with rest or nitroglycerin. Reflects a stable, flow-limiting plaque. Unstable angina (acute coronary syndrome) presents with chest tightness/ pain and/or shortness of breath, typically at rest, that does not totally improve with nitroglycerin or recurs soon after nitroglycerin. Reflects plaque rupture with formation of a clot in the lumen of the blood vessel.

EXAM ■

Unstable angina is any new angina or accelerating stable angina. ■

■

Exam can be normal when the patient is asymptomatic. During episodes of angina, an S4 or a mitral regurgitation murmur may occasionally be heard. Look for signs of heart failure (eg, ↑ JVD, bibasilar crackles, lower extremity edema) from prior MI causing left ventricular dysfunction. Look for vascular disease elsewhere—eg, bruits, asymmetric or diminished pulses, and lower extremity ischemic ulcers.

DIFFERENTIAL

Consider pericarditis, pulmonary embolism, pneumothorax, aortic dissection, peptic ulcer, esophageal disease (including diffuse esophageal spasm), GERD, and musculoskeletal causes. DIAGNOSIS KEY FACT Watch out for diabetics! They often present with ischemic disease with highly atypical symptoms. Diabetes is considered a CAD equivalent.

■

■

■

Initial workup: Elevated cardiac biomarkers (troponin, CK, CK-MB) +/– ECG changes (ST elevation/depression/Q waves); CXR to rule out dissection. Stress testing: Exercise or dobutamine to ↑ HR; ECG, echocardiography, or radionuclide imaging to assess perfusion (see the discussion of advanced cardiac evaluation below). Cardiac catheterization: Defines the location and severity of lesions.

TREATMENT ■

■

■

■

■

Acute coronary syndrome: Initial treatment includes heparin (frequently LMWH), aspirin, nitroglycerin, oxygen, morphine, and an ACEI. GPIIb/ IIIa antagonists (abciximab, eptifibatide, tirofiban) and angioplasty are also employed. To slow progression: Control diabetes, ↓ BP, ↓ cholesterol (goal for lowdensity cholesterol < 70 mg/dL), and encourage smoking cessation. To prevent angina: β-blockers ↓ HR, ↑ myocardial perfusion time, and ↓ cardiac workload, which ↓ exertional angina. If symptoms arise on a β-blocker, a long-acting nitrate or calcium channel blocker (CCB) can be added. To prevent MI: Aspirin; clopidogrel can be given to aspirin-sensitive patients. Drugs that have been shown to improve mortality after MI: Aspirin, β-blockers, ACEIs (or angiotensin receptor blockers [ARBs] in ACEIintolerant patients), and HMG-CoA reductase inhibitors.

CARDIOVASCULAR

CHAPTER 3

KEY FACT

Valvular Disease Table 3-1 describes the clinical characteristics and treatment of common valvular lesions.

TA B L E 3 - 1 .

33

Ventricular septal defects are holosystolic murmurs that radiate all over the precordium with a thrill. They are the most common cardiac malformation at birth.

Presentation and Treatment of Select Valvular Lesions

LESION

SYMPTOMS

EXAM

TREATMENT

COMMENTS

Mitral

Symptoms of heart failure;

Diastolic murmur best heard

HR control, balloon

Usually caused by

stenosis

hemoptysis; atrial fibrillation

at the apex; opening snap;

valvuloplasty, valve

rheumatic fever.

(AF).

usually does not radiate.

replacement.

Mitral

Has a long asymptomatic

Blowing systolic murmur at

If acute, surgery is always

Long-standing regurgitation

regurgitation

period; when severe

the apex, radiating to the

required. For chronic mitral

dilates the atrium,

or acute, presents with

axillae. The posterior leaflet

regurgitation, repair or

increasing the chance of AF.

symptoms of heart failure.

may lead to a murmur

replace the valve when

along the sternal border.

symptomatic or if the ejection fraction (EF) is < 60%.

Mitral valve

Asymptomatic.

prolapse

Midsystolic click;

Endocarditis prophylaxis is

Questionable association

also murmur if mitral

not required.

with palpitations and panic attacks. The most

regurgitation is present.

common cause of mitral regurgitation. Aortic

Chest pain, syncope, heart

Harsh systolic crescendo-

Avoid overdiuresis; avoid

Once symptoms appear,

stenosis

failure, shortness of breath.

decrescendo murmur

vasodilators such as

mortality is 50% at three

radiating to the carotids and

nitrates and ACEIs. Surgery

years.

right sternal border. A small

for all symptomatic patients.

and slow carotid upstroke (parvus et tardus) is seen with severe stenosis. Aortic

Usually asymptomatic until

Wide pulse pressure;

Afterload reduction with

Many cases are associated

regurgitation

advanced; then presents

soft, high-pitched diastolic

ACEIs, hydralazine; valve

with aortic root disease,

with symptoms of heart

murmur along the left

replacement if symptomatic

dissection, syphilis,

failure.

sternal border. Radiates

or in the setting of a ↓ EF.

ankylosing spondylitis, and

toward the apex.

Marfan’s syndrome.

34

CHAPTER 3

CARDIOVASCULAR

Heart Failure (Congestive Heart Failure) A 58-year-old man with long-standing hypertension is admitted to the hospital with dyspnea on exertion and bibasilar crackles, and you suspect CHF as the cause of his symptoms. Which imaging modality would you order to confirm your diagnosis? Echocardiography.

Defined as inability of the heart to pump adequate blood to meet the demands of the body. Can be categorized in different ways. One such categorization scheme includes the following: ■ ■ ■ ■

Systolic dysfunction Diastolic dysfunction Valvular dysfunction Arrhythmia causing heart failure S YS TOLI C HE AR T F AI LU R E

Weakened pumping function of the heart. Common causes include ischemic heart disease, long-standing hypertension, and viral or idiopathic cardiomyopathy in younger patients. SYMPTOMS ■

■

Patients present with poor exercise tolerance, exertional dyspnea, and easy fatigability. If patients are volume overloaded, they may present with orthopnea, paroxysmal nocturnal dyspnea, and ankle swelling.

EXAM

Exam will reveal bibasilar crackles, a diffuse PMI that is displaced to the left (reflects cardiomegaly), an S3 gallop, JVD (normal is about 0–2 cm vertical elevation above the sternomanubrial junction), and lower extremity edema. DIFFERENTIAL

Deconditioning, lung disease (eg, COPD), other categories of heart failure (eg, diastolic dysfunction), other causes of edema (eg, vascular incompetence, low albumin, nephrotic syndrome). DIAGNOSIS ■

■

The history and exam are suggestive, but determination of the EF via an imaging study (eg, echocardiography, radionuclide imaging, cardiac MRI) confirms the diagnosis. Look for the cause of the low EF: ■ Perform a stress test or cardiac catheterization to look for CAD; obtain TSH levels. ■ Look for a history of alcohol use or exposure to offending medications such as doxorubicin. ■ Dilated cardiomyopathy is seen in postpartum females. ■ A myocardial biopsy may be performed in selected cases.

CARDIOVASCULAR

TREATMENT ■

■

■

■

Maintenance medications include the following: ■ β-blockers: Metoprolol, bisoprolol, carvedilol. ■ Afterload reduction: Ideally an ACEI or an ARB. ■ Other: Give spironolactone if the potassium level is not high and the patient is on optimal dosages of β-blockers and ACEIs/ARBs. Digoxin may lower the frequency of hospitalizations and improve symptoms but does not ↓ mortality. Hydralazine and long-acting nitrates may be used in African Americans. Exacerbations: Give loop diuretics such as furosemide when the patient is volume overloaded. Automatic implantable cardiac defibrillators (AICDs) are associated with ↓ mortality from VT/VF when the EF is < 35%. Treat the cause of the systolic heart failure (eg, CAD).

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35

KEY FACT ACEIs, ARBs, and spironolactone all cause hyperkalemia.

KEY FACT Ventricular tachycardia leading to ventricular fibrillation is a common cause of death in patients with a ↓ ejection fraction. For this reason, AICD placement is indicated for patients with an EF < 35%.

D I A S T O L IC H E A R T F A ILU R E

During diastole, the heart is stiff and does not relax well, resulting in ↑ diastolic filling pressure. Hypertension with left ventricular hypertrophy (LVH) is the most common cause; other causes include hypertrophic cardiomyopathy and infiltrative diseases such as amyloidosis and sarcoidosis. SYMPTOMS/EXAM ■ ■

Symptoms are the same as those of systolic heart failure. Exam findings are similar to those of systolic failure. Listen for an S4 rather than an S3.

KEY FACT Important 2° causes of diastolic heart failure: ■ Sarcoidosis ■ Amyloidosis ■ Hemochromatosis ■ Scleroderma ■ Fibrosis (radiation, surgery)

DIFFERENTIAL

The same as that for systolic heart failure.

KEY FACT

DIAGNOSIS ■

■

Presents with symptoms of heart failure with a normal EF on echocardiogram. Echocardiography usually shows ventricular hypertrophy. Biopsy may be needed to establish the underlying diagnosis if infiltrative disease is suspected. MRI is becoming increasingly popular.

Don’t forget—systolic heart failure is associated with a low ejection fraction, whereas diastolic heart failure often has a normal-to-elevated ejection fraction.

TREATMENT ■ ■

Control hypertension. Give diuretics to control volume overload and symptoms, but avoid overdiuresis, which ↓ preload and cardiac output. C A R D IO M Y O PA T H IE S

■

■

Dilated cardiomyopathy: Frequently caused by ischemia, tachycardia, hypertension, alcohol, and Chagas’ disease (in South America). Echocardiography is useful for diagnosis. Treat with ACEIs, ARBs, β-blockers, and spironolactone. Digoxin can improve symptoms but does not improve mortality. Restrictive cardiomyopathy: Associated with sarcoid, amyloid, hemochromatosis, cancer, and glycogen storage disease. ECG shows low voltage. Echocardiography is useful for diagnosis and shows LVH, but biopsy is occasionally required to determine the underlying cause. Treatment is directed at the underlying cause and also involves diuretics.

KEY FACT Active ischemia can acutely worsen diastolic dysfunction, so treat any coexisting CAD!

KEY FACT Alcoholic and tachycardia-induced cardiomyopathy are almost completely reversible through removal of the offending source.

36

CHAPTER 3

CARDIOVASCULAR

■

Hypertrophic cardiomyopathy: Genetically inherited in an autosomal dominant pattern; associated with sudden death. Echocardiography is useful for diagnosis and may reveal a normal EF and an asymmetrically thickened ventricle. Treat with β-blockers, CCBs, or disopyramide. Inotropes (eg, digoxin), vasodilators, and excessive diuresis should be avoided. VAL VU LAR C AU S E S OF HE AR T F AI LU R E

■

■

Right-sided valvular lesions do not typically cause heart failure but can cause profound edema that is refractory to diuresis. Left-sided valvular lesions can produce heart failure. AR R HYTHM I A C AU S I NG HE AR T F AI LU R E

■ ■

This cause of heart failure is generally apparent from palpitations or ECG. Rhythms that can cause symptoms of heart failure include rapid AF and bradyarrhythmias. Others present abruptly with palpitations, shortness of breath, or even syncope.

Pericardial Disease PE R I C AR DI TI S

A 54-year-old business executive develops chest pain while at work. His vital signs remain stable. The chest pain is partially relieved by nitroglycerin but worsens with cough and deep inspiration. He is brought to the ER, where his ECG reveals diffuse ST-T elevations. His cardiac enzymes are normal. What is the appropriate treatment? NSAIDs for pericarditis.

KEY FACT Remember, chest pain that is improved by sitting up or leaning forward and diffuse ST-segment elevation with PR depression are frequently associated with pericarditis.

Inflammation of the pericardial sac. May be acute (< 6 weeks; most common), subacute (6 weeks to 6 months), or chronic (> 6 months). Causes include viral infection (especially enterovirus), mediastinal radiation, post-MI (Dressler’s syndrome), cancer, rheumatologic diseases (SLE, RA), uremia, TB, and prior cardiac surgery. May also be idiopathic. SYMPTOMS/EXAM ■

■ ■

Presents with chest pain that is often improved by sitting up or leaning forward. The pain may radiate to the back and to the left trapezial ridge. If a large effusion is present, the patient may be short of breath. Exam may reveal a pericardial friction rub (a leathery sound that is inconstant).

DIFFERENTIAL

Myocardial ischemia, aortic dissection, pneumonia, pulmonary embolism, pneumothorax.

CARDIOVASCULAR

I

aVR

V1

V4

II

aVL

V2

V5

III

aVF

V3

V6

FIGURE 3-1.

Pericarditis. Note diffuse ST-segment elevation.

DIAGNOSIS ■

■ ■

■

Look for diffuse ST-segment elevation (often with upward concavity) on ECG (see Figure 3-1) and PR-segment depression. ECG changes in pericarditis tend to be more generalized. Sequential ECGs are helpful in distinguishing pericarditis from MI, as in the latter, ECG changes tend to normalize more rapidly. Echocardiography may reveal an associated effusion. Search for an underlying cause—ie, take a history for viral illness, radiation exposure, and malignancy. Check ANA, PPD, blood cultures if febrile, and renal function. In North America, TB is an uncommon cause of chronic constrictive pericarditis that presents with ascites, hepatomegaly, and distended neck veins. A chest CT or cardiac MRI will be needed for diagnosis, and pericardial resection may be required. Prior pericardiotomy for cardiac surgery is a more common cause of chronic constrictive pericarditis in North America.

TREATMENT ■

■

Where possible, treat the underlying disorder, such as SLE or advanced renal failure. For viral or idiopathic pericarditis, give NSAIDs, colchicine, or aspirin. Avoid NSAIDs in post-MI pericarditis, as they may interfere with scar formation.

COMPLICATIONS

Patients may develop a clinically significant pericardial effusion and tamponade (see below).

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38

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CARDIOVASCULAR

PE R I C AR DI AL E F F U S I ON AND C AR DI AC TAM P ONADE

A 62-year-old man suddenly develops hypotension and shortness of breath one day after CABG surgery. Exam reveals JVD and muffled heart sounds. Echocardiography reveals tamponade physiology. What is your next step? Pericardiocentesis.

Accumulation of fluid (usually chronic) or blood (usually acute and posttraumatic/postsurgical) in the pericardial cavity surrounding the heart. SYMPTOMS/EXAM ■

■

If acute, patients may present with shock. If chronic, patients may present with shortness of breath and heart failure. One to two liters of fluid may gradually accumulate. Exam reveals distant heart sounds, elevated JVP, and pulsus paradoxus (more than a 10-mm Hg drop in systolic BP during inspiration).

DIFFERENTIAL

Pneumothorax, MI, cardiac failure. KEY FACT Echocardiography is the diagnostic procedure of choice when tamponade is suspected.

DIAGNOSIS

Echocardiography is needed to confirm the diagnosis. CXR may show a large cardiac silhouette (see Figure 3-2), and ECG may show low voltages and electrical alternans. TREATMENT

Consider emergent pericardiocentesis for patients with post–chest trauma shock as well as for those in whom echocardiography shows evidence of tamponade physiology. Also consider a pericardial window for those with recurrent or malignant effusions.

PE PE

A

B

Pericardial effusion and tamponade. (A) CXR with enlargement of the cardiac silhouette (“water-bottle heart”) in a patient with a pericardial effusion. (B) Apical fourchamber transthoracic echocardiogram with a large pericardial effusion (PE) and collapse of the right atrium and right ventricle during diastole in a patient with cardiac tamponade. (Image

FIGURE 3-2.

A reproduced with permission from USMLERx.com. Image B reproduced with permission from Hall JB et al. Principles of Critical Care, 3rd ed. New York: McGraw-Hill, 2005, Fig. 28-7A.)

CARDIOVASCULAR

TA B L E 3 - 2 .

Stressing Modalities in Cardiac Testing

STRESSING MODALITY Treadmill

PROS

CONS

Good for patients who can

—

walk. Dobutamine

Good for patients who

—

cannot exercise. Adenosine or dipyridamole

Good for patients who

Can cause bronchospasm—

(with nuclear imaging)

cannot exercise.

be cautious in patients with asthma/COPD.

Advanced Cardiac Evaluation ■

■

■

Indications for stress testing include the following (not exhaustive): ■ Diagnosis of CAD/evaluation of symptoms. ■ Preoperative evaluation. ■ Risk stratification in patients with known disease. ■ Decision making about the need for revascularization. Contraindications include severe aortic stenosis, acute coronary syndrome, and decompensated heart failure. Testing consists of a stressing modality and an evaluating modality (see Tables 3-2 and 3-3). ■ The stressor can be walking on a treadmill or IV dobutamine. ■ Evaluating modalities are ECG, echocardiography, and nuclear imaging such as thallium.

TA B L E 3 - 3 .

Evaluating Modalities in Cardiac Testing

EVALUATING MODALITY ECG

PROS Inexpensive.

CONS Cannot localize the lesion; cannot use with baseline ST-segment abnormalities or left bundle branch block (LBBB); cannot use if the patient is on digoxin.

Echocardiography

Good in patients with

Technically limited echo

LBBB; cheaper than nuclear

images or resting wall

imaging.

motion abnormalities can limit usefulness.

Radionuclide tracer

Localizes ischemia; localizes

(thallium or technetium)

infarcted tissue.

Expensive.

CHAPTER 3

39

40

CHAPTER 3

CARDIOVASCULAR

■

An additional testing method combines adenosine or dipyridamole with nuclear imaging. ■ These agents dilate the coronary arteries, but areas with plaque cannot vasodilate. ■ Such agents thus ↑ blood flow in healthy arteries but cause no change in diseased arteries, thereby creating a differential flow that is detected on nuclear imaging.

Hypertension A 40-year-old patient with a history of diabetes and hypertension who is currently on a thiazide and metformin has BP readings of 150/90 and 140/95 on multiple office visits. In the past you have tried adding an ACEI, but the patient developed a cough with the medication. What class of antihypertensive would you start next? Discontinue the ACEI and start the patient on an ARB.

A major contributor to cardiovascular disease; more common with increasing age and among African Americans. SYMPTOMS

Asymptomatic unless severe. If severe, patients may complain of chest tightness, shortness of breath, headache, or visual disturbances. EXAM ■ ■ ■

■

BP > 140/90. A displaced PMI or an S4 indicates LVH. Fundi show AV nicking and “copper-wire” changes to the arterioles. Listen for bruits, which indicate peripheral vascular disease. In severe hypertension, look for papilledema and retinal hemorrhages.

DIFFERENTIAL

Most cases are essential hypertension, but consider causes of 2° hypertension: ■

■

■

■ ■

Endocrine causes: Cushing’s syndrome, Conn’s syndrome (aldosteroneproducing tumor), hyperthyroidism, pheochromocytoma. Renal causes: Chronic kidney disease; renal artery stenosis (listen for an abdominal bruit). Young patients: Fibromuscular dysplasia of the renal arteries; aortic coarctation. Medications: OCPs, NSAIDs. Other: Obstructive sleep apnea, alcohol.

DIAGNOSIS ■

■

Diagnosed in the setting of a BP > 140/90 on two separate occasions (elevation of either systolic or diastolic BP). A systolic BP of 120–139 or a diastolic BP of 80–89 is considered “prehypertension” and predicts the development of hypertension.

CARDIOVASCULAR

TA B L E 3 - 4 .

CHAPTER 3

41

Antihypertensive Medications

COMMONLY USED CLASSES

OPTIMAL USE

MAIN SIDE EFFECTS

Thiazide

First-line treatment if there is no

↓ excretion of calcium and uric acid;

diuretics

indication for other agents.

hyponatremia.

β-blockers

Low EF, angina, CAD.

Bradycardia, erectile dysfunction, bronchospasm in asthmatics.

ACEIs

Low EF, chronic kidney disease,

Cough, angioedema, hyperkalemia.

diabetes with microalbuminuria. ARBs

Same as ACEIs; cough with ACEIs.

Hyperkalemia.

CCBs

Second-line agents.

Lower extremity edema.

TREATMENT ■

■

The goal BP is < 140/90. In diabetics and those with renal insufficiency, the goal is < 130/80. Interventions include the following: ■ Step 1—lifestyle modification: Weight loss, exercise, ↓ sodium intake, smoking cessation. ■ Step 2—medications: Begin with a thiazide diuretic unless there is an indication for another class (see Table 3-4). Consider starting two drugs initially if systolic BP is > 160. ■ Control other cardiovascular risk factors, such as diabetes, smoking, and high cholesterol.

COMPLICATIONS

Long-standing hypertension contributes to renal failure, heart failure (both systolic and diastolic), CAD, peripheral vascular disease, and stroke.

Aortic Dissection A 69-year-old man presents to the ER with severe chest pain that radiates to his back. His CXR is unrevealing, but your clinical suspicion for aortic dissection remains high. The patient indicates that he went into anaphylactic shock the last time he received IV contrast. What imaging test do you order? Transesophageal echocardiography (TEE) in light of the contraindication to performing a CT scan with IV contrast in this patient.

Most common in patients with a history of long-standing hypertension, cocaine use, or aortic root disease such as Marfan’s syndrome or Takayasu’s arteritis.

KEY FACT The goal BP in patients with diabetes or chronic kidney disease is < 130/80.

42

CHAPTER 3

CARDIOVASCULAR

SYMPTOMS/EXAM KEY FACT Always think about dissection in patients with chest pain!

■

■

Presents with sudden onset of severe chest pain that sometimes radiates to the back. May also present with neurologic symptoms resulting from occlusion of vessels supplying the brain or spinal cord. On exam, look for aortic regurgitation, asymmetric pulses and blood pressures, and neurologic findings.

DIFFERENTIAL

MI, pulmonary embolus, pneumothorax. KEY FACT

DIAGNOSIS ■

Risk factors for aortic aneurysm include age > 60, smoking, hypertension, a family history of aortic aneurysm, and hypercholesterolemia. The risk of rupture is low for aneurysms < 4 cm.

■

■ ■ ■

Requires a high index of suspicion. CXR has low sensitivity but may show a widened mediastinum or a hazy aortic knob (see Figure 3-3). CT scan with IV contrast is diagnostic and shows the extent of dissection. TEE is highly sensitive and specific. MRI may be used, but it is often time consuming and may not be optimal in the setting of an unstable patient.

TREATMENT ■

KEY FACT ■

Surgery is indicated for rapidly expanding aneurysms (> 0.5 cm per year) as well as for large aneurysms to avert the catastrophe of dissection.

■

Initial medical stabilization: Aggressive HR and BP control, first with β-blockers (typically IV esmolol) and then with IV nitroprusside if needed. Ascending dissection—Stanford type A (involves the ascending aorta): Emergent surgical repair. Descending dissection—Stanford type B (distal to the left subclavian artery): Medical management is indicated unless there is intractable pain, progressive dissection in patients with chest pain, or vascular occlusion of the aortic branches (see Figure 3-4).

T

FL

A

B

C

Aortic dissection. (A) Frontal CXR showing a widened mediastinum in a patient with an aortic dissection. (B) Transaxial contrast-enhanced CT showing a dissection involving the ascending and descending aorta (FL, false lumen). (C) Sagittal MRA image showing a dissection involving the descending aorta, with a thrombus (T) in the false lumen. (Images A and C reproduced with permission from USMLERx.com. Im-

FIGURE 3-3.

age B reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 19-17.)

CARDIOVASCULAR

A

CHAPTER 3

43

B

Ascending vs. descending aortic dissection. (A) Proximal or ascending (type A). (B) Distal or descending (type B). (Reproduced with permission from Doherty GM. Current Diagnosis &

FIGURE 3-4.

Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 19-16.)

COMPLICATIONS

Aortic rupture, acute aortic regurgitation, tamponade, neurologic impairment, limb or mesenteric ischemia, renal ischemia.

Peripheral Vascular Disease Atherosclerotic disease of vessels other than the coronary arteries. Risk factors are similar to those for CAD and include smoking, diabetes, hypercholesterolemia, hypertension, and increasing age. SYMPTOMS

Presentation depends on the organ affected: ■ ■ ■

■

Mesenteric ischemia: Postprandial abdominal pain and food avoidance. Lower extremities: Claudication, ulceration, rest pain. Kidneys: Usually asymptomatic, but may present with difficult-to-control hypertension. CNS: Stroke and TIA (see Chapter 13).

EXAM ■

■

■

Mesenteric disease: No specific findings. The patient may be thin because of weight loss from avoidance of food. Lower extremity disease: Exam reveals ulcers, diminished pulses, ↓ anklebrachial indices, skin atrophy and loss of hair, and bruits over affected vessels (abdominal, femoral, popliteal). Renal artery stenosis: Listen for a bruit during systole and diastole (highly specific).

KEY FACT Acute vessel occlusion from an embolus or an in situ thrombus presents with sudden pain (abdominal or extremity) and is an emergency.

44

CHAPTER 3

CARDIOVASCULAR

DIFFERENTIAL ■

■

Abdominal pain: Stable symptoms can mimic peptic ulcer disease or biliary colic. If the colon is predominantly involved, episodes of pain and bloody stool can look like infectious colitis. Lower extremities: Spinal stenosis can produce lower extremity discomfort similar to claudication. Claudication improves with standing still, but spinal stenosis classically improves with sitting (lumbar flexion improves spinal stenosis symptoms).

DIAGNOSIS ■ ■

KEY FACT Peripheral vascular disease is a predictor of CAD.

■

Mesenteric disease: A diagnosis of exclusion. Angiography reveals lesions. Lower extremity disease: Diagnosed via the ankle-brachial index (compares BP in the lower and upper extremities) and Doppler ultrasound. Angiography or MRA is used in preparation for revascularization but is generally not used for diagnosis. Renal artery stenosis: CT angiography, MRA, conventional angiography, or ultrasound with Doppler flow (technically difficult).

TREATMENT ■ ■ ■

■

Control risk factors, especially smoking. Mesenteric disease: Treat with surgical revascularization or angioplasty. Lower extremity disease: Treat with exercise to improve functional capacity, surgical revascularization, and sometimes angioplasty. Cilostazol is moderately useful (improves pain-free walking distance 50%), whereas pentoxifylline is of marginal benefit. Renal artery stenosis: Surgery or angioplasty may be of benefit.

Hypercholesterolemia A 73-year-old man with a history of diabetes mellitus comes to your office for the results of his recent blood work. His fasting lipid panel is significant for an LDL of 130 mg/dL. In addition to educating him on diet and lifestyle changes, what medication would you start? A statin.

One of the principal factors contributing to atherosclerotic vascular disease. An ↑ LDL and a low concentration of HDL are the 1° contributors. Hypercholesterolemia can be idiopathic, genetic, or 2° to other diseases, such as diabetes, nephrotic syndrome, and hypothyroidism. SYMPTOMS

Asymptomatic unless the patient develops ischemia (eg, angina, stroke, claudication) or unless severe hypertriglyceridemia leads to pancreatitis. EXAM ■

■

Look for evidence of atherosclerosis—eg, carotid, subclavian, and other bruits; diminished pulses; or ischemic foot ulcers. Look for xanthomas (lipid depositions) over the tendons, above the upper eyelid, and on the palms.

CARDIOVASCULAR

CHAPTER 3

45

DIAGNOSIS ■

■

■

Diagnosis is based on a lipid panel. A full fasting lipid panel consists of total cholesterol, HDL, LDL, and triglycerides. ■ Because triglycerides rise following a meal, only total cholesterol and HDL can be measured after a meal. Triglycerides and LDL can be measured only when fasting. ■ LDL is not measured directly; it is calculated on the basis of total cholesterol, HDL, and triglycerides. High triglycerides (> 400 mg/dL) make LDL calculation unreliable. Look for other contributing conditions. Check glucose and TSH; check body weight, and consider nephrotic syndrome. In patients with a family history of early heart disease, consider novel risk factors such as homocysteine, Lp(a), and C-reactive protein. These are treated with folic acid supplementation, niacin, and statins, respectively.

TREATMENT

Treatment is aimed at preventing pancreatitis when triglycerides are very high as well as preventing atherosclerotic disease (see Table 3-5). ■

■

■

Triglycerides: If > 500 mg/dL, recommend dietary modification (↓ total fat and ↓ saturated fat) and aerobic exercise, and begin medication (fibrate or nicotinic acid). At lower levels, treatment can begin with diet and exercise, and medication can be added as needed. Treat diabetes if present. LDL: In patients with diabetes or CAD, the goal LDL is < 70 mg/dL. The mainstay of treatment is diet, exercise, and a statin. LDL control is the 1° cholesterol-related goal in patients with CAD or diabetes. HDL: Can be modestly ↑ with fibrate or nicotinic acid.

TA B L E 3 - 5 .

Mechanisms and Side Effects of Cholesterol-Lowering Medications

MEDICATION HMG-CoA

PRIMARY EFFECT ↓ LDL

SIDE EFFECTS Hepatitis, myositis.

COMMENTS A potent LDLlowering medication.

reductase inhibitors (“statins”) ↓ LDL

Generally well

Introduced in 2003;

absorption

tolerated; side

its role in therapy is

inhibitors

effects are the same

being defined.

(ezetimibe)

as those of placebo.

Cholesterol

Fibrates

↓ triglycerides,

Potentiates myositis

(gemfibrozil)

slightly ↑ HDL

with statins.

Bile acid–binding

↓ LDL

Bloating and

Most patients cannot

cramping.

tolerate GI side

resins

—

effects. Nicotinic acid (niacin)

↓ LDL, ↑ HDL

Hepatitis, flushing.

Aspirin before doses ↓ flushing.

KEY FACT LDL control is the number-one cholesterol-related goal in patients with CAD or diabetes!

CHAPTER 3

46

CARDIOVASCULAR

Infective Endocarditis A 26-year-old IV drug user is admitted to the hospital with fevers and chills. Despite broad antibiotic therapy, blood cultures remain persistently ⊕. You suspect infective endocarditis and order a transthoracic echocardiogram (TTE), which is normal. What is your next step? Order a TEE.

Inflammation of the heart valves. Can be infectious or noninfectious. Infectious endocarditis is commonly seen in IV drug abusers and in those with valvular lesions or prosthetic heart valves. SYMPTOMS ■

■

■

Acute endocarditis: Presents with fever, rigors, heart failure from valve destruction, and symptoms related to systemic emboli (neurologic impairment, back pain, pulmonary symptoms). Subacute bacterial endocarditis: Characterized by weeks to months of fever, malaise, and weight loss. Also presents with symptoms of systemic emboli. Noninfectious endocarditis: Generally asymptomatic. Can cause heart failure by destroying valves.

EXAM ■ ■

■

Look for a new murmur. Findings associated with emboli include focal neurologic deficits and tenderness to percussion over the spine. With infectious endocarditis, look at the fingers and toes for deep-seated, painful nodules (Osler’s nodes, or “Ouchler’s nodes”) and small skin infarctions (Janeway lesions). Retinal exudates are called Roth’s spots.

DIFFERENTIAL

The differential diagnosis of endocarditis is outlined below and in Table 3-6. ■

TA B L E 3 - 6 .

Differential of a vegetation found on echocardiography: Infectious endocarditis, nonbacterial thrombotic endocarditis (NBTE, also known as

Causes of Endocarditis

ACUTE

SUBACUTE

CULTURE NEGATIVE

NBTE (MARANTIC

VERRUCOUS

ENDOCARDITIS)

(LIBMAN-SACKS)

Most commonly

Viridans streptococci

HACEK organisms a

Thrombus formation

Seen in lupus;

S aureus

Enterococcus

Coxiella burnetii

on the valve is seen in

vegetation is composed

Staphylococcus

Noncandidal fungi

many cancers

of fibrin, platelets,

epidermidis Gram-negative rods

immune complexes, and inflammatory cells

Candida a

HACEK organisms: Haemophilus aphrophilus and H parainfluenzae, Actinobacillus actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae.

CARDIOVASCULAR

■

marantic endocarditis), verrucous endocarditis (Libman-Sacks endocarditis), valve degeneration. Differential of bacteremia: Infectious endocarditis, infected hardware (eg, from a central line), abscess, osteomyelitis.

DIAGNOSIS ■

■

The discovery of noninfectious endocarditis is usually an incidental finding on echocardiography. It may be found during the workup of systemic emboli. Infectious endocarditis is diagnosed by a combination of lab and clinical data. If suspicious, obtain three sets of blood cultures and an echocardiogram. If the TTE is 䊞, proceed to TEE (more sensitive). ⊕ blood cultures and echocardiogram findings diagnose endocarditis. The Duke criteria are often used for diagnosis.

CHAPTER 3

47

KEY FACT Streptococcus bovis bacterial endocarditis should raise suspicions for occult GI malignancy. These patients need a colonoscopy.

KEY FACT Any patient with S aureus bacteremia should be evaluated for endocarditis with echocardiography.

TREATMENT ■

■

■

■

■

Treat with prolonged antibiotic therapy, generally for 4–6 weeks. Begin empiric therapy with gentamicin and antistaphylococcal penicillin (oxacillin or nafcillin). If there is a risk of methicillin-resistant S aureus, use vancomycin instead of oxacillin/nafcillin. Valve replacement is appropriate for fungal endocarditis, heart failure from valve destruction, valve ring abscess, or systemic emboli despite adequate antibiotic therapy. Following treatment for infectious endocarditis, patients should receive endocarditis prophylaxis. For NBTE, treat the underlying disorder (often malignancy). Heparin is useful in the short term. For verrucous endocarditis, no treatment is required. Patients should receive endocarditis prophylaxis (see below).

KEY FACT Surgery is indicated in the setting of hemodynamic instability, valvular destruction, perivalvular extension, and persistently positive blood cultures and should not be delayed while the acute infection is cleared with antibiotics.

PREVENTION ■

■

Administer endocarditis prophylaxis only to patients whose cardiac conditions are associated with the highest risk of an adverse outcome from endocarditis. These include the following: ■ Congenital cardiac disease: ■ Patients with unrepaired cyanotic disease, including those with palliative shunts and devices. ■ Patients with congenital cardiac defects that have been completely repaired through use of prosthetic material/devices, whether surgically or percutaneously, during the first six months after the repair procedure (endothelialization occurs after six months). ■ Patients with repaired congenital cardiac disease who have residual defects at or adjacent to the site of a patch device that may inhibit endothelialization. ■ Other: Patients with prosthetic heart valves, those with previous infective endocarditis, and cardiac transplant patients with cardiac valvulopathy. Guidelines for antibiotic prophylaxis: ■ Dental procedures: Prophylaxis is appropriate for all dental procedures that involve the manipulation of gingival tissue or the periapical region of teeth, or for procedures involving perforation of the oral mucosa (but not for routine anesthetic infections through noninfected tissue, dental radiographs, bleeding from trauma, adjustment of orthodontic devices, or shedding of deciduous teeth).

KEY FACT Don’t forget—infective endocarditis requires prolonged antibiotic therapy for 4–6 weeks.

48

CHAPTER 3

CARDIOVASCULAR

Respiratory tract procedures: Prophylaxis is indicated for any of the above-mentioned cardiac patients who are undergoing an invasive procedure of the respiratory tract that involves incision or biopsy of the respiratory mucosa (but not for bronchoscopy if no biopsy is performed). ■ Skin procedures: Prophylaxis is appropriate for any of the above-mentioned cardiac patients who are undergoing procedures involving infected skin, skin structures, or musculoskeletal tissue. ■ GI and GU procedures: Prophylaxis is not recommended but may be considered in special scenarios involving the above-mentioned cardiac patients. Prophylactic regimens: Amoxicillin (or clindamycin/azithromycin for those with penicillin allergy) 30–60 minutes before the procedure. ■

■

COMPLICATIONS

Spinal osteomyelitis, valve destruction and heart failure, septic emboli, stroke.

CHAPTER 4

EMERGENCY MEDICINE Trauma

50

Environmental Emergencies

64

ABCS AND THE 1° SURVEY

50

COLD EMERGENCIES

64

2° SURVEY

51

HEAT EMERGENCIES

65

Shock

53

Burns

66

Common Dysrhythmias

54

Electrical Injuries

67

Advanced Cardiac Life Support

56

Ophthalmology

68

UNSTABLE BRADYCARDIA

56

OCULAR TRAUMA

68

PULSELESS ARREST

57

CONJUNCTIVITIS

68

TACHYCARDIA

57

OTHER CONDITIONS OF THE EYE

69

Toxicology

58

Dental Emergencies

70

Sexual Assault

62

DENTAL AVULSION

70

Animal and Insect Bites

62

MANDIBULAR FRACTURE

70

Tetanus

63

Radiology

71

49

50

CHAPTER 4

EMERGENCY MEDICINE

Trauma The acute management of a trauma victim follows a linear algorithm that should be performed in the same order every time: AcBCDE, 1° survey, 2° survey. Stabilize the patient at each step before moving on. ABC s AND THE 1° S U R VE Y

Trauma treatment should proceed as follows: ■

KEY FACT Trauma nurses will help you with their own trauma mnemonic: O-MI (Oxygen, cardiac Monitor, IV access). ■

■

■

KEY FACT The maximum score on the GCS is 15; the lowest is 3.

■

Ac: Airway maintenance with Cervical spine control. ■ Check the patency of the airway first, and then give supplemental O2 via nasal cannula, face mask, airway adjunct (nasopharyngeal or oropharyngeal airway), or bag-valve mask (Ambu-Bag) as appropriate. ■ Indications for intubation include impending airway compromise, a Glasgow Coma Scale (GCS) score of ≤ 8, ↓ mental status, apnea, and severe closed-head injuries. ■ A surgical airway (cricothyroidotomy) should be performed in the setting of significant maxillofacial trauma. B: Breathing with ventilation. ■ Quickly evaluate for causes of impending cardiopulmonary death— eg, tension pneumothorax, cardiac tamponade, open pneumothorax, massive hemothorax, or airway obstruction. C: Circulation with hemorrhage control. ■ Resuscitation: Think short and fat IV lines—eg, two large-bore (16- or 18-gauge) antecubital lines. ■ A good rule of thumb is to give three times as much isotonic fluid (NS or LR) as the estimated blood lost. D: Disability—determined by a brief neurologic examination: ■ AVPU system: A = Alert; V = responds to Vocal stimuli; P = responds to Painful stimuli; U = Unresponsive. ■ GCS: Based on the best response of E + V + M (see Figure 4-1). ■ Focused neurologic exam: Examine for unequal pupils, depressed skull fracture, focal weakness, and posturing. E: Exposure/Environmental control: Completely undress the patient to assess for injury, but avoid hypothermia.

Eye Opening (E)

Verbal Response (V)

Motor Response (M)

4 Spontaneous 3 Responds to voice 2 Responds to pain 1 No response

5 Oriented 4 Confused speech 3 Inappropriate speech 2 Incomprehensible 1 No response

6 Obeys commands 5 Localizes pain 4 Withdraws to pain 3 Abnormal flexion 2 Abnormal extension 1 No response

FIGURE 4-1.

Scoring of the Glasgow Coma Scale.

EMERGENCY MEDICINE

CHAPTER 4

2° SURVEY

The 2° survey consists of total patient evaluation as outlined below. This is also the time to order appropriate lab tests and radiographs based on the mechanism of injury, past medical history, and the like. ■

■

■

Obtain an AMPLE history: Inquire about Allergies, Medications, Past medical history, Last oral intake, and Events/Environmental factors related to the injury. If the patient can speak, ask about other symptoms that may not be obvious on exam. Obtain as much information as possible about the circumstances of the trauma from EMTs/paramedics, witnesses, and the like. Conduct a focused physical exam: ■ Head and skull: Inspect for trauma, pupils, and loss of consciousness. Examine for hemorrhage around the mastoid (Battle’s sign), eyes (“raccoon eyes”), and tympanic membrane, all of which are indicative of a basilar skull fracture. Inspect the nose for CSF leakage and for an unstable airway due to facial fractures. ■ Neck: Look for trauma; palpate for midline tenderness, crepitus, and tracheal deformity. ■ Chest: Inspect for irregular or paradoxical breathing patterns resulting from multiple rib fractures—ie, flail chest. Listen for equal and bilateral breath sounds (if not found, or if there is crepitus on palpation of the chest, suspect pneumothorax). Listen for clear heart sounds (if muffled and accompanied by JVD, suspect cardiac tamponade). A new diastolic murmur after trauma suggests aortic dissection. ■ Abdomen: Inspect the anterior and posterior abdomen for signs of trauma. Palpate the pelvis for tenderness or instability. ■ Perineum/rectum/vagina: Assess for trauma, including urethral bleeding (suggests urethral tear). Check for prostate position, rectal tone, and rectal blood. In female patients, check for vaginal trauma and blood in the vaginal vault. ■ Musculoskeletal system: Look for evidence of trauma, including contusions, lacerations, and deformities. Inspect the extremities for tenderness, crepitus, abnormal range of motion, and sensation. An externally rotated, shortened leg suggests hip fracture. Management: ■ Head and skull: Maintain the airway; continue oxygenation and ventilation. Obtain a CT scan of the head and face if indicated; intubate if necessary. ■ Neck: Maintain in-line immobilization and protection with a hard cervical collar. Obtain radiographs if the C-spine cannot be cleared clinically. If indeterminate, consider CT of the cervical spine (see Figure 4-2). ■ Chest: Obtain a CXR and, if necessary, a CT scan. Tube thoracostomy for pneumothorax (needle thoracostomy for tension pneumothorax); pericardiocentesis for cardiac tamponade; and emergent surgical repair for aortic disruption (see Figure 4-3). Consider placing an NG tube. ■ Abdomen: Obtain a pelvic x-ray; arrange for a FAST (focused abdominal sonography for trauma) and/or abdominal CT if indicated. Transfer to an OR in the presence of a penetrating wound to the abdomen deeper than the fascia or with any significant bleeding or bowel injury. Keep any impaled objects in place, and do not remove them until the patient has been taken to the OR. Stable patients who are cleared of metal shrapnel may have a triple-contrast CT exam first (see Figures 4-4 and 4-5).

51

KEY FACT A “trauma series” consists of AP chest, AP abdomen/pelvis, and AP/lateral/ odontoid C-spine x-rays.

KEY FACT Criteria for clinical clearance of the cervical spine: The patient is alert and not intoxicated; no posterior midline C-spine tenderness; no neurologic deficit; and no painful distracting injuries.

KEY FACT The spleen is the most commonly injured solid organ in blunt abdominal trauma.

KEY FACT Cushing’s triad (widening pulse pressure, bradycardia, and irregular breathing) indicates ↑ ICP, as from a closed-head injury.

FIGURE 4-2. Cervical spine fracture. A sagittal reformation of a cervical

spine CT shows a fracture through the base of the dens, a type 2 odontoid fracture (red arrows). (Reproduced with permission from USMLERx.com.)

CHAPTER 4

52

EMERGENCY MEDICINE

S L

K Aortic injury. A frontal CXR in a trauma patient shows widening of the superior mediastinum (red arrows) with bilateral “apical caps” (white arrows) corresponding to mediastinal bleeding extending into the extrapleural spaces above the lung apices. (Reproduced

FIGURE 4-3.

with permission from Brunicardi FC et al. Schwartz’s

Abdominal trauma. A transaxial image from an abdominal CT in a trauma patient shows a splenic laceration (red arrow) that enhances less-than-normal splenic tissue (blue arrow) and hemoperitoneum (red arrowheads). L, liver; S, stomach; K, left kidney. (Repro-

Principles of Surgery, 9th ed. New York: McGraw-Hill,

duced with permission from Stone CK, Humphries RL. Current Diagnosis & Treatment: Emergency Medicine, 6th ed. New York:

2010, Fig. 7-23A.)

McGraw-Hill, 2008, Fig. 23-2.)

KEY FACT Beck’s triad (JVD, muffled heart tones, and hypotension) indicates cardiac tamponade. Sometimes pulsus paradoxus is also noted. Pericardiocentesis brings back unclotted blood.

FIGURE 4-5.

■

■

Urinary system: Insert a Foley catheter (contraindications include blood at the urethral meatus, a severe pelvic fracture, or abnormal position of the prostate). See Figure 4-6. Musculoskeletal system: Wound irrigation and tissue debridement. Obtain an arteriogram if vascular injury is suspected. Obtain radiographs as needed. Maintain immobilization of the patient’s thoracic and lumbar spine; apply a splint as indicated. Open fractures and suspected compartment syndromes require urgent orthopedic consultation. Administer tetanus immunization and antibiotics as required.

Positive FAST. Longitudinal image from a trauma FAST ultrasound shows hemoperitoneum (labeled “fluid”) in the hepatorenal space.

FIGURE 4-4.

(Reproduced with permission from Brunicardi FC et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill, 2010, Fig. 7-28A.)

FIGURE 4-6. Pelvic fractures. Frontal pelvic radiograph in a trauma patient shows bilateral superior and inferior pubic ramus fractures (red arrows) and a left sacral fracture (red arrowhead). (Reproduced with permission from Brunicardi FC et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill, 2010, Fig. 7-30A.)

EMERGENCY MEDICINE

Tachycardia

FIGURE 4-7.

Oliguria

Tachypnea Acidosis Change in skin temperature

CHAPTER 4

53

AMS Hypotension Anuria

Symptoms of shock over time.

Shock Described in the broadest strokes, shock is a physiologic oxygen supply/demand mismatch. ↓ tissue perfusion leads to cell hypoxia and eventual tissue death. Rapid clinical assessment of circulatory status includes pulse, skin color, and level of consciousness. The evolution of the symptoms of shock is shown in Figure 4-7. Classically, shock has been divided into four types—hypovolemic, cardiogenic, distributive, and obstructive—based on physiologic response. Distributive shock, the penultimate, is further subdivided into septic, anaphylactic, and neurogenic shock. These types are all reviewed in Table 4-1.

TA B L E 4 - 1 .

With increasing blood loss, a patient’s mental status progresses from anxiety to agitation to confusion and then to lethargy/unconsciousness.

Hemodynamic Characteristics of Shock

TYPE OF SHOCK Hypovolemic

KEY FACT

MAJOR CAUSES Trauma, blood loss, inadequate fluid

PCWP

SVR

CARDIAC

(≈ LA

(VASOCON-

OUTPUT

PRESSURE)

STRICTION)

SVO2

↓

↓a

↑

↓

Crystalloid/blood.

↓a

↑

↑

↓

Treat the cause and give pressors

TREATMENT

repletion, third spacing, burns. Cardiogenic

Distributive

MI, CHF, arrhythmia, structural heart disease (eg, severe mitral

(dopamine; norepinephrine or

regurgitation, VSD).

dobutamine if necessary).

Septic: Bacteremia (especially

↑

Normal

↓a

↑

gram 䊞).

For septic shock, obtain cultures; then give antibiotics, fluid, and pressors (norepinephrine,

Anaphylactic: Bee stings; food/

dopamine). For anaphylactic

medication allergies.

shock, give diphenhydramine

Neurogenic: Trauma to the spinal

(epinephrine if severe).

cord (leading to loss of autonomic/ motor reflexes). Obstructive

Cardiac tamponade, tension

↓

↑/↓ b

↑

↓

For tamponade, needle

pneumothorax, pulmonary embolism

pericardiocentesis. For PE,

(PE).

thrombolytics.

a

Driving force.

b

↑ PCWP for tamponade; ↓ PCWP for PE.

54

CHAPTER 4

KEY FACT After a premature ventricular contraction (PVC), the sinus rhythm resumes as if the PVC never occurred. After a premature atrial contraction (PAC), however, the sinus rhythm resets as if the PAC were a normal beat.

EMERGENCY MEDICINE

Common Dysrhythmias Tables 4-2 and 4-3 illustrate a variety of important dysrhythmias. Narrow-complex arrhythmias (eg, reentry supraventricular tachycardia, pulseless electrical activity [PEA]) are more likely to have noncardiac causes (eg, hypovolemia, poor vascular tone), whereas wide-complex arrhythmias (eg, V-tach, VF) are more likely to have cardiac causes (or electrolyte imbalances and toxins). TA B L E 4 - 2 .

KEY FACT “Geminy” refers to the sequence of normal beats with PVCs; bigeminy is a pattern of one normal beat followed by a PVC; and trigeminy is that with two normal beats followed by a PVC.

Common Bradyarrhythmias

BRADYARRHYTHMIA Sinus bradycardia

1° AV block

Mobitz I (Wenckebach)

Mobitz II

3° AV block

EXAMPLE

EMERGENCY MEDICINE

TA B L E 4 - 3 .

CHAPTER 4

55

Common Tachyarrhythmias

TACHYARRHYTHMIA

EXAMPLE SUPRAVENTRICULAR TACHYARRHYTHMIAS

Sinus tachycardia

Atrial fibrillation (A-fib)

Atrial flutter

Premature atrial contraction (PAC)

Multifocal atrial tachycardia (MAT)

Atrioventricular nodal reentrant tachycardia (AVNRT)

Wolff-Parkinson-White syndrome (slurred upstroke; delta wave)

III

aVF

V3

(continues)

CHAPTER 4

56

TA B L E 4 - 3 .

EMERGENCY MEDICINE

Common Tachyarrhythmias (continued)

TACHYARRHYTHMIA

EXAMPLE VENTRICULAR TACHYARRHYTHMIAS

Premature ventricular contraction (PVC) (unifocal vs. multifocal)

↓

↓

↓

↓

↓

↓

↓

↓

↓

Ventricular tachycardia (V-tach) (monomorphic vs. polymorphic)

Torsades de pointes (a type of V-tach that can lead to VF as well)

Ventricular fibrillation (VF)

MNEMONIC ACLS steps—

ABCDEF Airway Breathing Circulation Drugs Electricity (shock) Fluids

Advanced Cardiac Life Support (ACLS) The evolution of cardiac arrest (VF → asystole) involves three phases—electrical, hemodynamic, and metabolic—reflecting increasingly worsening ischemia. When a patient suffers an arrest, start with CPR and determine rhythm. Then proceed as outlined below. U NS TABLE BR ADYC AR DI A

A patient found to be in unstable bradycardia (HR < 60 with hypotension, chest pain, changes in mental status, or other signs/symptoms of shock) needs to be paced. Patients with Mobitz II (2° AV block type II) and 3° AV block, even if they are asymptomatic, also merit transcutaneous pacing. While preparing for pacing, give atropine 0.5 mg IV q 3–5 min × 3. Dopamine 2–10 μg/kg/min or epinephrine 2–10 μg/min may also be used, particularly if transcutaneous pacing is ineffective. Transvenous pacing and/or pressor drips may also be needed.

EMERGENCY MEDICINE

P U L S E LE S S A R R E S T

In the setting of pulseless arrest, perform a 1° survey to determine which of four rhythms is involved: VF, pulseless V-tach, asystole, or PEA. ■

■

■

VF or pulseless V-tach: ■ Attempt unsynchronized cardioversion (shock) prior to performing the 2° survey. ■ Next, give a vasopressor: epinephrine 1 mg IV q 3–5 min × 3 or vasopressin 40 units IV (replaces only the first or second dose of epinephrine). ■ Give another shock and then an antiarrhythmic agent: amiodarone 300 mg IV (150 mg for subsequent doses) q 3–5 min or lidocaine 1.0– 1.5 mg/kg IV (0.50–0.75 mg/kg for subsequent doses) q 5–10 min. ■ Give another shock and return to the vasopressor step. Continue in this “vasopressor-shock-antiarrhythmic-shock” loop until the patient regains a pulse or resuscitation efforts are stopped. ■ If torsades de pointes develops, give magnesium 1–2 g IV. Asystole or PEA: ■ Proceed to the 2° survey (asystole and PEA are not shockable rhythms) and then give vasopressors only. ■ If bradycardia develops, give atropine 1 mg IV q 3–5 min × 3. Regardless of type, attempt to identify and treat the underlying cause(s) of cardiac arrest. T A C H Y CA R D IA

■

■

If signs/symptoms of unstable tachycardia develop (eg, shortness of breath, chest pain, hypotension, ischemic ECG changes), perform immediate synchronized cardioversion (at 100, 200, 300, and then 360 J). If stable tachycardia develops, quickly perform 1° and 2° surveys, and then determine if it is narrow complex (QRS < 0.12 sec) or wide complex. ■ Narrow complex and regular: First attempt vagal stimulation, and then try adenosine 6 mg IV followed by 12 mg q 2 min × 2. If the rhythm persists, give metoprolol 5 mg IV q 5 min × 3 or diltiazem 15–20 mg IV over 2 minutes (if no CHF). ■ Narrow complex and irregular: Give metoprolol or diltiazem as described above. ■ Wide complex and regular: Give amiodarone 150 mg IV over 10 minutes or procainamide 17 mg/kg at 50 mg/min (if no CHF). If the rhythm persists, proceed with synchronized cardioversion. ■ Wide complex and irregular: Further evaluate the rhythm. ■ Torsades de pointes: Give magnesium 1–2 g IV over 5–60 minutes with overdrive pacing. ■ Wolff-Parkinson-White syndrome: Follow the treatment pathway for regular wide-complex tachycardia (ie, amiodarone or procainamide, then synchronized cardioversion). ■ If neither of these rhythms exists, follow the treatment pathway for persistent regular narrow-complex tachycardia (ie, metoprolol or diltiazem).

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57

KEY FACT When possible, pretreat the patient with sedation (eg, midazolam) before pacing. It won’t reduce the pain, but it should keep the patient from remembering it.

KEY FACT For VF and pulseless V-tach, the defibrillator is set to 360 J if monophasic or 250 J if biphasic for unsynchronized cardioversion.

MNEMONIC Potential underlying causes of pulseless electrical activity—

The 5 H’s and 5 T’s Hypovolemia Hypoxia H+ (acidosis) Hyper-/Hypokalemia Hypothermia Toxins/Tablets (drug overdose) Cardiac Tamponade Tension pneumothorax Coronary Thrombosis (ACS) Pulmonary Thrombosis (PE)

KEY FACT Expert consultation is recommended for wide-complex tachycardia, irregular narrow-complex tachycardia, and persistent regular narrow-complex tachycardia.

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Toxicology A 14-year-old boy is hospitalized for acute cholinergic toxicity after having been exposed to pesticides in a local orchard. Without treatment, what neuromuscular effects might he have experienced? Muscle fasciculations, weakness, and paralysis.

In dealing with a patient who has been exposed to a toxin, begin by determining which toxin was involved and the means by which the patient was exposed—eg, through ingestion (most common), inhalation, injection, or absorption. Also determine the time and extent of the exposure, and ascertain if any other substances were involved. Ask about symptoms and determine if the exposure was intentional. SYMPTOMS/EXAM/DIAGNOSIS

Vital signs may yield clues to the type of ingestion: ■

■ ■

■

■ ■ ■ ■

Hyperthermia: Amphetamines, anticholinergics, ASA, cocaine, neuroleptics, nicotine, PCP, SSRIs, thyroid medication. Hypothermia: Alcohol, barbiturates, carbon monoxide, sedative-hypnotics. Tachycardia: Amphetamines, anticholinergics, cocaine, PCP, thyroid medication, TCAs. Bradycardia: β-blockers, calcium channel blockers (CCBs), cholinergics, clonidine, digitalis, opiates, parasympathomimetics. Tachypnea: Organophosphates (eg, pesticides), salicylates. Respiratory depression: Barbiturates, benzodiazepines, opiates. Hypertension: Amphetamines, anticholinergics, cocaine, PCP. Hypotension: Alcohol, β-blockers, CCBs, digitalis, opiates, organophosphates, sedative-hypnotics, TCAs.

Other diagnostic clues derived from physical findings include the following: ■

■

KEY FACT Meperidine is an exception to the opioid toxidrome and does not cause miosis.

■

■

■

Breath odor: ■ Violets: Turpentine. ■ Pear: Chloral hydrate. ■ Bitter almonds: Cyanide. ■ Garlic: Arsenic, DMSO, organophosphates. ■ Mothballs: Camphor, naphthalene. Pupils: ■ Constricted (miosis): “COPS” (Clonidine, Opiates, Pontine bleed, Sedative-hypnotics). ■ Dilated (mydriasis): Amphetamines, anticholinergics, cocaine. Pulmonary edema: Cocaine, ethylene glycol, opiates, organophosphates, salicylates, toxic inhalations (chlorine, nitric oxide, phosgene). Bowel sounds: ■ Increased: Sympathomimetics, opiate withdrawal. ■ Decreased: Anticholinergics, opiate toxicity. Skin findings: ■ Needle tracks: Opiates. ■ Diaphoresis: Organophosphates, salicylates, sympathomimetics. ■ Jaundice: Acetaminophen (after liver failure), mushroom poisoning. ■ Alopecia: Arsenic, chemotherapeutic agents, thallium. ■ Cyanosis: Drugs causing methemoglobinemia (eg, aniline dyes, “caine” anesthetics, chlorates, dapsone, nitrates/nitrites, sulfonamides).

EMERGENCY MEDICINE

TA B L E 4 - 4 .

CHAPTER 4

59

Classic Toxidromes

TOXIDROME Cholinergic

SYMPTOMS/SIGNS

EXAMPLES

DUMBBELS: Diarrhea, Urination, Miosis,

Muscarine-containing

Bradycardia, Bronchospasm, Emesis,

mushrooms,

Lacrimation, Salivation.

organophosphates, pilocarpine, pyridostigmine.

Anticholinergic

Opioid

“Hot as a hare, red as a beet, dry as a bone,

Antihistamines,

mad as a hatter, blind as a bat”: fever, skin

antipsychotics,

flushing, dry mucous membranes, psychosis,

atropine, Jimson

mydriasis. Also tachycardia and urinary

weed, scopolamine,

retention.

TCAs.

Triad of coma, respiratory depression, and

Heroin, morphine,

miosis. Also bradycardia, hypothermia, and

oxycodone.

diminished bowel sounds. Sedative-hypnotic

Hallucinogenic

Extrapyramidal

CNS depression, respiratory depression, and

Alcohol, barbiturates,

coma.

benzodiazepines.

Disorientation, panic, seizures, hypertension,

Amphetamines,

tachycardia, tachypnea.

cocaine, PCP.

Parkinsonian symptoms: tremor, torticollis,

Haloperidol,

trismus, rigidity, oculogyric crisis,

metoclopramide,

opisthotonos, dysphonia, and dysphagia.

phenothiazines.

Table 4-4 lists symptoms and signs associated with common toxin-induced syndromes (“toxidromes”). TREATMENT

Treatment options are as follows: ■

■

Elimination: ■ Activated charcoal: Constitutes first-line treatment. Administer in a dose of 1 g/kg. Avoid multiple doses of cathartics (eg, sorbitol), especially in young children. ■ Whole bowel irrigation (eg, polyethylene glycol with electrolytes to wash toxins from the GI tract): Useful for ingestions of lithium, iron, heavy metals, sustained-released drugs, and “body packers” (eg, cocaine). Removal of unabsorbed toxin: ■ Emesis: Induced vomiting through use of ipecac. (No longer within the standard of care.) ■ Gastric lavage: ■ Indications: The ingestion is known or suspected to be serious; the ingestion was recent (< 30–60 minutes before presentation); the patient is awake and cooperative or is intubated; the patient can be placed in the left lateral decubitus position.

KEY FACT The anticholinergic and sympathomimetic toxidromes are similar, but the latter is associated with hyperactive bowel sounds and diaphoresis.

KEY FACT With a paucity of objective data to support their theoretical benefits, emesis and gastric lavage have fallen out of favor. Gastric lavage is rarely performed in practice today, and emesis not at all.

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EMERGENCY MEDICINE

For patients presenting with altered mental status of unknown etiology, start out by giving them a ThONG: Thiamine, Oxygen, Naloxone, and Glucose.

TA B L E 4 - 5 .

Contraindications: Altered mental status, ↓ or absent gag reflex, caustic agents (to prevent reinjury of the esophagus if the patient vomits), esophageal trauma (eg, Mallory-Weiss tears), agents that are easily aspirated, nontoxic ingestion. Removal of absorbed toxin: ■ Alkalization methods: Involve mixing D5W with 2–3 amps of NaHCO3. ■ Alkalinization of blood improves clearance of TCAs. ■

KEY FACT

■

Specific Antidotes and Treatments

TOXIN

ANTIDOTE/TREATMENT

Acetaminophen

N-acetylcysteine

Anticholinesterases (eg, organophosphates)

Atropine, pralidoxime

Anticholinergics (antimuscarinics—

Physostigmine (crosses the blood-brain barrier)

eg, atropine; antinicotinics) Benzodiazepines

Flumazenil

β-blockers

Glucagon

Carbon monoxide

O2

Cyanide

Amyl nitrite pearls, sodium nitrite, sodium thiosulfate, hydroxocobalamin

Digoxin

Anti-digitalis Fab; magnesium, lidocaine (for torsades)

Ethylene glycol (antifreeze), methanol

Fomepizole, ethanol drip, dialysis; calcium gluconate for ethylene glycol

Heparin

Protamine sulfate

Iron

Deferoxamine

Isoniazid (INH)

Pyridoxine (vitamin B 6)

Leada

Chelator agents: penicillamine and succimer for lower levels; EDTA and dimercaprol (British anti-Lewisite, aka BAL) for higher levels

a

Nitrites (eg, methemoglobin)

Methylene blue

Opioids

Naloxone

Phenothiazines

Diphenhydramine, benztropine

Salicylates

Sodium bicarbonate, dialysis

TCAs

Sodium bicarbonate (for QRS prolongation); benzodiazepines (for seizures)

tPA, streptokinase

Aminocaproic acid

Warfarin

Vitamin K, fresh frozen plasma (FFP)

Arsenic, copper, gold, and mercury are also treated with similar combinations of chelator agents.

EMERGENCY MEDICINE

Alkalinization of urine to a pH > 8 ionizes weak acids into ionized molecules, thereby increasing the excretion of salicylates, phenobarbital, and chlorpropamide. Charcoal hemoperfusion: ↑ absorption of toxic substances in the blood by filtering blood from a shunt through a column of activated charcoal. Particularly useful for aminophylline, barbiturates, carbamazepine, and digoxin. Hemodialysis: Filters small, ionized molecules such as salicylates, theophylline, methanol, lithium, barbiturates, and ethylene glycol.

CHAPTER 4

■

■

■

Substance-specific antidotes are outlined in Table 4-5. Drug withdrawal treatments are delineated in Table 4-6. Additional information on drug intoxication and withdrawal can be found in Chapter 17.

TA B L E 4 - 6 .

61

MNEMONIC Indications for emergent hemodialysis—

AEIOU Metabolic Acidosis that cannot be corrected with NaHCO3 Severe Electrolyte imbalances (eg, hyperkalemia) Toxic Ingestions (eg, lithium or aspirin) Fluid Overload that is resistant to treatment with diuretics Uremia (eg, uremic encephalopathy, uremic serositis)

Drug Withdrawal Syndromes and Treatment

DRUG Alcohol

WITHDRAWAL SYMPTOMS

TREATMENT

6–12 hours: Tremor.

Benzodiazepines; haloperidol for hallucinations.

Within 48 hours: Tachycardia, hypertension, agitation,

Thiamine (B1), folate, B12, and multivitamin replacement—

seizures. Within 2–7 days: Hallucinations, DTs (autonomic instability, including tachycardia, hypertension, and

ie, banana bag (does not affect withdrawal but may prevent Wernicke’s encephalopathy). Give thiamine before glucose.

delirium). Mortality is 15–20%. Barbiturates

Anxiety, seizures, delirium, tremor, cardiac and respiratory

Benzodiazepines.

depression. Benzodiazepines

Rebound anxiety, seizures, tremor. May lead to DTs.

Benzodiazepine taper.

Cocaine,

Depression, hyperphagia, hypersomnolence.

Supportive treatment. Avoid β-blockers (may lead to uninhibited α-cardiac stimulation with cocaine use—ie,

amphetamines

hypertension). Opioids

Anxiety, insomnia, flulike symptoms, sweating,

Symptom management. Clonidine and/or buprenorphine

piloerection, fever, rhinorrhea, nausea, stomach cramps,

for moderate withdrawal; methadone for severe

diarrhea, mydriasis.

symptoms. Naltrexone can be used when the patient has been drug free for 7–10 days.

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Sexual Assault In working with a victim of sexual assault, begin by diagnosing and treating the victim’s physical and emotional injuries. It is also critical to collect legal evidence as well as to document that evidence carefully and completely. Information sought should include the following: ■ ■

■

■

Where and when did the assault occur? What happened during the assault? Determine the number of assailants; the use of force, weapons, objects, or restraints; which orifices were penetrated; and whether alcohol and/or drugs were involved. What happened after the assault? Are there any specific symptoms or pains? Did the patient bathe, defecate, urinate, brush teeth, or change clothes? Has the patient had sexual intercourse in the last 72 hours? Determine the risk of pregnancy. Last menstrual period? Any birth control?

DIAGNOSIS ■ ■

■

Conduct a general trauma and pelvic exam. Collect physical evidence (eg, debris, fingernail scrapings, dried secretions from the skin, pubic hairs). Medically indicated tests include a pregnancy test; cultures for gonorrhea and chlamydia; serology for syphilis; and HBV, HCV, and HIV testing.

TREATMENT ■ ■

■

Treat traumatic injuries. Infection prevention: ■ Where appropriate, treat gonorrhea, chlamydia, trichomoniasis, and bacterial vaginosis. ■ Institute HBV and HIV prophylaxis. Pregnancy prevention: ■ Administer two Ovral (ethinyl estradiol and norgestrel) tablets PO immediately and again 12 hours later. ■ Offer counseling.

Animal and Insect Bites KEY FACT A 25-year-old man becomes involved in a barroom brawl and sustains a Tearing dog bites cause considerably more physical trauma, but puncturelike cat bites are more likely to become infected.

“fight bite” (closed-fist injury) to his hand. The wound culture grows gram-䊞 rods. What is the most likely pathogen in this case, and how should it be treated? Eikenella corrodens; treat with amoxicillin/clavulanate.

■

KEY FACT Scorpion stings are treated with antivenom and a midazolam drip to control agitation and involuntary muscle movements. Monitor for hypertension, arrhythmias, and pancreatitis.

The rabies treatment protocol for animal bites is as follows: ■ If the bite is from a domestic animal that can be captured/secured and its behavior observed as normal for 10 days, no treatment is necessary. ■ If the bite is from a domestic animal that exhibits abnormal behavior or becomes ill, the animal should be sacrificed and its head/brain tested for rabies via a direct immunofluorescent antibody study. If that study is 䊞, no treatment is necessary. If it is ⊕, immediate treatment is indicated. ■ If the animal is wild, immediate treatment is indicated.

EMERGENCY MEDICINE

T A B L E 4 - 7.

BITE TYPE Dog

Cat

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63

Bite Types, Infecting Organisms, and Treatment

LIKELY ORGANISMS/TOXINS

TREATMENT

α-hemolytic streptococci, S aureus,

Amoxicillin/clavulanate or a first-generation cephalosporin +/– tetanus and rabies

Pasteurella multocida, and anaerobes.

prophylaxis.

P multocida (high rate of infection),

Amoxicillin/clavulanate +/– tetanus prophylaxis.

anaerobes. Human

Polymicrobial. Viridans streptococci

Second- or third-generation cephalosporins, dicloxacillin + penicillin, amoxicillin/

are most frequently implicated.

clavulanate or clarithromycin +/– tetanus prophylaxis, HBV vaccine, HBIG, and postexposure HIV prophylaxis.

Rodent

Streptobacillus moniliformis,

Penicillin VK or doxycycline.

P multocida, Leptospira spp. Bat

Rabies and other viruses.

Vaccination against rabies.

Snake

Pseudomonas aeruginosa, Proteus

Antivenom as appropriate. Venomous snakes (eg, coral snake, pit viper, rattlesnake)

spp, Bacteroides fragilis, Clostridium

may not require antibiotics; ampicillin/sulbactam (or, alternatively, a fluoroquinolone

spp, venom.

or clindamycin + TMP-SMX) are given to combat the snake’s oral flora. Monitor for rhabdomyolysis, neurologic impairment, and serum sickness.

Spider

■

■

■

Venom (can cause tissue necrosis

Antivenom as appropriate; otherwise supportive care (analgesics, antihistamines,

and/or rigid paralysis, depending on

wound irrigation/debridement). Tetanus prophylaxis. Dapsone may be used to prevent

species).

further tissue necrosis.

Treatment options for rabies include the following: ■ Active immunization with human diploid cell vaccine (HDCV). ■ Passive immunization with human rabies immune globulin (HRIG). Regardless of treatment, be sure to reevaluate the wound 24–48 hours after injury. Table 4-7 summarizes bite types (including human), associated infecting organisms, and appropriate treatment.

Tetanus A 42-year-old carpenter presents to the ER after a rusty nail pierces his work boot. What are the most likely pathogens involved? Clostridium tetani (tetanus) and Pseudomonas aeruginosa (osteomyelitis).

Presents with trismus (ie, lockjaw), glottal spasm, and convulsive spasms. High-risk patients include the elderly (due to inadequate immunization), IV drug users, and ulcer patients.

KEY FACT For monkey bites, add postexposure prophylactic valacyclovir or acyclovir x 14 days.

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TA B L E 4 - 8 .

Tetanus Prophylaxis Schedule

NON-TETANUSPRONE WOUNDS HISTORY OF ADSORBED TETANUS TOXOID (DOSES) Unknown or < 3 doses

TETANUS-PRONE WOUNDSa

Td

Td

TIG

√

√

√

Three doses: √

Last dose > 5 years Last dose > 10 years

√

√

a

Tetanus-prone wounds are those that are present > 6 hours; are nonlinear; are > 1 cm deep; and show signs of infection, devitalized tissue, and contamination.

TREATMENT ■

■ ■

Benzodiazepines to control muscle spasms; neuromuscular blockade if needed to control the airway. Metronidazole is the antibiotic of choice. Administer tetanus immune globulin (TIG) and/or adsorbed tetanus and diphtheria toxoid (Td) vaccine as indicated in Table 4-8.

Environmental Emergencies COL D E M E R G E NC I E S

KEY FACT

Frostbite ■

Do not rewarm frostbite until refreezing can be prevented.

■

Cold injury with pallor and loss of cold sensation. Results from exposure to cold air or direct contact with cold materials. Nonviable structures demarcate and slough off. Subtypes are as follows: ■ Superficial: Injury to cutaneous and subcutaneous tissue. Skin is soft under a frozen surface. Large, clear, fluid-filled vesicles develop within two days (indicating a good prognosis); sloughing leaves new skin that is pink and hypersensitive (see Figure 4-8). ■ Deep: Injury to the above tissues plus deep structures (muscle, bone). Skin is hard under a frozen surface. Tx: Rapidly rewarm once refreezing can be prevented. Circulating water at 40°C (104°F); wound care; tetanus prophylaxis.

Hypothermia A 20-year-old woman is pulled from the water unconscious five minutes FIGURE 4-8. Frostbite injury in a child. (Courtesy of Mark Sochor, MD.)

after her sailboat capsizes. Despite the problems associated with hypothermia, victims of cold-water submersion injuries usually have a better outcome. Why is this? Activation of the diving reflex (reflex bradycardia and breath holding), which reduces metabolic demands (and the effects of hypoxemia), shunts blood to the vital organs, and limits aspiration of water.

EMERGENCY MEDICINE

■ ■

■

■

Defined as a core body temperature of < 35°C (< 95°F). Causes include environmental exposure, alcohol ingestion, drugs (barbiturates, benzodiazepines, narcotics), hypoglycemia, CNS or hypothalamic dysfunction (via loss of stimulus of shivering response and adrenal activity), hypothyroidism, skin disorders, and sepsis. Dx: Look for arrhythmias and/or Osborn/J waves (positive deflection in the QRS complex) on ECG (see Figure 4-9). Tx: ■ ABCs, CPR, and stabilization. ■ Rewarming: ■ Passive external: Blankets. ■ Active external: Warmed blankets; hot-water bottles. ■ Active internal: Warm humidified O2; heated IV fluids; gastric, colonic, bladder, or peritoneal lavage; extracorporeal rewarming. ■ Do not pronounce patients until they have been rewarmed to 35°C (95°F); full recovery is not uncommon. ■ Associated with a risk of dysrhythmias, especially VF at core temperatures of < 30°C (86°F). Bretylium is generally the drug of choice.

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65

KEY FACT The “J” in J waves refers not only to the approximate shape of these waves but also to the initials of the man who first described them: John J. Osborn.

KEY FACT “No one is dead until they’re warm and dead.”

H E A T E M E R G E N C IE S

Heat Exhaustion ■

■

■

Extreme fatigue with profuse sweating. Also presents with nausea/vomiting and a dull headache. Sx/Exam: Body temperature is normal or slightly elevated. Patients are tachypneic, tachycardic, and hypotensive. Tx: Treat with IV NS and a cool environment.

FIGURE 4-9. Sinus bradycardia, Osborn wave. J-point elevation with ST-

segment elevation and a prolonged QT interval (0.56 sec) is seen in a patient with hypothermia.

Heat Stroke A 35-year-old migrant worker with no past medical history has a syncopal episode while harvesting tobacco. His exam reveals diminished mentation, tachypnea, and rales. His blood work reveals hypovolemic hyponatremia, hypoglycemia, leukocytosis, and elevated LFTs. What single diagnosis can account for all of these abnormalities? Exertional heat stroke.

■

■

■

Elevation of body temperature above normal due to temperature dysregulation (> 40°C [104°F]). Constitutes a true emergency. Monitor for convulsions and cardiovascular collapse. Sx/Exam: Presents with ↑ body temperature and altered mental status. Patients have hot, dry skin, often with no sweating. Ataxia may be seen. Tx: Treat with aggressive cooling. Remove from the heat source and undress. Use an atomized tepid water spray; apply ice packs to the groin/axillae. (Some facilities use cooled IV fluids run through a central line.) Treat neuroleptic malignant syndrome and drug fever with dantrolene. Treat seizures with diazepam.

KEY FACT Heat stroke presents with altered mental status and ↑ temperature, often with no sweating.

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Burns In dealing with burn patients, begin by determining if the victim was in an enclosed or an open space. Are there any toxic products of combustion? Any respiratory symptoms? Consider carbon monoxide poisoning (symptoms are nonspecific). EXAM ■

■

Gauge the body surface area (BSA) involved. Observe the rule of 9’s: 9% BSA for the head and each arm; 18% BSA for the back torso, the front torso, and each leg. In children, the rule is 9% BSA for each arm; 18% BSA for the head, back torso, and front torso; and 14% BSA for each leg. Determine the depth of the burn (see Table 4-9 and Figure 4-10).

TREATMENT ■

■

■

Prehospital treatment: ■ Administer IV fluids and high-flow O2. ■ Remove the patient’s clothes and cover with clean sheets or dressings. ■ Administer pain medications. In-hospital treatment: ■ ABCs: Early airway control is critical. Intubate if: ■ The patient is unconscious or obtunded. ■ The patient is in respiratory distress with facial burns, soot in the airway, singed nasal hairs, and carbonaceous sputum. ■ Fluid resuscitation: Appropriate for patients with > 20% BSA seconddegree burns. ■ Give 4 cc/kg per % total BSA (Parkland formula) over 24 hours— the first half over the first 8 hours and the second half over the next 16 hours. ■ Maintain a urine output of 1 cc/kg/hr. ■ Tetanus prophylaxis; pain control. Disposition: ■ Minor burns: Discharge with pain medications. ■ Moderate burns (partial-thickness 15–25% or full-thickness < 10% BSA): Admit to the hospital.

TA B L E 4 - 9 .

Burn Classification

SEVERITY OF BURN

TISSUE INVOLVEMENT

FINDINGS

First degree

Epidermis only.

Red and painful.

Second degree (superficial)

Epidermis and superficial

Red, wet, and painful with

dermis.

blisters.

Second degree (deep)

Epidermis and deep dermis.

White, dry, and tender.

Third degree

Epidermis and entire

Charred/leathery, pearly

dermis.

white, and nontender.

Fourth degree

Below the dermis to bone, muscle, and fascia.

EMERGENCY MEDICINE

FIGURE 4-10.

CHAPTER 4

67

Fourth-degree burns involving underlying bone and/or muscle. (Reproduced

with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 94-1D.)

■

Major burns (partial-thickness > 25% BSA or full-thickness > 10% BSA; burns to the face, hands, joints, feet, or perineum; electrical or circumferential burns): Refer to a burn center.

Electrical Injuries Electrical current flows most easily through tissues of low resistance, such as nerves, blood vessels, mucous membranes, and muscles. The current pathway determines which organs are affected. SYMPTOMS/EXAM

Symptoms vary according to the nature of the current. ■

■

Alternating current (household and commercial): ■ Associated with explosive exit wounds (see Figure 4-11). ■ Effects are worse with AC than with DC current at the same voltage. ■ VF is common. Direct current (industrial, batteries, lightning): ■ Causes discrete exit wounds. ■ Asystole is common.

TREATMENT ■ ■ ■

■ ■

ABCs; IV fluids for severe burns. Administer pain medications and treat burns. Treat myoglobinuria by administering IV fluids to maintain a urine output of 1.5–2.0 cc/kg/hr. Tetanus prophylaxis. Asymptomatic low-voltage (< 1000-V) burn victims can be discharged.

FIGURE 4-11. Circumferential electrical burn of the right lower extremity. (Courtesy of Benjamin Silverberg, MD.)

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Ophthalmology OCU LAR TR AU M A

Corneal Abrasion ■

■

■

KEY FACT

Ruptured Globe ■

A CT scan of the orbit, though sometimes helpful, usually reveals more about damage to the temporal bone than about injury to the eyeball itself.

Sx/Exam: Presents with pain out of proportion to the exam as well as with a foreign-body sensation and photophobia. Dx: Fluorescein staining (cobalt-blue light source via slit-lamp or Wood’s lamp examination) reveals an abraded area. Tx: Treat with topical broad-spectrum antibiotics (eg, gentamicin, sulfacetamide, bacitracin), tetanus prophylaxis, and oral analgesics.

■ ■

Sx/Exam: Patients present with trauma and loss of vision. Exam may reveal a vitreous humor leak leading to a teardrop-shaped pupil as well as a marked ↓ in visual acuity. Dx: Diagnosis can often be made only by clinical means. Tx: Manage with a rigid eye shield to prevent pressure on the globe. An immediate ophthalmologic consultation is necessary. CON JU NC TI VI TI S

Allergic Conjunctivitis ■

■

■

Intensely pruritic, watery eyes. Most commonly affects males with a family history of atopy. Sx/Exam/Dx: Look for diffuse conjunctival injection with normal visual acuity. Lid edema and cobblestone papillae under the upper lid may also be seen. Tx: Treat with topical antihistamine/vasoconstrictor preparations such as naphazoline/pheniramine or with mast cell stabilizers such as cromolyn or olopatadine. Cool compresses are also of benefit.

KEY FACT Chemical Conjunctivitis Alkali burns do far more damage than acid burns.

■ ■

■

Caused by acid or alkali exposure. Dx: Determine pH from litmus paper. Coagulation necrosis is associated with acid burns; liquefaction necrosis is seen in alkali burns. Tx: Treat with copious irrigation with a Morgan lens until pH is neutral; provide tetanus prophylaxis.

Bacterial Conjunctivitis ■

■

Painful, red eye that is usually unilateral. Causative organisms include Staphylococcus, Streptococcus, Neisseria gonorrhoeae, and Chlamydia trachomatis (in newborns and sexually active adults). Sx/Exam: Presents with photophobia, a gritty foreign-body sensation, and a purulent exudate.

EMERGENCY MEDICINE

■

■

Dx: Diffuse conjunctival injection with normal visual acuity. Bacteria can be seen on Gram stain. Tx: ■ Treat staphylococcal and streptococcal infection with topical 10% sulfacetamide or aminoglycoside. ■ Treat suspected N gonorrhoeae with IV ceftriaxone and topical erythromycin or tetracycline (if left untreated, can lead to blindness and sepsis). ■ PO doxycycline or PO/topical erythromycin is appropriate for chlamydial infection (if left untreated, can lead to corneal scarring and/or C trachomatis pneumonia). ■ Warm compresses and frequent flushes are also of benefit.

Viral Conjunctivitis (“Pink Eye”) ■

■

■

Sx/Exam: Presents as an irritated, red eye with watery discharge and crusting. Frequently bilateral, and often occurs in conjunction with cold symptoms (eg, rhinorrhea, sore throat, cough). Dx: Diffuse conjunctival injection with normal vision and preauricular lymphadenopathy. Multiple superficial punctate corneal lesions are seen on fluorescein staining. Tx: Generally no treatment is necessary, but topical antibiotics may limit infectivity and duration. OT H E R CO N D IT IO N S O F T H E E Y E

■

■

■

■

■

■

■ ■

■ ■

■ ■ ■

Dacryostenosis: Congenital nasolacrimal duct obstruction (can lead to conjunctivitis). Hordeolum: Infection of the meibomian glands; most frequently caused by S aureus. Periorbital/preseptal cellulitis: Infection of the tissue around the eye/eyelid; usually caused by S aureus. Blepharoconjunctivitis: Concurrent inflammation of the conjunctiva and eyelid. Keratitis: Inflammation of the cornea; may be caused by syphilis or by UV light exposure. Uveitis: Inflammation of the inner eye (iris or retina); usually 2° to inflammatory diseases (eg, SLE). Hyphema: Blood in the anterior chamber of the eye; usually 2° to trauma. Retinal detachment: Painless, unilateral “veil” or “floaters”; requires emergent ophthalmologic evaluation/referral. Xerophthalmia: Dry eyes. Strabismus (“lazy eye”): Can lead to blindness (amblyopia) if not treated during childhood. Presbyopia: Normal age-related reduction in accommodation. Cataracts: Painless, progressive loss of vision; absent red reflex. Glaucoma: Refer to Chapter 2 for a detailed discussion of open- and closedangle glaucoma.

CHAPTER 4

69

KEY FACT Timeline of neonatal conjunctivitis (ophthalmia neonatorum): ■ Within 24 hours = chemical ■ 2–5 days = gonorrheal ■ 5–14 days = chlamydial

CHAPTER 4

70

C

D

E

EMERGENCY MEDICINE

F G

6 5

H

Primary B maxillary right first molar A

4

I J

T

Primary maxillary left second molar

L

R Primary Q PO N M mandibular right lateral incisor

Primary mandibular left canine

8 9

10 11 12 13 14

Permanent maxillary left second premolar

15 16

1

K

S

Permanent 32 mandibular right third molar 31 30

17 18

19 20 29 21 28 Permanent 22 27 mandibular 26 25 24 23 left canine

A FIGURE 4-12.

Permanent 3 maxillary right first molar 2

7

B Numbering system and types of teeth in children and adults. .

Dental Emergencies The numbering system for 1° and permanent teeth is shown in Figure 4-12. DE N TAL AVU LS I ON

Fractures of the teeth are classified by the deepest layer violated (enamel, dentin, or pulp). They should be evaluated by a dentist within 24 hours. Complete removal of the tooth from its socket, or an avulsion, represents a dental emergency, and reimplantation should occur within 2–3 hours of injury. TREATMENT ■

■

■

CT reconstruction of a double fracture through the right body and left mandibular angle. (Courtesy of BenFIGURE 4-13.

jamin Silverberg, MD.)

Wash the tooth in clean water to remove debris; then attempt to reimplant it in its socket. If this is not possible (eg, if the tooth doesn’t fit or if the patient is unconscious and likely to swallow it), place the tooth in an isotonic solution such as sterile saline or milk. There are also commercially available solutions intended for this purpose. Further treatment depends on the amount of time the tooth has been “dry.” The patient should be referred to a dentist or an oral surgeon. MA NDI BU LAR F R AC TU R E

Consider fracture of the mandible in any patient with blunt-force trauma to the face with subsequent jaw pain, asymmetry, and/or difficulty speaking/eating. Because of the semiannular shape of the mandible, contrecoup fractures are likely (see Figure 4-13). Be sure to stabilize the patient’s airway before focusing on his facial injuries.

EMERGENCY MEDICINE

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71

SYMPTOMS/EXAM

Malalignment of the teeth (malocclusion), ecchymosis of the floor of the mouth, intraoral lacerations (including open fractures into the mouth), dental fractures, inferior alveolar or mental nerve paresthesia, trismus. See Figure 4-14. DIAGNOSIS

Diagnosis is confirmed with a panoramic dental x-ray or AP/oblique plain films. TREATMENT

Clindamycin or amoxicillin/clavulanate against anaerobic oral flora. Tetanus prophylaxis if needed. Analgesia; immobilization of the jaw. Refer to an oral surgeon.

FIGURE 4-14. Likely mandibular fracture. Note the dislocation of teeth 25

and 26 while still tethered in the gum line. (Courtesy of Benjamin Silverberg, MD.)

Radiology Appropriate radiology screening modalities and confirmation for various diagnoses are listed by test below: ■

■

■

■

■ ■

■ ■

■

■ ■ ■ ■ ■

CT with contrast: Abdominal abscess, abdominal trauma, aortic aneurysm/dissection, appendicitis, bowel perforation, chest mass/trauma, colitis, diverticulitis, hemoptysis, hydronephrosis, intestinal obstruction, persistent hematuria, PE, tumor diagnosis/staging. CT without contrast: Head trauma (including skull fracture), intracranial bleed, nephrolithiasis, suspected spinal trauma/fracture. MRI with contrast: Brain/spinal tumor/infection, joint imaging, MS, osteomyelitis, vascular imaging. Plain film: Chest mass/trauma, hemoptysis, intestinal obstruction/perforation, most orthopedic problems, multiple myeloma, pneumonia. Duplex ultrasound: Carotid stenosis, DVT. Ultrasound: Abdominal aortic aneurysm screening, appendicitis (in pediatric/pregnant patients), gallstones/cholecystitis, hydronephrosis, intussusception, liver screening, pregnancy/most gynecologic pathology, pyloric stenosis, scrotal pathology (torsion, hydrocele, epididymitis/orchitis, scrotal mass), thyroid nodules, TIPS evaluation. Barium swallow: Esophageal obstruction. Barium enema: Colonic masses (single contrast), IBD/diverticulosis (double contrast). Upper (or lower) endoscopy: Esophageal obstruction, hematemesis, pepric ulcer disease, upper (or lower) GI bleeding. Cystoscopy: Persistent hematuria. PET scan: Malignancy staging. Bone scan: Bone metastases, osteomyelitis. HIDA scan: Cholecystitis. V/Q scan: PE.

KEY FACT Oral water-soluble contrast agents such as Gastrografin should be avoided if the patient is an aspiration risk (can lead to chemical pneumonitis). Barium contrast, on the other hand, should not be used if intestinal perforation is suspected (can lead to barium peritonitis with fibrin deposition and ascites). This is generally an issue only with fluoroscopy studies.

72

CHAPTER 4

EMERGENCY MEDICINE

NO T E S

CHAPTER 5

ENDOCRINOLOGY Diabetes Mellitus

74

Osteoporosis

84

Cushing’s Syndrome (Hypercortisolism)

85

Adrenal Insufficiency

86

Prolactinoma

88

Multiple Endocrine Neoplasia

89

TYPE 1 DIABETES MELLITUS

74

TYPE 2 DIABETES MELLITUS

76

COMPLICATIONS OF DIABETES MELLITUS

78

Thyroid Disorders

80

FUNCTIONAL THYROID DISORDERS

80

THYROID NODULES

82

Hypercalcemia

PHEOCHROMOCYTOMA

89

83

73

74

CHAPTER 5

ENDOCRINOLOGY

Diabetes Mellitus (DM) TYP E 1 DI ABE TE S M E LLI TU S

MNEMONIC

Destruction of pancreatic beta cells leads to insulin deficiency (see Table 5-1). Generally immune mediated.

The 3 P’s of DM type 1:

Polyuria Polydipsia Polyphagia

SYMPTOMS/EXAM

Presents with the classic symptoms of Polyuria (including nocturia), Polydipsia, and Polyphagia (the 3 P’s). Patients may also have rapid or unexplained weight loss, blurry vision, or recurrent infections (eg, candidiasis). DIFFERENTIAL

Pancreatic disease (eg, chronic pancreatitis), glucagonoma, Cushing’s disease, iatrogenic factors (eg, corticosteroids), gestational diabetes, diabetes insipidus. DIAGNOSIS

At least one of the following is required to make the diagnosis: ■

■

A random plasma glucose concentration of ≥ 200 mg/dL with classic symptoms of diabetes. A fasting plasma glucose level of ≥ 126 mg/dL on two separate occasions.

TA B L E 5 - 1 .

Type 1 vs. Type 2 DM

TYPE 1 (INSULIN-DEPENDENT

TYPE 2 (NON-INSULIN-

DM)

DEPENDENT DM)

Failure of the pancreas to

Insulin resistance and

secrete insulin as a result of

inadequate insulin

autoimmune destruction of

secretion by the pancreas to

beta cells.

compensate.

Incidence

15%.

85%.

Age (exceptions are

< 30 years of age.

> 40 years of age.

Association with obesity

No.

Yes.

“Classic symptoms”

Common.

Sometimes.

Diabetic ketoacidosis

Common.

Rare.

Genetic predisposition

Weak, polygenic.

Strong, polygenic.

Association with HLA

Yes (HLA-DR3 and -DR4).

No.

↓; can be normal during the

↓ late in the disease.

Pathophysiology

common)

system Serum C-peptide

“honeymoon period.”

ENDOCRINOLOGY

■

■

A two-hour postprandial glucose level of ≥ 200 mg/dL after a 75-g oral glucose tolerance test on two separate occasions. A hemoglobin A1c (HbA1c) level > 6.5% has recently been added to the diagnostic criteria by the American Diabetes Association.

TREATMENT ■

■

■

Type 1 diabetics should be started on insulin (see Table 5-2). Both basal and bolus insulin are required. Oral hypoglycemic agents are not effective. Most patients with type 1 diabetes are on a multiple-daily-injection (MDI) regimen consisting of premeal short-acting insulin (eg, lispro or aspart) and bedtime glargine or twice-daily NPH. Others are on insulin pumps consisting of short-acting insulin. Long-term management should include the following: ■ Check an HbA1c level every three months. Maintain an HbA1c < 7. ■ Maintain a low-fat, reduced-carbohydrate diet, and refer patients to a dietitian. ■ Manage CAD risk factors (hypertension, smoking, obesity, hyperlipidemia). ■ Obtain a baseline ECG if the patient has heart disease or is > 35 years of age. ■ Check eyes annually for retinopathy or cataracts. An ophthalmologic exam is also indicated if the patient is planning a pregnancy. ■ Screen newly diagnosed type 1 diabetics for thyroid disease. ■ Order an annual BUN/creatinine and UA for microalbuminuria to screen for diabetic nephropathy. ■ Check the feet annually for neuropathy, ulcers, and peripheral vascular disease. Patients should inspect their feet daily and wear comfortable shoes. ■ Administer an annual flu shot and keep pneumococcal vaccinations up to date.

TA B L E 5 - 2 .

Types of Insulin a

INSULIN

ONSET

PEAK EFFECT

DURATION

Regular

30–60 minutes

2–4 hours

5–8 hours

Humalog (lispro)

5–10 minutes

0.5–1.5 hours

6–8 hours

NovoLog (aspart)

10–20 minutes

1–3 hours

3–5 hours

Apidra (glulisine)

5–15 minutes

1.0–1.5 hours

1.0–2.5 hours

NPH

2–4 hours

6–10 hours

18–28 hours

Levemir (detemir)

2 hours

No discernible peak

20 hours

Lantus (glargine)

1–4 hours

No discernible peak

20–24 hours

a Combination preparations mix longer-acting and shorter-acting types of insulin together to provide immediate and extended coverage in the same injection, eg, 70 NPH/30 regular = 70% NPH + 30% regular.

(Reproduced with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2007: 114.)

CHAPTER 5

75

KEY FACT The “honeymoon period” is a remission phase that is seen in type 1 diabetics days after the initiation of insulin therapy. During this phase, which may last several months, patients often have ↓ insulin requirements.

76

CHAPTER 5

ENDOCRINOLOGY

TYP E 2 DI ABE TE S M E LLI TU S

A 45-year-old obese man presents with polyuria and weight loss. What level of serum glucose is diagnostic of diabetes mellitus (DM)? A serum glucose level of ≥ 200 mg/dL is diagnostic of DM in a symptomatic patient.

Patients with type 2 DM have two defects: insufficient insulin secretion and ↑ insulin resistance (see Table 5-1). SYMPTOMS/EXAM

The 3 P’s (see type 1 DM), recurrent blurred vision, paresthesias, and fatigue are common to both forms of diabetes. Because of the insidious onset of hyperglycemia, however, patients with type 2 DM may be asymptomatic at the time of diagnosis. DIFFERENTIAL

Similar to that of type 1 DM. DIAGNOSIS

Similar to that of type 1 DM. TREATMENT ■

■

■

■

KEY FACT Step 3 loves to ask about lifestyle changes in diseases like diabetes!

■

Diet and exercise are critical. Type 2 diabetics should be started on an oral antidiabetic medication (see Table 5-3). Typical stepwise pharmacologic management includes metformin, a “glitazone,” and a sulfonylurea (eg, glyburide). If the patient continues to have inadequate control on three oral antidiabetic drugs, glyburide should be replaced with NPH or glargine insulin at bedtime. For those who require more intense therapy, a split/mixed regimen of regular or short-acting and NPH or glargine insulin may be used. ■ Prebreakfast glucose level: Reflects predinner NPH dose. ■ Prelunch glucose level: Reflects prebreakfast regular insulin dose. ■ Predinner glucose level: Reflects prebreakfast NPH dose. ■ Bedtime glucose level: Reflects predinner regular insulin dose. Long-term management includes monitoring blood glucose (see Table 5-4) and checking a fasting glucose level once a day. Otherwise, management is similar to that of type 1.

ENDOCRINOLOGY

TA B L E 5 - 3 .

CHAPTER 5

77

Oral Antidiabetic Medications

MEDICATION

EXAMPLES

MECHANISM OF ACTION

First generation:

Sulfonylureas

SIDE EFFECTS

CONTRAINDICATIONS

↑ insulin secretion.

Hypoglycemia.

Renal/liver disease.

Chlorpropamide Second generation: Glipizide, glyburide Meglitinides

Repaglinide

↑ insulin secretion.

Hypoglycemia.

Renal/liver disease.

Biguanides

Metformin

Inhibit hepatic

Lactic acidosis, diarrhea,

Renal insufficiency, any

gluconeogenesis; ↑

GI discomfort, metallic

form of acidosis, liver

glucose utilization; ↓

taste, weight loss.

disease, severe hypoxia.

↑ flatulence, GI

Renal/liver disease.

insulin resistance. α-glucosidase inhibitors

↓ glucose absorption.

Acarbose

discomfort, elevated LFTs. Thiazolinediones

Rosiglitazone,

↓ insulin resistance; ↑

Hepatocellular injury,

Liver disease, CHF (class

(“glitazones”)

pioglitazone

glucose utilization.

anemia, pedal edema,

III/IV), LFTs > 2 times

CHF.

normal.

↑ postprandial glucose

Nausea, vomiting, weight

Renal disease.

utilization.

loss, hypoglycemia.

Same as that of GLP-1

Same as those of GLP-1

Same as that of GLP-1

agonists.

agonists.

agonists.

Glucagon-like peptide-1

Exenatide

(GLP-1) agonists Dipeptidyl peptidase

Sitagliptin, vildagliptin

(DPP-4) inhibitors

TA B L E 5 - 4 .

Target Glucose Levels in Diabetics

Preprandial

TARGET GLUCOSE

ADJUST DOSAGE OF

NORMAL GLUCOSE

LEVEL WITH DRUG

DRUG WHEN GLUCOSE

LEVEL (mg/dL)

TREATMENT (mg/dL)

LEVEL IS:

< 110

80–120

< 80 or > 140

< 120

100–140

< 100 or > 160

glucose Bedtime glucose

78

CHAPTER 5

ENDOCRINOLOGY

COM P LI C ATI ONS OF DI ABE TE S M E LLI TU S

Diabetic Ketoacidosis (DKA) An eight-year-old boy presents with a two-day history of a productive cough and a fever of 38.4°C (101.1°F). Labs reveal leukocytosis, a blood glucose level of 341 mg/dL, a serum bicarbonate level of 13 mEq/L, and a UA positive for 2+ ketones. CXR reveals lobar pneumonia. Which serum ketone is likely elevated? β-hydroxybutyrate.

KEY FACT Symptoms and signs of DKA: ■ “Fruity” breath ■ Kussmaul hyperpnea ■ Dehydration ■ Abdominal pain ■ ↑ anion gap ■ Hyperkalemia ■ Hyperglycemia ■ Ketones in blood/urine

DKA may be the initial manifestation of type 1 DM and is usually precipitated by a stressor (eg, infection, surgery). ↑ catabolism due to lack of insulin action plus ↑ counterregulatory hormones lead to life-threatening metabolic acidosis. Hyperkalemia is due to ↓ insulin and hyperosmolality, not to H+-K+ shifts. SYMPTOMS/EXAM

Symptoms and signs of DKA include a “fruity” breath odor, Kussmaul hyperpnea (an abnormal ↑ in the depth and rate of breathing), dehydration, abdominal pain, an ↑ anion gap, hyperkalemia, hyperglycemia, and ketones in the blood and urine. DIAGNOSIS ■

■

Order a CBC, electrolytes, BUN/creatinine, glucose, ABGs, serum ketones, a CXR, a blood culture, a UA and urine culture, and an ECG. Labs reveal hyperglycemia (blood glucose > 250 mg/dL), acidosis with a blood pH < 7.3, serum bicarbonate < 15 mEq/L, and ↑ serum/urine ketones.

TREATMENT ■

■ ■

KEY FACT ■

In DKA, improvement is monitored via anion gap, not blood glucose levels.

■

Admission to the ICU/floor may be necessary depending on the patient’s clinical status. Fluid resuscitate (3–4 L in eight hours) with NS and IV insulin. Sodium, potassium, phosphate, and glucose must be monitored and repleted every two hours (change NS fluids to D5NS when glucose levels are < 250 mg/L). Change IV insulin to an SQ insulin sliding scale once the anion gap normalizes. Continue IV insulin for at least 30 minutes following the administration of the first dose of SQ insulin.

Hyperglycemic Hyperosmolar Nonketotic State (HHNK)

Typically occurs in type 2 DM. Can be precipitated by dehydration, infection, or medications (eg, β-blockers, steroids, thiazides). SYMPTOMS/EXAM

Patients are acutely ill and dehydrated with altered mental status.

ENDOCRINOLOGY

CHAPTER 5

79

DIAGNOSIS

Diagnostic criteria for HHNK are as follows: ■ ■ ■ ■ ■

Serum glucose > 600 mg/dL (hyperglycemia). Serum pH > 7.3. Serum bicarbonate > 15 mEq/L. Anion gap < 14 mEq/L (normal). Serum osmolality > 310 mOsm/kg.

TREATMENT ■ ■ ■

Fluid resuscitate with 4–6 L NS within the first eight hours. Identify the precipitating cause and treat. Monitor and replete sodium, potassium, phosphate, and glucose every two hours. Give IV insulin only if glucose levels remain elevated after sufficient fluid resuscitation.

Other Complications

Both type 1 and type 2 diabetics are at ↑ risk for macro- and microvascular disease and infections. The three most common microvascular complications are as follows: ■

■

■

Retinopathy: ■ Correlates with the duration of DM and the degree of glycemic control. ■ Sx/Exam: Classified as nonproliferative or proliferative. ■ Nonproliferative diabetic retinopathy: Characterized by retinal vascular microaneurysms, blot hemorrhages, and cotton-wool spots. Macular edema may be seen. ■ Proliferative diabetic retinopathy: Neovascularization in response to retinal hypoxia is the hallmark. ■ Tx: Prevention, regular eye exams, and laser therapy are the mainstays of therapy. Nephropathy: ■ Sx/Exam: Usually asymptomatic, but can present with bilateral lower extremity edema (from nephrotic syndrome). ■ Dx: ■ Kimmelstiel-Wilson lesions (nodular glomerulosclerosis) may be seen on kidney biopsy. ■ Look for coexisting retinopathy. ■ Tx: ■ Patients with microalbuminuria or proteinuria should be started on an ACEI to keep their BP < 130/80. ■ End-stage nephropathy requires chronic hemodialysis or transplantation. Neuropathy: ■ Sx/Exam: Can present as polyneuropathy, mononeuropathy, and/or autonomic neuropathy. Patients are also at ↑ risk for the development of diabetic foot ulcers. ■ Tx: ■ Strict glycemic control improves nerve conduction. ■ TCAs, carbamazepine, and gabapentin are used to treat sensory dysfunction.

KEY FACT The risk of microvascular complications in DM is ↓ by tight glycemic control.

KEY FACT Diabetics have ↑ susceptibility to the following: ■ Pseudomonal otitis externa ■ Mucormycosis facial infection ■ Pyelonephritis ■ Emphysematous cholangitis

80

CHAPTER 5

ENDOCRINOLOGY

Thyroid Disorders FU N C TI ONAL THYR OI D DI S OR DE R S

A 30-year-old woman presents with weight loss and heat intolerance and is found to be tachycardic. Labs reveal a suppressed TSH and an elevated T4 level. What is the most common cause of hyperthyroidism? Graves’ disease.

Classified as hyperthyroidism or hypothyroidism. SYMPTOMS/EXAM

Table 5-5 lists distinguishing features of hypo- and hyperthyroidism. DIAGNOSIS ■

■

TA B L E 5 - 5 .

Order a TSH and a free T4 to distinguish hyperthyroidism from hypothyroidism. ■ Hyperthyroid patients (↓ TSH): Order a radioactive iodine uptake scan as well as thyroid-stimulating immunoglobulin assays. ■ Hypothyroid patients (↑ TSH): Order an anti–thyroid peroxidase (anti-TPO) antibody assay. Figure 5-1 and Table 5-6 outline the workup, differential, and treatment of functional thyroid disease.

Clinical Presentation of Functional Thyroid Disease

HYPOTHYROIDISM

HYPERTHYROIDISM

General

Fatigue, lethargy.

Hyperactivity, nervousness, fatigue.

Temperature

Cold intolerance.

Heat intolerance.

GI

Constipation leading to ileus; weight gain despite a poor

Diarrhea; weight loss despite good appetite.

appetite. Cardiac

Bradycardia, pericardial effusion, hyperlipidemia.

Tachycardia, atrial fibrillation, CHF; systolic hypertension, ↑ pulse pressure.

Neurologic

Delayed DTRs.

Fine resting tremor; apathetic hyperthyroidism (elderly).

Menstruation

Heavy.

Irregular.

Dermatologic

Dry, coarse skin; thinning hair; thin, brittle nails; myxedema.

Warm, sweaty skin; fine, oily hair; nail separation from matrix.

Other

Arthralgias/myalgias.

Osteoporosis.

ENDOCRINOLOGY

81

TSH

Hashimoto’s or subacute thyroiditis in transition from hyperthyroid to hypothyroid stage

Decrease

Increase

Normal Free T4 Increase

Decrease – Pituitary hypothyroidism – Hypothalamic hypothyroidism

Radioactive iodine uptake scan Increase

Decrease

– Graves’ disease – Toxic adenoma – Multinodular goiter

FIGURE 5-1.

CHAPTER 5

– Subacute thyroiditis (hyperthyroid stage) – Hashimoto’s thyroiditis (hypothyroid stage) – Exogenous T3/T4: levothyroxine – Postpartum thyroiditis

1° hypothyroidism – Hashimoto’s thyroiditis (hypothyroid stage) – Iatrogenic post–radioactive thyroid ablation or thyroidectomy – Subacute thyroiditis (hypothyroid stage) – Drugs: lithium, propylthiouracil, methimazole – Infiltrative disease: sclerodema, amyloidosis – Congenital

Workup of functional thyroid disease.

TREATMENT ■

Symptomatic hyperthyroidism: ■ Treat with propranolol, hydration, rest, and adequate nutrition. Cooling measures are required for severe hyperthermia. ■ Mild cases of hyperthyroidism can then be treated with propylthiouracil or methimazole, which block thyroid hormone synthesis. More severe cases require radioactive 131I thyroid ablation. ■ Thyroidectomy is indicated for large goiters, pregnant patients, or obstruction of the trachea. Patients who have undergone radioactive ablation or thyroidectomy become hypothyroid and are treated with levothyroxine.

TA B L E 5 - 6 .

KEY FACT Methimazole should not be given during pregnancy because it can cause aplasia cutis in the fetus.

Differential and Treatment of Functional Thyroid Disease

GRAVES’ DISEASE

SUBACUTE THYROIDITIS

Etiology/

Antibody directed at TSH receptor.

Viral (possibly mumps or

pathophysiology

More prevalent in females.

coxsackievirus).

Symptoms/

Hyperthyroidism; diffuse, painless

Hyperthyroidism leading to

exam

goiter. Proptosis, lid lag, diplopia, conjunctival injection. Pretibial myxedema.

Diagnosis

↑ radioactive uptake scan, ⊕ thyroid-

hypothyroidism.

HASHIMOTO’S THYROIDITIS Autoimmune disorder.

Hypothyroidism. Painless thyroid enlargement.

Tender thyroid. Malaise, upper respiratory tract symptoms, fever early on. ↓ radioactive uptake scan, high ESR.

⊕ anti-TPO antibody.

NSAIDs for pain control; steroids for

Levothyroxine.

stimulating immunoglobulin. Disease-specific treatment

Propylthiouracil, methimazole, thyroid ablation with 131I. Ophthalmopathy may require surgical decompression, steroids, or orbital radiation.

severe pain. Self-limited.

82

CHAPTER 5

ENDOCRINOLOGY

Thyroid storm is a form of severe hyperthyroidism that is characterized by high fever, dehydration, tachycardia, coma, and high-output cardiac failure. Hypothyroidism: ■ Treat with levothyroxine. Patients with myxedema coma require IV levothyroxine and IV hydrocortisone. ■ Mechanical ventilation and warming blankets are required for hypoventilation and hypothermia, respectively. ■ Myxedema coma is a form of severe hypothyroidism characterized by altered mental status and hypothermia. ■

■

TH YR OI D NODU LE S

A 55-year-old woman on no medications presents with abdominal pain, nausea, and fatigue. Routine lab evaluations reveal an elevated serum calcium level. What is the next step in the diagnostic workup? Laboratory screening with a CBC and a chemistry panel that includes PO4, 24-hour urine calcium, PTH, 25-OH vitamin D, and SPEP.

The basic workup of a solitary thyroid nodule is outlined in Figure 5-2.

Thyroid nodule

TSH

Normal

Low

123

FNA/US-guided biopsy

Follicular cells or malignant

Indeterminate or benign

Total or partial thyroidectomy

Repeat FNA in 6 months or monitor with US

FIGURE 5-2.

Workup of a thyroid nodule.

Cold

I thyroid scan

Hot

Ablate/resect vs. medical management

ENDOCRINOLOGY

Hypercalcemia Most cases of 1° hyperparathyroidism are caused by a parathyroid adenoma. Initial treatment is focused on correcting the underlying hypercalcemia. Table 5-7 lists the clinical characteristics of 1° hyperparathyroidism and other causes of hypercalcemia.

T A B L E 5 - 7.

Clinical Characteristics of Hypercalcemia

1° HYPERPARATHYROIDISM Etiology

OTHER

Adenoma.

Malignancy that produces

Multiglandular disease.

PTH-related peptide, multiple myeloma, sarcoidosis, vitamin D excess, vitamin A excess, thiazide diuretics, lithium, bone metastasis.

Symptoms/exam

Diagnosis

Fatigue, constipation, polyuria,

Presentation is the same as that

polydipsia, bone pain, nausea.

of 1° disease.

↑ calcium and PTH; low PO4.

↑ calcium; low PTH; sometimes ↑ PO4.

Treatment

Parathyroidectomy. Hydrate with IV fluids; give

Sarcoidosis, multiple myeloma: steroids.

furosemide after volume deficit

Low-calcium diet.

is corrected; bisphosphonates

Hydrate with IV fluids; give

for severe hypercalcemia.

furosemide after volume deficit is corrected; bisphosphonates for severe hypercalcemia.

Complications

Nephrolithiasis, nephrocalcinosis, osteopenia, osteoporosis, pancreatitis, cardiac valve calcifications.

Same as those for 1° disease.

CHAPTER 5

83

84

CHAPTER 5

ENDOCRINOLOGY

Osteoporosis A 68-year-old woman presents to her primary care physician for a routine checkup. The physician orders a DEXA scan of the spine and hip. What T-score value denotes osteoporosis? T-score ≤ –2.5.

A common metabolic bone disease characterized by ↓ bone strength and abnormal bone density. More common among inactive, postmenopausal Caucasian women. SYMPTOMS/EXAM

Commonly asymptomatic. Patients may present with hip fractures, vertebral compression fractures (resulting in loss of height and progressive thoracic kyphosis), and/or distal radius fractures following minimal trauma. DIFFERENTIAL

Osteomalacia (inadequate bone mineralization), hyperparathyroidism, multiple myeloma, metastatic carcinoma (pathologic fracture). DIAGNOSIS ■

■

KEY FACT ■

Avoid HRT in osteoporotic patients in view of the risk of cardiovascular mortality and breast cancer.

All patients > 65 years of age, as well as patients 40–60 years of age with at least one risk factor for osteoporotic fractures after menopause, should be screened with a DEXA scan of the spine and hip. Take the lowest T-score between the hip and the spine: ■ T-score –1 to –2.5: Osteopenia. ■ T-score ≤ –2.5: Osteoporosis. Rule out 2° causes, including smoking, alcoholism, renal failure, hyperthyroidism, multiple myeloma, 1° hyperparathyroidism, vitamin D deficiency, hypercortisolism, heparin use, and chronic steroid use.

TREATMENT ■

■

■

■

Treat when a T-score is < –2 or when a T-score is < –1.5 in a patient with risk factors for osteoporotic fractures. Drugs of choice, in order of efficacy, include bisphosphonates (alendronate, risedronate, etidronate, ibandronate), teriparatide, selective estrogen receptor modulators (SERMs) such as raloxifene, and intranasal calcitonin. Eliminate or treat 2° causes, and add weight-bearing exercises and calcium/vitamin D supplementation. A DEXA scan should be repeated 1–2 years after the initiation of drug therapy. If the T-score is found to have worsened, combination therapy (eg, a SERM and a bisphosphonate) or a change in therapy should be initiated, with consideration given to ruling out 2° causes.

ENDOCRINOLOGY

Cushing’s Syndrome (Hypercortisolism) A 30-year-old woman with a history of SLE who is on chronic steroids presents with ↑ truncal obesity, a “buffalo hump,” and moon facies. What is the first step in diagnosis? A 24-hour urine collection should reveal an elevated cortisol level, which is diagnostic for Cushing’s syndrome.

Cushing’s disease is Cushing’s syndrome caused by hypersecretion of ACTH from a pituitary adenoma. The etiologies of hypercortisolism include adrenal (adenoma, carcinoma), pituitary (adenoma), ectopic (lung cancer), and exogenous (corticosteroid administration). SYMPTOMS/EXAM ■ ■

■

Look for truncal obesity with moon facies and a “buffalo hump.” Psychiatric disturbances, hypertension, hyperglycemia, impotence, oligomenorrhea, growth retardation, hirsutism (excessive hair growth, acne), easy bruisability, and purple striae can also be seen. Table 5-8 lists the laboratory characteristics of Cushing’s syndrome according to etiology.

DIFFERENTIAL

Chronic alcoholism, depression, DM, chronic steroid use, adrenogenital syndrome, acute stress, obesity. DIAGNOSIS ■ ■

↑ 24-hour urine cortisol is diagnostic for Cushing’s syndrome. Check A.M. serum ACTH. ■ A.M. serum ACTH < 5 pg/mL: Obtain an adrenal CT scan or an MRI to look for an adrenal adenoma or carcinoma (unilateral) or adrenal hyperplasia (bilateral).

TA B L E 5 - 8 .

Laboratory Characteristics of Endogenous Cushing’s Syndrome

ACTH DEPENDENT

ACTH INDEPENDENT

Plasma cortisol

↑

↑

Urinary cortisol

↑

↑

ACTH

↑

↓

Source

Pituitary (suppressible)

Adenoma (↓ DHEA)

Ectopic (nonsuppressible)

Carcinoma (↑ DHEA)

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A.M. serum ACTH > 5 pg/mL: Administer a high-dose dexamethasone suppression test. ■ Suppressed cortisol response: Cushing’s disease (eg, ACTH-secreting pituitary adenoma). Confirm with a pituitary MRI. ■ Nonsuppressed cortisol response: Ectopic ACTH-producing tumor such as carcinoid tumors and small cell lung cancer. Can be seen on octreotide scan and/or MRI/CT of the chest. If 䊞, do a pituitary MRI. DHEA is most elevated in adrenal carcinoma. ■

■

TREATMENT ■ ■ ■

■

Ectopic ACTH-secreting tumor: Surgical resection of the tumor. Adrenal carcinoma, adenoma, or hyperplasia: Adrenalectomy. ACTH-secreting pituitary adenoma: Transsphenoidal resection or radiation treatment. Exogenous steroids: Minimize use.

Adrenal Insufficiency A 65-year-old man with a known recent diagnosis of melanoma presents with vague complaints of dizziness, weakness, fatigue, and weight loss. Basic lab testing reveals hyponatremia. What testing will help determine the diagnosis? A.M.

KEY FACT Addison’s Disease is due to Adrenocortical Deficiency.

serum cortisol and A.M. serum ACTH.

Adrenocortical hypofunction can stem from adrenal failure (1° adrenal insufficiency, also known as Addison’s disease) or from ↓ ACTH production from the pituitary (2° adrenal insufficiency). Etiologies are as follows: ■

■

1° adrenal insufficiency: Autoimmune disease (idiopathic), metastatic tumors, hemorrhagic infarction (from coagulopathy or septicemia), adrenalectomy, granulomatous disease (TB, sarcoid). 2° adrenal insufficiency: Withdrawal of exogenous steroids; hypothalamic or pituitary pathology (tumor, infarct, trauma, infection, iatrogenic).

SYMPTOMS/EXAM ■

■

KEY FACT Hyperpigmentation, dehydration, hyperkalemia, and salt craving are specific to 1° adrenal insufficiency.

Symptoms include weakness, anorexia, weight loss, nausea, vomiting, postural hypotension, diarrhea, abdominal pain, and myalgias/arthralgias. Infection, surgery, or other stressors can trigger an addisonian crisis with symptomatic adrenal insufficiency, confusion, and vasodilatory shock.

DIAGNOSIS ■

An A.M. serum cortisol < 5 μg/dL or a serum cortisol < 20 μg/dL after an ACTH stimulation test or an ↑ of < 9 μg/dL in serum cortisol after the same test is diagnostic.

ENDOCRINOLOGY

A

B

Addison’s disease. (A) Note the characteristic hyperpigmentation in sunexposed areas. (B) Contrast the hyperpigmented palmar creases (arrow) with the normal hand of a different patient. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine,

FIGURE 5-3.

7th ed. New York: McGraw-Hill, 2008, Fig. 152-16.)

■

■

Nonspecific findings include hyponatremia, hyperkalemia, hyperpigmentation (see Figure 5-3), and eosinophilia. Check A.M. serum ACTH to distinguish 1° from 2° adrenal insufficiency (see Table 5-9).

TREATMENT ■

■

■

Treat with glucocorticoids, and add mineralocorticoids in the setting of 1° adrenal insufficiency. Hydrocortisone is the drug of choice. Add fludrocortisone for orthostatic hypotension, hyponatremia, or hyperkalemia. Glucocorticoid doses should be ↑ in times of illness, trauma, or surgery. Patients in adrenal crisis need immediate fluid resuscitation and IV hydrocortisone.

TA B L E 5 - 9 .

1° vs. 2° Adrenal Insufficiency

ADDISON’S DISEASE

2° ADRENAL INSUFFICIENCY

ACTH

↑

↓

Cortisol after ACTH challenge

↓

↑

(Reproduced with permission from Le T et al. First Aid for the USMLE Step 2 CK, 4th ed. New York: McGraw-Hill, 2004: 121.)

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ENDOCRINOLOGY

Prolactinoma A 60-year-old man with a history of erectile dysfunction presents with headaches and associated temporal field visual loss. Lab testing reveals elevated prolactin levels. What is the imaging test of choice? MRI to assess the pituitary for possible prolactinoma.

The most common functional pituitary tumor. SYMPTOMS/EXAM

Women typically present with galactorrhea and amenorrhea. Men may develop impotence and, later in the disease (and often when the adenoma is larger), symptoms related to mass effect (eg, CN III palsy, diplopia, temporal field visual loss, headache). DIAGNOSIS

↑ prolactin levels; ↓ LH and FSH. Order an MRI to confirm the tumor (see Figure 5-4). TREATMENT

Treat medically with a dopamine agonist such as bromocriptine or cabergoline. If medical therapy is not tolerated or if the tumor is large, transsphenoidal surgery followed by irradiation is indicated.

A

B

Pituitary adenomas. Coronal gadolinium-enhanced MR images demonstrating (A) a microadenoma (arrow), which enhances less than the adjacent pituitary tissue, and (B) a pituitary macroadenoma (arrowheads) extending superiorly from the sella turcica to the suprasellar region. Arrows denote the internal carotid arteries. (Image A reproduced with permission from Schorge JO et al. Williams Gynecology. New York:

FIGURE 5-4.

McGraw-Hill, 2008, Fig. 15-8A. Image B reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 333-4.)

ENDOCRINOLOGY

Multiple Endocrine Neoplasia (MEN) A group of familial, autosomal dominant syndromes (see Table 5-10).

CHAPTER 5

MNEMONIC The 3 P’s of primary MEN:

Parathyroid hyperplasia Pancreatic islet cell tumor Pituitary adenoma

P H E O CH R O M O CY T O M A

A 40-year-old woman with a history of difficult-to-control hypertension presents with a headache. A review of systems reveals associated palpitations and diaphoresis. On exam, she is found to have a BP of 200/100.

MNEMONIC

What lab test will yield the suspected diagnosis? Urine or plasma free metanephrines and normetanephrines.

■

■

■

A clinical syndrome that typically presents as hypertension along with the triad of headache, palpitations, and sweating. Dx: The diagnosis is confirmed with lab testing for urine or plasma free metanephrines and normetanephrines along with a CT/MRI. Tx: Treat preoperatively with α-blockade (phenoxybenzamine) followed by surgical resection.

TA B L E 5 - 10 .

Characteristics of MEN Syndromes

SYNDROME Wermer’s syndrome

TYPE 1

CHARACTERISTICS Parathyroid hyperplasia Pancreatic islet cell tumor Pituitary adenoma

Sipple’s syndrome

2A

Parathyroid hyperplasia Thyroid medullary cancer Pheochromocytoma

2B

Thyroid medullary cancer Pheochromocytoma Mucocutaneous neuromas Ganglioneuromatosis of the colon Marfan-like habitus

MEN 2A and 2B—two common characteristics:

Thyroid medullary cancer Pheochromocytoma

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NO T E S

CHAPTER 6

ETHICS AND STATISTICS Basic Principles

92

Autonomy

92

INFORMED CONSENT

92

RIGHTS OF MINORS

92

Competency COMPETENCY VS. CAPACITY

93 93

DETENTION AND USE OF RESTRAINTS

93

DURABLE POWER OF ATTORNEY FOR HEALTH CARE

93

SURROGATE/PROXY

Confidentiality

93

93

IMPORTANCE OF CONFIDENTIALITY (AND HIPAA)

93

WHEN TO VIOLATE CONFIDENTIALITY

94

REPORTABLE CONDITIONS

94

ASKING FOLLOW-UP QUESTIONS

94

End-of-Life Care

94

ADVANCE DIRECTIVES

94

DO NOT RESUSCITATE ORDERS/CODE STATUS

95

PAIN IN TERMINALLY ILL PATIENTS

95

THE PRINCIPLE OF “DOUBLE EFFECT”

95

PERSISTENT VEGETATIVE STATE

95

QUALITY OF LIFE

95

EUTHANASIA

95

PALLIATION AND HOSPICE

95

WITHDRAWAL OF TREATMENT

96

Biostatistics SENSITIVITY AND SPECIFICITY

96 96

PREDICTIVE VALUES

97

INCIDENCE

97

PREVALENCE

97

ABSOLUTE RISK

97

RELATIVE RISK

97

ODDS RATIO

98

ABSOLUTE RISK REDUCTION OR ATTRIBUTABLE RISK

98

RELATIVE RISK REDUCTION

98

NUMBER NEEDED TO TREAT

98

STATISTICAL SIGNIFICANCE/p-VALUE

98

CONFIDENCE INTERVAL

98

Study Design

99

SURVEYS

99

PROSPECTIVE AND RETROSPECTIVE STUDIES

99

COHORT STUDY

99

CASE-CONTROL STUDY

100

RANDOMIZED CONTROLLED TRIAL

101

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ETHICS AND STATISTICS

Basic Principles Be familiar with the following principles: ■

■ ■ ■ ■ ■

■

Autonomy: The right to make decisions for oneself according to one’s own system of morals and beliefs. Paternalism: Providing for patients’ needs without their input. Beneficence: Action intended to bring about a good outcome. Nonmaleficence: Action not intended to bring about harm. Truth telling: Revealing all pertinent information to patients. Proportionality: Ensuring that a medical treatment or plan is commensurate with the illness and with the goals of treatment. Distributive justice: Allocation of resources in a manner that is fair and just, though not necessarily equal.

Autonomy A 22-year-old man who is a Jehovah’s Witness presents with GI bleeding. The patient clearly states that he does not want a blood transfusion. His hematocrit falls from 40 to 22, and his blood pressure is decreasing as well. The physicians urge the patient to accept lifesaving treatments, but the patient refuses. When his blood pressure reaches a critical level, one of the physicians initiates plans to transfuse the patient. The rest of the team vetoes the plan. Which two principles of ethics are involved, and which principle trumps the other? This is a conflict between beneficence and autonomy. The physician aims to bring a good outcome for the patient, but the patient is making a decision in accordance with his belief system. The principle of autonomy trumps beneficence in this situation.

INF OR M E D C ONS E NT

Involves discussing diagnoses and prognoses with patients as well as any proposed treatment, its risks and benefits, and its alternatives. Only with such information can a patient reach an informed decision. Do not conceal a diagnosis from a patient; doing so violates the principle of truth telling. However, respect your patients’ wishes if they tell you to share only certain things with them. RI G HTS OF M I NOR S

The treatment of patients < 18 years of age requires parental consent unless: ■

■

They are emancipated (ie, financially independent, married, raising children, living on their own, or serving in the armed forces). They are requesting contraception or treatment of pregnancy, STDs, or psychiatric illness. Note that many states require parental consent or notice for termination of pregnancy in a minor.

ETHICS AND STATISTICS

Most questions on the Step 3 test regarding parental consent will deal with situations such as those cited above. In general, this means that for the Step 3 test, the governing principle should be to let minors make their own decisions.

Competency C O M P E T E N C Y V S . C A P A C IT Y

It is a mistake to use the terms competency and capacity interchangeably. Competency is a legal determination made only by a court, whereas capacity is a clinical assessment. Each involves the assessment of a patient’s ability to think and act rationally (not necessarily wisely). Incompetence is permanent (eg, severe dementia), and incompetent patients are generally assigned a surrogate by the court. Incapacity may be temporary (eg, delirium), and careful decision making is important when considering therapeutic interventions for patients with questionable capacity. D E T E N T IO N A N D U S E O F R E S T R AI NTS

Psychiatric patients may be held against their will only if they are a danger to themselves or to others (in accordance with the principle of beneficence). The use of restraints can be considered if a patient is at risk of doing harm to self or others, but such use must be evaluated on at least a daily basis. D U R A B L E P O WE R O F A T T O R N E Y ( DP oA) F OR HE ALTH C AR E

DPoA has two related meanings. First, it can refer to a document signed by the patient assigning a surrogate decision maker in the event that he or she becomes incapacitated. Second, it can refer to the person to whom that authority has been granted. SURROGATE/PROXY

Defined as an alternate decision maker, designated by the patient (DPoA), by law, or by convention. If no person has been formally designated to represent the patient, surrogacy falls to relatives in accordance with a hierarchy that may vary from state to state (typically, a spouse is at the top of this hierarchy).

Confidentiality I M P O R T A N C E O F C O N F I D E N T IA LI TY ( AND HI P AA)

Maintaining the confidentiality of patient information is critical. Violations are unethical, can result in legal troubles, and may irreparably harm the patient-physician relationship. The Health Insurance Portability and Accountability Act (HIPAA) outlines rules and guidelines for preserving patient privacy.

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ETHICS AND STATISTICS

WH E N TO VI OLATE C ONF I DE NTI ALI TY

If a physician learns about a threat to an individual’s life or well-being (ie, a danger to self or to others), violating confidentiality is mandatory. In a similar manner, information about child abuse or elder abuse must be reported. RE P OR TABLE C ONDI TI ONS

Most contagious, rare, and incurable infections, as well as other threats to public health, are reportable. The list of reportable infections varies by state but often includes HIV/AIDS, syphilis, gonorrhea, chlamydia, TB, mumps, measles, rubella, smallpox, and suspected bioterrorist events. Such reporting is mandatory and does not constitute a violation of confidentiality. AS K I NG F OLLOW -U P QU E S TI ONS

Follow-up questions should be used to clarify unclear issues regarding questions such as which family members can be included in discussions of care, who is the primary surrogate, and what patients want to know about their own conditions.

End-of-Life Care Patients in the end stages of a terminal illness have the right to obtain medical treatment that is intended to preserve human dignity in dying. The best means of reaching an agreement with the patient and his or her family regarding end-of-life care is to continue to talk about the patient’s condition and to resolve decision-making conflicts. Ultimately, this is the same task that an ethics consultant would attempt to perform for the physician and the patient. There is a growing body of literature addressing the importance of cultural issues in end-of-life care. In the United States, emphasis is placed on patient autonomy, full disclosure of medical information, and the primacy of objective over subjective medical findings. However, members of other cultures may lend more credibility to family-based decisions, particular methods of diagnosis communication, and the importance of subjective aspects of illness. It is important to elicit and respect these frameworks and interactional dynamics in end-of-life care. AD VANC E DI R E C TI VE S

Defined as oral or written statements regarding what a patient would want in the event that intensive resuscitative intervention becomes necessary to sustain life. These instructions can be detailed—which is obviously preferable—or they can be broad. Oral statements are ethically binding but are not legally binding in all states. Remember that an informed, competent adult can refuse treatment even if it means that doing so would lead to death. Such instructions must be honored.

ETHICS AND STATISTICS

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D O N O T R E S U S C IT A T E ( D N R ) O RDE R S / C ODE S TATU S

The express wishes of a patient (eg, “I do not want to be intubated”) supersede the wishes of family members or surrogates. Physicians should inquire about and follow DNR orders during each hospitalization. If code status has not been addressed and the matter becomes relevant, defer to the surrogate. P A I N I N T E R M IN A L L Y I L L P A T IE NTS

Terminally ill patients are often inadequately treated for pain. Prescribe as much narcotic medication as is needed to relieve patients’ pain and suffering. Do not worry about addiction in this setting. Two-thirds of patients in their last three days of life stated that they felt moderate to severe pain. T H E P R I N CI PLE O F “ D O U B LE E F FE C T”

Actions can have more than one consequence, some intended, others not. Unintended medical consequences are acceptable if the intended consequences are legitimate and the harm proportionately smaller than the benefit. For example, a dying patient can be given high doses of analgesics even if it may unintentionally shorten life. P ER SI S T E N T V E G E T A T I V E S T A T E (P VS )

Defined as a state in which the brain stem is intact and the patient has sleepwake cycles, but there is no awareness, voluntary activity, or ability to interact with the environment. Reflexes may be normal or abnormal. Some patients survive this way for five years or more, with the aggregate annual cost reaching into the billions of dollars. QU A L I T Y O F L IF E

Defined as a subjective evaluation of a patient’s current physical, emotional, and social well-being. This must be evaluated from the perspective of the patient. EUTHANASIA

Euthanasia is assisting an informed, competent, terminally ill patient to end life, usually through the administration of a lethal dose of medication. Euthanasia is different from physician-assisted suicide, in which the physician prescribes a medication that the patient administers to himself or herself to end life. Neither of these is the same as withdrawal of care. Currently, euthanasia is illegal in all states, and physician-assisted suicide is legal only in Oregon. P A L LI A T I O N A N D H O S P IC E

These related concepts involve the provision of end-of-life care within (palliation) or outside (hospice) a traditional medical system. Each is an attempt to manage psychosocial and physical well-being in a manner that preserves dignity and maximizes comfort. Both involve interdisciplinary collaboration (MD, RN, chaplain, social worker, aide), focusing on patient-defined goals of care.

KEY FACT The Elisabeth Kübler-Ross psychological stages at the end of life are denial, anger, bargaining, depression, and acceptance.

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WI THDR AW AL OF TR E ATM E NT

Withdrawal of treatment is the removal of life-sustaining treatment and is legally and ethically no different from never starting treatment. The decision to withdraw treatment may come from the patient, an advance directive, a DPoA, or, absent any of these, the closest relative and/or a physician. It is easiest when all parties are in agreement, although this is not required. When there is conflict, the patient’s wishes take precedence. In futile cases or those involving extreme suffering, a physician may withdraw or withhold treatment; if the family disagrees, the physician should seek input from an ethics committee or a court’s approval.

Biostatistics Not everyone with a given disease will test positive for that disease, and not everyone with a positive test result has the disease. S E NS I TI VI TY AND S P E C I F I C I TY

You have a test that has a sensitivity of 0.95 and a specificity of 0.95. How helpful is this test in your diagnostic reasoning for the following scenarios? 1. Disease prevalence of 1% 2. Disease prevalence of 10% 3. Disease prevalence of 50% 4. Disease prevalence of 90% 1. Not helpful. Most of the positives will be false positives, so further evaluation will be necessary. 2. Somewhat helpful. A negative test reduces the probability of disease below a threshold for further testing, while a positive test helps stratify a high-risk population that requires further testing. 3. Very helpful. Both positive and negative results make significant changes in disease probability and can confirm or disprove a diagnosis. This is the situation in which a laboratory test is most helpful. 4. Not helpful. The positive result adds nothing to your clinical suspicion, and a negative test is likely to be a false negative.

KEY FACT Sense (sensitivity) who does have a disease. Specify (specificity) who does not.

Sensitivity is the probability that a person with a disease will have a positive result on a given test. High sensitivity is useful in a screening test, as the goal is to identify everyone with a given disease. Specificity is the probability that a person without a disease will have a negative result on a test. High specificity is desirable for a confirmatory test. Ideally, a test will be highly sensitive and specific, but this is rare. A test that is highly sensitive but not specific will yield many false positives, whereas one that is highly specific but not sensitive will yield many false negatives.

ETHICS AND STATISTICS

TA B L E 6 - 1 .

Determination of PPV and NPV

DISEASE PRESENT

NO DISEASE

Positive test

a

b

PPV = a/(a + b)

Negative test

c

d

NPV = d/(c + d)

Sensitivity = a/(a + c)

Specificity = d/(b + d)

P R E D I CT IV E V A LU E S

Positive predictive value (PPV) is the probability that a person with a positive test result has the disease (true positives/all positives; see Table 6-1). If a disease has a greater prevalence, then the PPV is higher. Negative predictive value (NPV) is the probability that a person with a negative test result is disease free (see Table 6-1). A test has a higher NPV value when a disease has a lower prevalence. It is important to note that PPV and NPV can be determined only if the incidence in the sample is representative of the population. For example, if the data for Table 6-1 are derived from a case-control study, then the PPV and NPV cannot be calculated. Generally, one needs a cohort study design to get PPV or NPV. INCIDENCE

Defined as the number of new cases of a given disease per year; for example, four cases of X per year. P R E V A LE N C E

Defined as the total number of existing cases of a given disease in the entire population; for example, 20 people have X (right now). A B S O LU T E R IS K

The probability of an event in a given time period; for example, 0.1% chance of developing X in 10 years. RE L A T I V E R IS K (R R )

Used to evaluate the results of cohort (prospective) studies. The RR compares the incidence of a disease in a group exposed to a particular risk factor with the incidence in those not exposed to the risk factor (see Table 6-2). An RR

TA B L E 6 - 2 .

Determination of RR and OR

DISEASE DEVELOPS

NO DISEASE

Exposure

a

b

RR = [a/(a + b)]/[c/(c + d)]

No exposure

c

d

OR = ad/bc

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ETHICS AND STATISTICS

< 1 means that the event is less likely in the exposed group; conversely, an RR > 1 signifies that the event is more likely in that group. ODDS R ATI O ( OR )

Used in case-control (retrospective) studies. The OR compares the rate of exposure among those with and without a disease (see Table 6-2). It is considered less accurate than RR, but in rare diseases the OR approximates the RR. ABS OLU TE R I S K R E DU C TI ON ( AR R ) OR ATTR I BU TABLE R ISK

KEY FACT ARR and RRR give very different values and should not be confused. ARR is a much better measure of benefit; because it is a ratio, RRR can look deceptively large. Watch out for drug advertising that touts RRR.

Measures the risk accounted for by exposure to a given factor, taking into account the background of the disease. Useful in randomized controlled trials. Numerically, ARR = the absolute risk (rate of adverse events) in the placebo group minus the absolute risk in treated patients. RE L ATI VE R I S K R E DU C TI ON ( R R R )

Also used in randomized controlled trials, this is the ratio between two risks. Numerically, RRR = [the event rate in control patients minus the event rate in experimental patients] ÷ the event rate in control patients. RRR can be deceptive and is clinically far less important than ARR. Consider a costly intervention that reduces the risk of an adverse event from 0.01% to 0.004%. ARR is 0.01 – 0.004 = 0.006%, but RRR is (0.01 – 0.004)/0.01 = 0.6, or 60%! Would you order this intervention?

KEY FACT If a 95% CI includes 1.0, the results are not significant. So if an RR is 1.9 but the 95% CI is 0.8–3.0, the RR is not significant.

S TA TI S TI C AL S I G NI F I C ANC E /p -VALU E

CON F I DE NC E I NTE R VAL ( C I )

2 Smoker Nonsmoker 0 –1 FIGURE 6-1.

The number of patients who would need to be treated to prevent one event. NNT = 1/ARR. In the example above, the NNT is 167.

The p-value expresses the likelihood that an observed outcome was due to random chance. A p-value < 0.05 is generally accepted as indicating that an outcome is statistically significant.

3

1

NU M BE R NE E DE D TO TR E AT ( NNT)

Relative risk of cancer.

Like the p-value, the CI expresses the certainty that the observation is real or is a product of random chance. Used with ORs and RR, the 95% CI says that the observed risk or odds have a 95% chance of being within the interval. Thus, in Figure 6-1, the relative risk of cancer with smoking is 2.0 with a 95% CI of 1.3–3.5—meaning that the observed RR of cancer was 2.0, and that there is a 95% certainty that the actual RR of cancer from smoking falls somewhere between 1.3 and 3.5.

ETHICS AND STATISTICS

Study Design Statistical analyses are used as a means of assessing relationships between events and outcomes. They do not prove irrefutably that a relationship exists but point to the likelihood. The validity of the results depends on the strength of the design. SURVEYS

These are self-reporting of symptoms, exposures, feelings, and other subjective data. Such data may be analyzed with descriptive statistics or qualitative methodologies. P R O S PE C T I V E A N D R E T R O S P E CTI VE S TU DI E S

Prospective studies assess future outcomes relating to present or future events; this enables the study designer to control for biases and to modify inputs/exposures. Retrospective studies relate to outcomes from past events. They may be less reliable than prospective studies. COHORT STUDY

In a cohort study (see Figure 6-2), a population is observed over time, grouped on the basis of exposure to a particular factor, and watched for a specific outcome. Such studies are not good for rare conditions. Studies can be prospective or retrospective. Use RR to interpret results. Examples include the Nurses’ Health Study and the Framingham Heart Study.

Onset of study

Time Disease Exposed No disease

Eligible subjects Disease Unexposed No disease

Direction of inquiry Schematic diagram of a cohort study. Shaded areas in the diagram represent exposed persons; unshaded areas represent unexposed persons. (Reproduced with permission from Green-

FIGURE 6-2.

berg RS et al. Medical Epidemiology, 4th ed. New York: McGraw-Hill, 2005, Fig. 8-2.)

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CA S E -C ONTR OL S TU DY

A case-control study (see Figure 6-3) is a retrospective study involving a group of people with a given disease and an otherwise similar group of people without the disease who are compared for exposure to risk factors. Good for rare diseases. Use OR to interpret results.

Onset of study

Time

Exposed Cases Unexposed

Exposed Controls Unexposed

Direction of inquiry FIGURE 6-3. Schematic diagram of a case-control study. Shaded areas represent subjects who were exposed to the risk factor of interest. (Reproduced with permission from Greenberg RS et al. Medical Epidemiology, 4th ed. New York: McGraw-Hill, 2005, Fig. 9-1.)

ETHICS AND STATISTICS

RA N D O M IZ E D CO N T R O LLE D T R IA L ( R C T)

A prospective study that randomly assigns participants to a treatment group or to a placebo group (see Figure 6-4). The placebo group and the treatment group are then compared to determine if the treatment made a difference. The double-blind RCT is the gold standard of experimental design.

Onset of study

Time

Intensive insulin therapy

Retinopathy

No retinopathy Eligible subjects

Randomize

Standard insulin therapy

Retinopathy

No retinopathy

Direction of inquiry FIGURE 6-4. Schematic diagram of a randomized controlled clinical trial. The study above compares standard therapy with intensive insulin therapy for the treatment of diabetes mellitus. Shaded areas correspond to patients randomized to intensive insulin therapy. (Reproduced with permission from Greenberg RS et al. Medical Epidemiology, 4th ed. New York: McGraw-Hill, 2005, Fig. 7-2.)

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NO T E S

CHAPTER 7

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104

Approach to Liver Function Tests

117

Gastroesophageal Reflux Disease

105

Gallstone Disease

118

Peptic Ulcer Disease

106

Viral and Nonviral Hepatitis

119

Inflammatory Bowel Disease

107

Cirrhosis and Ascites

122

CROHN’S DISEASE

107

Acetaminophen Toxicity

124

ULCERATIVE COLITIS

109

Hereditary Hemochromatosis

124

Wilson’s Disease

125

α1-Antitrypsin Disorder

125

Autoimmune Hepatitis

125

1° Biliary Cirrhosis

125

1° Sclerosing Cholangitis

126

Irritable Bowel Syndrome

110

Diarrhea

111

Celiac Sprue

112

Upper GI Bleed

113

Lower GI Bleed

114

Pancreatitis

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Esophageal Pathology A 56-year-old man presenting for a routine physical exam mentions that he has had increasing difficulty swallowing over the past six months, more with solids than with liquids. He adds that he has never smoked or consumed alcohol. What is the likely diagnosis? Esophageal adenocarcinoma.

Obstruction of passage of food or liquid through the esophagus. SYMPTOMS/EXAM KEY FACT Think cancer in older patients with worsening dysphagia, weight loss, and heme-⊕ stools.

■

■

Patients note difficulty swallowing (dysphagia) or state that food “sticks” or “hangs up.” Distinguish from odynophagia, or pain with swallowing that is typically caused by Candida, CMV, HSV infection, or pill esophagitis, usually in immunocompromised patients (eg, HIV patients or those on chemotherapy).

DIAGNOSIS KEY FACT

■ ■

Think food impaction when a patient has sudden difficulty swallowing—even swallowing saliva.

KEY FACT It is unlikely that a patient will present with food impaction or esophagitis without an underlying cause. Remember to keep eosinophilic esophagitis on your differential in light of its increasing incidence. ■

Workup includes barium swallow and/or EGD. If difficulty is with solids alone, consider the following: ■ Lower esophageal ring: Characterized by intermittent symptoms or sudden obstruction with a food bolus (“steakhouse syndrome”). The ring is located at the gastroesophageal junction. ■ Zenker’s diverticulum: Outpouching of the upper esophagus. Presents with foul-smelling breath and food regurgitation as well as with difficulty initiating swallowing. ■ Plummer-Vinson syndrome: Cervical esophageal web and iron-deficiency anemia. Associated with esophageal cancer. ■ Peptic stricture: Progressive symptoms with long-standing heartburn (see Figure 7-1A). ■ Esophagitis: Inflammation 2° to gastroesophageal reflux or eosinophilic esophagitis. Pill esophagitis can also occur in patients taking bisphosphonates. ■ Carcinoma: Progressive symptoms in an older patient, often with weight loss. If difficulty is with both solids and liquids, consider the following: ■ Achalasia: Progressive symptoms that worsen at night with no heartburn (see Figure 7-1B). Presents with a “bird’s beak” on barium swallow. ■ Esophageal spasm: Intermittent symptoms with chest pain. Triggered by acid, stress, and hot and cold liquids. Diagnosed by esophageal manometry; presents with “corkscrew esophagus” on barium swallow (see Figure 7-1C). ■ Scleroderma: Progressive symptoms with heartburn and Raynaud’s phenomenon. Patients have lower esophageal pressure and aperistalsis of the distal esophagus leading to reflux (CREST syndrome: Calcinosis cutis, Raynaud’s phenomenon, Esophageal dysmotility, Sclerodactyly, and Telangiectasia).

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KEY FACT GERD is a common cause of hoarseness and chronic cough and can exacerbate or mimic asthma.

A

B

C

FIGURE 7-1. Esophageal disease on barium esophagram. (A) Peptic stricture (arrow) secondary to GERD above a hiatal hernia (right). (B) Achalasia. Note the dilated esophagus tapering to a “bird’s-beak” narrowing at the LES. (C) Esophageal spasm. (Image A reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. 10-14. Image B reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 20-5. Image C reproduced with permission from USMLERx.com.)

Gastroesophageal Reflux Disease (GERD) Risk factors include hiatal hernia, obesity, collagen vascular disease, alcohol, caffeine, nicotine, chocolate, fatty foods, and pregnancy. SYMPTOMS/EXAM ■

■

Presents with an uncomfortable hot and burning sensation beneath the sternum. Symptoms usually worsen after meals, on reclining, and with use of tight clothes.

DIFFERENTIAL

Angina pectoris, esophageal motility disorders, peptic ulcer.

FIGURE 7-2. Barrett’s esophagus with adenocarcinoma on barium esophagram. Note the nodular mucosa

(arrow) and the raised filling defect (arrowhead), representing adenocarcinoma. (Reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig.

DIAGNOSIS

10-19.)

Barium swallow, endoscopy, esophageal biopsy, and ambulatory pH monitoring. TREATMENT ■

■

■

Lifestyle modification: Elevate the head of the bed; avoid bedtime snacks, trigger foods (fatty foods, chocolate, mint, alcohol), cigarettes, and NSAIDs; and promote weight loss. Drugs: Antacids, H2 blockers, PPIs. If symptomatic relief is achieved with an H2 blocker or a PPI, an attempt to discontinue treatment after 8–12 weeks may be successful. Other: ■ If the disorder is refractory to medical therapy, consider evaluation for Nissen fundoplication or other hiatal hernia repair. ■ Consider endoscopy to screen for Barrett’s esophagus (see Figures 7-2 and 7-3), especially in patients with long-standing or severe GERD.

Barrett’s esophagus on endoscopy. Note the pink tongues FIGURE 7-3.

characteristic of Barrett’s (arrows). (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-3A.)

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Peptic Ulcer Disease (PUD)

KEY FACT Warning signs of more serious disease than PUD include age > 45, weight loss, anemia, and heme-⊕ stools.

A 56-year-old woman was recently diagnosed with osteoarthritis. Two months later she started having abdominal pain that is aggravated by the consumption of food. What is the likely diagnosis? Gastric ulcer 2° to the use of NSAIDs for joint pain.

The most common sites of PUD are the stomach and duodenum. H pylori infection and NSAID/ASA use are the major causes; Zollinger-Ellison syndrome, HSV infection, CMV, and cocaine use are less common etiologies. SYMPTOMS/EXAM ■

■

■

FIGURE 7-4. Gastric ulcer on barium upper GI. A benign gastric ulcer

can be seen as pooling of contrast (arrowhead) extending beyond the adjacent gastric wall. (Reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill,

Presents with epigastric abdominal pain that patients describe as a “gnawing” or “aching” sensation that comes in waves. May also present with dyspepsia and upper GI bleed. Perforation and/or penetration into adjacent structures (eg, the pancreas, vascular structures such as the SMA, and the bile ducts) can lead to hemodynamic instability and associated symptoms (ie, pancreatitis). Symptoms can often be further distinguished by disease site: ■ Duodenal ulcers: Pain is relieved by food and comes on postprandially. ■ Gastric ulcers: Pain worsens with food (pain with eating). Red flags: With diarrhea, weight loss, and excessive gastric acid (elevated basal acid output), think of more uncommon causes (Zollinger-Ellison syndrome, systemic mastocytosis, hyperparathyroidism, extensive small bowel resection, gastric cancer).

DIAGNOSIS ■

■

2004, Fig. 10-21.)

Detect the ulcer: Perform endoscopy with rapid urease testing for H pylori; biopsy any gastric ulcers to rule out malignancy (see Figures 7-4 and 7-5). Look for H pylori infection by the following means: ■ Urease testing of the biopsy sample. ■ Serum antibody: Easy to obtain, but a ⊕ antibody may not necessarily indicate active infection. Antibody remains ⊕ even after treatment. ■ Urea breath test: Good for detecting active infection, but patients must be off PPIs for two weeks and off antibiotics and bismuth for four weeks. ■ Fecal antigen test: Can also be used to test for H pylori, but as above, patients must be off antibiotics, PPIs, and bismuth.

TREATMENT ■

■

FIGURE 7-5. Benign gastric ulcer on endoscopy. (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-2A.)

■

Discontinue ASA/NSAIDs; promote smoking cessation and encourage weight loss. Give PPIs to control symptoms, ↓ acid secretion, and heal the ulcer (4 weeks for duodenal ulcers; 8–12 weeks for gastric ulcers). For H pylori infection, initiate multidrug therapy. Two of the following three drugs may be used—amoxicillin 1 g BID, clarithromycin 500 mg BID, or metronidazole 500 mg BID—along with a PPI (omeprazole, lansoprazole) for 10–14 days.

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Indications for surgery include recurrent/refractory upper GI bleed, gastric outlet obstruction, recurrent/refractory ulcers, perforation, and ZollingerEllison syndrome.

Inflammatory Bowel Disease (IBD) Describes two distinct chronic idiopathic inflammatory diseases: Crohn’s disease and ulcerative colitis. IBD clusters in families and is more common among Jewish persons and four times more common in Caucasians but can occur in anyone, including young children and older adults. C R O H N ’ S D IS E A S E

A 30-year-old man comes to your office complaining of diarrhea and weight loss. He states that his diarrhea often has mucus, but he denies any blood in his stool. He also mentions having difficulty eating food because of ulcers in his mouth. What is the next step in management? In light of his age and presenting symptoms, this patient needs a colonoscopy and an evaluation for possible Crohn’s disease.

Transmural inflammation (skip lesions) anywhere from the mouth to the anus. Most often affects the terminal ileum, small bowel, and colon. Has a bimodal distribution with peaks in the 20s and 50s–70s. SYMPTOMS/EXAM ■

■

Patients may be pale or thin with temporal wasting and often have RLQ tenderness/fullness; some present with perianal fistula. Symptoms include the following: ■ GI: Colicky RLQ pain, diarrhea (mucus-containing, nonbloody stools), weight loss, anorexia, low-grade fever, perirectal abscess/fistula, and, less often, GI blood loss, fecal incontinence, and oral ulcers. ■ Other: Low-grade fever, erythema nodosum, pyoderma gangrenosum (see Figure 7-6), iritis and episcleritis, gallstones, kidney stones, and peripheral arthritis.

DIAGNOSIS ■

■

Labs: Obtain a CBC, iron, folate, B12, ESR, LFTs, a stool WBC count, an RBC count, and a stool O&P. ■ Look for normocytic anemia of chronic disease or anemia due to iron, vitamin B12, or folate deficiency. ■ ESR or C-reactive protein (CRP) may be ↑; ASCA is ⊕. ■ O&P is 䊞, but fecal leukocytes and occult blood may be ⊕. ■ LFTs should be normal or mildly elevated. Imaging: ■ Skip lesions are seen on colonoscopy; cobblestoning is seen on barium enema. ■ Biopsy may show noncaseating granulomas with mononuclear cell infiltrate (see Figure 7-7A and B). ■ Stricture formation, pseudodiverticula, abscesses, and fistulas (to the skin, bladder, vagina, or other bowel loops) may be seen on imaging (see Figure 7-8).

FIGURE 7-6. Pyoderma gangrenosum. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, 5th ed. New York: McGraw-Hill, 2005: 153.)

KEY FACT Crohn’s involves transmural inflammation, so the outer layers can make fistulas. Ulcerative colitis is not transmural and therefore is not associated with fistulas.

KEY FACT Crohn’s disease often affects the terminal ileum, so think of things that are absorbed in the terminal ileum.

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A

B

C

Inflammatory bowel disease. (A)–(B) Crohn’s disease. Transmural inflammation with noncaseating granulomas (arrow) is seen deep in the serosal fat on pathology. (C) Ulcerative colitis. Inflammation is confined to the mucosa and submucosa, with a crypt abscess (arrow). (Reproduced with permission from USMLERx.com.)

FIGURE 7-7.

TREATMENT ■ ■

■

■

A

Mild cases: 5-ASA compounds. Moderate cases: Oral corticosteroids +/– azathioprine, 6-mercaptopurine (6-MP), or methotrexate. Refractory disease: IV steroids +/– immunomodulators (anti-TNF). Imaging (CT, MRI, CT enterography) is important for ruling out perforation, megacolon, fistula, or abscess formation. In some cases, stricturoplasty +/– resection may be needed. Follow-up: Surveillance colonoscopy with multiple biopsies to look for dysplasia in patients with a large extent of colonic involvement 8–10 years after diagnosis and biannually or annually thereafter.

B

C

FIGURE 7-8. Crohn’s disease. (A) Small bowel follow-through (SBFT) barium study shows skip areas of narrowed small bowel with nodular mucosa (arrows) and ulceration. Compare with normal bowel (arrowhead). (B) Spot compression image from SBFT shows “string sign” narrowing (arrow) due to stricture. (C) Deep ulcers in the colon of a patient with Crohn’s disease, seen at colonoscopy. (Image A reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. 10-30. Image B reproduced with permission from USMLERx.com. Image C reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-4B.)

GASTROENTEROLOGY

U L C E R A T IV E CO LI T I S

Continuous colonic mucosal inflammation extending proximally for variable distances from the anal verge. Usually occurs in a bimodal distribution (ages 15–30 and 60–80). Can lead to toxic megacolon. SYMPTOMS/EXAM ■

■

Presents with cramping abdominal pain, urgency, bloody diarrhea, weight loss, and fatigue. Exam reveals low-grade fever, tachycardia, orthostatic hypotension, heme-⊕ stools, and mild tenderness in the lower abdomen.

DIAGNOSIS ■

■

Labs: Laboratory studies reveal normocytic, normochromic anemia or iron-deficiency anemia; low albumin; ⊕ p-ANCA; and 䊞 stool cultures. Imaging: ■ Colonoscopy shows friable mucosa with ulcerations and erosions along with inflammation that is continuous from the anus up. ■ Barium enema shows a lead-pipe colon and loss of haustra (characteristic of long-standing disease; see Figure 7-9). ■ Biopsy reveals crypt abscess and microulcerations but no granulomas (see Figure 7-7C).

TREATMENT ■ ■

■

■

■

A

Mild cases: 5-ASA compounds. Moderate cases: Oral corticosteroids +/– azathioprine, 6-MP, or methotrexate. Refractory disease: IV steroids +/– cyclosporine, +/– anti-TNF antibody. Serial imaging to rule out perforation or toxic megacolon. In some cases resection may be needed, especially if complications arise or if the patient fails medical therapy. Follow-up: Surveillance colonoscopy with multiple biopsies 8–10 years after diagnosis and biannually or annually thereafter. Some patients may elect to get a prophylactic colectomy given that the incidence of colon cancer is 0.5–1.0% per year after 10 years of disease. Total colectomy cures the disease.

B

C

FIGURE 7-9. Ulcerative colitis. (A) Radiograph from a barium enema showing a featureless (“lead pipe”) colon with small mucosal ulcerations (arrow). Compare with normal haustral markings in (B). (C) Diffuse mucosal ulcerations and exudates at colonoscopy in chronic ulcerative colitis. (Image A reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 30-17. Image B reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. 10-10A. Image C reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-4A.)

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Irritable Bowel Syndrome (IBS) A 30-year-old woman comes to your clinic complaining of vague, crampy abdominal pain that is mitigated with defecation. The patient is concerned that her illness may be serious and that her children may be taken away from her, as she recently divorced and is now a single mother. What is the likely diagnosis? Irritable bowel syndrome. The patient has pain associated with defecation, and her background points to recent stressors and a possible anxiety disorder.

KEY FACT Pain that is unrelated to defecation or that is induced with activity, menstruation, or urination is unlikely to be IBS.

A GI disorder characterized by abdominal pain and altered bowel function (diarrhea or constipation) with or without bloating. Possible etiologies include altered gut motor function, autonomic nervous system abnormalities, and psychological factors. SYMPTOMS/EXAM ■

■

Characterized by abdominal pain with complete or incomplete relief with defecation; intermittent diarrhea or constipation; a feeling of incomplete rectal evacuation; urgency; passage of mucus; and bloating. Abdominal pain is poorly localized, migratory, and variable in nature.

DIAGNOSIS ■

■

A diagnosis of exclusion based primarily on the history and physical exam. Basic labs to exclude other causes should include CBC, BMP, calcium, TSH, and stool O&P. The Rome III criteria can be used to aid in diagnosis and consist of 12 weeks of the following within one year: ■ Improvement of pain with bowel movement. ■ Often associated with a change in frequency of bowel movements. ■ Onset associated with a change in the form/appearance of stool.

TREATMENT ■ ■

■

■

High-fiber diet (20–30 g/day), exercise, and adequate fluid intake. TCAs are often used even in the absence of depression, especially in the setting of chronic pain and diarrhea. Additional treatment options depend on symptom predominance. ■ If constipation predominates: Use bulking agents (psyllium), lactulose, PEG, or enemas. ■ If diarrhea predominates: Give loperamide, cholestyramine, or TCAs. ■ If bloating predominates: Simethicone, charcoal, or Lactobacillus may be used. Postprandial symptoms: Treat with anticholinergic agents, dicyclomine, or hyoscyamine.

GASTROENTEROLOGY

Diarrhea A 74-year-old woman is transported from a rehabilitation facility where she was being treated for osteomyelitis. She was sent to the hospital after having had many foul-smelling bowel movements over the past two days. What is the likely cause of her diarrhea, and what is the treatment of choice? This patient was likely receiving long-term antibiotics for osteomyelitis, thereby putting her at risk for Clostridium difficile infection. She needs to be treated with metronidazole.

Described as watery consistency and/or ↑ frequency of bowel movements. Stool weight is > 200–300 g/day. Small bowel pathology will show voluminous watery diarrhea; large bowel pathology is associated with more frequent but smaller-volume output. Distinguish acute from chronic diarrhea as follows: ■ ■

Acute diarrhea: Defined as < 2 weeks in duration; usually infectious. Chronic diarrhea: Defined as lasting > 4–6 weeks.

SYMPTOMS/EXAM ■

■

The most important goal is to assess the degree of fluid loss/dehydration and nutritional depletion. If bloating predominates, it is suggestive of malabsorption. If fever is present, think of infectious causes. If guaiac ⊕, consider inflammatory processes or enteroinvasive organisms. Etiologies can be further distinguished as follows: ■ Infectious: The leading cause of acute diarrhea. Characterized by vomiting, pain, fever, or chills. If stools are bloody, think of enteroinvasive organisms. To characterize, check stool leukocytes, Gram stain, culture, and stool O&P. Treat severe disease with ciprofloxacin or metronidazole for C difficile. ■ Osmotic: Associated with lactose intolerance and with the ingestion of magnesium, sorbitol, or mannitol; ↑ stool osmotic gap. Bloating and gas are prominent with malabsorption. Treat by stopping the offending agent. ■ Secretory: Caused by hormonal stimulation (gastrin, VIP) or by viruses or toxins. Stool osmotic gap is normal; no change in the diarrhea occurs with fasting. Treatment is mainly supportive. Viral syndromes are common and self-limited. ■ Exudative: Associated with mucosal inflammation, enteritis, TB, colon cancer, and IBD. Labs reveal ↑ ESR and CRP. Characterized by tenesmus, often small volume, and frequent diarrhea. Diagnose by colonoscopy, endoscopy with small bowel biopsies (celiac disease), and imaging studies. Treatment varies depending on the etiology. ■ Rapid transit: Associated with laxative abuse or, rarely, hyperthyroidism. Management involves checking TSH or stopping laxative use. ■ Slow transit: Small bowel bacterial overgrowth syndromes, structural abnormalities (small bowel diverticulum, fistulas), radiation damage, slow motility (DM, scleroderma). Treat the underlying cause; give a short course of antibiotics to ↓ bacterial growth.

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DIAGNOSIS ■

■

KEY FACT Common bugs in acute diarrhea: ■ Bacterial: E coli, Shigella, Salmonella, Campylobacter jejuni, Vibrio parahaemolyticus, Yersinia. ■ Viral: Rotavirus, Norwalk virus. ■ Parasitic: Giardia, Cryptosporidium, Entamoeba histolytica.

■

Evaluation of acute diarrhea: ■ In the setting of high fever, bloody diarrhea, or a duration of > 4–5 days, obtain fecal leukocytes and bacterial cultures and test for C difficile toxin; obtain a stool O&P for immunocompromised patients. ■ If symptoms started within six hours of ingestion, think of a preformed toxin such as Staphylococcus or Bacillus cereus. If symptoms started after 12 hours, the etiology is more likely to be bacterial or viral, especially if symptoms are accompanied by vomiting. Evaluation of chronic diarrhea: ■ Consider malabsorption syndromes, lactose intolerance, previous bowel surgery, medications, systemic disease, and IBD. ■ Tests to consider include fecal leukocytes, occult blood, flexible sigmoidoscopy with biopsy, endoscopy with small bowel biopsies, small bowel imaging, or colonoscopy. Calculate the osmotic gap: 290 – 2 (stool Na + stool K). A normal gap is < 50. ■ Normal gap: If the stool is of normal weight, consider IBS and factitious causes. If weight is ↑, consider a secretory cause or laxative abuse. ■ Increased gap: Normal stool fat points to lactose intolerance or sorbitol, lactulose, or laxative abuse. ↑ stool fat is associated with small bowel malabsorption, pancreatic insufficiency, or bacterial overgrowth.

TREATMENT

Treat according to the etiology as indicated above. General treatment guidelines are as follows: ■

KEY FACT ■

If a patient is on antibiotics, think C difficile.

■

If acute, give oral or IV fluids and electrolyte repletion. Loperamide may be given if the patient does not have bloody stools or high fevers, as this may precipitate toxic megacolon (especially with C difficile colitis). Avoid antimotility agents in the presence of a high fever, bloody diarrhea, severe abdominal pain, or systemic toxicity. If testing for C difficile toxin is ⊕, treat initially with oral metronidazole; if refractory to metronidazole, treat with oral vancomycin.

Celiac Sprue Usually affects those of northern European ancestry. Can be familial; thought to be an autoimmune disease triggered by an environmental agent (wheat, rye, barley, and some oats). More prevalent than previously thought; associated with osteoporosis, an ↑ risk of GI malignancies (small bowel lymphoma), and dermatitis herpetiformis. SYMPTOMS/EXAM ■

■

Celiac sprue leads to malabsorption with chronic diarrhea. Patients complain of steatorrhea and weight loss. Can also present with nonspecific symptoms (nausea, abdominal pain, weight loss), iron-deficiency anemia, increased LFTs, or muscle wasting.

DIAGNOSIS ■ ■

■

Histology reveals flattening or loss of villi and inflammation. Antibody assays are ⊕ for antiendomysial antibody or anti–tissue transglutaminase antibodies and are 䊞 only with IgA deficiency. A gluten-free diet improves symptoms and the histology of the small bowel.

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TREATMENT

Institute a gluten-free diet. Gluten is found in most grains in the Western world (eg, wheat, barley, rye, some oats, additives, many prepared foods).

Upper GI Bleed Bleeding in the section of the GI tract extending from the upper esophagus to the duodenum to the ligament of Treitz. Primarily due to PUD, gastritis, varices, or Mallory-Weiss syndrome (see Figure 7-10). KEY FACT SYMPTOMS ■ ■

May present with dizziness, lightheadedness, weakness, and nausea. Patients may also report vomiting of blood or dark brown contents (hematemesis—vomiting of fresh blood, clots, or coffee-ground material) or passing of black stool (melena—dark, tarry stools composed of degraded blood from the upper GI tract).

Melena by definition points to an upper GI bleed. There is no other location in the GI tract that is acidic enough to result in melena.

EXAM ■

■

■

Associated with pallor, abdominal pain, tachycardia, and hypotension; rectal exam reveals blood. If patients show signs of cirrhosis (telangiectasia, spider angiomata, gynecomastia, testicular atrophy, palmar erythema, caput medusae), think varices. Vital signs reveal tachycardia at 10% volume loss, orthostatic hypotension at 20% blood loss, and shock at 30% loss.

DIAGNOSIS ■ ■

■

■ ■

Assess the severity of the bleed beginning with the ABCs. Check hematocrit (may be normal in acute blood loss), platelet count, BUN/creatinine (an ↑ ratio reflects volume depletion), PT/PTT, and LFTs. NG tube placement and lavage can help determine the activity and severity of the bleed (if clear, the bleed could be intermittent or from the duodenum). If perforation is suspected, obtain upright and abdominal x-rays. Endoscopy can be both diagnostic and therapeutic.

A

B

C

D

Causes of upper GI bleed at endoscopy. (A) Esophageal varices. (B) Mallory-Weiss tear. (C) Gastric ulcer with protuberant vessel. (D) Duodenal ulcer with active bleeding (arrow). (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New

FIGURE 7-10.

York: McGraw-Hill, 2008, Figs. 285-16, 285-18, and 285-15D and E.)

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TREATMENT ■

■

■

■

■

■ ■

Start with the ABCs. Use at least two large-bore peripheral IV catheters. Transfusion and intravascular volume replacement are indicated. Consult GI and surgery if bleeding does not stop or if difficulty is encountered with resuscitation 2° to a brisk bleed. Treat variceal bleeds with octreotide, endoscopic sclerotherapy, or band ligation. If the bleed is severe, balloon tamponade is appropriate, followed by embolization, transjugular intrahepatic portosystemic shunt (TIPS), or a surgical shunt if endoscopic therapy fails. To prevent variceal bleeds, treat with nonselective β-blockers (eg, propranolol), obliterative endoscopic therapy, shunting, and, if the patient is an appropriate candidate, liver transplantation. For PUD, use PPIs, endoscopic epinephrine injection, thermal contact, and laser therapy. Begin H pylori eradication measures. Mallory-Weiss tears usually stop bleeding spontaneously. Treat esophagitis/gastritis with PPIs or H2 antagonists. Avoid ASA and NSAIDs.

Lower GI Bleed Bleeding that is distal to the ligament of Treitz. SYMPTOMS/EXAM ■ ■

■

KEY FACT A small number of GI bleeds (3.5%) are called obscure GI bleeds because they are associated with a 䊞 EGD and colonoscopy followed by a 䊞 small bowel pill camera.

Presents with hematochezia (fresh blood or clot per rectum). Diarrhea, tenesmus, bright red blood per rectum, or maroon-colored stools are also seen. As with upper GI bleeds, check vital signs to assess the severity of the bleed. Obtain orthostatics; perform a rectal exam for hemorrhoids, fissures, or a mass.

DIFFERENTIAL

Hemorrhoids, diverticulosis, angiodysplasia, carcinoma, enteritis, IBD, polyps, Meckel’s diverticulum. DIAGNOSIS ■ ■

KEY FACT Think diverticulosis with painless lower GI bleeding. Think diverticulitis in the presence of pain.

■

■

First rule out an upper GI bleed. Bleeding usually stops spontaneously. However, colonoscopy should be performed; in the majority of cases, the diagnosis can be made at the time of visualization. If the bleed continues, a bleeding scan (99Tc-tagged RBC scan) can be done to detect bleeding if it is > 1.0 mL/min. If the bleed is refractory, arteriography or exploratory laparotomy may be done.

TREATMENT ■

■

Although bleeding generally stops spontaneously, resuscitative efforts should be initiated, as with upper GI bleeds, until the source is found and the bleeding stops. With diverticular disease, bleeding usually stops spontaneously, but epinephrine injection, catheter-directed vasopressin, or embolization can be used. In some cases, surgery may be needed.

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Pancreatitis A 32-year-old man presents to the ER with sharp abdominal pain. He states that the pain radiates to his back and is constant in nature. He adds that the pain started after he attended a barbecue with friends, at which he drank 14 beers. What is your diagnosis, and how should this patient be managed? The patient likely has alcoholic pancreatitis. Initial management should consist of bowel rest, IV hydration, and pain control.

Gallstones and alcohol account for 70–80% of acute cases. Other causes include obstruction (pancreatic or ampullary tumors), metabolic factors (severe hypertriglyceridemia, hypercalcemia), abdominal trauma, endoscopic retrograde cholangiopancreatography (ERCP), infection (mumps, CMV, clonorchiasis, ascariasis), and drugs (thiazides, azathioprine, pentamidine, sulfonamides). SYMPTOMS ■

■

Acute pancreatitis often presents with abdominal pain, typically in the midepigastric region, that radiates to the back, may be relieved by sitting forward, and lasts hours to days. Nausea, vomiting, and fever also are seen.

EXAM ■

■

Exam reveals midepigastric tenderness, ↓ bowel sounds, guarding, jaundice, and fever. Cullen’s sign (periumbilical ecchymoses) and Grey Turner’s sign (flank ecchymoses) reflect hemorrhage and severe pancreatitis, although they are often seen long after symptoms manifest and the diagnosis has been made.

DIAGNOSIS ■

■

■ ■

■

■

Typically, both amylase and lipase will be elevated; however, amylase may be normal, especially if the disease is due to hyperlipidemia. Lipase has the greatest specificity and remains more significantly elevated than amylase in acute pancreatitis. Abdominal CT within 48–72 hours is especially useful in detecting complications of pancreatitis, such as necrotic or hemorrhagic pancreatitis. In chronic pancreatitis (especially alcohol induced), calcifications may be seen (see Figure 7-11). However, CT scans are not required if the patient is improving. Elevated ALT levels suggest gallstone pancreatitis. If patients are female and > 60 years of age or if they abstain from alcohol or use it only moderately, gallstones are the more likely etiology. Ultrasound may allow visualization of gallstones or sludge in the gallbladder. In chronic pancreatitis, a 72-hour fecal fat test (100-g/day fat diet) is ⊕ if there are > 7 g/day of fat in the stool. The etiology of chronic pancreatitis includes alcohol, cystic fibrosis, a history of severe pancreatitis, and idiopathic causes (excluding gallstones).

MNEMONIC Causes of acute pancreatitis—

GET SMASH’D Gallstones Ethanol, ERCP Trauma Steroids Mumps Autoimmune Scorpion bites Hyperlipidemia Drugs

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P

A

B

Pancreatitis. Transaxial contrast-enhanced CT images. (A) Uncomplicated acute pancreatitis. Peripancreatic fluid and fat stranding can be seen (arrows). P = pancreas. (B) Chronic pancreatitis. Note the dilated pancreatic duct (arrowhead) and pancreatic calcifications (arrow). (Reproduced with permission from USMLERx.com.)

FIGURE 7-11.

TREATMENT ■

■

Acute: ■ Supportive (NPO, IV fluids, pain management). ■ In the setting of gallstone pancreatitis, ERCP with sphincterotomy is appropriate if the common bile duct is obstructed or if there is evidence of cholangitis. If the gallstone has passed, perform a cholecystectomy once the patient is sufficiently stable for surgery. ■ Prophylactic antibiotics are used for severe pancreatitis and consist of imipenem monotherapy or a fluoroquinolone + metronidazole. Chronic: ■ Treat malabsorption with pancreatic enzyme and vitamin B12 replacement. ■ Treat glucose intolerance; encourage alcohol abstinence. ■ Management of chronic pain.

COMPLICATIONS ■

■

Acute: Pseudocyst, peripancreatic effusions, necrosis, abscess, ARDS, hypotension, splenic vein thrombosis. Chronic: Malabsorption, osteoporosis, DM, pancreatic cancer.

GASTROENTEROLOGY

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117

Approach to Liver Function Tests A 48-year-old woman with a past medical history of diabetes, obesity, and hyperlipidemia comes to your clinic for a routine physical and lab work. Routine labs show a normal bilirubin level but an AST and ALT of 58 and 72 U/L, respectively; alkaline phosphatase is within normal limits. What is the likely cause of her transaminitis? Nonalcoholic fatty liver disease.

The algorithm in Figure 7-12 outlines a general approach toward the interpretation of LFTs.

Approach to liver function tests

Hepatocellular injury Predominantly ↑ AST and ALT

Cholestasis Predominantly ↑ alkaline phosphatase and bilirubin

No sign of obstruction (no biliary duct dilation on imaging)

Hepatitis Cirrhosis (expect mostly indirect bilirubin)

FIGURE 7-12.

1˚ biliary cirrhosis Drug-induced postop sepsis

Abnormal liver tests.

Obstruction (biliary duct dilation on imaging)

Viral hepatitis

Choledocholithiasis Cholangiocarcinoma/pancreatic cancer Sclerosing cholangitis Pancreatitis

HAV, HBV, HCV, HDV, HEV, CMV, EBV, HSV, VZV

Autoimmune hepatitis or genetic liver disease Wilson’s disease Hemochromatosis α1-antitrypsin deficiency

Drugs/toxins Alcohol Acetaminophen Medications

118

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GASTROENTEROLOGY

Gallstone Disease In the United States, gallstone disease is most likely due to cholesterol stones. In trauma patients, burn patients, or those on TPN, acute cholecystitis may occur in the absence of stones (acalculous cholecystitis). SYMPTOMS/EXAM ■ ■

KEY FACT Symptoms of cholangitis: ■ RUQ pain ■ Fever ■ Jaundice ■

Most patients with gallstones are asymptomatic (80%). May also present as follows: ■ Biliary colic: Characterized by episodic RUQ or epigastric pain that may radiate to the right shoulder; usually postprandial and accompanied by vomiting. Nocturnal pain that awakens the patient is common. Associated with fatty food intolerance. ■ Cholangitis: Suggested by the presence of fever and persistent RUQ pain. ■ Charcot’s triad: RUQ pain, jaundice, and fever/chills. ■ Reynolds’ pentad: Charcot’s triad plus shock and altered mental status may be seen in suppurative cholangitis. Look for RUQ tenderness and Murphy’s sign (inspiratory arrest during deep palpation of the RUQ). Look for jaundice as a sign of common bile duct obstruction.

DIAGNOSIS MNEMONIC

■ ■

Risk factors for cholecystitis—

The 5 F’s Female Fertile Fat Forties Familial

■

Labs reveal leukocytosis, ↑ amylase, and ↑ LFTs. Ultrasound is 85–90% sensitive for gallbladder gallstones and cholecystitis (echogenic focus that casts a shadow; pericholecystic fluid = acute cholecystitis). A thickened gallbladder wall and biliary sludge are less specific findings (see Figure 7-13). If ultrasound is equivocal and suspicion for acute cholecystitis is high, proceed to a HIDA scan.

TREATMENT ■

Acute cholecystitis: ■ IV antibiotics (generally a third-generation cephalosporin plus metronidazole in severe cases); IV fluids, electrolyte repletion.

L L

A

B

Gallstone disease. (A) Cholelithiasis. Ultrasound image of the gallbladder shows a gallstone (arrow) with posterior shadowing. (B) Acute cholecystitis. Ultrasound image shows a gallstone (red arrow), a thickened gallbladder wall (arrowheads), and pericholecystic fluid (white arrow). L = liver. (Reproduced with permission from USMLERx.com.)

FIGURE 7-13.

GASTROENTEROLOGY

Early cholecystectomy within 72 hours with an intraoperative cholangiogram to look for common bile duct stones. If the patient is a highrisk surgical candidate, elective surgery may be appropriate if the clinical condition allows. ■ If the patient is not a candidate for surgery, consider a percutaneous biliary drain. Cholangitis: ■ Admission, NPO, hydration, pressors if needed, IV antibiotics (ciprofloxacin is preferred). ■ For very ill patients who are not responsive to medical treatment, urgent next-day ERCP with endoscopic sphincterotomy may be needed. Other emergency options are ERCP with stent placement, percutaneous transhepatic drainage, and operative decompression. ■

■

Viral and Nonviral Hepatitis A 59-year-old man comes to your clinic for a checkup. He lived in Vietnam until the age of 32 and has not seen a primary care physician since that time. He is concerned that many of the people in his Vietnamese community have had hepatitis B. Which labs should be ⊕ if this patient has chronic hepatitis B? HBsAg, HBeAg, and HBcAb IgG.

May be acute and self-limited or chronic and symptomatic. May not be detected until years after the initial infection. SYMPTOMS/EXAM ■

■

In acute cases, patients may present with anorexia, nausea, vomiting, malaise, and fever but are frequently asymptomatic. Exam is often normal but may reveal an enlarged and tender liver, dark urine, and jaundice.

DIFFERENTIAL ■

■

■

In the setting of a high level of transaminase elevation (> 10–20 times the upper limit of normal), consider acute viral infection as well as ischemia (“shock liver”), acute choledocholithiasis, or toxins (acetaminophen). With moderate transaminase elevation, consider the most common cause of nonalcoholic fatty liver disease. Also consider chronic viral infection, autoimmune disorders, mononucleosis, CMV, 2° syphilis, drug-induced illness, and Budd-Chiari syndrome. With mild transaminase elevation, also consider hemochromatosis, celiac disease, IBD, and right-sided heart failure.

DIAGNOSIS

Diagnose on the basis of the following: ■

■

■

The presence of hepatitis based on clinical presentation as well as ↑ transaminases. Serology and/or PCR testing confirming a specific virus (see Tables 7-1 and 7-2). Biopsy showing hepatocellular inflammation (rarely indicated).

CHAPTER 7

119

120

CHAPTER 7

GASTROENTEROLOGY

TA B L E 7- 1 .

Viral Hepatitis and Serologic Tests

⊕ SEROLOGY

TYPE OF VIRAL HEPATITIS Acute HAV

Anti-HAV IgM.

Previous HAV

Anti-HAV IgG.

Acute HBV

HBsAg; HBeAg; HBcAb IgM.

Acute HBV, window period

HBcAb IgM only.

Chronic active HBV

HBsAg, HBeAg, HBcAb IgG.

Recovery HBV

HBsAb IgG, HBcAb IgG, normal ALT.

Immunized HBV

HBsAb IgG.

Acute HCV with recovery

HCV RNA early; anti-HCV Ab; recombinant immunoblot assay (RIBA); ALT elevated early.

■

KEY FACT There is an ↑ (25–40%) risk of cirrhosis and hepatocellular carcinoma with chronic HBV.

Acute HCV with chronic infection

HCV RNA, anti-HCV Ab, RIBA, elevated/normal ALT.

Recovery HCV

Anti-HCV Ab and normal ALT.

An RUQ ultrasound may be performed to see if the liver is enlarged in acute hepatitis (vs. cirrhotic nodular liver in the advanced disease state).

TREATMENT

Treat according to subtype as outlined in Table 7-1. Additional guidelines are as follows: ■ ■ ■

Rest during the acute phase. Avoid hepatotoxic agents; avoid morphine; avoid elective surgery. Although most symptoms resolve in 3–16 weeks, LFTs may remain elevated for much longer.

GASTROENTEROLOGY

TA B L E 7- 2 .

SUBTYPE HAV

CHAPTER 7

121

Etiologies, Diagnosis, and Treatment of Viral Hepatitis

TRANSMISSION

CLINICAL/LAB FINDINGS

TREATMENT

OTHER KEY FACTS

Supportive;

Give immunoglobulin to close

contaminated food, water,

generally no

contacts without HAV infection or

milk, and shellfish. Known

sequelae.

vaccination.

Vaccinate patients with chronic HBV

Transmitted via

No chronic infection.

day-care-center outbreaks have been identified. Fecal-oral transmission; has a six-day to six-week incubation period. Virus is shed in stool up to two weeks before symptom onset. HBV

HCV

Transmitted by infected

High prevalence in men who have

Interferon and

blood, through sexual

sex with men, prostitutes, and

other nucleotide/

contact, or perinatally.

IV drug users. Fewer than 1% of

nucleoside

Incubation is six weeks to six

cases are fulminant. Adult acquired

analogs. (The goal

glomerulonephritis, and

months. HDV can coinfect

infection usually does not become

is to ↓ viral load

polyarteritis nodosa.

persons with HBV.

chronic. Much more common in

and improve liver

Chronic infection can result in

Asian countries and immigrants

histology; cure is

hepatocellular carcinoma.

from that region.

uncommon.)

Illness is often mild or

against HAV. Associated with arthritis,

Interferon

Vaccinate patients with HCV against

transfusion or IV drug

asymptomatic and is

+ ribavirin

HAV and HBV. Complications

use as well as through

characterized by waxing and

combination

include cryoglobulinemia

intranasal cocaine use or

waning aminotransferases.

therapy.

and membranoproliferative

body piercing. Incubation is

HCV antibody is not protective.

Transmitted through blood

6–7 weeks.

glomerulonephritis, as well as hepatocellular carcinoma in patients

Antibody appears six weeks to nine

with cirrhosis.

months after infection. Diagnose acute infection with HCV RNA. More than 70% of infections become chronic. HDV

Requires a coexistent HBV

Anti-HDV IgM is present in acute

Similar to HBV

If acquired as a superinfection in

infection. Percutaneous

cases. Immunity to HBV implies

infection.

chronic HBV, there is an ↑ in the

exposure. Usually found in

immunity to HDV.

severity of the infection. Fulminant

IV drug users and high-risk

hepatitis or severe chronic hepatitis

HBsAg carriers.

with rapid progression to cirrhosis can occur. Associated with an ↑ risk of hepatocellular carcinoma.

HEV

Fecal-oral transmission.

Will test 䊝 on serology for HEV.

Supportive.

Self-limited; endemic to India, Afghanistan, Mexico, and Algeria. Carries a 10–20% mortality rate in pregnant women.

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CHAPTER 7

GASTROENTEROLOGY

Cirrhosis and Ascites Chronic irreversible changes of the hepatic parenchyma, including fibrosis and regenerative nodules. The most common cause in the United States is alcohol abuse, followed by chronic viral hepatitis. SYMPTOMS/EXAM ■

■

■

■

Cirrhosis can be asymptomatic for long periods. Symptoms reflect the severity of hepatic damage, not the underlying etiology of the liver disease (see Figure 7-14). ↓ hepatic function leads to jaundice, edema, coagulopathy, and metabolic abnormalities. Fibrosis and distorted vasculature lead to portal hypertension, which leads in turn to gastroesophageal varices and splenomegaly. ↓ hepatic function and portal hypertension result in ascites and hepatic encephalopathy.

DIAGNOSIS

Cirrhosis is diagnosed as follows: ■

Labs: ■ Laboratory abnormalities may be absent in quiescent cirrhosis. ■ ALT/AST levels are elevated during active hepatocellular injury. However, levels may not be elevated in cirrhosis because a large portion of the liver is replaced by fibrous tissue, and little new cell injury may be occurring.

Effects of portal hypertension

Effects of liver cell failure s#OMA

s%SOPHAGEALVARICES

(EMATEMESIS

s&ETORHEPATICUSBREATH SMELLSLIKEAFRESHLY OPENEDCORPSE s3PIDERNEVI s'YNECOMASTIA

'ASTROPATHY s-ELENA

s*AUNDICE

s3PLENOMEGALY

s!SCITES

s$ILATEDABDOMINALVEINS CAPUTMEDUSAE

s,OSSOFSEXUALHAIR

s2ECTALVARICES HEMORRHOIDS

s4ESTICULARATROPHY s,IVERFLAPCOARSEHAND TREMOR s"LEEDINGTENDENCY DECREASEDPROTHROMBIN s!NEMIA -ACROCYTIC )RONDEFICIENCYBLOOD LOSS s!NKLEEDEMA

FIGURE 7-14.

Clinical effects of cirrhosis. (Modified with permission from Chandrasoma P, Taylor CE.

Concise Pathology, 3rd ed. Originally published by Appleton & Lange. Copyright © 1998 by The McGraw-Hill Companies, Inc.)

GASTROENTEROLOGY

CHAPTER 7

123

Additional lab findings include anemia from suppressed erythropoiesis; leukopenia from hypersplenism or leukocytosis from infection; thrombocytopenia from alcoholic marrow suppression; ↓ hepatic thrombopoietin production and splenic sequestration; and a prolonged PT from failure of hepatic synthesis of clotting factors. Imaging: ■ Ultrasound: Used to assess liver size and surface contour and to detect ascites or hepatic nodules. Doppler ultrasound can establish the patency of the splenic, portal, and hepatic veins. Commonly used in the setting of chronic liver disease without known cirrhosis (see Figure 7-15). ■ CT or MRI with contrast: Used to characterize hepatic nodules. A biopsy may be needed to rule out malignancy. ■ Liver biopsy is the most accurate means of assessing disease severity. ■

■

Ascites is diagnosed in the following manner: ■

■

Ultrasound and paracentesis: Check cell count, differential, albumin, and bacterial cultures +/– acid-fast stain and +/– cytology. The etiology of the ascites can be further characterized as follows: ■ Related to portal hypertension (serum-ascites albumin gradient [SAAG] ≥ 1.1): Cirrhosis, heart failure, Budd-Chiari syndrome (hepatic vein thrombosis). ■ Unrelated to portal hypertension (SAAG < 1.1): Peritonitis (eg, TB), cancer, pancreatitis, trauma, nephrotic syndrome. If a patient with cirrhosis and established ascites presents with worsening ascites, fever, altered mental status, renal dysfunction, or abdominal pain, think of spontaneous bacterial peritonitis (SBP).

S

FIGURE 7-15. Cirrhosis. Transaxial image from contrast-enhanced CT shows a nodular liver contour (arrowheads) and the stigmata of portal hypertension, including splenomegaly (S) and perisplenic varices (arrow). (Reproduced with permission from USMLERx.com.)

KEY FACT Diagnose spontaneous bacterial peritonitis with ⊕ cultures or a peritoneal fluid neutrophil count > 250.

CHAPTER 7

124

GASTROENTEROLOGY

TREATMENT

Treatment for cirrhosis is as follows: ■ ■

■ ■

■

■

Abstain from alcohol. The diet should include ample protein. Dietary protein should not be restricted except occasionally in refractory hepatic encephalopathy. Restrict fluid intake to 800–1000 mL/day if the patient is hyponatremic. Treat hypoprothrombinemia with vitamin K and FFP if clinically indicated. Treat anemia with iron (in iron-deficiency anemia) or folic acid (in alcoholics). Liver transplantation is required in the setting of progressive liver disease.

Treatment for ascites includes the following: ■

KEY FACT Treat hepatic encephalopathy with lactulose, rifaximin (Xifaxan), and neomycin.

■

■

Plasma concentration

4000 3000

500 400

2000

300

1300

200

1000

150

Lower limit for high-risk group Lower limit for probable-risk group Study nomogram line

Portal hypertension: ■ Sodium restriction to < 2 g/day. ■ Diuretics: Furosemide and spironolactone in combination. ■ Large-volume paracentesis for ascites that is refractory to diuretics. ■ TIPS can be used in refractory cases, but this ↑ the rate of encephalopathy. ■ Ultimately, liver transplantation if the patient is a candidate. No portal hypertension: ■ Treat the underlying disorder. ■ Therapeutic paracentesis also can be performed. Treat SBP with a third-generation cephalosporin (first-line therapy) or a fluoroquinolone. Often recurs.

Acetaminophen Toxicity Within 2–4 hours of an acute overdose, patients present with nausea, vomiting, diaphoresis, and pallor. Within 24–48 hours, hepatotoxicity is manifested by RUQ tenderness, hepatomegaly, and ↑ transaminases.

100 500 50

TREATMENT 100

■ 10 50 30

5

μmol/L μg/mL

■ 4

8

12

16

20

24

28

Hours after ingestion

FIGURE 7-16. Estimation of the severity of acetaminophen ingestion.

Supportive measures; oral administration of activated charcoal or cholestyramine within 30 minutes of ingestion to prevent absorption of residual drug. Begin N-acetylcysteine administration up to 36 hours after ingestion if the acetaminophen level is > 200 μg/mL measured at 4 hours or > 100 μg/mL at 8 hours after ingestion or if the time of ingestion is unknown and ↑ levels are seen (see Figure 7-16). Even late treatment can be helpful.

Hereditary Hemochromatosis ■

■

■

■

An autosomal recessive disorder of iron overload. Usually affects middleaged Caucasian men at a rate of 1 in 300. Sx/Exam: Presents with mild transaminitis, DM, arthritis, infertility, and heart failure. Dx: Diagnosis is made with ↑ iron saturation (> 60% in men and > 50% in women), ↑ ferritin, ↑ transferrin saturation, and the presence of the HFE gene mutation. Tx: Treat with phlebotomy to ↓ the iron burden. Genetic counseling is useful to assess the likelihood of transmission.

GASTROENTEROLOGY

Wilson’s Disease ■ ■

■

■

An autosomal recessive disorder of copper overload. Sx/Exam: Exam may reveal Kayser-Fleischer rings and neuropsychiatric disorders. Dx: Labs reveal ↑ urinary copper, ↓ serum ceruloplasmin, and ↑ hepatic copper content on liver biopsy. Tx: Treatment is via chelation with penicillamine and trientine.

α1-Antitrypsin Disorder ■ ■

■

Usually affects the liver (cirrhosis) and the lung (emphysema). Dx: Diagnosed by the quantitative absence of α1-antitrypsin on serum protein electrophoresis (SPEP) as well as by genotype analysis (autosomal recessive). Tx: Treatment is via liver transplantation and α1-antitrypsin replacement for the lung.

Autoimmune Hepatitis ■

■

■

Primarily affects young women; usually suspected when transaminases are elevated. Dx: Hypergammaglobulinemia is seen on SPEP; autoantibodies are sometimes seen (ANA, anti–smooth muscle antibody [ASMA], liver/ kidney microsomal antibody [LKMA]). Ultimately, a liver biopsy is needed to confirm the diagnosis. Tx: Treat with corticosteroids and azathioprine. A significant number of patients relapse when off therapy and thus require long-term treatment.

1° Biliary Cirrhosis A 46-year-old woman presents to your clinic with scleral icterus, pruritus, and abnormal LFTs. Her AST, ALT, and alkaline phosphatase are 48, 56, and 603 U/L, respectively. What lab test will reveal the likely diagnosis? A ⊕ antimitochondrial antibody will reveal the likely diagnosis of 1° biliary cirrhosis.

■

■

■

■

Autoimmune destruction of microscopic intrahepatic bile ducts. Usually associated with other autoimmune diseases. More commonly occurs in women. Sx/Exam: Presents with fatigue, pruritus, jaundice, fat malabsorption, and osteoporosis. Dx: Suggested by markedly ↑ alkaline phosphatase, ↑ bilirubin (late), and antimitochondrial antibody (AMA). Confirmed by biopsy. Tx: Ursodeoxycholic acid, fat-soluble vitamins, cholestyramine for pruritus, and transplantation.

CHAPTER 7

125

126

CHAPTER 7

GASTROENTEROLOGY

1° Sclerosing Cholangitis ■

■

■

■

Idiopathic intra- and extrahepatic fibrosis of the bile ducts. Affects men 20–50 years of age; associated with IBD, usually ulcerative colitis. Sx/Exam: Can present with RUQ pain and pruritus but is often asymptomatic. Dx: Look for ↑ bilirubin and alkaline phosphatase; ⊕ ASMA; ⊕ p-ANCA; and multiple areas of beaded bile duct strictures on ERCP (see Figure 7-17). Tx: Treat with ursodeoxycholic acid, cholestyramine, fat-soluble vitamins, stenting of the strictures, and ultimately liver transplantation.

Primary sclerosing cholangitis. ERCP image following contrast injection through a catheter in the common bile duct with the balloon (blue arrow) inflated. Multifocal structuring and dilation of the intrahepatic bile ducts can be seen. (Reproduced with permission from FIGURE 7-17.

USMLERx.com.)

CHAPTER 8

HEMATOLOGY 128

Bleeding Disorders

MICROCYTIC ANEMIA

128

PLATELET DISORDERS

137

MACROCYTIC ANEMIA

130

COAGULOPATHIES

138

NORMOCYTIC NORMOCHROMIC ANEMIA

131

Hypercoagulable State (Thrombophilia)

140

136

Transfusion

142

Anemia

Polycythemia Vera

136

127

CHAPTER 8

128

HEMATOLOGY

Anemia A nine-year-old boy who was recently treated for meningitis in a developing country develops purpura and then pallor. He is found to have a platelet count of 42,000/μL, a hematocrit of 26%, and a WBC count of 1700. Which antibiotic that is now rarely used in the United States is known to cause pancytopenia? Chloramphenicol.

Anemia can be classified by the size of the red cell (mean corpuscular volume, or MCV) as microcytic, normocytic, or macrocytic: ■ ■ ■

Microcytic: MCV < 80 fL. Normocytic: MCV 80–100 fL. Macrocytic: MCV > 100 fL.

DIAGNOSIS ■ ■

KEY FACT Normal hemoglobin and hematocrit values for pediatric patients are lower than those for adults, so check agestandardized ranges.

■

■

Initially, order a CBC, an MCV, a blood smear, and a reticulocyte count. On the basis of the initial results, order 2° tests such as iron studies (serum ferritin, serum iron, TIBC, % transferrin saturation), serum folate, TSH, serum B12, hemolysis labs (LDH, unconjugated bilirubin, haptoglobin, Coombs’ test), and a DIC panel (D-dimer, fibrinogen, blood smear, soluble fibrin monomer complex). Serum ferritin studies may be less accurate in patients with acute illness or chronic inflammatory/chronic liver disease. Look for a bleeding source, and order a type and cross if the patient is actively bleeding or symptomatic from anemia. Look for pancytopenia. Etiologies include toxins, drugs, infection, myelodysplasia, malignancy, radiation, vitamin B12/folate deficiency, SLE, and congenital causes.

KEY FACT TREATMENT If possible, check all necessary lab studies pertaining to anemia prior to transfusion.

Patients with severe anemia and those who are symptomatic initially require fluid resuscitation and RBC transfusion. Transfuse to keep serum hemoglobin > 7 g/dL, or > 8 g/dL for CAD patients. Identify the cause of the anemia and treat the underlying disorder. MI C R OC YTI C ANE M I A

MNEMONIC Causes of microcytic anemia–

Anemia with an MCV of < 80 fL. Anemia with an MCV of > 70 fL is due to either iron-deficiency anemia or thalassemia. Other causes include anemia of chronic disease and sideroblastic anemia (see the mnemonic TICS).

TICS Thalassemia Iron deficiency Chronic disease Sideroblastic anemia

SYMPTOMS/EXAM ■ ■

Iron-deficient patients may have pica. Ask about melena and blood in the stools, and check for fecal occult blood. Ask female patients about heavy menstrual periods. A family history of anemia should raise suspicion for thalassemia.

HEMATOLOGY

■

CHAPTER 8

The Mentzer index can be used to help distinguish iron-deficiency anemia from thalassemia:

129

KEY FACT In iron-deficiency anemia, first RDW widens and then MCV ↓.

Mentzer index = MCV/RBC count If the Mentzer index is > 13, the condition is more likely to be irondeficiency anemia. DIAGNOSIS ■

■

Examine iron studies, a blood smear, and a CBC to identify the cause of the microcytic anemia (see Table 8-1). Suspect colorectal cancer in elderly patients with microcytic anemia, and refer these patients for a colonoscopy.

TREATMENT ■

If iron-deficiency anemia is the cause, identify the site of blood loss and initiate oral iron supplementation (patients intolerant of oral therapy and those with GI disease may need parenteral therapy). To help replenish stores, treatment should be continued 3–6 months after lab values have normalized.

TA B L E 8 - 1 .

KEY FACT Serum ferritin, a measure of iron stores, is ↓ in iron-deficiency anemia but is ↑ in infection and inflammation (anemia of chronic disease). Low serum ferritin is highly specific but not sensitive for iron deficiency.

Causes of Microcytic Anemia

IRON-DEFICIENCY ANEMIA Serum

↓ (may be normal in

ferritin

inflammatory states,

ANEMIA OF CHRONIC THALASSEMIA Normal to ↑

DISEASE (LATE)

SIDEROBLASTIC ANEMIA ↑

↑ (may be normal in early stages).

including cancer). Serum iron

↓

Normal to ↑

Slightly ↓

Iron-binding

↑

Normal to ↑

Normal to ↓

↑ Normal or ↓

capacity Other tests

Wide RDW.

Normal RDW.

Smear shows normal and dimorphic

Order hemoglobin electro-

RBCs with basophilic stippling.

phoresis to confirm the

Confirm the diagnosis with

diagnosis.

bone marrow biopsy (shows erythroid hyperplasia and ringed sideroblasts).

Comments

Etiologies include

Characterized by ↓ or

Etiologies include chronic

Etiologies include chronic alcohol

malabsorption,

absent production of one

inflammation, infection,

use, drugs (antitubercular,

chronic blood loss,

or more globin chains in

and malignancy.

chloramphenicol), and lead

and malnutrition. Thrombocytosis is common.

the hemoglobin. Also marked by an elevated MCHC and a Mentzer index of < 13.

poisoning. Has ↑ transferrin levels. Order lead levels if lead toxicity is suspected.

CHAPTER 8

130

HEMATOLOGY

■

■

KEY FACT Clinically significant α-thalassemia can present at birth because the α chain is made in fetal and neonatal hematopoiesis, but β-thalassemia won’t present until the α-chain predominance (present in fetal hemoglobin) changes to the β chain in infancy.

Thalassemia

A group of disorders resulting from ↓ synthesis of α- or β-globin protein subunits. α-thalassemia is most common among Asians and African Americans; β-thalassemia is most frequently found in people of Mediterranean origin as well as in Asians and African Americans. SYMPTOMS/EXAM

Clinical presentation varies according to subtype: ■

MNEMONIC Features of β-thalassemia major—

■

BETA THAL D Basophilic stippling Excess iron from transfusions Transplant, bone marrow HbA decreased Tower skull and bony abnormalities Heart failure Anisocytosis Liver and spleen enlargement Deferoxamine

Erythropoietin (Epogen) should be administered to patients with anemia of chronic disease, particularly those with chronic kidney disease. The treatment of thalassemia is outlined separately in the discussion below.

α-thalassemia: If all four α alleles are affected, babies are stillborn with hydrops fetalis or die shortly after birth. HbH disease with three affected alleles leads to chronic hemolytic microcytic anemia and splenomegaly. Carriers of one or two affected alleles are usually asymptomatic. β-thalassemia: β-thalassemia major (homozygous; no β-globin production and hence no HbA) presents in the first year of life as the fraction of HbF declines. Manifestations include growth retardation, bony deformities, hepatosplenomegaly, and jaundice. β-thalassemia minor (heterozygous) is usually less severe and is diagnosed by an ↑ HbA2 on electrophoresis.

DIAGNOSIS

CBC reveals severe microcytic anemia with a normal RDW and an ↑ RBC count (vs. iron deficiency). Hemoglobin electrophoresis is the definitive diagnostic test. TREATMENT ■

KEY FACT ■

With a severely low MCV, a Mentzer index of < 13, microcytic anemia not responsive to iron supplementation, or familial anemia, suspect thalassemia and order a hemoglobin electrophoresis.

■

Although an emerging treatment for patients with severe thalassemia is allogeneic bone marrow transplantation, blood transfusions should be given as necessary for symptomatic control, and patients must receive folate supplementation. To prevent 2° hemosiderosis due to iron overload, deferoxamine, an iron chelator, is usually given concomitantly. Prenatal diagnosis is now available, and genetic counseling should be offered to high-risk families. MA C R OC YTI C ANE M I A

A 32-year-old woman with Crohn’s disease and a history of partial bowel resection, including resection of the terminal ileum, comes to you for fatigue and is found to have a hematocrit of 29% and an MCV of 104 fL. Why is she at risk for vitamin B12 deficiency? Intrinsic factor receptors are located in the terminal ileum. Patients with B12 absorption deficiencies, such as those with intestinal disease or pernicious anemia, should be treated with injected vitamin B12.

HEMATOLOGY

CHAPTER 8

131

Anemia with an MCV of > 100 fL. The most common etiologies include the following: ■

■

■

Folate deficiency: Common causes include poor dietary intake (including that which occurs with alcoholism) and drugs (eg, phenytoin, zidovudine, TMP-SMX, methotrexate, and other chemotherapeutic agents). B12 deficiency: Commonly caused by a strict vegan diet, pernicious anemia, gastrectomy, PPIs (which inhibit B12 absorption), and ileal dysfunction (IBD, surgical resection). B12 deficiency can cause neurologic deficits (paresthesias, gait disturbance, and mental status changes). Other: Liver disease, hypothyroidism, alcohol abuse, myelodysplasia, reticulocytosis.

KEY FACT An MCV of > 110 fL is usually due to vitamin B12 or folate deficiency.

DIAGNOSIS ■

■

■

Initial diagnostic labs should include a serum B12 level, an RBC folate level, and a blood smear to look for megaloblastic anemia, which shows oval macrocytes and hypersegmented neutrophils (see Figure 8-1). If B12 deficiency is suspected, check intrinsic factor antibody and anti– parietal cell antibody for pernicious anemia. A Schilling test may be used to confirm the cause. Elevated methylmalonic acid levels will confirm the diagnosis in patients with borderline levels.

TREATMENT ■

■

Treat B12 deficiency with monthly B12 shots; treat folate deficiency with oral replacement. Discontinue any medications that could be contributing to megaloblastic anemia; minimize alcohol use. NO R M O CY T IC N O R M O C H R O M I C A NE M I A

While evaluating a 59-year-old woman for dyspnea on exertion, you find that she has a hematocrit of 31% with an MCV of 89 fL. What are your next steps? Check a blood smear, a reticulocyte count, renal function tests (creatinine), LDH, haptoglobin, and indirect bilirubin, and look for possible bleeding sites.

Anemia with an MCV of 80–100 fL. Can be due to blood loss (hemorrhage), hemolysis, or ↓ production. SYMPTOMS/EXAM

Look for evidence of acute bleeding on history and exam. Patients with hemolytic anemia may present with jaundice and dark urine from unconjugated hyperbilirubinemia as well as with pigment gallstones and splenomegaly. DIAGNOSIS

The initial workup should focus on reticulocyte count, creatinine, hemolysis labs, and blood smear. ■

■

Normal reticulocyte count: Anemia of chronic disease or chronic kidney disease. ↑ reticulocyte count with normal hemolysis labs: Hemorrhage.

FIGURE 8-1. Hypersegmented neutrophil seen in megaloblastic anemia. (Reproduced with permission from USMLERx.com.)

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■

MNEMONIC Patients with PNH have morning FITS of pink urine:

Flow cytometry to diagnose Intravascular hemolysis Thrombosis Supportive treatment for complications

↑ reticulocyte count, ↑ LDH, ↑ unconjugated bilirubin, and ↓ haptoglobin: Hemolysis. Causes include the following: ■ Microangiopathic hemolytic anemia: Schistocytes or helmet cells are seen on blood smear (see Figure 8-2 and the subtopic below). These RBC fragments are thought to be due to RBC shearing through partially coagulated capillaries. ■ Hereditary spherocytosis: Characterized by spherocytes, a ⊕ family history, and a 䊞 Coombs’ test. ■ Autoimmune hemolytic anemia: Marked by spherocytes with a ⊕ Coombs’ test. ■ Cold agglutinin disease: Acrocyanosis in cold exposure. The cold agglutinin test is ⊕. Seen with mycoplasmal infection and mononucleosis. ■ Sickle cell anemia: See the subtopic below. ■ G6PD deficiency: Hemolysis in the presence of infection or drugs (most commonly sulfa drugs). Peripheral blood smear may show characteristic bite cells (which have the appearance of a bite taken out from the periphery). G6PD levels may be normal during hemolytic episodes but are ↓ thereafter. ■ Myelofibrosis: A myeloproliferative disorder of abnormally activated marrow fibroblasts, with subsequent medullary fibrosis and anemia. Most commonly idiopathic or 2° to polycythemia vera or hematologic malignancy. Extramedullary hematopoiesis causes hepatosplenomegaly. Labs show reticulocytosis, teardrop RBCs, and elevated LDH. Marrow biopsy is diagnostic. See Table 8-2 for lab features differentiating myelofibrosis from other myeloproliferative disorders. ■ Paroxysmal nocturnal hemoglobinuria (PNH): An acquired disorder with intravascular hemolysis (with ensuing hemoglobinuria) and recurrent thrombosis. May involve pancytopenia. Diagnosed by flow cytometry.

FIGURE 8-2.

Schistocytes (arrows) and helmet cells (arrowheads) in a patient with DIC.

(Reproduced with permission from USMLERx.com.)

HEMATOLOGY

TA B L E 8 - 2 .

CHAPTER 8

133

Laboratory Features of Myeloproliferative Disorders

RBC WBC COUNT

HEMATOCRIT

PLATELET COUNT

MORPHOLOGY

CML

↑↑

Normal

Normal or ↑

Normal

Myelofibrosis

Normal or ↓/↑

Normal or ↓

Normal or ↓/↑

Abnormal

PCV

Normal or ↑

↑

Normal or ↑

Normal

Essential

Normal or ↑

Normal

↑

Normal

thrombocytosis (Reproduced with permission from Tierney LM et al [eds]. Current Medical Diagnosis & Treatment: 2004. New York: McGraw-Hill, 2004: 481.)

TREATMENT ■

■

■

Patients who are hemorrhaging must be resuscitated with fluids and RBC transfusions. The cause of the bleeding must be identified and treated. Hereditary spherocytosis usually responds to splenectomy. Remember to vaccinate against encapsulated organisms (Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae type b). Treatment for autoimmune hemolytic anemia includes steroids, immunosuppressive agents, IVIG, and, if necessary, splenectomy.

Microangiopathic Hemolytic Anemia An eight-year-old boy eats at a local burger joint at which meat was later found to be contaminated with bacteria. Two days after his fast-food meal, he develops bloody diarrhea and is hospitalized. On day 4 he is noted to have dark urine. Labs reveal a hemoglobin level of 8.5 g/dL, a platelet count of 41,000/μL, a creatinine level of 5.6 mg/dL, and schistocytes on blood smear. You diagnose HUS. What is the treatment for his renal failure?

MNEMONIC

Hemodialysis. The pentad of TTP, a medical emergency—

Defined as the presence of intravascular hemolysis with fragmented RBCs (schistocytes and helmet cells on blood smear). Constitutes a medical emergency. Distinguished as follows (see also Table 8-3): ■

■

■

DIC: Overwhelming systemic activation of the coagulation system stimulated by serious illness. Causes include sepsis, shock, malignancy, obstetric complications, and trauma. HUS: The triad of hemolytic anemia, thrombocytopenia, and ARF. Causes include viral illness and E coli O157:H7. Most common in children > 10 years of age. TTP: Presents as a pentad of the HUS triad plus fever and fluctuating neurologic signs, although patients may not have all five. Causes include HIV, pregnancy, and OCP use.

TREATMENT ■

DIC: Treat the underlying condition; transfuse platelets; give protein C concentrate or cryoprecipitate (to replace fibrinogen) and FFP (to replace coagulation factors).

Run FAST! Renal failure Fever Anemia (microangiopathic hemolytic anemia)

Seizure (CNS dysfunction) Thrombocytopenia

KEY FACT Differentiate HUS and TTP by the presence of neurologic signs in TTP. The treatment of choice for TTP is plasmapheresis; that for HUS is dialysis.

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TA B L E 8 - 3 .

Differential of Microangiopathic Hemolytic Anemia

TTP or HUS DIC

PLATELETS

PT/PTT

D-DIMER

↓↓↓

Normal

Normal

↓↓

↑

↑↑

OTHER FINDINGS ARF, CNS dysfunction. ↑ fibrin split products, ↓ fibrinogen, ↑ D-dimer.

Mechanical valve Severe vasculitis, severe

Normal

Normal

Normal

Heart murmur.

↓

Normal

Normal

Elevated liver enzymes in

hypertension, HELLP

■ ■

HELLP.

HUS: Treat with dialysis for ARF. TTP: The treatment of choice is plasmapheresis. In urgent situations, give FFP until plasmapheresis becomes available. Do not give platelets, as this may exacerbate the TTP.

Sickle Cell Anemia A five-year-old girl with sickle cell disease is in a kindergarten class with a child who recently came down with a facial rash and was diagnosed with fifth disease. The girl’s mother calls you for advice. What complication is a concern? Aplastic crisis due to parvovirus B19.

An autosomal recessive disease resulting from the substitution of valine for glutamic acid at the sixth position in the globin chain. SYMPTOMS/EXAM FIGURE 8-3.

Sickled red blood

cells. The elongated and crescent-shaped

RBCs seen on this smear represent circulating irreversibly sickled cells. Target cells and a nucleated red blood cell are also seen. (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 99-4.)

KEY FACT

Seen predominantly among African Americans, who often have a family history. Clinical features include stigmata of chronic hemolysis such as gallstones, poorly healing ulcers, jaundice, splenomegaly (usually during childhood), and CHF. DIAGNOSIS

Blood smear reveals sickled cells (see Figure 8-3), Howell-Jolly bodies, and evidence of hemolysis. Hemoglobin electrophoresis is the definitive diagnostic test. TREATMENT ■

Hydroxyurea is a chemotherapeutic agent that ↓ HbS and ↑ fetal hemoglobin, HbF. It should be considered in patients with frequent pain crises and a history of strokes or other serious complications.

■ ■ ■

■

Vaccinate all patients for S pneumoniae, H influenzae, HBV, and the influenza virus in the appropriate season. Give folic acid supplementation. Consider transfusions for severe anemia, sickle cell crisis, and priapism. Instruct patients to avoid dehydration, hypoxia, intense exercise, and high altitudes. In patients with frequent pain crisis, hydroxyurea or bone marrow transplantation should be considered.

HEMATOLOGY

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135

COMPLICATIONS

The complications of sickle cell disease include the following (see also Figure 8-4): ■

■

■

■ ■ ■ ■

■ ■

Pain (vaso-occlusive) crisis: ■ Sickled cells cause occlusion of arterioles, leading to tissue ischemia and/or infarction. ■ Characterized by pain in the back, limbs, abdomen, and ribs; precipitated by dehydration, acidosis, infection, fever, or hypoxia. ■ Treat with hydration, analgesia, and supplemental O2. Aplastic crisis: A sudden ↓ in hemoglobin and reticulocyte count caused by parvovirus B19. Support with transfusions. Acute chest syndrome: ■ Presumed to be due to a combination of factors, including infection, infarction, and pulmonary fat embolism. ■ Clinical findings include fever, chest pain, cough, wheezing, tachypnea, and new pulmonary infiltrate on CXR. ■ Treat with O2, analgesia, transfusions, and antibiotics (a second- or thirdgeneration cephalosporin with a macrolide such as erythromycin). Lungs: Pulmonary infarcts can cause pulmonary hypertension. Heart: Sickle cell cardiomyopathy may lead to heart failure. GI tract: Cholecystitis, splenic infarcts. Kidneys: Sickling of cells can cause infarcts, leading to papillary necrosis and ARF (particularly in sickle cell trait). Genital: Priapism, impotence in males. Infections: The absence of a functional spleen predisposes patients to encapsulated organisms, including S pneumoniae, H influenzae, N meningitidis, and gram-䊞 bacterial infections.

CHRONIC COMPLICATIONS Retinopathy Anemia, leukocytosis

ACUTE COMPLICATIONS Stroke, meningitis Post-hyphema glaucoma, retinal infarction

Obstructive sleep apnea Pulmonary hypertension

Acute chest syndrome

Indirect hyperbilirubinemia Cardiomegaly Isosthenuria, chronic kidney disease

Sickle hepatopathy Functional asplenia

Splenic sequestration, splenic infarction Papillary necrosis Avascular necrosis

Cholelithiasis

Delayed puberty

Priapism

Bone marrow infarction, osteomyelitis

Skin ulcers

FIGURE 8-4.

Complications of sickle cell disease.

KEY FACT As in thalassemia, sickle cell patients who receive frequent transfusions need prophylactic treatment of hemosiderosis with iron chelators such as deferoxamine.

MNEMONIC Treatment of acute chest syndrome—

TO AID Transfusion Oxygen Antibiotics Incentive spirometry Dilators (bronchodilators)

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■ ■ ■

Bones: Avascular necrosis, Salmonella osteomyelitis. CNS: Stroke is one of the most devastating complications. Pregnancy: Patients are at ↑ risk of spontaneous abortions.

Polycythemia Vera (PCV) A myeloproliferative syndrome in which the predominant abnormality is ↑ RBCs. Classically affects males > 60 years of age. Remember, the most common cause of erythrocytosis is chronic hypoxia 2° to lung disease rather than 1° PCV. SYMPTOMS/EXAM ■

■

KEY FACT

DIAGNOSIS ■

Distinguish polycythemia vera from other causes of 2° polycythemia through an erythropoietin level. An elevated erythropoietin level excludes the diagnosis of PCV.

Patients present with malaise, fever, pruritus (especially after a warm shower), and signs of vascular sludging (eg, stroke, angina, MI, claudication, hepatic vein thrombosis, headache, and blurred vision). Exam may reveal plethora, large retinal veins on funduscopy, and splenomegaly.

■

■

Labs show ↑ hematocrit (≥ 50%), ↑ RBC mass, and a normal erythropoietin level (↑ in chronic hypoxia-induced polycythemia). Basophilia suggests proliferative myelopoiesis. JAK-2 ⊕. Establish the diagnosis by bone marrow biopsy, which shows a hypercellular marrow. Table 8-2 outlines the laboratory features of PCV in contrast to those of other myeloproliferative disorders.

TREATMENT ■

■

Treatment includes serial phlebotomy until hematocrit is < 45 (men) and < 42 (women) along with daily ASA. Hydroxyurea is appropriate for those at high risk of thrombosis (age > 70, prior thrombosis, platelet count > 1,500,000/μL, presence of cardiovascular risk factors). Anagrelide can be used to ↓ platelets in refractory patients.

COMPLICATIONS

PCV, like other myeloproliferative syndromes, is associated with an ↑ risk of conversion to other myeloproliferative syndromes or AML.

Bleeding Disorders Disorders in coagulation or platelets that predispose patients to bleed (see Table 8-4). DIAGNOSIS ■

Initial tests to order include PT/PTT, CBC, platelet count, and a DIC panel (D-dimer, fibrinogen, blood smear). Use these laboratory data to determine if the cause of the bleeding is 2° to a coagulopathy or a platelet problem. ■ Think thrombocytopenia when the platelet count is < 90,000 cells/μL (see the discussion of platelet pathology below). ■ Think coagulopathy if the PT or PTT is ↑ (see the discussion of coagulopathies).

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TA B L E 8 - 4 .

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137

Coagulopathy vs. Platelet Disorders

CLINICAL FEATURE Amount of bleeding after

PLATELET DISORDER

COAGULOPATHY

Excessive, prolonged.

Normal to slightly ↑.

Immediate bleeding.

Delayed bleeding after

surface cuts Onset of bleeding after injury

surgery or trauma. Spontaneous bleeding into joints or hematoma.

Clinical presentation

Superficial and mucosal

Deep and excessive bleeding

bleeding (GI tract, gingival,

into joints, muscles, GI tract,

nasal).

and GU tract.

Petechiae, ecchymosis.

■

If platelet count and PT/PTT are normal, check bleeding time (PFA-100 test) and thrombin time. An ↑ bleeding time suggests a platelet dysfunction. An ↑ thrombin time suggests a defect in the cross-linking of fibrin such as that in dysfibrinogenemia or DIC.

TREATMENT ■

■

Patients who are hemodynamically unstable need immediate resuscitation with IV fluids. The source of hemorrhage should be identified and stopped. Blood transfusions should be given to maintain a hemoglobin of > 8 g/dL. FFP should be given to normalize PTT and PT. Platelets should be given as needed. PLATELET DISORDERS

You are called to the ICU to evaluate a 64-year-old woman who was admitted six days ago, following cardiac surgery, for a “black” rash. On exam, you find necrotic patches of skin on the distal extremities. The woman’s medications include furosemide, enoxaparin, enalapril, amlodipine, insulin, and ASA. Her platelet count is 36,000/μL with ⊕ PF-4 antibodies. You diagnose heparin-induced thrombocytopenia (HIT). What condition accounts for the patient’s skin necrosis? HIT causes platelet activation and thrombosis.

Disorders associated with a ↓ in the number of platelets (thrombocytopenia) or a ↓ in the functioning of platelets that predisposes patients to bleed (platelet dysfunction). Look for petechiae and easy bruising. In addition to TTP and HUS, common platelet disorders include the following: ■

Drug-induced thrombocytopenia: One of the most common causes of mild asymptomatic thrombocytopenia. Common drugs include quinine, antibiotics, sulfa drugs, and glycoprotein IIb/IIIa inhibitors. Usually resolves within one week of stopping the implicated drug.

KEY FACT Petechiae = Platelet deficiency. Cavity/joint bleeding = Clotting factor deficiency.

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HEMATOLOGY

■

■

■

KEY FACT Idiopathic Thrombocytopenic Purpura: Treat with Prednisone.

KEY FACT Generally, treat with platelet transfusion if platelet count is: ■ < 90,000 before neurosurgery ■ < 50,000 before a general procedure ■ < 50,000 in a symptomatic/ bleeding patient ■ < 20,000 in an asymptomatic patient with fever/sepsis ■ < 10,000 in an asymptomatic patient

■

■

ITP/autoimmune thrombocytopenia: Severe thrombocytopenia due to platelet-associated IgG antibodies. A diagnosis of exclusion. DIC panel is 䊞. Treatment involves prednisone and, if the patient is unresponsive to steroids, splenectomy. HIT: Immune-mediated thrombocytopenia occurring 4–14 days after the initiation of heparin. Platelet factor-4 (PF-4) antibodies are used for diagnosis. Treat by stopping heparin immediately and starting an alternative anticoagulant such as lepirudin, argatroban, or danaparoid sodium (not warfarin). Acquired disease: Platelet proliferation and function can be impaired as a result of severe liver disease, severe renal disease, or multiple myeloma. ASA impairs platelet function. Treat with desmopressin, OCPs for menorrhagia, and FFP or cryoprecipitate for major bleeding. Do not use ASA. Inherited disease: Includes Bernard-Soulier syndrome, Glanzmann’s thrombasthenia, and storage pool disease. Treatment is the same as that for acquired disease. Platelet dysfunction: Normal platelet count.

DIAGNOSIS ■

■

■

First confirm or disprove the presence of thrombocytopenia (ie, recheck platelets in citrated blood). Then obtain a CBC, a peripheral blood smear, and a one-hour posttransfusion platelet count to distinguish between low platelet production (pancytopenia; small platelets; ↑ platelet count following platelet transfusion) and ↑ platelet destruction (large platelets; no significant ↑ in platelet count following platelet transfusion). Obtain a bone marrow biopsy in cases of severe thrombocytopenia.

TREATMENT

See above. COA G U LOP ATHI E S

A seven-year-old boy with hemophilia A comes to the ER after having fallen on his knee two hours ago. His knee is now red, warm, and held in partial flexion due to an effusion. What medication should be used to reverse his coagulopathy? Recombinant factor VIII. Adjunctive treatments include joint rest, ice, analgesia (but avoid salicylates and NSAIDs), and sometimes joint aspiration.

Conditions in which a defective clotting cascade predisposes patients to bleeding. Ask about medications that predispose to bleeding (eg, warfarin, enoxaparin, heparin); note factors that predispose to vitamin K deficiency (eg, malnutrition, antibiotic use, alcoholism). A history of recurrent spontaneous bleeding suggests a factor deficiency. A history of delayed bleeding after trauma or surgery (classically after the umbilical cord falls off) suggests factor XIII deficiency.

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139

DIAGNOSIS ■

■

■

Look for evidence of liver disease on exam, and order LFTs to look for evidence of liver dysfunction. Defects in the clotting cascade can be due to defects in the intrinsic pathway, the extrinsic pathway, or the common pathway. ■ Intrinsic pathway: Involves factors VIII, IX, XI, and XII. Abnormality results in an ↑ in aPTT. Impaired in patients with hemophilia A or B. ■ Extrinsic pathway: Involves factor VII. Abnormality leads to an ↑ in PT (INR). Prolonged by warfarin. ■ Combined pathway: Involves factors V, X, and II (fibrinogen). Abnormality leads to an ↑ in both aPTT and PT (INR). Thrombin time or reptilase time assesses the function of fibrin cross-linking; both are abnormal in fibrinolytic disorders. A diagnostic approach toward patients with coagulation disorders is summarized in Figure 8-5.

KEY FACT The EX-PAT (EXtrinsic PAThway) went to WAR(farin).

BLEEDING DISORDER SUGGESTIVE OF COAGULATION DEFECT

Order PTT and PT

↑ aPTT and normal PT: • Heparin use

↑ PT and normal PTT: • Early DIC • Liver disease • Warfarin use • Vitamin K deficiency

↑ PT and ↑ aPTT: • Heparin use • Severe DIC • Severe liver disease • Severe vitamin K deficiency

Not present

Not present

Order mixing study

Order factor levels

aPTT becomes normal: Factor VIII deficiency Factor IX deficiency Factor XI deficiency

FIGURE 8-5.

aPTT still ↑: Factor VIII inhibitor Factor IX inhibitor Factor XI inhibitor

Low factor level: Factor II deficiency Factor V deficiency Factor X deficiency

Approach to patients with bleeding disorders suggestive of a coagulation defect.

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CHAPTER 8

HEMATOLOGY

TREATMENT ■

■

■

Coagulopathic patients who are actively bleeding need FFP to normalize their PT and PTT levels. Heparin and warfarin must be stopped. If vitamin K deficiency is suspected, it is reasonable to empirically give a patient 10 mg of oral vitamin K for three days to see if the PT normalizes. Patients with hemophilia A or B require factor VIII (either recombinant factor VIII or as cryoprecipitate) or factor IX replacement, respectively.

von Willebrand’s Disease (vWD)

KEY FACT Desmopressin, also known as ADH, ↑ circulating concentrations of factor VIII and vWF while also improving platelet adhesion. Classic uses are to reverse coagulopathic hemorrhage in vWD and hemophilia.

An autosomal dominant condition that represents the most common bleeding disorder. It is characterized by low levels of von Willebrand’s factor (vWF), which is involved in the transport of factor VIII and also helps platelets form a hemostatic plug. SYMPTOMS/EXAM

Clinical features can mimic platelet dysfunction (causing mucocutaneous bleeds and ↑ bleeding time) as well as hemophilia (joint bleeds, ↑ aPTT), depending on the subtype. DIAGNOSIS

Diagnosed by ↓ levels of vWF antigen and/or by abnormal vWF activity (ristocetin cofactor activity). KEY FACT TREATMENT von Willebrand’s Disease: Treat With Desmopressin.

Generally, no treatment is routinely required except before surgical procedures or in the setting of bleeding. Desmopressin is first-line therapy in symptomatic cases.

Hypercoagulable State (Thrombophilia)

KEY FACT Factor V Leiden deficiency, the most common inherited hypercoagulable disorder, is screened with an activated protein C (APC) resistance assay and is confirmed with a factor V Leiden genotypic mutation assay. Remember: factor Vee—check APC.

A 28-year-old G2P1 at 28 weeks’ gestation comes to a routine pregnancy check complaining of unilateral ankle swelling. You find her left leg to be > 2 cm larger in girth than her right, and ultrasound shows a noncompressible left popliteal vein. Which anticoagulant will you start, and for what duration? Start low-molecular-weight heparin (LMWH), and continue until 24 hours prior to delivery (more easily done if you are inducing). Restart after delivery, and continue anticoagulation four weeks after pregnancy. Although a known teratogen,

KEY FACT

Virchow’s triad of factors allowing for venous thrombosis are vessel wall trauma, venous stasis, and alterations in coagulation.

warfarin is considered safe for nursing mothers and is an option postpartum.

A group of conditions that predispose patients to blood clotting. Common causes of thrombophilia include the following: ■

■

Inherited: Includes factor V Leiden deficiency, prothrombin 20210 mutation, protein C or S deficiency, anti–thrombin III deficiency, homocystinemia, and fibrinolysis defects. Acquired: Associated with prolonged rest, immobilization, smoking, OCP use, pregnancy, nephrotic syndrome, cancer, DIC, and lupus anticoagulant.

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141

DIAGNOSIS

Two weeks after the completion of anticoagulation, look for possible 1° causes of hypercoagulability in the following patients: ■ ■ ■

■

Those with a history of a first venous thrombotic event before age 50. Those with recurrent thrombotic episodes. Those who have had a thrombotic event as well as a first-degree relative who experienced a thromboembolic event before age 50. Screening should include APC resistance, prothrombin mutation, antiphospholipid antibody, plasma homocysteine, antithrombin deficiency, protein C deficiency, and protein S deficiency.

TREATMENT ■

■

■

■

■

Acute thrombosis must be treated with at least six months of anticoagulation with warfarin. Indications for lifelong warfarin use include > 2 spontaneous thromboses, antithrombin deficiency, antiphospholipid syndrome, spontaneous lifethreatening thrombosis, and thrombosis in an unusual site (eg, the mesenteric or cerebral vein). Warfarin takes 3–5 days to reach its therapeutic effect; can lead to serious skin necrosis in people with protein C deficiency; and can initially be thrombotic. Thus, bridge with heparin. Pregnant women with a history of hypercoagulable state need to be treated with LMWH. Homocystinemia can be treated with vitamin B12 and folate.

KEY FACT Bridge the initiation of warfarin therapy with heparin for 3–5 days until INR rises to the therapeutic goal.

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142

HEMATOLOGY

Transfusion The complications of transfusion-related reactions are listed in Table 8-5.

TA B L E 8 - 5 .

Transfusion Complications

Major/minor hemolytic reaction

CLINICAL

TESTS

Chills, fever, SOB, nausea, chest/flank

⊕ Coombs’ test, agglutination

pain, hypotension, flushing. Complications: ARF (from hemoglobinuria), DIC.

of RBC on smear, low haptoglobin (best test). UA for hemoglobinuria (⊕ urine dip for hematuria in

MANAGEMENT Stop transfusion. Maintain BP and urine output with IV fluids; give patient furosemide (Lasix) if urine output is < 100 mL/hr. Type and cross RBCs just transfused.

the setting of few RBCs on microscopy). Delayed hemolysis

Onset 4–14 days posttransfusion.

↑ LDH, unconjugated

Jaundice, anemia, hemoglobinuria,

hyperbilirubinemia, ↓

fever. Febrile, nonhemolytic reaction

Onset within two hours posttransfusion.

↑ risk in patients with congenital IgA

transfusions.

haptoglobin.

Acetaminophen for fever.

Rule out biochemical

For future transfusions, use leukocyte-

evidence of hemolysis.

reduced RBCs. Avoid transfusion when febrile.

Fever, rigors, nausea, vomiting, chills. Anaphylaxis

Type and screen blood before future

None.

IV epinephrine. Use saline-washed packed RBCs in

deficiency.

future RBC transfusions.

Sudden onset, flushing, hypertension followed by hypotension, edema, respiratory distress, shock, wheezing, chest pain. Urticaria

Rash, pruritus.

Stop transfusion; monitor for anaphylaxis. Give diphenhydramine (Benadryl). Resume transfusion at a slower rate when symptoms resolve.

Transfusion-related

Occurs 1–6 hours posttransfusion.

CXR shows bilateral

Ventilation (O2, intubation), diuretics,

acute lung injury

Like ARDS of lung.

pulmonary infiltrates without

steroids.

(TRALI)

Acute respiratory distress, cyanosis,

CHF.

fever; gone in 24 hours. DDx: Fluid overload. Bacterial infection

More likely with platelets.

Culture remaining blood

Fever, hypotension; onset within four

product.

Antibiotics.

hours. (Reproduced with permission from Le T et al. First Aid for the USMLE Step 2, 4th ed. New York: McGraw-Hill, 2003: 202.)

CHAPTER 9

ONCOLOGY Hematologic Malignancies

144

PROSTATE CANCER

158

LEUKEMIA

144

TESTICULAR CANCER

158

LYMPHOMA

147

RENAL CELL CARCINOMA

159

148

OVARIAN CANCER

160

Breast Cancer

150

CERVICAL CANCER

160

Lung Cancer

151

GI Tumors

153

MULTIPLE MYELOMA

PANCREATIC CANCER

153

HEPATOCELLULAR CANCER (HEPATOMA)

154

COLORECTAL CANCER

155

MISCELLANEOUS GI TUMORS

156

Genitourinary Tumors BLADDER CANCER

157 157

Skin Tumors

161

MELANOMA

161

BASAL CELL CARCINOMA

162

SQUAMOUS CELL CARCINOMA

162

CNS Tumors

163

MENINGIOMA

163

GLIAL TUMORS

164

Tumor Markers

164

143

144

CHAPTER 9

ONCOLOGY

Hematologic Malignancies LE U K E M I A

Defined as malignant proliferations of hematopoietic cells. Categorization is based on cellular origin (ie, myeloid or lymphoid) and on the level of differentiation. ■

■

KEY FACT Patients with Down syndrome have an ↑ risk of malignancy, especially leukemias.

Acute Lymphocytic Leukemia (ALL)

Most common in children; has an ↑ incidence in those with Down syndrome. SYMPTOMS/EXAM ■

■ ■

KEY FACT Lymphadenopathy, splenomegaly, and CNS involvement are common in ALL but are rare in AML.

■

■

■ ■

Recombinant human hematopoietic growth factors (G-CSF or GM-CSF) can be used to treat neutropenia.

■

■

■

Before initiating chemotherapy, administer allopurinol to patients with acute leukemia to prevent tumor lysis syndrome.

The leukocyte count may be ↑ or ↓. Look for ↓↓ platelets and ↑ LDH and uric acid. Peripheral blood smear shows a predominance of lymphoblasts. Bone marrow biopsy is necessary to confirm the diagnosis and is superior to blood for cytogenetic studies (CALLA ⊕, TdT ⊕). Obtain a CXR, an LP, and a CT scan to rule out mediastinal involvement and brain metastases. Cytogenetic tests are very important for obtaining key prognostic information.

TREATMENT ■

KEY FACT

The symptomatology can be explained by the infiltration of bone marrow and other tissues by malignant cells. Often presents as a viral-like prodrome of fever, sore throat, and lethargy. Children may present with limpness and refusal to walk together with bone pain, easy bruising, and fever. Exam may reveal pallor, widespread petechiae/purpura, multiple ecchymoses, and bleeding. Patients often have signs of extramedullary spread with adenopathy, hepatosplenomegaly, and testicular/CNS involvement.

DIAGNOSIS ■

KEY FACT

Acute leukemia: Proliferation of minimally differentiated cells (myeloblasts, lymphoblasts); defined as > 20% blasts in bone marrow (< 20% blasts is defined as myelodysplastic syndrome). Chronic leukemia: Proliferation of more mature differentiated cells (metamyelocytes/myelocytes, lymphocytes).

■

Treat with chemotherapy. The prognosis is largely determined by age of onset and cytogenetic studies. Nearly all children achieve complete remission, and 80% achieve long-term leukemia-free survival. For adults, these numbers are lower. Phases of treatment and their objectives are as follows: ■ Induction therapy: To induce remission (ie, to destroy all blasts). Usually involves vincristine + prednisone + daunorubicin. ■ Consolidation therapy: To kill any residual leukemia. High-dose methotrexate is used. ■ Maintenance therapy: To maintain remission. Involves daily methotrexate, 6-mercaptopurine (6-MP), or both.

ONCOLOGY

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145

Acute Myelogenous Leukemia (AML)

Most cases occur in adults, with the incidence increasing with each decade of life. SYMPTOMS/EXAM ■

■ ■

Similar to ALL, presenting with fatigue, easy bruising, anemia, fever, leukemia cutis (small, raised, painless skin lesions), and a history of frequent infections. May also present with DIC, gingival hyperplasia, or CNS involvement. Exam reveals fever, lethargy, bleeding, and petechiae/purpura.

KEY FACT AML is associated with exposure to smoking, benzene, radiation, and chemotherapeutic agents.

DIFFERENTIAL

Leukemoid reactions (ie, prominent leukocytosis) due to infection, stress, chronic inflammation, and certain neoplasms can result in WBC counts of 40,000–100,000 cells/μL but lack the cytogenetic changes and ↓ leukocyte alkaline phosphatase (LAP) seen with AML and CML. DIAGNOSIS ■

■

■

In addition to ↑ myelocytic cell lines, there is ↓ LAP. Hyperuricemia is often seen from ↑ cell turnover. Peripheral blood smear shows a predominance of myeloblasts, distinguished by the presence of Auer rods (see Figure 9-1). Bone marrow biopsy is necessary to confirm the presence of blasts by ⊕ myeloperoxidase staining, Auer rods, and cytogenetic tests.

nent nucleoli. (Reproduced with permission from

TREATMENT ■

■

Fauci AS et al. Harrison’s Principles of Internal Medicine,

The prognosis depends on subtype, but generally 70–80% of adults < 60 years of age achieve complete remission. Treatment phases consist of induction (generally with cytosine arabinoside [Ara-C] + anthracycline) and consolidation chemotherapy. Exceptions are as follows: ■ All-trans-retinoic acid is used for induction and maintenance therapy for the promyelocytic form (AML M3). ■ Allogeneic bone marrow transplantation (BMT) is considered for patients with poor prognostic factors for long-term disease-free survival as well as for those < 60 years of age.

Chronic Lymphocytic Leukemia (CLL) A 70-year-old man presents with fatigue. His physical exam is unrevealing, but a routine CBC reveals lymphocytosis with a normal hematocrit and platelet count. What is the next step in diagnosis? Obtain a peripheral smear.

Malignancy of mature lymphocytes, typically seen in patients > 65 years of age. SYMPTOMS/EXAM ■

■

FIGURE 9-1. Leukemic myeloblast with an Auer rod. Note the large, promi-

Usually an indolent disease; many patients are diagnosed by the incidental finding of lymphocytosis. Lymphadenopathy, fatigue, and hepatosplenomegaly may be present on exam.

17th ed. New York: McGraw-Hill, 2008, Fig. 104-1B.)

KEY FACT Cytoplasmic Auer rods are diagnostic for AML.

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DIAGNOSIS ■

■ ■

KEY FACT Although symptomatic CLL does not require treatment, it may transform to intermediate- or high-grade lymphoma (Richter’s transformation) or may be complicated by autoimmune hemolytic anemia, which requires splenectomy +/– steroids.

Isolated lymphocytosis with a normal hematocrit and platelet count is seen on CBC. Peripheral blood smear shows a predominance of small lymphocytes. Bone marrow biopsy is necessary for confirmation (infiltrated with lymphocytes). Aberrant CD5+ expression (T-cell marker) is characteristic, and smudge cells may be present on peripheral smear.

TREATMENT ■ ■

■

No treatment is indicated for asymptomatic patients. Anemia and thrombocytopenia are associated with ↓ survival and are treated symptomatically or with fludarabine. CLL may be associated with autoimmune hemolytic anemia and immune thrombocytopenia, which are treated with splenectomy and/or steroids.

Chronic Myelogenous Leukemia (CML)

Malignancy of myeloid cells that is seen in middle-aged adults. CML can occur de novo or may result from other myeloproliferative disorders. It is often stable for several years (chronic phase) and then transforms into an acute leukemia (blast crisis) that typically proves fatal within a few months. CML is associated with prior radiation and benzene exposure. SYMPTOMS/EXAM ■

■

■

CML is typically diagnosed on a routine CBC that demonstrates leukocytosis with myeloid precursors. Patients may have mild, nonspecific symptoms such as fatigue, fever, malaise, ↓ exercise tolerance, weight loss, and night sweats. Blast crisis presents as fever, bone pain, weight loss, and splenomegaly.

DIFFERENTIAL

Hairy cell leukemia can be another cause of pancytopenia in the elderly. It is a malignancy of B lymphocytes that is characterized by cells with hairy cytoplasmic projections and CD11c positivity. In addition to aplastic anemia and myelofibrosis, it is a common cause of a “dry bone marrow tap.” KEY FACT

DIAGNOSIS ■

The Philadelphia chromosome is pathognomonic for CML and forms the target of imatinib (Gleevec), the new first-line therapy for CML.

■ ■

Peripheral smear reveals an ↑↑ WBC count (median of 150,000 cells/μL at the time of diagnosis) and prominent myeloid cells with basophilia. Also seen are ↓ LAP and ↑↑ B12 levels. Confirm the diagnosis through detection of the t(9;22) Philadelphia chromosome bcr-abl gene by karyotyping, PCR, or fluorescence in situ hybridization (FISH) analysis of blood or bone marrow aspirate.

TREATMENT ■

■

Imatinib mesylate (Gleevec), currently the first-line therapy for CML, specifically targets and inhibits bcr-abl tyrosine kinase and eliminates the CML clone, leading to rapid hematologic and cytogenetic remission. Allogeneic BMT, if performed while the patient is in the chronic phase (within one year of diagnosis), may result in long-term survival. Although the best results are achieved in patients < 40 years of age, treatment can be complicated by graft-versus-host disease.

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L Y M PH O M A

A 30-year-old man presents with a temperature of 38.7°C (101.7°F), drenching night sweats, and weight loss of six months’ duration. Physical exam reveals cervical lymphadenopathy. What is the next step in diagnosis? Lymph node biopsy.

Lymphomas result from monoclonal proliferation of cells of lymphocyte lineage. Approximately 90% are derived from B cells, 9% from T cells, and 1% from monocytes or natural killer (NK) cells. Hodgkin’s Lymphoma

Malignancy of neoplastic Reed-Sternberg (RS) cells (see Figure 9-2), which are of B-cell origin. EBV infections play a role in the pathogenesis of this disease. Usually affects young adults. SYMPTOMS/EXAM ■

■

Usually presents with cervical lymphadenopathy and spreads in a predictable manner along the lymph nodes. The spleen is the most commonly involved intra-abdominal site. “B symptoms” are defined as 10% weight loss in six months, night sweats requiring a change of clothes, and fever > 38.5°C (101.3°F). These symptoms indicate bulky disease and a worse prognosis.

DIAGNOSIS ■

■

Diagnosis is usually based on biopsy of an enlarged lymph node that demonstrates the presence of RS cells. Staging is predicated on the anatomically based Ann Arbor system and on the presence of prognostic factors. Chest and abdominal/pelvic CT as well as bilateral bone marrow biopsies and aspirates are routine.

FIGURE 9-2.

Hodgkin’s lymphoma.

A Reed-Sternberg cell—a large cell with a bilobed nucleus and prominent nucleoli, giving an “owl’s eye” appearance— can be seen near the center of the image (arrow). (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 105-11.)

KEY FACT TREATMENT

Treat with chemotherapy consisting of doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD cocktail) with or without radiation of the involved field.

EBV is a common cause of aggressive lymphoma in patients with immune deficiencies.

Non-Hodgkin’s Lymphoma (NHL)

Classified as low, intermediate, or high grade on the basis of histologic type. Associated with infections—EBV with Burkitt’s lymphoma; HIV with CNS lymphoma; HTLV with T-cell lymphoma; and H pylori with gastric MALToma. SYMPTOMS

Symptoms are similar to that of other lymphomas, including B symptoms. DIAGNOSIS

Diagnosis is similar to that of other lymphomas. LDH is a prognostic marker.

KEY FACT Reed-Sternberg cells (“owl’s eye” nuclei) are pathognomonic for Hodgkin’s lymphoma.

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TREATMENT ■

■

KEY FACT Treatment of lymphoma: ■ Hodgkin’s—think ABVD cocktail. ■ Non-Hodgkin’s—think CHOP/ R-CHOP.

■

■

■

Treat with chemotherapy consisting of cyclophosphamide, hydroxydoxorubicin, vincristine, and prednisone (CHOP therapy). The addition of rituximab (monoclonal anti-CD20) to the chemotherapeutic regimen improves outcomes (R-CHOP). The treatment of high-grade NHL may be complicated by tumor lysis syndrome, which consists of hyperkalemia, hyperphosphatemia, hyperuricemia, and hypocalcemia. Treat with aggressive hydration and allopurinol. Gastric MALTomas can be treated with antibiotics for H pylori as initial therapy. All HIV-related NHL requires immediate institution of antiretroviral therapy (HAART). MU LTI P LE M YE LOM A

A 65-year-old woman presents with back pain and fatigue. Routine lab testing reveals anemia and renal failure. A diagnosis of multiple myeloma is suspected. What is the next step in management? Testing for serum protein electrophoresis (SPEP) and urine protein electrophoresis (UPEP).

A malignancy of plasma cells within bone marrow, often with unbalanced, excessive production of immunoglobulin heavy/light chains. Typically seen in older adults. SYMPTOMS/EXAM ■

■

Symptoms include back pain (the presenting symptom in 80% of patients), hypercalcemic symptoms (“stones, bones, abdominal moans, and psychiatric overtones”), pathologic fractures, fatigue, and frequent infections (2° to dysregulation of antibody production). Exam may reveal pallor, fever, bone tenderness, and lethargy.

DIFFERENTIAL

Waldenström’s macroglobulinemia is a plasma cell disorder that is similar to multiple myeloma but has a predominance of IgM as well as a higher incidence of cold agglutinins and hyperviscosity syndrome (visual disturbance, dizziness, headache). The latter is treated with urgent plasmapheresis. DIAGNOSIS ■

KEY FACT Plain radiographs of the axial skeleton show the characteristic lytic lesions of multiple myeloma. Bone scans are not helpful, since they show blastic activity.

■

■

Critical tests to evaluate for the presence of multiple myeloma (and to distinguish it from Waldenström’s) include UPEP (to examine for Bence Jones protein) and SPEP (to look for monoclonal immunoglobulin, most commonly IgG, > 3 g/dL). Bone marrow aspirate can enumerate plasma cells (> 10%), and a fullbody skeletal survey can demonstrate punched-out osteolytic lesions of the skull and long bones (see Figure 9-3). LAP levels are normal (lesions are osteolytic, not osteoblastic).

ONCOLOGY

Multiple myeloma. Lateral view of the tibia and fibula shows the typical radiographic appearance of focal lytic lesions resulting from multiple myeloma (arrows). (Reproduced with

FIGURE 9-3.

permission from Lichtman MA et al. Williams Hematology, 7th ed. New York: McGraw-Hill, 2006, Fig. 100-10A.)

TREATMENT ■

■

■

Treatment is aimed at reducing tumor burden, relieving symptoms, and preventing complications. β-microglobulin is a prognostic marker. Chemotherapy involves use of melphalan and steroids +/– thalidomide or bortezomib. Autologous stem cell transplantation is used for patients who are < 60 years of age and in advanced stages of disease. Treatment measures aimed at alleviating symptoms or preventing complications include the following: ■ Hypercalcemia: Treat with hydration, glucocorticoids, and diuresis. ■ Bone pain/destruction/fractures: Treat with bisphosphonates and local radiation. ■ Renal failure: Give hydration to aid in the excretion of light-chain immunoglobulins. ■ Infections: Vaccinate against preventable infections; diagnose early and treat aggressively. ■ Anemia: Administer erythropoietin.

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Breast Cancer A 62-year-old woman presents with a suspicious breast mass. Mammography reveals clusters of microcalcifications and stellate lesions. A biopsy confirms invasive cancer. What is the next step in management? Testing for estrogen and progesterone receptor status and HER2/neu status.

The most common cancer and the second most common cause of cancer death in women in the United States (after lung cancer). Routine annual or biennial mammography is recommended after age 50 (or earlier for high-risk cases and patients with a family history of breast cancer). Routine mammography for those who are 40–50 years of age and are not at high risk is controversial. Risk factors include the following: ■ ■ ■ ■ ■ ■

■ ■ ■

KEY FACT

SYMPTOMS/EXAM ■

Women should be tested for BRCA-1 and BRCA-2 mutations if they have a “genetic” risk—ie, a strong family history of breast and/or ovarian cancer.

Female gender. Older age. Breast cancer in first-degree relatives. A prior history of breast cancer. A history of atypical ductal or lobular hyperplasia or carcinoma in situ. Early menarche, early menopause, or late first full-term pregnancy (before age 35). HRT use for > 5 years. Obesity. Prior radiation (eg, for treatment of Hodgkin’s lymphoma).

■

■

Most masses are discovered by the patient and present as a hard, irregular, immobile, painless breast lump, possibly with nipple discharge. Skin changes (dimpling, erythema, ulceration) and axillary adenopathy indicate more advanced disease. Any breast mass in postmenopausal women is breast cancer until proven otherwise. The most common location is the upper outer quadrant.

DIAGNOSIS ■

■

■

■

The diagnosis is suggested by a palpable mass or by mammographic abnormalities (eg, microcalcifications, hyperdense regions, irregular borders) and is confirmed by biopsy. In clinically suspicious cases involving patients > 35 years of age with any breast lump, a 䊞 mammogram should be followed by ultrasound (to look for cysts vs. solid masses), FNA (for palpable lumps), stereotactic core biopsy (for nonpalpable lesions), or excisional biopsy until convincing evidence has been gathered to support the absence of cancer. In clinically suspicious cases involving patients < 35 years of age and those with dense breasts, the initial workup should also include ultrasound. Be wary of biopsying lesions too early; sometimes the correct course of action is to watch and observe. A mass that fluctuates with menstruation is likely benign in this age group. Biopsied specimens should be tested for prognostic factors such as estrogen/progesterone receptors (ER/PR) and HER2.

ONCOLOGY

■

Special forms of breast cancer include the following: ■ Inflammatory breast cancer: A highly aggressive, rapidly growing cancer that invades the lymphatics and causes skin inflammation (ie, mastitis). Has a poor prognosis. ■ Paget’s disease: Ductal carcinoma in situ (DCIS) of the nipple with unilateral itching, burning, and nipple erosion. May be mistaken for infection; associated with a focus of invasive carcinoma.

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KEY FACT The sensitivity of mammography for breast cancer is 75–80%, so do not stop workup with a 䊞 mammogram in clinically suspicious cases.

TREATMENT ■

■

■

Intraductal carcinoma (DCIS): Warrants only local therapy (either mastectomy or wide excision plus radiation therapy). Lobular carcinoma in situ (LCIS): Associated with a high risk (up to 20%) of developing a subsequent infiltrating breast cancer, including cancer in the contralateral breast. Therapy options include close monitoring, mastectomy, or the use of tamoxifen for prophylaxis. Invasive cancer: The choice of treatment for invasive breast cancer is based on lymph node status, tumor size, and hormone receptor status: ■ Those with node-䊞 disease (stage I) can be treated with breast conservation therapy (wide tumor excision) or modified radical mastectomy with radiation therapy. ■ Adjuvant chemotherapy (two or more agents such as 5-FU, methotrexate, doxorubicin, cyclophosphamide, or epirubicin for 3–6 months) is usually given for tumors > 2 cm or those with axillary lymph node involvement (stages II–III). ■ Endocrine therapy such as tamoxifen, raloxifene, or aromatase inhibitors (anastrozole) is beneficial only for patients with ER-⊕ or PR-⊕ tumors. ■ Trastuzumab (Herceptin) is beneficial for those with HER2-neu-⊕ tumors.

KEY FACT ER/PR-⊕ status is a good prognostic indicator in breast cancer, and such patients should be treated with hormonal therapy.

KEY FACT Breast conservation therapy is generally as effective as modified radical mastectomy in patients with a unifocal tumor size of < 4 cm.

Lung Cancer Once a diagnosis of lung cancer is suspected, which imaging studies can aid in the completion of staging? Chest and abdominal CT with contrast, bone scan, and CT or MRI of the head.

The leading cause of cancer death. The major risk factor is tobacco use. Other risk factors include radon and asbestos exposure. Subtypes are described in Table 9-1. SYMPTOMS/EXAM ■

■

■

In some cases, an asymptomatic lesion is discovered incidentally on either CXR or chest CT (see Figure 9-4). Most patients develop signs that herald a problem—eg, chronic cough, hemoptysis, weight loss, or postobstructive pneumonia. Less frequently, patients may present late with complications of a large tumor burden: ■ Pancoast’s syndrome: Presents with shoulder pain, Horner’s syndrome (miosis, ptosis, anhidrosis), and lower brachial plexopathy.

MNEMONIC The 3 C’s of squamous cell carcinoma of the lung:

Central Cavitary HyperCalcemia

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TA B L E 9 - 1 .

ONCOLOGY

Classification of Lung Cancers

SUBTYPE

CHARACTERISTICS

TREATMENT

Small cell lung cancer

Highly related to cigarette exposure.

(SCLC)

Usually centrally located and always

Chemotherapy is the treatment of choice.

presumed to be disseminated at the time of diagnosis. Non–small cell lung cancer (NSCLC)

Adenocarcinoma: The most common

Potentially curable with resection of localized disease, but only

lung cancer; has a peripheral

modestly responsive to chemotherapy. Patients are classified into

location. More common in women

one of three clinical groups at the time of diagnosis:

than in men.

■

Adenocarcinoma, bronchoalveolar subtype: Associated with multiple

surgical resection. ■

mediastinal lymphadenopathy or chest wall/pleural/pericardial

metastases late in the disease course.

invasion): Treated with combination chemotherapy and radiation;

centrally and is usually cavitary. Large cell carcinoma: Least common.

■

■

FIGURE 9-4.

Locally or regionally advanced disease (supraclavicular or

nodules, bilateral lung infiltrates, and Squamous cell carcinoma: Presents

A

Stages I and II: Early-stage disease. Represents candidacy for

surgery is not indicated. ■

Distant metastases: The goal of any chemotherapy or radiation is palliation only.

Superior vena cava syndrome: Characterized by swelling of the face and arm, most often on the right side, and elevated JVP. Treated with radiation therapy. Hoarseness: Vocal cord paralysis from entrapment of the recurrent laryngeal nerve, most often on the left.

B Lung cancer. Lung cancer (arrows) on (A) frontal CXR and (B) transaxial CT. (Reproduced with permission from USMLERx.com.)

ONCOLOGY

■

■ ■

Hypercalcemia: Most often seen with squamous cell carcinoma. Treat with bisphosphonates. Hyponatremia/SIADH: Small cell carcinoma. Lambert-Eaton syndrome: Similar to myasthenia gravis, except that muscle fatigue improves with repeated stimulation (vs. myasthenia gravis, in which such measures yield no improvement).

DIFFERENTIAL ■

■

Other common causes of lung masses include TB/other granulomatous diseases, fungal disease (aspergillosis, histoplasmosis), lung abscess, metastasis, benign tumors (bronchial adenoma), and hamartoma. Serial CXRs are useful for distinguishing benign lesions from malignant ones. Lesions that remain stable over > 2 years are generally not cancerous. Other features suggestive of benign lesions include young age, smooth margins, small size (< 2 cm), and the presence of satellite lesions. However, any lung nodule in a smoker or an ex-smoker should be evaluated for the presence of cancer.

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MNEMONIC Paraneoplastic syndromes—

CLASH Carcinoid Lambert-Eaton syndrome ACTH SIADH Hypercalcemia

DIAGNOSIS ■

■

■

■

If there is a palpable lymph node (axillary, supraclavicular), consider biopsy of the node first. If not, order a CXR initially, and in doubtful/suspicious cases, obtain a chest CT and, if needed, bronchoscopy. If mediastinal lymph nodes are enlarged, consider a PET scan and mediastinoscopy for proper staging. Centrally located cancers can be diagnosed by bronchoscopy or sputum cytology. Staging includes chest and abdominal CT with contrast, bone scan, and CT or MRI of the head.

KEY FACT All supraclavicular lymph nodes should be biopsied.

TREATMENT

See Table 9-1.

GI Tumors P A N C R E A T I C CA N CE R

A 60-year-old woman presents with painless obstructive jaundice and weight loss. What is the most likely location of the obstructing mass? The pancreatic head.

Typically seen in patients > 50 years of age. Ductal adenocarcinoma accounts for 90% of 1° tumors; > 50% arise in the head of the pancreas. Risk factors include smoking, chronic pancreatitis, and diabetes mellitus (DM). Trousseau’s syndrome, a hypercoagulable state seen with adenocarcinoma, was first described in association with pancreatic cancer. KEY FACT SYMPTOMS/EXAM

Common symptoms include nausea, anorexia, lumbar back pain, new-onset DM, venous thromboembolism, and painless obstructive jaundice (associated with adenocarcinoma in the head of the pancreas).

Painless jaundice and/or a palpable gallbladder—think pancreatic cancer.

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RK

LK

Pancreatic adenocarcinoma. Transaxial contrast-enhanced CT shows a mass in the head of the pancreas (arrowheads) and multiple liver metastases (arrows). RK = right kidney; LK = left kidney. (Reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill,

FIGURE 9-5.

2004, Fig. 11-72.)

DIAGNOSIS ■

■

■

Characterized by ↑ bilirubin, ↑ aminotransferases, and normocytic normochromic anemia. Ultrasound is useful as an initial diagnostic test. Abdominal/pelvic CT can evaluate the extent of disease; a thin-section helical CT through the pancreas (see Figure 9-5) can determine if the mass is resectable. Endoscopic ultrasonography yields excellent anatomic detail and can help confirm if the tumor is resectable.

TREATMENT ■

■

Pancreaticoduodenectomy (Whipple procedure) is appropriate for patients with resectable tumors. Chemotherapy or radiation is used for palliative care in patients with advanced or unresectable disease. HE P ATOC E LLU LAR C ANC E R ( HE P ATOM A)

Risk factors for hepatocellular cancer (HCC) include viral hepatitis (HBV, HCV), alcoholic cirrhosis, aflatoxin, hemochromatosis, and α1-antitrypsin deficiency. OCPs are associated with benign hepatic adenoma (vs. HCC). KEY FACT SYMPTOMS/EXAM 2° liver tumors (metastases) are more common than 1° liver tumors.

Presents with abdominal discomfort together with laboratory abnormalities (↑ aminotransferases, ↑ bilirubin, coagulopathy) that warrant abdominal imaging (see Figure 9-6). TREATMENT ■ ■

Surgical resection and liver transplantation can yield long-term survival. Alternatives for unresectable tumors include percutaneous alcohol injections, arterial chemoembolization, radiofrequency ablation, and chemotherapeutic agents such as sorafenib.

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S

St

Hepatocellular carcinoma. Coronal reformation from a contrast-enhanced CT shows a large HCC in the left hepatic lobe (arrows). St = stomach; S = spleen. (Reproduced

FIGURE 9-6.

with permission from USMLERx.com.)

COLORECTAL CANCER

A 60-year-old man with a known diagnosis of colon cancer in remission is found to have a CEA level that is ↑ from baseline. What does this indicate? Cancer recurrence.

Most cases occur after age 50. Suspect hereditary nonpolyposis colorectal cancer (HNPCC) in a younger person with colon cancer and a family history of colon, ovarian, and endometrial cancer. Table 9-2 discusses risk factors. Screen all asymptomatic individuals > 50 years of age with annual fecal occult blood testing (FOBT) and flexible sigmoidoscopy every 5 years, or with colonoscopy every 10 years. SYMPTOMS/EXAM

Symptoms depend on the site of the 1° tumor and may include a change in bowel habits, melena, bright red blood per rectum, weight loss, fatigue, vomiting, and abdominal discomfort.

KEY FACT If there is a family history of polyps or colorectal cancer, start screening when the patient is 10 years younger than the age of the affected relative at the time of diagnosis.

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ONCOLOGY

TA B L E 9 - 2 .

Risk Factors for Colorectal Cancer

FAMILY HISTORY

PATIENT AGE > 50 years

PERSONAL HISTORY Previous colorectal cancer

Colon cancer.

Colonoscopy reveals an adenocarcinoma growing into the lumen of the colon.

HEREDITARY COLORECTAL

ADENOMATOUS POLYPS

CANCER SYNDROMES

One first-degree relative < 60 years

Familial adenomatous polyposis (FAP)

Adenomatous polyps

of age or two first-

HNPCC

IBD, particularly

degree relatives of

Hamartomatous

ulcerative colitis

FIGURE 9-7.

COLORECTAL CANCER OR

any age

polyposis syndromes

DIAGNOSIS ■

(Reproduced with permission from Fauci AS et al. Har-

■

rison’s Principles of Internal Medicine, 17th ed. New

■

York: McGraw-Hill, 2008, Fig. 285-6.)

Diagnosed by a mass palpated by DRE or detected by FOBT. Iron-deficiency anemia or ↑ transaminases may be seen. Confirm the diagnosis via colonoscopy and biopsy in suspected cases (see Figure 9-7).

TREATMENT MNEMONIC

■

Esophageal cancer risk factors— ■

ABCDEF Achalasia Barrett’s esophagus Corrosive esophagitis Diverticulitis Esophageal web Familial

■

Treatment decisions are influenced by tumor stage at diagnosis. 1° surgical resection involves resection of the bowel segment with adjacent mesentery and regional lymph nodes. Solitary liver/lung metastases can be resected. Stage I patients have an excellent prognosis with surgery alone (90% survival at five years). Adjuvant chemotherapy (5-FU based) is warranted for patients at stage III and above. MI S C E LLANE OU S G I TU M OR S

A 65-year-old man with a history of GERD presents with a 10-lb weight loss, dysphagia, and epigastric pain. What will biopsy results from EGD most likely reveal? Esophageal adenocarcinoma.

Esophageal Tumors ■

■ ■

FIGURE 9-8.

Esophageal cancer. An

esophageal adenocarcinoma (arrowhead) is seen on endoscopy against a background of the pink tongues of Barrett’s esophagus (arrows). (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-3D.)

Sx/Exam: The classic symptom is dysphagia in the elderly, especially in smokers and alcoholics; tumors are usually squamous in nature. Esophageal adenocarcinoma can arise from long-standing esophageal reflux with Barrett’s disease. Dx: Confirm the diagnosis by EGD with biopsy (see Figure 9-8). Tx: Treatment involves resection for localized disease and radiation therapy with chemotherapy for advanced disease.

Gastric Tumors ■ ■

More common among those of Asian ethnicity. Sx/Exam: Classically presents as iron-deficiency anemia with vague abdominal pain in the elderly.

ONCOLOGY

■ ■

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157

Dx: Confirm the diagnosis via EGD with biopsy (see Figure 9-9). Tx: Treatment involves resection for localized disease and radiation therapy with chemotherapy for advanced disease.

Carcinoid Tumors ■ ■

■ ■

Usually occur in the appendix or small bowel. Sx/Exam: Clinical features include flushing, abdominal pain, diarrhea, and tricuspid regurgitation (carcinoid syndrome). Dx: Diagnosed by elevated levels of 5-HIAA or chromogranin A. Tx: Surgical resection is curative in localized disease. Consider octreotide for symptomatic control.

Islet Cell Tumors ■

■

■

Sx/Exam: Presentation depends on tumor type. ■ Insulinoma (elevated proinsulin, C-peptide, and insulin levels): Should be suspected with a triad consisting of hypoglycemic symptoms, a fasting blood glucose level of < 40 mg/dL, and immediate relief with glucose administration. ■ VIPoma (elevated VIP levels): Suspect in the setting of profuse watery diarrhea that causes hypokalemia. ■ Glucagonoma (elevated glucagon levels): Characterized by persistent hyperglycemia with necrolytic erythema (intertriginous and perioral rash). Dx: Islet cell tumors and their metastases (liver is most common) can be localized by somatostatin receptor scintigraphy. Tx: Options vary according to tumor type. Treatment includes surgical resection, debulking, chemotherapy, and somatostatin analogs with glucagonomas and VIPomas.

Genitourinary Tumors B L A D D E R CA N CE R

A 60-year-old man with a 35-pack-year smoking history presents with pink-colored urine. UA reveals macrohematuria. CT urogram reveals no abnormalities of the kidneys or ureters. What is the diagnostic test of choice? Cystoscopy with possible biopsy.

The most common malignant tumor of the urinary tract; usually transitional cell carcinoma. Risk factors include smoking, exposure to aniline (rubber) dyes, and chronic bladder infections (eg, schistosomiasis). SYMPTOMS/EXAM

Gross hematuria is the most common presenting symptom. Other urinary symptoms, such as frequency, urgency, and dysuria, may also be seen.

FIGURE 9-9. Gastric cancer. A malignant gastric ulcer (arrowhead) involving the greater curvature of the stomach is seen on endoscopy. (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 285-2B.)

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DIAGNOSIS ■

■

■

UA is the most basic diagnostic modality and often shows hematuria (macro- or microscopic). Lack of dysmorphic RBCs helps distinguish this from glomerular bleeding. Cytology may show dysplastic cells (a firstmorning specimen is best). CT urography or IVP can examine the upper urinary tract as well as defects in bladder filling. Cystoscopy with biopsy is diagnostic.

TREATMENT

Treatment depends on the extent of spread beyond the bladder mucosa. ■ ■

■

Carcinoma in situ: Intravesicular chemotherapy. Invasive cancers without metastases: Aggressive surgery, radiation therapy, or both. Distant metastases: Chemotherapy alone. PR OS TATE C ANC E R

KEY FACT Incidental asymptomatic prostate cancer is especially common among men > 80 years of age and does not always need treatment.

The most common cancer in men. Ninety-five percent are adenocarcinomas. Risk ↑ linearly with age. SYMPTOMS/EXAM ■

■

■

Many patients are asymptomatic and are incidentally diagnosed either by DRE or by a PSA level that is obtained for screening purposes. If symptomatic, patients may present with urinary urgency/frequency/hesitancy and, in late or aggressive disease, with anemia, hematuria, or low back pain. Screening with DRE or PSA should be done in patients > 50 years of age with > 10 years of life expectancy; it is not routinely recommended in patients > 75 years of age.

DIAGNOSIS ■

■

Ultrasound-guided needle biopsy of the prostate allows for both diagnosis and staging. The Gleason score (2–10) remains the best predictor of tumor biology. It sums the scores of the two most dysplastic biopsy samples on a scale of 1–5 (well differentiated to poorly differentiated).

TREATMENT ■

■

■

■

Treatment choice is based on the aggressiveness of the tumor and on the patient’s risk of dying from the disease. Watchful waiting may be the best approach for elderly patients with low Gleason scores. Consider radical prostatectomy or radiation therapy (eg, brachytherapy or external beam) for node-䊞 disease. Treatment is associated with an ↑ risk of incontinence and/or impotence. Treat node-⊕ and metastatic disease with androgen ablation (eg, GnRH agonists, orchiectomy, flutamide) +/– chemotherapy. TE S TI C U LAR C ANC E R

The most common solid malignant tumor in men 20–35 years of age. It is highly treatable and often curable. Risk factors include cryptorchid testis and Klinefelter’s syndrome. Ninety-five percent are germ cell tumors.

ONCOLOGY

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T

FIGURE 9-10. Seminoma. Longitudinal ultrasound image of testicle (T) shows a homogeneous intratesticular mass (arrow) and an additional smaller focus of tumor (arrowhead). (Reproduced with permission from USMLERx.com.)

SYMPTOMS/EXAM ■ ■

A unilateral scrotal mass is testicular cancer until proven otherwise. Other presentations include testicular discomfort or swelling suggestive of orchitis or epididymitis.

DIAGNOSIS ■

■

■ ■

Serum levels of α-fetoprotein (AFP), LDH, and β-hCG should be measured. Scrotal ultrasound is also a useful means of differentiating cancer from nonneoplastic lesions (eg, hydrocele, spermatocele, infection) (see Figure 9-10). Definitive diagnosis is made by radical inguinal orchiectomy. Staging evaluation (TNM is widely used) should include serum LDH, AFP, β-hCG, and CT of the chest/abdomen and pelvis.

TREATMENT

Radical inguinal orchiectomy +/– chemotherapy/radiation therapy is the treatment of choice. R EN A L CE LL CA R C IN O M A

The most common cause of kidney cancer in adults. The cause is unknown, but risk factors include cigarette smoking, von Hippel–Lindau disease, tuberous sclerosis, and cystic kidney disease. SYMPTOMS/EXAM ■

■

Generally asymptomatic in the early stages, but symptoms can include hematuria, flank pain, a palpable mass, fevers, night sweats, anemia, or symptoms of disseminated disease such as dyspnea and bone pain. Paraneoplastic effects such as erythrocytosis, hypercalcemia, and hypertension may be seen.

KEY FACT Do not do a scrotal biopsy to diagnose testicular cancer, as this may result in seeding of the biopsy tract.

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DIAGNOSIS KEY FACT Do not do a biopsy to diagnose renal cell carcinoma unless disseminated disease or another 1° tumor is suspected. Risks include false negatives, bleeding, and tumor seeding.

CT with contrast is the modality of choice for diagnosis and operative planning. TREATMENT ■

■

Local disease: Partial vs. radical nephrectomy vs. cryoablation/radiofrequency ablation. Disseminated disease: Medical therapy with chemotherapeutic agents (eg, sorafenib, sunitinib) or biologic response modifiers (eg, IL-2, IFN-α) +/– nephrectomy. OVAR I AN C ANC E R

More than 90% are adenocarcinomas. Risk factors include age, use of infertility drugs, and familial cancer syndromes (eg, BRCA-1, BRCA-2). Risk is ↓ with sustained use of OCPs, having children, breast-feeding, bilateral tubal ligation, and TAH-BSO. SYMPTOMS/EXAM ■ ■

■

Usually asymptomatic until the disease has reached an advanced stage. Patients may have abdominal pain, bloating, pelvic pressure, urinary frequency, early satiety, constipation, vaginal bleeding, and systemic symptoms (fatigue, malaise, weight loss). Exam findings may include a palpable solid, fixed, nodular pelvic mass; ascites; and pleural effusion (Meigs’ syndrome). An ovarian mass in postmenopausal women is ovarian cancer until proven otherwise.

DIAGNOSIS/TREATMENT ■

■

Evaluate adnexal masses with pelvic ultrasound and possibly CT or MRI; obtain serum CA-125 and a CXR. Staging is surgical and includes TAH-BSO, omentectomy, and tumor debulking. CE R VI C AL C ANC E R

A 25-year-old woman is noted to have dysplastic cells on a routine screening Pap smear. What test is required to confirm a diagnosis of cervical cancer? Colposcopy and biopsy.

KEY FACT Infection with HPV types 16, 18, and 31 ↑ the risk of cervical cancer. An HPV vaccine has been approved for the prevention of cervical cancer.

Despite the screening Pap smear, cervical cancer remains the third most common gynecologic malignancy. Risk factors include HPV infection, tobacco use, early onset of sexual activity, multiple sexual partners, immune compromise (eg, HIV), and STDs. An HPV vaccine has recently been approved by the FDA for the prevention of cervical cancer. SYMPTOMS/EXAM ■ ■

Patients are usually asymptomatic and are diagnosed on routine Pap smear. If symptomatic, patients may present with menorrhagia and/or metrorrhagia, postcoital bleeding, pelvic pain, and vaginal discharge.

ONCOLOGY

DIAGNOSIS

Colposcopy and biopsy in patients with an abnormal Pap smear or visible cervical lesions. Cancers are categorized as invasive cervical carcinoma (depth > 3 mm, width > 7 mm) or cervical intraepithelial neoplasia (CIN).

■

■

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KEY FACT In suspicious cases, the Pap smear should be followed by colposcopy and biopsy.

TREATMENT

CIN I (mild dysplasia or low-grade squamous intraepithelial lesion [LGSIL]): Most regress spontaneously. Reliable patients can be observed with Pap smears and colposcopy every three months for one year. CIN II/III: Treat with cryosurgery, laser surgery, or LEEP. Invasive cancer: Early-stage disease can be treated with radical hysterectomy and lymph node dissection. Advanced disease requires radiation and chemotherapy.

■

■ ■

Skin Tumors The differences in appearance of the three most common dermatologic malignancies are depicted in Figures 9-11 and 9-12. ME L A N O M A

A patient presents for evaluation of a pigmented skin lesion. Biopsy reveals melanocytes with marked atypia characteristic of melanoma. What feature is the most important prognostic factor? Depth of invasion of the melanoma.

An aggressive malignancy of melanocytes and the leading cause of death from skin disease. Risk factors include sun exposure, fair skin, a family history, a large number of nevi, and the presence of dysplastic nevi.

A

FIGURE 9-11. Melanoma. Lesion illustrating the ABCDs of melanomas: asymmetry, border irregularity, color variegation, and a diameter greater than 6 mm. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 124-1A.)

B

Basal cell and squamous cell carcinomas. (A) Basal cell carcinoma showing a characteristic “pearly” appearance. (B) Undifferentiated squamous cell carcinoma consisting of a circular, dome-shaped, reddish nodule with a partly eroded surface. (Image A repro-

FIGURE 9-12.

duced with permission from USMLERx.com. Image B reproduced with permission from Wolff K, Johnson RA. Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, 6th ed. New York: McGraw-Hill, 2009, Fig. 11-9.)

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MNEMONIC

ONCOLOGY

SYMPTOMS/EXAM ■

The ABCDEs of melanoma:

Asymmetric shape Borders irregular Color variegated Diameter > 6 mm Enlargement of any lesion

■

A pigmented skin lesion that has recently changed in size or appearance should raise concern. Lesions are characterized by the ABCDEs of melanoma (see mnemonic) and may occur anywhere on the body. They are most commonly found on the trunk for men and on the legs for women.

DIAGNOSIS

Skin biopsy shows melanocytes with marked cellular atypia and melanocytic invasion into the dermis. TREATMENT ■

■

Surgical excision is the treatment of choice. The thickness of the melanoma (depth of invasion) is the most important prognostic factor. Depending on depth, lymph node dissection may be necessary. Systemic chemotherapy is used for metastatic disease. BAS AL C E LL C AR C I NOM A

The most common skin cancer; associated with excessive sun exposure. SYMPTOMS/EXAM ■

■

Exam reveals a pearl-colored papule of variable size. The external surface is frequently covered with fine telangiectasias and appears translucent. Lesions may be located anywhere on the body but are most commonly found on sun-exposed areas, particularly the face. Large ulcers are described as “rodent ulcers.”

DIAGNOSIS

Skin biopsy shows characteristic basophilic palisading cells with retraction. TREATMENT ■

■

Therapy depends on the size and location of the tumor, the histologic type, the history of prior treatment, the underlying health of the patient, and cosmetic considerations. Options include curettage, surgical excision, cryosurgery, and radiation. S QU AM OU S C E LL C AR C I NOM A

Risk factors include exposure to the sun or to ionizing radiation, prior actinic keratosis, immunosuppression, arsenic exposure, and exposure to industrial carcinogens. SYMPTOMS/EXAM ■

■

Lesions are usually slowly evolving and asymptomatic; occasionally, bleeding or pain may develop. Exam reveals small, red, exophytic nodules with varying degrees of scaling or crusting. Lesions are commonly found in sun-exposed areas, particularly the lower lip.

DIAGNOSIS

Biopsy shows irregular masses of anaplastic epidermal cells proliferating down to the dermis.

ONCOLOGY

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TREATMENT ■

■

■

Surgical excision is necessary for larger lesions and for those involving the periorbital, periauricular, perilabial, genital, and perigenital areas. Mohs’ micrographic surgery may be performed for recurrent lesions and on areas of the face that are difficult to reconstruct. Radiation may be necessary in cases in which surgery is not a viable option.

CNS Tumors 1° brain tumors make up < 2% of all tumors diagnosed. Meningioma, glioma, vestibular schwannoma, pituitary adenoma, and 1° CNS lymphoma are the most common CNS tumors in adults and can occur in association with AIDS. ME N I N G IO M A

A 60-year-old woman is involved in a motor vehicle accident in which she sustains head trauma. Aside from some minor bruising of the forehead, her physical exam is unrevealing and includes a nonfocal neurologic exam. Routine imaging reveals a 9-mm calcified lesion. What is the most likely diagnosis? Benign meningioma.

■ ■

■

The most common tumor of the brain; usually benign. Sx/Exam: Most tumors are small, asymptomatic, and discovered incidentally. When symptoms are present, they usually consist of progressive headache or a focal neurologic deficit reflecting the location of the tumor. Dx: CT or MRI of the head typically demonstrates a partially calcified, homogeneously enhancing extra-axial mass adherent to the dura (see Figure 9-13). Craniopharyngioma is another highly calcified tumor in

FIGURE 9-13. Meningioma. Coronal postcontrast T1-weighted MRI demonstrates an enhancing extra-axial mass arising from the falx cerebri (arrows). (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 374-5.)

KEY FACT MRI is superior to CT for viewing skullbase/cerebellar lesions but is less reliable for detecting calcifications.

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ONCOLOGY

■

children but is present around the pineal gland and can cause bitemporal hemianopia. Tx: Surgical resection is appropriate for large or symptomatic tumors; observation with serial scans is the preferred approach for small or asymptomatic lesions. G LI AL TU M OR S

■ ■

FIGURE 9-14. Glioblastoma multiforme. Transaxial contrast-enhanced im-

age shows an enhancing intra-axial mass with central necrosis crossing the corpus callosum (“butterfly glioma”). (Reproduced

■ ■

with permission from USMLERx.com.)

Include astrocytomas, oligodendrogliomas, mixed gliomas, and ependymomas. Sx/Exam: ■ Headache is the most common symptom and may be generalized or unilateral; often awakens the patient from sleep and induces vomiting; and worsens with the Valsalva maneuver. ■ Tumors appear as a diffusely infiltrating area of low attenuation on CT or an ↑ T2 signal on MRI. ■ Glioblastoma multiforme is usually a unifocal and centrally necrotic enhancing lesion with surrounding edema and mass effect (see Figure 9-14). Dx: Biopsy is required for definitive diagnosis. Tx: Surgical resection followed by external beam radiation is used for high-grade tumors. Chemotherapy is reserved for high-grade gliomas.

Tumor Markers Usually sensitive but not specific. Thus, they are most useful for monitoring of recurrence and disease activity following resection. However, tumor markers can also be useful in diagnosis if they are supported by clinical evidence. Common tumor markers and associated malignancies include the following: MNEMONIC

■ ■

Common tumor markers:

CEA = Colon cancer hCG = Choriocarcinoma PSA= ProState LDH = LympHoma

■ ■ ■ ■ ■ ■ ■ ■

CA 125: Ovarian cancer. CA 15-3: Breast cancer. CA 19-9: Pancreatic cancer. CEA: GI cancer, particularly of the colon. AFP: Liver, yolk sac (testicular) cancer. hCG: Choriocarcinoma (testicular/ovarian). PSA: Prostate cancer. LDH: Lymphoma. Calcitonin: Medullary thyroid carcinoma. Chromogranin A: Carcinoid tumor.

CHAPTER 10

INFECTIOUS DISEASE Soft Tissue Infections

166

Genitourinary Tract Infections

181

CELLULITIS

166

CYSTITIS

181

NECROTIZING FASCIITIS

166

PYELONEPHRITIS

181

Periorbital/Orbital Infections

167

PROSTATITIS

181

Acute Osteomyelitis

167

Septic Arthritis

168

Diverticulitis Encephalitis

182

SYPHILIS

182

GENITAL HERPES

183

169

CERVICITIS/URETHRITIS

183

170

PELVIC INFLAMMATORY DISEASE

184

HERPES SIMPLEX VIRUS ENCEPHALITIS

170

WEST NILE ENCEPHALITIS

170

Bacterial Meningitis

Sexually Transmitted Diseases

HIV Infection

184

Travel Medicine

186

170

MALARIA PROPHYLAXIS

186 186

187

172

TRAVELER’S DIARRHEA

ACUTE SINUSITIS

172

Tick-Borne Diseases

CHRONIC SINUSITIS

172

LYME DISEASE

OTITIS MEDIA

173

EHRLICHIOSIS

188

OTITIS EXTERNA

173

BABESIOSIS

188

PHARYNGITIS

173

Upper Respiratory Tract Infections

Pneumonia

174

COMMUNITY-ACQUIRED PNEUMONIA

174

VENTILATOR-ASSOCIATED PNEUMONIA

176

PNEUMOCYSTIS JIROVECI PNEUMONIA

176

Bronchitis

177

Tuberculosis

177

187

Neutropenic Fever

189

Sepsis

189

Fungal Infections

191

CRYPTOCOCCOSIS

191

HISTOPLASMOSIS

191

COCCIDIOIDOMYCOSIS

192

Antimicrobial Selection

192

165

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Soft Tissue Infections Soft tissue infections are infections of the dermis, subcutaneous fat, and/or fascia. Patients with diabetes, HIV or other immunosuppressed states, peripheral vascular disease, and edema are at ↑ risk. CE L LU LI TI S

Infection of the dermis that may be associated with an identifiable portal of entry—eg, cuts, tinea pedis, animal/insect bites, ulcers, or injection sites. SYMPTOMS/EXAM ■

■

Presents with warm, erythematous, and tender skin. The erythema usually has well-demarcated borders. Patients may also present with fever, chills, regional lymphadenopathy, or lymphangitis (seen as red streaks).

DIFFERENTIAL

Stasis dermatitis, necrotizing fasciitis, allergic reactions. DIAGNOSIS ■ ■

■

Primarily a clinical diagnosis. Consider getting blood cultures, CBC, ESR, and radiographs if there is a possibility of deeper infection such as necrotizing fasciitis or osteomyelitis. Lower extremity cellulitis can also be associated with DVT. If clinically indicated, ultrasound may be useful for evaluation.

TREATMENT ■

■

Demarcate borders and select the antimicrobial and route on the basis of patient risk factors and clinical severity. For most patients, a first-generation cephalosporin or a second-generation penicillin is appropriate, but consider pseudomonal coverage in diabetics, and weigh the possibility of methicillin-resistant S aureus (MRSA). NE C R OTI ZI NG F AS C I I TI S

Rapidly spreading infection of the subcutaneous fat and fascia, with risk factors including diabetes, other immunosuppressed states, IV drug use, and peripheral vascular disease. SYMPTOMS/EXAM ■

■

Presents with erythematous, warm, tender, and edematous skin that may rapidly progress to dark, indurated skin with bullae. Patients are typically more toxic appearing than those with simple cellulitis. Assess for compartment syndrome by checking for distal symptoms and signs, including Pulselessness, Pain, Pallor, Paresthesias, Poikilothermia, and Paralysis (the 6 P’s).

DIFFERENTIAL

Cellulitis, myonecrosis.

INFECTIOUS DISEASE

CHAPTER 10

DIAGNOSIS

Clinical diagnosis can be difficult. Obtain radiographs and a CT or an MRI to look for gas and soft tissue involvement. TREATMENT ■

■

A penicillin is best for group A strep coverage, with clindamycin used to shut down toxin production. Vancomycin can be added for MRSA coverage. If mixed infection is possible, a broad-spectrum penicillin with anaerobic coverage (piperacillin/tazobactam) should be used. Obtain a surgery consult for debridement and fasciotomy.

COMPLICATIONS

If it is not treated early, the condition may rapidly progress to compartment syndrome, shock, multiorgan failure, and death.

Periorbital/Orbital Infections ■

■

■ ■

Differentiating between periorbital and orbital infection is critical. A periorbital infection can be treated as a simple cellulitis. However, an orbital infection may require surgical intervention to prevent blindness, meningitis, and cavernous sinus thrombosis. Sx/Exam: Patients with orbital cellulitis can present with oculomotor dysfunction, proptosis, chemosis, ↓ visual acuity, and significant lid erythema. Dx: Obtain a CT, blood cultures, and a CBC. Tx: Start broad-spectrum IV antimicrobials and request a surgical consult.

Acute Osteomyelitis A 23-year-old woman is diagnosed with osteomyelitis. She is an IV heroin user and has a past medical history that is significant for sickle cell anemia. While you are awaiting culture results, she needs to begin empiric antibiotic treatment. In addition to S aureus, what other organisms is this patient at risk for? Her IV drug use puts her at risk for Pseudomonas infection, and her sickle cell anemia puts her at risk for Salmonella.

Infection of the bone that is spread hematogenously or, more commonly, by direct inoculation. Those with peripheral vascular disease, diabetes, and recent orthopedic surgery are at ↑ risk. SYMPTOMS/EXAM

Presents with pain with overlying erythema, edema, and tenderness. Patients may also have an overlying ulcer or skin interruption. Systemic symptoms include fevers, chills, and fatigue. DIFFERENTIAL

Cellulitis, necrotizing fasciitis.

KEY FACT If necrotizing fasciitis is suspected, prompt medical and surgical management is imperative.

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168

A

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INFECTIOUS DISEASE

B

C

Acute osteomyelitis. (A) Radiograph of the right foot first metatarsal following puncture injury, with no foreign body and no evidence of osteomyelitis. (B) Follow-up radiograph reveals interval development of focal lucency (red arrow) and periosteal reaction (red arrowheads) consistent with acute osteomyelitis. (C) Planar image from a bone scan obtained at the same time as Image B shows increased radiotracer uptake in the region of the first metatarsal of the right foot (red arrow), confirming osteomyelitis. (Reproduced with permission from Skinner

FIGURE 10-1.

HB. Current Diagnosis & Treatment in Orthopedics, 4th ed. New York: McGraw-Hill, 2006, Fig. 8-8A, C, and D.)

DIAGNOSIS ■

■

Obtain blood cultures and a radiograph of the suspected area. If imaging is 䊞 but there is a high index of suspicion, order an MRI or a bone scan (see Figure 10-1). Consider obtaining an ESR and a CRP, both of which should be elevated. A bone biopsy with culture is the definitive means of diagnosis.

TREATMENT ■

■

■

Unless the patient is septic, delay antimicrobial therapy until a microbiologic specimen has been obtained through surgical debridement. Then start with broad coverage of the likely organisms and narrow coverage once the organism has been identified. Treatment duration is 4–6 weeks of directed antimicrobial therapy. The most common organism is S aureus. Consider Salmonella if the patient has sickle cell anemia, and consider Pseudomonas in the setting of IV drug use. Axial skeleton osteomyelitis can resolve with antimicrobials alone, but all other cases will need surgical debridement for cure.

COMPLICATIONS

Amputation, sepsis, and death.

Septic Arthritis Infection of a joint, with risk factors including recent instrumentation of a joint (injection, arthroscopy, arthroplasty), joint damage (osteoarthritis, trauma, RA), gonococcal infection, and bacteremia.

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SYMPTOMS/EXAM

Presents as an erythematous, warm, swollen, and painful joint with ↓ range of motion. Gonococcal septic arthritis may present with multiple infected joints. Systemic symptoms include fever and chills. DIFFERENTIAL

Trauma, hemarthrosis, osteoarthritis, crystalline arthropathy, RA. DIAGNOSIS ■

■

Arthrocentesis with Gram stain, culture, cell count/differential, and crystal analysis. Blood cultures.

TREATMENT ■

■

Unless the patient is septic, delay antimicrobial therapy until a microbiologic specimen has been obtained through aspiration or surgical debridement, and then start with broad coverage of the likely organisms. Coverage should be narrowed once the organism has been identified. Surgical management with washout and 4–6 weeks of directed antimicrobials is necessary for appropriate management.

COMPLICATIONS

L

S

GB

Joint destruction, sepsis, and death.

Diverticulitis Inflammation and microperforation of the diverticula. UB

SYMPTOMS/EXAM

Presents with fever, chills, nausea, vomiting, and abdominal pain, classically in the LLQ. Occasionally there may be a palpable mass in the LLQ. DIFFERENTIAL

Ulcerative colitis, Crohn’s disease, perforating colon cancer. DIAGNOSIS

A clinical diagnosis that is nonetheless often made with CT scan (see Figure 10-2). Do not scope patients, since they are at high risk for perforation. Obtain a CBC and blood cultures. TREATMENT

Bowel rest and antimicrobial coverage of gram-䊞 and anaerobic organisms (eg, ciprofloxacin and metronidazole). If a diverticular abscess is present, manage surgically with a drain or resection. COMPLICATIONS

Abscess, obstruction, sepsis, death.

FIGURE 10-2.

Acute diverticulitis.

Coronal reconstruction from a contrastenhanced CT demonstrates sigmoid diverticula with perisigmoid inflammatory “fat stranding.” The area of abnormality is circled in red. (L = liver; S = stomach; GB = gallbladder; UB = urinary bladder.) (Reproduced with permission from USMLERx.com.)

KEY FACT If diverticulitis is suspected, do not perform lower endoscopy until the acute process resolves, as patients are at high risk for perforation.

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Encephalitis Usually involves the brain parenchyma. HSV is the leading cause. Patients may have nonspecific complaints that are initially consistent with a viral prodrome (eg, fever, malaise, body aches) and may then go on to develop confusion, seizures, and focal neurologic deficits (eg, weakness, cranial nerve/ sensory deficits). Headaches, photophobia, and meningeal signs can be seen in meningoencephalitis. HE R P E S S I M P LE X VI R U S ( HS V) E NC E P HALI TI S ■ ■

■

■

The majority of cases are due to HSV-1 reactivation. Sx/Exam: Think of HSV encephalitis when patients present with bizarre behavior, speech disorders, gustatory or olfactory hallucinations, or acute hearing impairment. Dx: Key CSF studies include HSV polymerase chain reaction (PCR) tests and HSV culture. MRI will show a characteristic pattern in the temporal lobes, usually bilaterally. Tx: Treat empirically with IV acyclovir. WE S T NI LE E NC E P HALI TI S

■

■

■

■

Suspect in anyone presenting with an acute febrile illness in late spring, summer, or early autumn. Sx/Exam: Patients have fever +/– a maculopapular rash. Look for acute flaccid paralysis suggestive of Guillain-Barré syndrome. Dx: CSF findings resemble those of viral meningitis. Test serum or CSF by ELISA for IgM antibody to West Nile virus or a rise in IgG titer. Tx: Treatment is supportive (eg, fluids).

Bacterial Meningitis A 33-year-old man with HIV/AIDS and a CD4 count of 20 is admitted to the ER with a 12-hour history of fever, photophobia, and headache. A major trauma has just arrived in the ER, so his LP will be delayed by two hours. What medications should the patient be given before the LP is performed? Vancomycin, ampicillin, cefepime, and dexamethasone. Given that the patient’s immunocompromised status and clinical presentation raise concern for bacterial meningitis, he should be covered for both gram-䊝 and gram-䊞 organisms. Additionally, he should be given a dose of dexamethasone 10 minutes before his first dose of antibiotics. This may be discontinued if the Gram stain is not consistent with Streptococcus pneumoniae.

Common causative organisms vary with age group (see Table 10-1).

INFECTIOUS DISEASE

TA B L E 10 - 1 .

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171

Common Causes of Bacterial Meningitis by Age

PREDISPOSING FACTORS

TYPICAL BACTERIAL PATHOGEN

Neonates (0–4 weeks)

Group B strep, E coli, Listeria.

Infants (1–23 months)

Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae.

Age 2–50 years

S pneumoniae, N meningitidis.

Elderly (> 50 years)

S pneumoniae, N meningitidis, Listeria monocytogenes.

SYMPTOMS/EXAM ■

■ ■

Typical symptoms include fever, malaise, headaches, photophobia, and neck stiffness. Patients may also complain of nausea and vomiting. Be sure to look for fever, nuchal rigidity, and Kernig’s or Brudzinski’s sign. Funduscopic exam may reveal papilledema, indicating ↑ ICP.

DIAGNOSIS

Obtain an LP in any patient suspected of having meningitis. When clinical features suggest a possible intracranial mass or ↑ ICP, obtain a head CT prior to LP. See Table 10-2 for common CSF findings in meningitis. KEY FACT TREATMENT ■

■

Begin empiric therapy immediately in anyone suspected of having bacterial meningitis, as even a short delay will ↑ mortality. Consider the patient’s risk factors, and then choose an antimicrobial regimen that will cover the most likely organisms (see Table 10-3).

TA B L E 10 - 2 .

Common CSF Findings in Meningitis

CSF PARAMETER

BACTERIAL

VIRAL

TB

Opening pressure (mmH2O)

200–500

< 250

180–300

Cell type

PMNs

Lymphocytes

Lymphocytes

Glucose (mg/dL)

Low

Normal

Low to normal

Protein (mg/dL)

High

Normal

Normal to high

Treat suspected meningitis immediately; don’t wait for CT or LP results! Therapy can always be tailored later.

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TA B L E 10 - 3 .

Antibiotic Regimens for Bacterial Meningitis

PATHOGEN S pneumoniae

THERAPY OF CHOICE Vancomycin + third-generation cephalosporin +/– dexamethasone.

N meningitidis

Ampicillin or third-generation cephalosporin.

L monocytogenes

Ampicillin (not cephalosporins).

Streptococcus agalactiae

Ampicillin.

H influenzae type b

Third-generation cephalosporin.

Upper Respiratory Tract Infections AC U TE S I NU S I TI S ■

■

■

■

Defined as inflammation of the mucosal lining of the paranasal sinuses. Viruses are the most common cause. The most common bacterial organisms include S pneumoniae, H influenzae, and Moraxella catarrhalis. Anaerobes and rhinoviruses may also be implicated. Sx/Exam: Look for acute onset of fever, headache, facial pain, or swelling. Most cases involve cough and purulent postnasal discharge. Patients with bacterial sinusitis are typically febrile and have unilateral tenderness over the affected sinus. Dx: Diagnosis is based on clinical findings. Radiographic imaging or CT may help (air-fluid level, inflammation of tissues). Tx: If symptoms persist after seven days or are suggestive of bacterial sinusitis, empiric therapy consists of a 10-day course of amoxicillin +/– clavulanate or cefpodoxime. If the patient has diabetes or is immunocompromised, it may be necessary to evaluate for fungi such as Mucor or atypical bacteria such as Pseudomonas. CH R ONI C S I NU S I TI S

■ ■

■

Defined as sinus symptoms lasting > 4 weeks. Dx: A noncontrast dedicated sinus CT with bone windows is the imaging modality of choice. Tx: ■ Amoxicillin +/– clavulanate × 21 days. ■ Intranasal corticosteroids, saline irrigation, mucolytics, and decongestants can provide symptomatic relief. ■ Refractory cases require endoscopic surgery.

INFECTIOUS DISEASE

OT I T I S M E D IA ■ ■

■

Causative agents are similar to those of acute sinusitis. Sx/Exam: ■ Typical features include fever and unilateral ear pain. ■ There may also be hearing loss, and children may be irritable or may tug at their ears. ■ The tympanic membrane is typically erythematous, lacks a normal light reflex, and may be bulging. Look for perforation of the tympanic membrane along with pus in the ear canal. Tx: ■ First-line treatment is with amoxicillin or TMP-SMX × 10 days. However, many recent studies suggest that a five- to seven-day course may be adequate if the patient is > 2 years of age and has no history of recurrent otitis media. ■ Patients who do not respond to antimicrobial therapy and develop hearing loss should have tympanostomy tubes placed. OT I T I S E X T E R N A

■

■

■

Predisposing factors include swimming, eczema, hearing aid use, and mechanical trauma (eg, cotton swab insertion). In most patients, the causative organism is Pseudomonas. S aureus is implicated in acute otitis externa. Sx/Exam: ■ Patients have a painful ear along with foul-smelling drainage. The external ear canal will be swollen and erythematous. There may also be pus. ■ Patients have tenderness upon movement of the pinna or tragus. Tx: Remove any foreign material from the ear canal and start a topical antimicrobial (typically ofloxacin) with steroids. PHARYNGITIS

A 28-year-old man with a past medical history significant for IV drug use presents to his primary care physician with sore throat, myalgia, fever, and night sweats of 10 days’ duration. He has cervical lymphadenopathy. In addition to being screened for group A streptococcus, what should this patient be evaluated for? He should also be evaluated for acute HIV infection. The symptoms of acute HIV are nonspecific but usually arise 2–4 weeks postexposure. Symptoms last anywhere from a few days to 10 weeks.

Typically due to viral causes such as rhinovirus or adenovirus. Group A streptococcus is implicated in up to 25% of cases. Untreated group A streptococcal infection can result in acute pyogenic complications and rheumatic fever. SYMPTOMS/EXAM

Symptoms include sore throat and fever +/– cough. Look for tonsillar exudates and tender anterior cervical adenopathy.

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174

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DIAGNOSIS ■

■

■

■

Think about infectious mononucleosis in patients with lymphadenopathy and malaise. In adults with pharyngitis, always consider HIV infection and acute retroviral syndrome. In children, think about epiglottitis (febrile patients with complaints of severe sore throat and dysphagia with minimal findings on exam). For streptococcal infection, check a rapid antigen test (good sensitivity and specificity) as well as a throat swab for culture.

TREATMENT ■

■

Treat group A streptococcal infections with penicillin. Use a macrolide for patients with penicillin allergy. Chronic carriers (ie, those who have a ⊕ throat culture or are asymptomatic) should be treated with clindamycin for eradication.

Pneumonia COM M U NI TY-AC QU I R E D P NE U M ONI A ( C AP )

Pneumonia still ranks as the sixth leading cause of death overall and is the leading cause of death from infection. Etiologies are as follows: ■

■

Typical pathogens: S pneumoniae, H influenzae, S aureus (in the setting of influenza virus). Atypical pathogens: Mycoplasma, Chlamydia, Moraxella, Legionella.

SYMPTOMS/EXAM ■

■

■

Think of pneumonia in any patient with acute onset of fever, chills, productive cough, and pleuritic chest pain. Atypical organisms present with low-grade fever, nonproductive cough, and myalgias (“walking pneumonia”). Look for evidence of consolidation (dullness to percussion, crackles, bronchial breath sounds) on lung exam.

DIAGNOSIS ■

KEY FACT Think of Legionella infection in a smoker with pneumonia, diarrhea, and elevated LDH.

■ ■

■

There should be radiographic evidence of an infiltrate in all immunocompetent patients (see Figure 10-3) as well as recovery of a pathogenic organism from blood, sputum, or pleural fluid. Urine Legionella antigen should be sent in patients with risk factors. Remember to check an ABG to determine the acid-base status of patients who appear to be in distress. If the patient is hospitalized, check blood cultures.

TREATMENT ■

Decide whether the patient needs to be hospitalized based on clinical risk factors. Admit patients who are > 50 years of age or those who have chronic underlying disease (eg, COPD, CHF, cancer), unstable vital signs, or a high fever.

INFECTIOUS DISEASE

A

B

Community-acquired pneumonia. Frontal (A) and lateral (B) radiographs show airspace consolidation in the right middle lobe (red arrows) in a patient with communityacquired pneumonia. (Reproduced with permission from USMLERx.com.)

FIGURE 10-3.

■

Initiate empiric antimicrobial therapy based on the patient’s risk factors (eg, community-dwelling and healthy vs. diabetic). Think about MRSA in patients with a history of colonization or in those who have been hospitalized (see Table 10-4).

TA B L E 10 - 4 .

Empiric Antibiotic Treatment Strategies for CAP

PATIENT PROFILE

INCLUDE COVERAGE FOR

Community-dwelling

S pneumoniae

outpatients

H influenzae

EMPIRIC ANTIBIOTIC CHOICE Azithromycin PO

Atypicals Patients with comorbidities

S pneumoniae

Fluoroquinolone or

(age > 60, DM, EtOH use,

Klebsiella

azithromycin PO

COPD)

Legionella

Inpatient (severe or multilobar

As above

Ceftriaxone IV + azithromycin IV

Gram-䊞 rods

Ceftriaxone IV + azithromycin

Pseudomonas

IV +/– vancomycin

pneumonia) Nursing home–acquired CAP

MRSA Patients with cystic fibrosis

Pseudomonas

Ceftazidime IV + levofloxacin IV + aminoglycoside

Aspiration

Anaerobes

Ceftriaxone IV + azithromycin

Gram-䊞 rods

IV + clindamycin IV

S aureus

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VE NTI LATOR -AS S OC I ATE D P NE U M ONI A

KEY FACT The sputum sample should have < 10 epithelial cells.

■

■

Dx: Typical agents in this setting include methicillin-sensitive S aureus, MRSA, Pseudomonas, Legionella, Acinetobacter, and other gram-䊞 rods. Tx: Always obtain sputum cultures before starting or changing antimicrobials. Tailor empiric therapy as soon as culture data become available. PNE U MOC YSTI S JI R OVE C I P NE U M ONI A

Formerly known as Pneumocystis carinii pneumonia (PCP). Can occur as an opportunistic infection in HIV-⊕ patients (usually when CD4 count < 200) as well as in anyone on immunosuppressive therapies such as high-dose steroids. SYMPTOMS/EXAM ■

■

Presents with fever, nonproductive cough, and dyspnea on minimal exertion that resolves quickly at rest. Patients may have findings consistent with atypical pneumonia, or there may be few physical exam findings. Look for pneumothorax.

DIAGNOSIS ■

■ ■

CXR ranges from normal to bilateral interstitial or alveolar infiltrates. The classic appearance is that of “ground-glass” infiltrates (see Figure 10-4). Other findings include ↑ LDH. Obtain a silver stain of sputum or bronchoalveolar lavage to look for PCP.

TREATMENT ■

■

First-line therapy is with IV TMP-SMX. Alternatives include IV pentamidine. Use concomitant prednisone if PaO2 is < 70 mm Hg or if the patient has an alveolar-arterial (A-a) oxygen gradient of > 35 mm Hg on room air.

Pneumocystis jiroveci pneumonia. Frontal CXR shows diffuse “groundglass” lung opacities characteristic of PCP in this patient with AIDS and a CD4 count of 26.

FIGURE 10-4.

(Reproduced with permission from USMLERx.com.)

INFECTIOUS DISEASE

Bronchitis Infection of the upper airways (bronchi), with risk factors including cigarette smoking and COPD. SYMPTOMS/EXAM

Presents with cough with or without sputum production, dyspnea, fever, and chills. The lungs are clear with possible upper airway noise. DIFFERENTIAL

URI, pneumonia, allergic rhinitis. DIAGNOSIS

CBC, CXR, sputum Gram stain and culture. TREATMENT ■

■

Depending on comorbidities and severity, patients may need hospitalization. If a bacterial etiology is suspected, give antimicrobials to cover S pneumoniae and atypicals.

Tuberculosis (TB) Caused primarily by Mycobacterium tuberculosis. May be 1°, latent, extrapulmonary, or reactivation (see Figure 10-5). Only about 10% of those infected with the bacterium develop active disease. SYMPTOMS/EXAM ■

■

■

■

1° TB: Symptoms include fevers and a dry cough. 1° TB usually involves the middle or lower lung zones and is associated with hilar adenopathy (Ghon complex) and radiographic abnormalities. The infection usually resolves, but reactivation occurs in 50–60% of patients. Latent TB infection (LTBI): Nonactive and noninfectious, but reactivation occurs in about 10% of patients, typically involving the upper lungs and cavitation. Latent infection can be detected by a ⊕ PPD. If the PPD is ⊕, the next step is to evaluate for possible active disease with a CXR (see Figure 10-6). Extrapulmonary TB: Usually associated with HIV-⊕ patients. May involve any organ, but those most commonly affected (in order of frequency) are the lymph nodes, pleura, GU tract, bones and joints, meninges, peritoneum, and pericardium. Symptoms are related to the organ involved. Diagnosis is based on an AFB culture of affected tissue. Reactivation TB: After 1° infection, TB can cause reinfection. Symptoms include fevers, productive cough, hemoptysis, night sweats, and weight loss. Reactivation TB is characterized by fibrocaseous cavitary lesions. Diagnosis is based on an AFB sputum culture.

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Infection with Mycobacterium tuberculosis

Nonimmune host (usually child)

Partially immune hypersensitized host (usually adult) Reinfection

Primary tuberculosis

Secondary tuberculosis

Primary complex

Fibrocaseous cavity lesion

Hilar nodes

Ghon focus

Heals by fibrosis

Progressive lung Severe disease bacteremia (in immunocompromised, malnourished children)

Immunity and hypersensitivity

Tuberculin positive

Death (rare)

Reactivation tuberculosis of the lung

Preallergic lymphatic or hematogenous dissemination

Miliary tuberculosis

Dormant tubercle bacilli in several organs

Death

REACTIVATION IN ADULT LIFE

Extrapulmonary tuberculosis

Meningitis, tuberculomas of the brain FIGURE 10-5.

Vertebral tuberculosis (Pott’s disease)

Tuberculous lymphadenitis

Renal tuberculosis

Intestinal tuberculosis

Evolution of pulmonary tuberculosis. (Modified with permission from Chandrasoma P,

Taylor CR. Concise Pathology, 2nd ed. Originally published by Appleton & Lange. Copyright © 1995 by The McGraw-Hill Companies, Inc.)

DIAGNOSIS ■

■

■

Screening by PPD placement should be conducted for LTBI in high-risk groups—eg, immigrants from endemic areas, HIV-⊕ patients, homeless persons, health care workers, IV drug users, and patients with chronic medical conditions (COPD, chronic kidney disease, DM, post-transplant, cancer). BCG vaccination status should be disregarded in the interpretation of test results (see Table 10-5). Active infection is diagnosed by AFB culture of sputum or tissue involved (see Figure 10-7).

INFECTIOUS DISEASE

A

B

C

D

FIGURE 10-6. Pulmonary tuberculosis. (A) Frontal CXR demonstrating diffuse, 1- to 2-mm nodules due to miliary TB. (B) A zoomed-in view corresponding to the area delineated by the red box in Image A. (C) Frontal CXR demonstrating left apical cavitary consolidation (red arrow) and patchy infiltrates in the right and left lung in a patient with reactivation TB. (D) Coronal reformation from a noncontrast chest CT in the same patient as Image C, better demonstrating left apical cavitary consolidation (red arrow) and other areas of parenchymal abnormality corresponding to the endobronchial spread of TB. (Reproduced with permission from USMLERx.com.)

TA B L E 10 - 5 .

PPD Interpretation

POPULATION

⊕ TB SKIN TEST

Low risk of disease

≥ 15 mm

Patients with exposure risk (health care workers, immigrants, diabetics)

≥ 10 mm

HIV-⊕, immunocompromised, recent contact with TB, CXR consistent

≥ 5 mm

with previous TB infection

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FIGURE 10-7.

Mycobacterium tuberculosis on AFB smear. (Courtesy of the Centers for Disease

Control and Prevention, Atlanta, GA, as published in Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 158-1.)

TREATMENT ■

KEY FACT Give vitamin B6 to prevent INHassociated neuropathy.

■ ■

The most commonly used regimen consists of four drugs described by the mnemonic RIPE—Rifampin, Isoniazid (INH), Pyrazinamide, and Ethambutol—given daily for eight weeks, followed by INH and rifampin for an additional 16 weeks. Table 10-6 outlines the common side effects of these drugs. Treatment of LTBI requires nine months of INH. Patients coinfected with TB and HIV should be treated with rifabutin instead of rifampin, as the latter can interact with anti-HIV medications.

TA B L E 10 - 6 .

Common Side Effects of Tuberculosis Drugs

DRUG Rifampin Isoniazid

SIDE EFFECTS Red-orange body fluids, hepatitis. Peripheral neuropathy (consider giving pyridoxine, or vitamin B6, with medication), hepatitis, lupus-like syndrome.

Pyrazinamide

Hyperuricemia, hepatitis.

Ethambutol

Optic neuritis.

INFECTIOUS DISEASE

Genitourinary Tract Infections CYSTITIS ■

■

■

■

■

Some 10% of U.S. women have at least one uncomplicated UTI each year. The most common pathogen is E coli. Sx/Exam: Dysuria, urgency, and frequency of urination are the most common complaints. DDX: ■ Think about urethritis/cervicitis in sexually active patients. ■ Renal stones may also present with colicky pain and dysuria. Dx: Check a UA for the presence of bacteria, WBCs, leukocyte esterase, and nitrites. Tx: ■ Give a three-day course of either TMP-SMX or a fluoroquinolone. Cultures are not necessary. A seven-day course is recommended for diabetics, patients with symptoms of > 7 days’ duration, and men. ■ Complicated UTIs (eg, hospital-acquired, catheter-associated, and recently treated cases) often require IV antibiotics such as ceftriaxone and a fluoroquinolone. P Y E L O N E PH R I T I S

■

Sx/Exam: Findings are similar to those of UTI except that patients are more acutely ill. ■ Be sure to check for CVA tenderness. Also look for signs of bacteremia such as fever, tachycardia, and hypotension. Dx: Urine specimens usually demonstrate significant bacteriuria, pyuria, and occasional WBC casts. A urine culture should be sent on all patients. Always obtain blood cultures on admission, as 15–20% of patients will be bacteremic. Tx: Begin a fluoroquinolone IV. If there is no clinical response, look for an intrarenal or perinephric abscess or for foreign bodies such as renal calculi with CT or ultrasound. ■

■

■

PROSTATITIS ■

Sx/Exam: Presenting symptoms include spiking fevers, chills, dysuria, cloudy urine, and even obstructive symptoms if prostate swelling is significant. ■ In patients with chronic infection, low back pain or perineal/testicular discomfort may be present. ■ The gland is exquisitely tender on prostate DRE. Dx: Obtain urine cultures before and after a prostatic massage to look for gram-䊞 rods. Tx: Treat with TMP-SMX or a fluoroquinolone × 14 days. Chronic prostatitis may cause more low-grade symptoms. Treatment should be extended to at least one month with a fluoroquinolone or to three months with TMP-SMX. ■

■

■

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Sexually Transmitted Diseases (STDs) S YP HI LI S

Caused by Treponema pallidum. Transmissible during early disease (1° and 2° syphilis) through exposure to open lesions (loaded with spirochetes!). SYMPTOMS ■

■

■

1° syphilis: Develops within several weeks of exposure; involves one or more painless, indurated, superficial ulcerations (chancre; see Figure 10-8). 2° syphilis: After the chancre has resolved, patients may develop malaise, anorexia, headache, diffuse lymphadenopathy, or rash (involves the mucosal surfaces, palms, and soles). 3° syphilis: Includes cardiovascular, neurologic, and gummatous disease (eg, general paresis, tabes dorsalis, aortitis, meningovascular syphilis).

A

B

C FIGURE 10-8. Syphilis. (A) Male and (B) female genital chancres, respectively, in primary syphilis infection. (C) Silver stain of sample from a chancre showing spiral-shaped spirochetes (arrows). (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Figs. 200-2, 200-5, and 200-1.)

INFECTIOUS DISEASE

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EXAM

Findings depend on the stage of syphilis—the painless chancre for 1° disease; maculopapular rash or diffuse lymphadenopathy for 2° disease; and multiple neurologic and/or cardiovascular signs for 3° disease. DIAGNOSIS ■

■ ■

1°: Do a nontreponemal serologic test (RPR or VDRL). Darkfield microscopy of the lesion’s exudate will show the spirochetes. Direct antigen tests (MHA-TP or FTA-ABS) are used for confirmation. 2°: Diagnosed by the presence of clinical illness and ⊕ serologic tests. 3°: Perform an LP when neurologic or ophthalmic signs and symptoms are present; in the setting of treatment failure; or with a VDRL of ≥ 1:32. Correlate with cardiovascular, neurologic, and systemic symptoms.

KEY FACT Patients who have had HIV or syphilis longer than a year should always undergo LP.

TREATMENT ■

■

1°/2°: Penicillin G 2.4 MU in a single IM dose. Alternatives include doxycycline or erythromycin × 14 days. If the disease duration is > 1 year, give three doses of penicillin G IM a week apart. Neurosyphilis: Penicillin G IV × 14 days. G EN I T A L H E R P E S

■

■

■ ■

Painful grouped vesicles in the anogenital region. Caused by the human herpes simplex virus, usually type 2. Sx/Exam: Frequently associated symptoms include tender inguinal lymphadenopathy, fever, myalgias, headaches, and aseptic meningitis. Symptoms are usually more pronounced during the initial episode and grow less frequent with recurrences. Dx: Diagnosis can be confirmed by viral PCR of the vesicle fluid. Tx: ■ Acyclovir × 7–10 days for 1° infections. Treatment should begin within one week of symptom onset. ■ Severe recurrences may necessitate repeat treatment with either acyclovir or valacyclovir × 5 days. Daily suppressive therapy can be used for frequent recurrences. C ER V IC IT IS / U R E T H R I T I S

■

■

■

■

Chlamydial and gonococcal infections often present as cervicitis or urethritis. Mycoplasma genitalium is an emerging pathogen in this syndrome. Sx/Exam: Dysuria, dyspareunia, and a mucopurulent vaginal discharge are frequent complaints in women. In men, dysuria and a purulent penile discharge predominate. Dx: A ⊕ endocervical or urethral culture or a ⊕ urine PCR for chlamydia/ gonorrhea is diagnostic. Tx: ■ Always treat for both infections simultaneously, and treat sexual partners. ■ Treat chlamydia with a single PO dose of azithromycin. ■ Treat gonorrhea with a single PO dose of ofloxacin or ciprofloxacin or with a single IM dose of ceftriaxone.

KEY FACT Counsel patients regarding safe-sex practices. HSV transmission can occur even in the absence of visible vesicles.

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Septic ovarian mass

Uterus

Pyosalpinx

FIGURE 10-9.

Tubo-ovarian abscess. (Reproduced with permission from Benson RC. Handbook of Obstet-

rics & Gynecology, 8th ed. Stamford, CT: Appleton & Lange, 1983.)

PE L VI C I NF LAM M ATOR Y DI S E AS E ( P I D) ■

■

KEY FACT IUDs greatly ↑ the risk of PID and should be removed in women who have been diagnosed with an STD.

■

■

An upper genital tract infection in women that is usually a complication of chlamydia and/or gonorrhea infection. Sx/Exam: Presents with pelvic pain, dyspareunia, vaginal discharge, fever, and menstrual irregularities as well as with lower abdominal tenderness, adnexal tenderness, and cervical motion tenderness. Dx: A finding of > 10 WBCs/low-power field on Gram stain and endocervical smear is consistent with a diagnosis of PID. Always remember to first rule out pregnancy. Tx: Treat with a second-generation cephalosporin IV and doxycycline IV. If the patient does not improve, consider imaging (ultrasound) to evaluate for a tubo-ovarian abscess that would require drainage (see Figure 10-9).

HIV Infection Acute retroviral syndrome occurs in 50–90% of cases. The incubation period is usually 2–6 weeks. Acute symptoms last 1–4 weeks, with an average of two weeks. SYMPTOMS/EXAM

Patients have a typical viral prodrome (eg, malaise, low-grade fever) followed by the development of adenopathy. Unusual presentations include Bell’s palsy, peripheral neuropathy, radiculopathy, cognitive impairment, and psychosis. DIAGNOSIS ■

■

HIV serology (ELISA) detects antibody to HIV. Serology becomes ⊕ 2–3 months after exposure, with > 95% seroconversion at six months. Send a confirmatory Western blot in patients with a ⊕ ELISA screen. For patients with suspected acute retroviral syndrome, check a viral load, as the ELISA may not have had time to turn ⊕.

INFECTIOUS DISEASE

TREATMENT ■

■

Begin highly active antiretroviral therapy (HAART) in any of the following situations: ■ In symptomatic patients (any CD4 or viral load). ■ In asymptomatic patients with a CD4 of < 350 and any viral load. ■ In pregnant women. ■ In the setting of a needle stick involving blood from an HIV-⊕ patient. Regimens should include three drugs, preferably from different categories (see Table 10-7).

COMPLICATIONS

Complications are numerous and typically involve opportunistic infections and side effects from drugs. See Table 10-8 for prophylaxis indications.

T A B L E 1 0 - 7.

Categories of Antiretroviral Drugs

MAJOR ANTIRETROVIRAL EXAMPLES

CLASSES Nucleoside reverse

Zidovudine (AZT)

Myopathy and bone marrow

Didanosine (ddI)

Pancreatitis.

Abacavir

Hypersensitivity reactions (eg,

Emtricitabine (FTC) and

Diarrhea, nausea, and

suppression.

transcriptase inhibitors (NRTIs)

COMMON SIDE EFFECTS

fever, chills, dyspnea). lamivudine (3TC)

headache.

Tenofovir (TNV)

Renal toxicity.

Non-nucleoside

Efavirenz

CNS toxicity and teratogenicity.

reverse transcriptase

Nevirapine

Rash and hepatic failure.

Atazanavir

Benign indirect

inhibitors (NNRTIs) Protease inhibitors

hyperbilirubinemia.

(PIs) Indinavir

Kidney stones.

Nelfinavir

Diarrhea.

Ritonavir

Potent P-450 inhibitor.

Saquinavir

Rare side effects. All PIs can ↑ lipids, redistribute fat, and cause DM.

Fusion inhibitors

Enfuvirtide (T20)

Injection site reactions.

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TA B L E 10 - 8 .

Prophylaxis in HIV

DISEASE PCP

INDICATION

TREATMENT

CD4 < 200 or previous PCP or

TMP-SMX, dapsone, or

thrush.

atovaquone.

CD4 < 50.

Azithromycin weekly.

CD4 < 100 and Toxoplasma

TMP-SMX or dapsone +

IgG ⊕.

leucovorin + pyrimethamine.

TB

Recent contact or PPD > 5 mm.

INH for nine months.

Pneumococcal

All HIV ⊕.

Vaccine every five years.

Influenza

All HIV ⊕.

Yearly vaccine.

Hepatitis B

Surface antigen/core antibody ⊕.

Hepatitis B vaccine.

Mycobacterium avium–intracellulare (MAI) Toxoplasma gondii

pneumonia

Travel Medicine MA LAR I A P R OP HYLAX I S ■

■

■

■

■

Prophylaxis must be tailored to reflect the prevalence of resistant Plasmodium falciparum (high mortality) in the area of proposed travel. Most regimens start 1–2 weeks prior to travel and continue for a month after return. Weekly chloroquine is the mainstay of therapy in chloroquine-sensitive areas. Mefloquine is active against chloroquine-resistant P falciparum and is also given weekly. Mefloquine resistance is emerging in Southeast Asia. Daily doxycycline or daily Malarone (atovaquone and proguanil) can be used in those who are unable to take mefloquine or who are traveling to chloroquine-resistant areas. Malarone can be used for short trips. Precautions: ■ Mefloquine has the potential for neuropsychiatric side effects. Caution should thus be exercised in prescribing it to people with recent or active depression, psychosis, schizophrenia, or anxiety disorders. ■ Other effects include sinus bradycardia and QT-interval prolongation; avoid in patients on β-blockers or in those with known conduction disorders. TR AVE LE R ’S DI AR R HE A ( TD)

■

Roughly 40–60% of people traveling to developing countries develop TD (see Table 10-9).

INFECTIOUS DISEASE

TA B L E 10 - 9 .

Common Pathogens Causing Traveler’s Diarrhea

BACTERIA

■

■

■

VIRUSES

PARASITES

ETEC (enterotoxic E coli)

Rotavirus

Giardia

Campylobacter

Enteric adenovirus

Cryptosporidium

Salmonella

Cyclospora

Shigella

Microsporidia

Vibrio

Isospora belli

Yersinia

Entamoeba histolytica

Sx/Exam: Patients with uncomplicated TD have watery, unformed stools without systemic symptoms. Those with complicated TD can have bloody diarrhea along with systemic symptoms such as nausea, vomiting, abdominal pain, and fever. Dx: Since uncomplicated TD is self-limited (48–72 hours), studies are usually not warranted, and treatment is symptomatic. Exceptions are as follows: ■ A stool culture should be considered in those with blood in the stool, fever, and symptoms of colitis. ■ Stool examination for Giardia should be done in patients with predominantly upper GI symptoms—eg, nausea, bloating, gas, and persistent nonbloody diarrhea. Tx: ■ Fluid replacement should be initiated in all cases; oral rehydration should be started in children with cholera. ■ Antimicrobials are indicated for moderate to severe disease. A fluoroquinolone or azithromycin is the first choice. Antimotility agents should not be used in severe TD.

Tick-Borne Diseases L Y M E D IS E A S E

A systemic disease caused by Borrelia burgdorferi, a spirochete carried by the deer tick (Ixodes genus). Patients may reside in the Northeast or Midwest. SYMPTOMS/EXAM ■

■

■

Stage 1: Presents with erythema migrans (target or bull’s-eye lesion; see Figure 10-10) as well as with fever, arthralgias, myalgias, and lymphadenopathy. Stage 2: Characterized by myocarditis, possibly accompanied by varying degrees of AV block, Bell’s palsy (unilateral or bilateral), peripheral neuropathy, and meningitis. Stage 3: Marked by arthritis and possibly by chronic neurologic symptoms.

DIFFERENTIAL

Erythema migrans is pathognomonic for Lyme disease. The differential for other nonspecific symptoms is broad.

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FIGURE 10-10. Lyme disease. The classic “target” or “bull’s-eye” lesion of erythema migrans is seen. (Courtesy of James Gathany, Public Health Image Library, Centers for Disease Control and Prevention, Atlanta, GA, as published in McPhee SJ et al. Current Medical Diagnosis & Treatment 2010. New York: McGraw-Hill, 2010, Plate 12.)

DIAGNOSIS

A Western blot or PCR can be used to confirm the diagnosis. TREATMENT ■

Treat with doxycycline or amoxicillin. If cardiac or neurologic symptoms are present, treat with ceftriaxone. E HR LI C HI OS I S

■

■

■

■

Caused by Ehrlichia and Anaplasma bacteria, which are transmitted by several different ticks, typically during the summer. Sx/Exam: Symptoms are often nonspecific and include fever, chills, malaise, headache, and myalgias with no physical exam findings. Dx: Diagnose with serology or PCR. On laboratory findings, patients may have thrombocytopenia, leukopenia, and elevated transaminases. Tx: Treat with doxycycline. BAB E S I OS I S

■

A systemic disease caused by Babesia organisms that infect RBCs, leading to a hemolytic anemia.

INFECTIOUS DISEASE

■

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189

Sx/Exam: Presents with nonspecific symptoms that include fever, chills, fatigue, and myalgias. ■ Patients have typically visited the Northeast, particularly Cape Cod, Martha’s Vineyard, or Nantucket. Dx: Diagnose with a peripheral blood smear or PCR. Tx: Treat with clindamycin and quinine. ■

■ ■

Neutropenic Fever Most often occurs after chemotherapy. Defined as a single temperature of > 38.3°C (101.3°F) or a sustained temperature of > 38°C (100.4°F) for > 1 hour in a neutropenic patient (ANC = PMNs + bands < 500). SYMPTOMS/EXAM ■

■

■

The skin should be examined for signs of erythema, rash, cellulitis, ulcers, or line infection. All indwelling lines should be carefully examined for subtle signs of infection, as erythema, tenderness, fluctuance, or exudate may be the only evidence of a serious “tunnel infection.” Do not conduct a DRE unless perirectal abscess is suspected.

DIAGNOSIS ■

■

Obtain a CBC with differential, a complete metabolic panel, amylase, lipase, and a CXR. Cultures of urine, blood, sputum, and stool should be sent. LP is warranted only if CNS symptoms are present.

TREATMENT ■

■

■

Empiric antimicrobials should cover Pseudomonas. Use cefepime IV or a carbapenem IV. Consider vancomycin in patients with a history of MRSA infections, hypotension, persistent fever on empiric therapy, or skin or catheter site infections. Think about fungal infections (especially Candida and Aspergillus) in patients with 5–7 days of persistent fever, and begin amphotericin B or voriconazole.

Sepsis A 52-year-old man presents to the ER with a fever of 39°C (102.2°F), a heart rate of 130 bpm, a BP of 100/60, and a WBC count of 13,500. He is somnolent and unable to provide an accurate review of systems. In addition to providing early goal-directed therapy that includes IV fluids and antibiotics, what should you obtain? In addition to providing supportive treatment, you should focus on finding the source of the infection. In this case, you should start with a CXR, a UA and urine culture, and blood cultures.

KEY FACT Elderly patients or those on corticosteroids may not be able to mount a fever that meets the diagnostic criteria for neutropenic fever.

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Defined as two systemic inflammatory response syndrome (SIRS) criteria with evidence of infection. Divided into three levels of severity (see Table 10-10). SIRS criteria are as follows: ■ ■ ■ ■

Temperature: < 36°C (< 97°F) or > 38°C (> 100°F). Heart rate: > 90 bpm. Respiratory rate: > 24 breaths/min or a PCO2 of < 32 mm Hg. Leukocytes: > 12,000 cells/mm3, < 4000 cells/mm3, or > 10% bands on peripheral blood smear.

SYMPTOMS/EXAM ■

■

■ ■

Presents with nonspecific infectious symptoms such as fever, chills, and fatigue. Symptoms and signs suggestive of cellulitis, necrotizing fasciitis, meningitis, sinusitis, pneumonia, endocarditis, UTI, or GI infection are seen. Vital signs are abnormal (see the SIRS criteria above). Evidence of hypoperfusion includes cool, pale extremities, ↓ pulses, altered mental status, and ↓ urine output.

DIFFERENTIAL

MI, PE, cardiac tamponade, acute pancreatitis, acute hemorrhage, transfusion reactions, drug reactions, anaphylaxis, acute adrenal insufficiency, myxedema coma. DIAGNOSIS ■ ■

■ ■

Find the focus of infection. If no clear infectious focus can be found, obtain a CXR, a UA, and a urine Gram stain and culture. Consider obtaining sputum, CSF, pleural fluid, and peritoneal fluid samples; a transesophageal echocardiogram (TEE); and an ultrasound of preexisting catheters or other foreign bodies (eg, pacemakers). Always obtain blood cultures and sensitivities. Obtain a CBC, electrolytes, glucose, lactate, AST, ALT, aPTT, and PT, and consider an ABG if respiratory failure is a concern.

TREATMENT ■ ■

■ ■

Treat hypotension with rapid fluid resuscitation. Consider central line access for cardiovascular and pulmonary monitoring as well as administration of high-volume fluid resuscitation, blood products, and/or pressors/inotropes. Consider an arterial line for continuous monitoring of BP. If an infectious focus is identified, appropriately tailor antimicrobial treatment. If the source cannot be identified, start broad-spectrum antimi-

TA B L E 10 - 10 .

SEVERITY

Severity of Sepsis

CRITERIA

Sepsis

Meets at least two of the SIRS criteria with evidence of infection.

Severe sepsis

Meets the criteria for sepsis with evidence of end-organ damage.

Septic shock

Meets the criteria for sepsis with BP not responding to fluid resuscitation and necessitating the initiation of pressors and/or inotropes.

INFECTIOUS DISEASE

■

crobials in accordance with patient risk factors (eg, immune compromise, nursing home residency, recent hospitalization). If the patient meets the criteria for severe sepsis or septic shock and has multiorgan failure or ARDS, consider starting activated protein C.

COMPLICATIONS

Can lead to ARDS, DIC, multiorgan failure, and death.

Fungal Infections Typically affect immunocompromised patients and should always be considered in this population. C R Y P T O C O CC O S IS ■ ■

■

■

Affects patients with depressed T-cell immunity. Sx/Exam: Presents as a disseminated infection, frequently causing meningoencephalitis. In healthy patients, it typically causes pneumonia that is often self-limited. Dx: ■ Diagnose with a fungal culture and antigen testing (eg, CSF, blood, sputum). Silver stains of biopsies can aid in diagnosis. ■ Although largely replaced by the antigen test, an India ink test may show a halo 2° to the capsule (see Figure 10-11). Tx: ■ Treat mild to moderate disease with fluconazole × 6–12 months. ■ Patients with severe disease, immunocompromised hosts, and those with CNS infections should be treated with amphotericin (+/– flucytosine) followed by long-term fluconazole. H I S T O P L A S M O S IS

■ ■

Affects both healthy and immunocompromised patients. Sx/Exam: ■ Usually manifests as a respiratory illness, but can present as disseminated disease in the immunocompromised.

FIGURE 10-11. Cryptococcus neoformans. India ink preparation demonstrating budding yeast (arrow) and thick, translucent polysaccharide capsules outlined by the dark India ink particles. (Courtesy of Dr. L. Haley, Public Health Image Library, Centers for Disease Control and Prevention, Atlanta, GA, as published in Levinson W. Review of Medical Microbiology and Immunology, 10th ed. New York: McGraw-Hill, 2008, Color Plate 38.)

CHAPTER 10

KEY FACT Early initiation of appropriate antimicrobials is critical in the management of sepsis.

191

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192

INFECTIOUS DISEASE

Disseminated disease can present with palatal ulcerations, fever, weight loss, splenomegaly, anemia, and an elevated ESR. ■ Patients have commonly visited the Ohio/Mississippi river valleys or have a history of exposure to bird excrement, bat guano, or construction sites. Dx: Diagnosis is best made with silver staining and culture of biopsied infected tissue, but Histoplasma antigen tests of urine and serum are available. Tx: Mild cases in healthy patients do not require treatment. Amphotericin should be used in severe cases, and itraconazole can be given if there is no CNS involvement. ■

■

■

COC C I DI OI DOM YC OS I S ■ ■

■

■

Typically affects immunocompromised individuals, but not exclusively. Sx/Exam: ■ 1° disease is usually a self-limited pneumonitis with dry cough and fever; however, disseminated disease affects the CNS (meningitis), skin (erythema nodosum), bones, and joints. ■ Patients have commonly visited the southwestern United States, particularly Arizona or the San Joaquin Valley in California. Dx: Diagnose with silver stains of culture or biopsy, serologic studies, or antibody detection in CSF if meningitis is present. Tx: Treat with fluconazole and amphotericin if the disease is progressive or disseminated or if the patient is immunocompromised.

Antimicrobial Selection When a pathogen has been definitively identified, it is important to choose an antimicrobial with narrow coverage. Table 10-11 illustrates common antimicrobials and their spectra of coverage.

TA B L E 10 - 11 .

Common Antimicrobials and Their Coverage

ANTIMICROBIAL GROUP First-generation or

COMMON EXAMPLES Penicillin G, penicillin V.

natural penicillins

ORGANISMS COVERED Treponema pallidum, Enterococcus, streptococci, and rare penicillin-sensitive staphylococci.

Second-generation

Dicloxacillin, methicillin (no longer

Used primarily for methicillin-sensitive staphylococci, but do cover

or β-lactamase-

used clinically, but important because

some streptococci.

resistant penicillins

of methicillin-resistant staphylococci), nafcillin, oxacillin.

Third-generation or

Amoxicillin, amoxicillin/clavulanic acid,

Natural penicillin coverage and E coli, Proteus, H influenzae, and

aminopenicillins

ampicillin, ampicillin/sulbactam.

Enterococcus. β-lactamase inhibitors add coverage for enteric gram-䊞 organisms and anaerobes.

Fourth-generation

Piperacillin/tazobactam, ticarcillin/

Aminopenicillin/β-lactamase inhibitor coverage in addition to

or extended-

clavulanic acid.

resistant gram-䊞 organisms and Pseudomonas.

spectrum penicillins

CHAPTER 10

INFECTIOUS DISEASE

TA B L E 10 - 11 .

193

Common Antimicrobials and Their Coverage (continued)

ANTIMICROBIAL GROUP First-generation

COMMON EXAMPLES Cefazolin, cephalexin.

cephalosporins Second-generation

Staphylococci, streptococci, Proteus, E coli, and Klebsiella (PEcK). Cephalosporins do not cover any enterococci.

Cefaclor, cefuroxime.

cephalosporins Cephamycins

ORGANISMS COVERED

First-generation cephalosporin coverage and H influenzae, Enterobacteriaceae, Neisseria (HEN PEcK).

Cefotetan, cefoxitin.

Second-generation cephalosporin coverage and gram-䊝/gram-䊞 anaerobes.

Third-generation

Cefotaxime, ceftazidime, ceftriaxone.

cephalosporins Fourth-generation

Most gram-䊞 aerobes. Ceftriaxone adds streptococcal coverage and ceftazidime adds Pseudomonas coverage.

Cefepime.

Gram-䊞 aerobes, streptococci, and Pseudomonas.

Ciprofloxacin.

Gram-䊞 aerobes and atypicals such as Legionella, Mycoplasma,

cephalosporins Second-generation quinolones Third-generation

and Chlamydia. Best Pseudomonas coverage of all quinolones. Levofloxacin.

Gram-䊞 aerobes, streptococci, and atypicals.

Gatifloxacin, moxifloxacin.

Gram-䊝 organisms, some anaerobes, weak gram-䊞 coverage, and

quninolones Fourth-generation quinolones Carbapenems

atypicals. Ertapenem, imipenem, meropenem.

Gram-䊝 organisms (except resistant Staphylococcus and Enterococcus); gram-䊞 organisms, including Pseudomonas and anaerobes. Ertapenem has no Pseudomonas or Enterococcus coverage.

Macrolides

Azithromycin, erythromycin, clarithromycin.

Gram-䊝 organisms and atypicals.

Aminoglycosides

Gentamicin, tobramycin.

Gram-䊞 aerobes.

Others

Aztreonam.

Gram-䊞 aerobes, including Pseudomonas.

Clindamycin.

Gram-䊝 anaerobes.

Dalfopristin/quinupristin.

MRSA and vancomycin-resistant enterococci (VRE).

Linezolid.

MRSA; VRE.

Metronidazole.

Anaerobes (Clostridium difficile).

TMP-SMX.

Gram-䊞 organisms, gram-䊝 organisms, PCP.

Vancomycin.

MRSA and C difficile.

Tetracyclines (doxycycline, minocycline,

Rickettsia and atypicals.

tigecycline).

194

CHAPTER 10

INFECTIOUS DISEASE

NO T E S

CHAPTER 11

MUSCULOSKELETAL Initial Diagnosis of Musculoskeletal Disorders

196

Common Orthopedic Injuries

206

Systemic Lupus Erythematosus

196

Temporal Arteritis (Giant Cell Arteritis)

208

Rheumatoid Arthritis

198

Polymyalgia Rheumatica

209

Gout

200

Fibromyalgia

209

Osteoarthritis

202

Polymyositis

210

Low Back Pain

204

Scleroderma

211

195

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Initial Diagnosis of Musculoskeletal Disorders Joint aspiration in warm, swollen joints aids in the preliminary diagnosis of arthritis by helping distinguish inflammatory from noninflammatory disease as well as infectious and hemorrhagic processes (see Table 11-1).

Systemic Lupus Erythematosus (SLE) A 27-year-old woman with SLE is symptomatic with serositis and a discoid rash, and you decide to start her on hydroxychloroquine. What is a potential toxicity associated with the long-term use of this drug and other antimalarials? Retinal toxicity. Monitor the patient with baseline and follow-up ophthalmologic exams.

A multisystem, chronic inflammatory disease that is 2° to ANA complex formation and deposition. Patients may experience acute flare-ups of their symptoms. SLE is generally 1° but sometimes occurs 2° to drug use (hydralazine, penicillamine, and procainamide). 2° SLE is reversible.

TA B L E 11- 1 .

Interpretation of Joint Aspiration

NORMAL

NONINFLAMMATORY

INFLAMMATORY

INFECTIOUS

HEMORRHAGIC

Color

Clear

Xanthochromic

Yellow

Opaque

Bloody

Viscosity

High

High

Low

Low

Variable

WBCs/mm3

< 200

200–3000

3000–50,000

> 50,000

Variable

% PMNs

< 25

< 25

> 50

> 75

Variable

Crystals

None

None

May be present

None

None

Differential

None

Osteoarthritis, SLE,

Gout, pseudogout, RA,

Bacterial, TB

Coagulopathy, trauma

trauma, aseptic,

SLE, TB, scleroderma,

necrosis, scleroderma,

ankylosing spondylitis,

Charcot’s joint

psoriatic arthritis

MUSCULOSKELETAL

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197

SYMPTOMS/EXAM

Patients tend to be young African American women; also common among Asians and Hispanics. Findings by organ system are as follows: ■ ■

■

■ ■

■

■ ■ ■ ■

Constitutional: Fatigue, weight loss, fever. Musculoskeletal: Arthritis is usually migratory and asymmetric, involving the hands. Skin: Many characteristic skin findings are associated with SLE. These include malar rash (a “butterfly rash” over the cheeks and nose), discoid rash (scaling papules that can leave residual scarring), alopecia, painless oral ulcers, Raynaud’s phenomenon, and photosensitive rash. Renal: Nephritis and nephrosclerosis, which can lead to renal failure. Pulmonary: Pleuritis, pleural effusion, interstitial lung disease, pulmonary hypertension. Cardiovascular: Pericarditis, pericardial effusion, Libman-Sacks endocarditis (aseptic valvular nodules). CNS: Seizures, neuropathies, headache. Psychological: Anxiety, depression, psychosis. Hematologic: Thrombocytopenia, hemolytic anemia, leukopenia. GI: Peritonitis.

DIAGNOSIS ■

■

■

■

The diagnostic criteria for SLE are summarized in the mnemonic DOPAMINE RASH. Diagnosis is clinical and requires at least four of the 11 criteria listed. ANA is highly sensitive but nonspecific, whereas anti-dsDNA and anti-Sm antibodies are highly specific. Drug-induced lupus is associated with antihistone antibodies. Obtain anticardiolipin antibody and lupus anticoagulant assays to screen for antiphospholipid antibody syndrome in patients with SLE. Note that most people with antiphospholipid antibody syndrome do not have fullblown SLE. Active SLE flare-ups are characterized by ↓ C3 and C4 but ↑ CRP and ESR.

TREATMENT ■

■

Arthritis and mild serositis are treated with NSAIDs. Hydroxychloroquine is used for rashes, serositis, and arthritis that is unresponsive to NSAIDs. Steroids and immunosuppressants are used for refractory symptoms or in the setting of significant organ involvement. Patients undergoing active SLE flare-ups are treated with steroids, which are tapered once remission has been induced. Those with antiphospholipid antibody syndrome need lifelong anticoagulation with warfarin.

COMPLICATIONS ■

■ ■

■

SLE patients who become pregnant have a higher incidence of spontaneous abortion. Neonates can get congenital complete heart block. Antiphospholipid antibody syndrome predisposes patients to arterial and venous thrombosis. Mortality in SLE is frequently due to accelerated atherosclerosis, infections, malignancy, or renal disease.

MNEMONIC SLE criteria—

DOPAMINE RASH Discoid rash Oral ulcers Photosensitive rash Arthritis Malar rash Immunologic criteria (⊕ anti-dsDNA or ⊕ anti-Sm)

NEurologic or psychiatric symptoms Renal disease ANA ⊕ Serositis (pleural, peritoneal, or pericardial)

Hematologic disorders (thrombocytopenia, anemia, or leukopenia)

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Rheumatoid Arthritis (RA) A 58-year-old woman with warm and tender joints at her wrists and the bases of her fingers has failed methotrexate therapy for her RA and wants to try anti-TNF therapy. What should you remember to screen for before initiating this treatment? Screen for latent TB with a PPD test and CXR, and test for hepatitis B and C

KEY FACT What complication of rheumatoid arthritis makes both roller coasters and intubation riskier than normal? Atlantoaxial instability.

antibodies.

A chronic, symmetrical, and erosive synovitis. SYMPTOMS/EXAM ■ ■

KEY FACT Typical RA hands: ■ MCP and PIP involvement ■ Sparing of the DIP joint ■ Ulnar deviation ■ Symmetric ■ Swan-neck deformities ■ Boutonnière deformities

■

Presents with insidious onset of a symmetrical arthritis. Nonspecific complaints include fever, fatigue, anorexia, and weight loss. Affected joints are swollen and tender. Other findings include joint deformities (see Figure 11-1), atlantoaxial joint subluxation, carpal tunnel syndrome, and Baker’s cyst rupture. Extra-articular features may include neuropathy, episcleritis and scleritis, Sjögren’s syndrome (dry eyes and mouth), pulmonary fibrosis, hepatosplenomegaly, pleuritis, lung nodules, pericarditis, and myocarditis.

DIAGNOSIS ■

Diagnosed in the presence of four or more of the following criteria for six weeks: ■ Morning stiffness (> 1 hour). ■ Arthritis of three or more joint areas (most commonly the PIP, MCP, wrist, elbow, knee, or ankle).

FIGURE 11-1. Rheumatoid arthritis. Typical ulnar deviation of the MCP joints and swelling of the PIP joints in a patient with RA. Multiple subcutaneous rheumatoid nodules are also seen. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 161-1A.)

MUSCULOSKELETAL

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Arthritis of the hand joints (MCP, PIP, or wrists). Symmetric arthritis. ■ Rheumatoid nodules (most commonly found at the elbow). ■ ↑ serum RF. ■ Radiographic changes (obtain plain films of affected joints in all RA patients). The classic radiographic changes are symmetric joint space narrowing and periarticular osteopenia (see Figure 11-2). RF is nonspecific but is ⊕ in 75% of RA cases. Anti–cyclic citrullinated peptide (anti-CCP) antibody is much more specific for RA. Joint aspiration is inflammatory (see Table 11-1). Look for periarticular osteoporosis with erosions around the affected MCP and PIP joints on x-ray (see Figure 11-1). ■ ■

■

TREATMENT ■

■ ■

■

■

Mild cases are treated with NSAIDs; if NSAIDs are inadequate, the next step up is hydroxychloroquine. Moderate to severe cases are treated with NSAIDs and methotrexate. If methotrexate fails or is contraindicated, give anti-TNF treatment (etanercept, infliximab, adalimumab). Patients on TNF inhibitors are at ↑ risk for infections and possibly malignancies. Immunosuppressants are used in patients who fail methotrexate and etanercept therapy. Patients with acute exacerbations of RA (ie, those who are febrile, toxic, or experiencing a rapid decline in function) are treated with a short course of prednisone. Other measures include weight loss, rest, smoking cessation, and physiotherapy. Screen for and treat osteoporosis resulting from steroid use.

A

B

C

Progression of radiographic findings in rheumatoid arthritis. (A) Normal MCP joint one year before the onset of RA. (B) Six months following disease onset, there is a bony erosion (arrow) adjacent to the joint along with joint space narrowing. (C) After three years of disease, diffuse loss of articular cartilage has led to marked joint space narrowing (arrowhead). (Reproduced with permission from Imboden JB et al. Current Rheumatology Diagnosis & Treatment, 2nd ed.

FIGURE 11-2.

New York: McGraw-Hill, 2007, Fig. 15-3.)

KEY FACT Methotrexate for RA is contraindicated in pregnant patients and in those with HIV, liver disease, renal failure, or bone marrow suppression.

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MUSCULOSKELETAL

Gout A 47-year-old man with hypertension and hypercholesterolemia celebrates his birthday by going out for steak and beer. The next morning, his

KEY FACT

first MTP joint is red and painful even to light touch. He is on lovastatin, ASA, chlorthalidone, and niacin. Which of his medications likely contributed to his

Monoarthritis? Think: ■ Gout ■ Septic arthritis ■ Lyme disease ■ Pseudogout ■ Trauma

gout? Chlorthalidone.

A metabolic condition resulting from the intra-articular deposition of monosodium urate crystals. Complications include nephrolithiasis and chronic urate nephropathy. SYMPTOMS/EXAM ■

■ ■

■

■

■

Typically presents in middle-aged, obese men (90%) from the Pacific Islands. Incidence in women ↑ after menopause. Acute gout attacks often occur at night between periods of remission. Patients initially present with severe pain, redness, and swelling in a single lower extremity joint (typically the first MTP joint); subsequent attacks may present in additive fashion with multiple joints. Differentiate from pseudogout, in which symptoms may be severe and often affect the knee (> 50%) or shoulder. Common precipitants of attacks include a high-purine diet (eg, meats, alcohol), dehydration or diuretic use, high-fructose corn syrup, stress, severe illness, trauma, and tumor lysis syndrome. Patients with long-standing disease may develop tophi that lead to joint deformation.

FIGURE 11-3.

Gout crystals. Note the needle-shaped, negatively birefringent crystals. (Re-

produced with permission from Milikowski C. Color Atlas of Basic Histopathology. Stamford, CT: Appleton & Lange, 1997: 546.)

MUSCULOSKELETAL

TA B L E 11- 2 .

Differential Diagnosis of Gout and Pseudogout

GOUT CRYSTALS

PSEUDOGOUT CRYSTALS

Composition

Urate

Calcium pyrophosphate dihydrate

Shape

Needle shaped

Rhomboid shaped

Refringence

Negatively birefringent

Strongly positively birefringent

Red compensator

YeLLow when paraLLel

Blue when parallel

Response to colchicine

Good

Weak

DIAGNOSIS ■

■

■

■

Joint aspirate is inflammatory with needle-shaped, negatively birefringent (yeLLow when paraLLel to the condenser) crystals (see Figure 11-3 and Table 11-2). Radiographs are normal in early gout. Characteristic punched-out erosions with overhanging cortical bone (“rat bites”) are seen in more advanced disease (see Figure 11-4). Most patients have ↑ serum uric acid (which is neither sensitive nor specific). Roughly 90% are underexcreters of uric acid, while the remainder are overproducers. If you are thinking about starting probenecid, collect a 24-hour urine sample for uric acid while the patient is off hyperuricemia-inducing medications (diuretics, alcohol, cyclosporine) to determine whether the hyperuricemia is due to undersecretion or overproduction of urate (see Table 11-3).

A

B

Gout. (A) A swollen left first MTP joint with overlying erythema and warmth, characteristic of an acute gout attack (podagra). (B) An AP radiograph showing the severe consequences of long-standing gout, including large, nonmarginal erosions with overhanging edges of bone (red arrows), soft tissue swelling, and destruction of the first MTP joint (arrowhead). Note the subtle calcification of a gouty tophus (orange arrow). (Image A reproduced with

FIGURE 11-4.

permission from LeBlond RF et al. DeGowin’s Diagnostic Examination, 9th ed. New York: McGraw-Hill, 2009, Plate 30. Image B reproduced with permission from USMLERx.com.)

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201

202

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MUSCULOSKELETAL

TA B L E 11- 3 .

Causes of Hyperuricemia

24-hour urine collection

OVERPRODUCTION OF

UNDERSECRETION OF

URIC ACID

URIC ACID

> 800 mg/day

< 800 mg/day

Idiopathic (1°), inherited

Chronic kidney disease, ASA,

enzyme defect,

diuretics

for uric acid Etiology

myeloproliferative disorders, lymphoproliferative disorders, tumor lysis syndrome, psoriasis

TREATMENT ■

■

KEY FACT Remember to Avoid Allopurinol in Acute gout Attacks.

■

For acute attacks, administer high-dose NSAIDs (eg, indomethacin) or colchicine. Use oral or intra-articular steroids when first-line therapy fails or is contraindicated. Once the acute attack resolves, begin maintenance therapy to ↓ serum uric acid levels (≤ 6 mg/dL). Overproducers are treated with allopurinol; undersecreters are treated with probenecid. Patients should avoid precipitants of acute attacks and should consume a low-purine diet (eggs, cheese, fruit, and vegetables). Other key factors in flare prevention are weight loss and BP control.

Osteoarthritis (OA) A chronic, noninflammatory joint disease characterized by degeneration of the articular cartilage, hypertrophy of the bone margins, and changes in the synovial membrane. OA can be 1° or 2° to trauma, chronic arthritis, congenital joint disease, or a systemic metabolic disorder (hemochromatosis, Wilson’s disease). SYMPTOMS/EXAM ■

■

■

Marked by insidious onset of joint pain without inflammatory signs (swelling, warmth, and redness). In contrast to the “morning stiffness” of inflammatory arthritis, OA worsens with activity during the day and improves with rest. Crepitus is a common nonspecific finding. There are no systemic manifestations. 1° OA usually involves the following joints: ■ Hands: DIP, PIP, and first carpometacarpal joints. The classic DIP deformities are also known as Heberden’s nodes (see Figure 11-5). Contrast this with the classic MCP lesions of RA. ■ Feet: First MTP joint. ■ Knees, hips. ■ Spine: C5, T9, and L3 are the most common spinal levels.

MUSCULOSKELETAL

Osteoarthritis. Severe osteoarthritis of the hands affecting the DIP joints (Heberden’s nodes) and the PIP joints (Bouchard’s nodes). (Reproduced with permission from Fauci AS et

FIGURE 11-5.

al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 326-2.)

DIAGNOSIS

OA is diagnosed by an overall clinical impression based on the history and physical as well as on radiographic findings (joint space narrowing that is frequently asymmetric [see Figure 11-6], subchondral sclerosis, and osteophytes) and labs (which are normal). TREATMENT ■

■

■

1° treatment consists of nonpharmacologic interventions such as weight loss, physiotherapy, and low-impact exercise. If medicating, start with acetaminophen or NSAIDs for mild symptoms. Complementary and alternative treatments include glucosamine and acupuncture. Intra-articular corticosteroid injections may be added for further pain control. Joint replacement is used for severe OA in patients who fail medical management and have marked limitation of their daily activities.

Radiographic changes in knee osteoarthritis. AP knee radiograph shows a narrowed joint space on the medial side of the joint only; subchondral sclerosis (arrowhead) and a cyst (lucency below the arrowhead); and osteophytes (arrow). (Reproduced with permission from

FIGURE 11-6.

Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. 7-40.)

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Low Back Pain (LBP) A 69-year-old man presents with back pain of > 1 year’s duration that radiates down his legs. He reports that the pain worsens when he walks downhill but is relieved with he walks uphill or bends over. You diagnose presumed spinal stenosis and order an MRI. You should ask about changes in bowel and bladder function to rule out what complication? Cauda equina syndrome.

The leading cause of missed workdays in the United States. Table 11-4 outlines the common causes of LBP. DIAGNOSIS ■

■

■

■

■

KEY FACT Order x-rays in geriatric patients with new-onset back pain or if the history and physical are suggestive of malignancy, infection, or inflammatory arthropathy.

■

Order a stat MRI if you suspect cauda equina syndrome. Assess the range of motion of the lower back. Localize the lower back tenderness to the spine or the paraspinal area. Conduct a neurologic exam to determine if the spinal nerves are affected (see Table 11-5). Suspect spinal cord involvement if the Babinski reflex is upgoing or if there is sphincter laxity. Remember, an UPgoing toe is an UPper motor neuron sign. A ⊕ straight leg raise test (in which a supine patient experiences leg, buttock, or back pain in the affected leg at < 30° of elevation of the affected leg) is sensitive for spinal nerve irritation or radiculopathy. A ⊕ crossed straight leg raise test (in which a supine patient experiences leg, buttock, or back pain in the affected leg at < 30° of elevation of the unaffected leg) is specific for spinal nerve irritation. Order a lumbar spine x-ray for patients in whom osteomyelitis, cancer, fractures, or ankylosing spondylitis is suspected or for those who fail to improve after 2–4 weeks of conservative therapy. Consider screening for osteoporosis if fractures are seen on x-ray. An MRI should be ordered if the patient has neurologic deficits for which surgery is being considered.

TREATMENT ■

■

Patients with cauda equina syndrome, spinal stenosis, or spinal nerve involvement require surgical evaluation. Degenerative LBP is treated with NSAIDs and physiotherapy. Heavy lifting should be avoided. Ankylosing spondylitis is treated with TNF inhibitors and physiotherapy. Most LBP from disk herniation will improve within six weeks; surgery should be considered in cases of progressive neurologic deficits.

MUSCULOSKELETAL

TA B L E 11- 4 .

CHAPTER 11

205

Causes of Lower Back Pain

SYMPTOMS/EXAM

TESTS

Cauda equina

Bowel and bladder incontinence or retention, saddle

Order a stat MRI if cauda equina is suspected.

syndrome

anesthesia. A medical emergency.

Degenerative

Chronic and progressive.

Order a lumbar spine x-ray to rule out other causes of

processes

Degeneration of disks leads to localized pain that can also

LBP.

refer to adjacent spinal nerves (eg, pain that radiates down the thigh). Severe disk disease can lead to spinal stenosis in which LBP worsens with standing and walking but improves with sitting or stooping forward (patients typically find it easier to walk uphill than downhill). Neoplastic

Traumatic

1° or metastatic to bone. Suspect in elderly patients with

A tumor mass may be seen on lumbar spine x-ray. Bone

unintentional weight loss or a history of cancer.

scan or MRI can detect disease not seen on plain film.

Acute onset of LBP is temporally associated with a traumatic

CT may be necessary to confirm a fracture and to assess the spinal columns for stability. Myofascial strain and disk

event.

herniations cannot be seen.

Look for local spinal tenderness 2° to a fracture or a herniated disk (pain worsens with cough; L4 or L5 nerve root compression). Perispinal tenderness indicates myofascial strain. Osteomyelitis

Fever, chills, or IV drug use.

X-ray may show disk narrowing and endplate destruction.

ESR will often be ↑ ↑.

MRI may be needed to aid in diagnosis and to assess for epidural abscess.

Ankylosing spondylitis

AP pelvic x-ray shows pseudo-widening, erosions, and

The typical patient is a young adult male presenting with

sclerosis of the sacroiliac joint.

chronic LBP that is worse in the morning and with

The classic “bamboo spine” on lumbar x-ray is from

sacroiliitis/arthritis of the hip, knee, or shoulder.

ossification of spinal ligaments.

Acute anterior uveitis, restriction of chest wall expansion,

HLA-B27 is 90% sensitive in Caucasians.

dactylitis, Achilles tendinitis, plantar fasciitis. Reduced spinal mobility. Referred

Can be 2° to disease from the aorta, kidneys, ureter, or

Conduct a thorough abdominal exam.

pancreas.

TA B L E 11- 5 .

SPINAL NERVE

Spinal Nerve Damage and Associated Sensorimotor Deficits

MOTOR DEFICITS

SENSORY DEFICIT

L3, L4

Problems rising from a chair and heel walking.

Over the anterior knee or the medial calf.

L5

Problems heel walking, extending the big toe, or

Over the medial aspect of the foot.

REFLEXES ↓ knee jerk.

dorsiflexing the ankle. S1

Problems toe walking or plantar flexing the ankle.

Over the lateral aspect of the foot.

↓ ankle jerk.

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MUSCULOSKELETAL

Common Orthopedic Injuries Tables 11-6 and 11-7 outline common adult and childhood orthopedic injuries.

TA B L E 11- 6 .

Common Adult Orthopedic Injuries

INJURY

MECHANICS

TREATMENT

Shoulder

Most commonly an anterior dislocation with the axillary artery and

Closed reduction followed by a sling and swath.

dislocation

nerve at risk. Posterior dislocations are associated with seizures and

Recurrent dislocations may need surgical repair.

electrocutions and can injure the radial artery. Patients with anterior injuries hold the arm in external rotation; those with posterior injuries hold the arm in internal rotation. Hip

Most often a posterior dislocation via a posteriorly directed force on

Closed reduction followed by abduction pillow/

dislocation

an internally rotated, flexed, adducted hip (“dashboard injury”).

bracing. Evaluate with CT scan after reduction.

Anterior dislocations can injure the obturator nerve; posterior dislocations can injure the sciatic nerve and cause avascular necrosis (AVN). Colles’

The most common wrist fracture. Involves the distal radius and

Closed reduction followed by application of a

fracture

commonly results from a fall onto an outstretched hand, resulting in

long-arm cast. Open reduction may be needed

a dorsally displaced, dorsally angulated fracture. Commonly seen in the

if the fracture is intra-articular.

elderly (osteoporosis) and in children. Boxer’s

Fracture of the fifth metacarpal neck. Often results from forward trauma

Closed reduction and ulnar gutter splint;

fracture

of a closed fist (eg, punching a wall, an individual’s jaw, or another

percutaneous pinning if the fracture is

fixed object).

excessively angulated. If skin is broken, assume infection by human oral pathogens (“fight bite”) and treat with surgical irrigation, debridement, and IV antibiotics to cover Eikenella.

Humerus

Results from direct trauma and puts the radial nerve at risk (the nerve

Hanging arm cast vs. coaptation splint and sling.

fracture

travels in the spiral groove of the humerus). Signs of radial nerve palsy

Functional bracing.

include wrist drop and loss of thumb abduction. Hip fracture

Most common in osteoporotic women who sustain a fall. Patients

Open or percutaneous reduction with internal

present with a shortened and externally rotated leg. Displaced

fixation with parallel pinning of the femoral

femoral neck fractures are associated with a high risk of AVN and

neck. Displaced fractures in elderly patients

fracture nonunion. Patients are at risk for subsequent DVTs.

(those > 80 years of age) may require a hip hemiarthroplasty. Anticoagulation is necessary for DVT prevention.

Achilles

Most commonly seen in unfit men who rupture while participating

Treatment is with a long-leg cast for six weeks

tendon

in sports and hear a sudden “pop” like a rifle shot. Exam shows

or surgical repair.

rupture

limited plantar flexion and a ⊕ Thompson test (squeezing the gastrocnemius does not result in foot plantar flexion).

MUSCULOSKELETAL

TA B L E 11- 6 .

207

Common Adult Orthopedic Injuries (continued)

INJURY Knee injuries

CHAPTER 11

MECHANICS Present with knee instability and possibly edema and hematoma. ■

ACL: Results from forced hyperflexion; anterior drawer and Lachman’s tests are ⊕. Rule out a meniscal or MCL injury.

TREATMENT Treatment of MCL/LCL and meniscal tears is conservative unless tears are associated with symptoms or concurrent ligamentous injuries.

■

PCL: Results from forced hyperextension; posterior drawer test is ⊕.

■

Meniscal tears: Clicking or locking may be present. Exam shows

reconstruction with graft from the patellar or

joint line tenderness and a ⊕ McMurray’s test.

hamstring tendons.

Treatment of ACL injuries is generally surgical

Operative PCL repairs are reserved for highly competitive athletes. Bucket-handle meniscal tears are generally treated arthroscopically. Other tears are treated conservatively. (Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 257–258.)

T A B L E 1 1 - 7.

Common Pediatric Orthopedic Injuries

INJURY

CHARACTERISTICS

TREATMENT

Clavicular

The most commonly fractured long bone in children. May be

Figure-of-eight sling vs. arm sling. The need

fracture

birth related (especially in large infants), and can be associated with

for surgical repair depends on the amount

brachial nerve palsies. Usually involve the middle third of the

of displacement and the patient’s level of

clavicle, with the proximal fracture end displaced superiorly due to the

function.

pull of the sternocleidomastoid muscle. Greenstick

Incomplete fracture involving the cortex of only one side of the bone.

fracture

Reduction with casting. Order films at 7–10 days.

Nursemaid’s

Radial head subluxation that typically occurs as a result of being

Manual reduction by gentle supination of the

elbow

pulled or lifted by the hand. The child complains of pain and will

elbow at 90° of flexion. No immobilization is

not bend the elbow.

necessary.

Osgood-

Overuse apophysitis of the tibial tubercle. Causes localized pain,

↓ activity for 1–2 years. A neoprene brace may

Schlatter

especially with quadriceps contraction, in active young boys.

provide symptomatic relief.

Fractures of the growth plate in children. Classified by fracture location

Types I and II can generally be treated

(see also Figure 11-7):

nonoperatively. Others, including unstable

disease Salter-Harris fractures

■

I: Physis (growth plate).

fractures, must be treated operatively to

■

II: Metaphysis and physis.

prevent complications such as leg length

■

III: Epiphysis and physis.

inequality.

■

IV: Epiphysis, metaphysis, and physis.

■

V: Crush injury of physis.

SALTeR-Harris: Slipped, Above, Lower (beLow), Through, Ruined (cRushed). (Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 273.)

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FIGURE 11-7. Mnemonic for Salter-Harris fractures. Imagine the number of the type drawn through the epiphyseal plate. Type 1 is a fracture of the growth plate (physis). Type 2 is a metaphyseal fracture. Type 3 is an epiphyseal fracture. Type 4 goes through both. This mnemonic doesn’t work well for type 5, so you just have to remember it is a crush injury of the physis.

Temporal Arteritis (Giant Cell Arteritis) A 73-year-old woman comes to your office, a small rural clinic with no vascular surgeon. She complains of a headache that has developed over the past month and is now accompanied by severe jaw pain when she chews her food. She has a palpable tender chord on her right temple, and you strongly suspect temporal arteritis. Should you wait to start systemic corticosteroids until she can get a temporal artery biopsy? No. It may be possible to get an accurate diagnostic biopsy weeks to months after starting treatment, but blindness resulting from temporal arteritis is permanent.

Affects older women more often than men by a ratio of 2:1. Can cause blindness 2° to occlusion of the central retinal artery (a branch of the internal carotid artery). Half of patients also have polymyalgia rheumatica. SYMPTOMS/EXAM ■

■

Classic symptoms consist of a new headache and scalp tenderness (eg, pain combing hair), temporal tenderness, jaw claudication, and visual symptoms such as monocular blindness. Temporal arteritis is also associated with weight loss, myalgias/arthralgias, and fever.

DIAGNOSIS

Obtain an ESR (often > 100 mm/hr), a prompt ophthalmologic evaluation, and a temporal artery biopsy. Biopsy will reveal thrombosis; necrosis of the media; and lymphocytes, plasma cells, and giant cells.

MUSCULOSKELETAL

CHAPTER 11

209

TREATMENT ■

■

Treat immediately with high-dose prednisone (40–60 mg/day) and continue for 1–2 months before tapering. Do not delay treatment, as blindness is permanent. Conduct serial eye exams for improvements or changes. Complications other than blindness can include angina, stroke, and aortic aneurysm.

Polymyalgia Rheumatica An inflammatory disease that causes severe pain and stiffness in proximal muscle groups without weakness or atrophy. Risk factors include female gender and age > 50. PMR is associated with giant cell arteritis, which may precede, coincide with, or follow polymyalgia symptoms.

KEY FACT Polymyalgia causes Pain but not weakness.

SYMPTOMS/EXAM ■

■

Typical symptoms include pain and stiffness of the shoulder and pelvic girdle areas with fever, malaise, weight loss, and minimal joint swelling. Patients classically have difficulty getting out of a chair or lifting their arms above their heads but have no objective weakness.

DIAGNOSIS

Look for concurrent anemia and an ↑↑ ESR. TREATMENT

Treat with low-dose prednisone (20 mg/day) followed by a long taper. Pain due to polymyalgia responds rapidly to corticosteroids (in 2–4 days).

Fibromyalgia A chronic pain disorder characterized by soft tissue and axial skeletal pain in the absence of joint pain or inflammation. It is thought to be a central amplification of pain sensory signals. It is typically a diagnosis of exclusion and can be frustrating to manage. SYMPTOMS/EXAM ■

■

Presents as a syndrome of myalgias, insomnia, weakness, and fatigue in the absence of inflammation; laboratory testing is 䊞. Associated with depression, anxiety, and irritable bowel syndrome; affects women more than men, and prevalence ↑ with age.

DIAGNOSIS

The research criteria used for diagnosis require 11 of 18 tender trigger points (see Figure 11-8) that reproduce pain with palpation.

KEY FACT Long-term steroid use can cause osteoporosis. Screen for bone loss with DEXA scans. Prevent and treat osteoporosis with calcium, vitamin D, weight-bearing exercise, and, when necessary, bisphosphonates.

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MUSCULOSKELETAL

FIGURE 11-8.

Trigger points in fibromyalgia. (Reproduced with permission from Le T et al. First Aid for

the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 265.)

TREATMENT ■

■

Treatment includes pregabalin (Lyrica), progressive physical reconditioning, improving restorative sleep, and supportive measures such as heat application. Consider hydrotherapy, transcutaneous electrical nerve stimulation (TENS), stress reduction, psychotherapy, or low-dose antidepressants.

Polymyositis A progressive, systemic connective tissue disease characterized by striated muscle inflammation. One-third of patients have dermatomyositis with coexisting cutaneous involvement. Patients may also develop myocarditis, pulmonary fibrosis, cardiac conduction deficits, or malignancy. More commonly seen in older women (50–70 years of age). SYMPTOMS/EXAM ■

Symmetric, progressive proximal muscle weakness sometimes accompanied by pain results in the classic complaint of difficulty rising from a chair. Patients may have trouble swallowing and difficulty with phonation, and they may eventually have difficulty breathing. Dyspnea may also be a sign of associated pulmonary fibrosis.

MUSCULOSKELETAL

CHAPTER 11

211

FIGURE 11-9. Gottron’s papules in dermatomyositis. Fingers of an elderly woman with classic dermatomyositis. Note the fully formed Gottron’s papules over the DIP joints, a hallmark cutaneous feature of dermatomyositis, along with the prominent nail-fold telangiectasias and dystrophic cuticles. The combination of Gottron’s papules and nail-fold changes is pathognomonic for dermatomyositis. (Reproduced with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Fig. 157-5.)

■

Dermatomyositis may present with a heliotrope rash (a violaceous periorbital rash) and Gottron’s papules (papules located on the dorsum of the hands over bony prominences; see Figure 11-9).

DIAGNOSIS ■ ■

Look for ↑ serum creatinine, aldolase, and CK. EMG demonstrates fibrillations. Muscle biopsy, which is necessary for definitive diagnosis, shows inflammatory cells and muscle degeneration.

TREATMENT ■

■

High-dose corticosteroids generally result in improved muscle strength in 4–6 weeks and are then tapered to the lowest effective dose for maintenance. Disease-modifying agents such as methotrexate may be used as steroidsparing therapy or for refractory symptoms.

Scleroderma A 64-year-old woman with diffuse scleroderma and stable angina underwent an echocardiogram and was found to have pulmonary hypertension. What medication, although typically prescribed for other purposes, is a possible treatment for pulmonary hypertension? Sildenafil. Remember, however, that nitrates such as sublingual nitroglycerin are strongly contraindicated for 24 hours after the use of sildenafil or other PDE-5 inhibitors.

KEY FACT Evaluate patients with dermatomyositis (more so than with polymyositis) for possible malignancy.

CHAPTER 11

212

MNEMONIC CREST syndrome:

Calcinosis Raynaud’s phenomenon Esophageal dysmotility Sclerodactyly Telangiectasias

MUSCULOSKELETAL

A multisystem disease with symmetric thickening of the skin on the face and extremities. It typically affects women 30–65 years of age. Diagnosis is clinical, supported by immunology and biopsy. There are two subtypes: limited and systemic (see Table 11-8).

TA B L E 11- 8 .

Limited vs. Diffuse Scleroderma

LIMITED (CREST)

DIFFUSE

Skin involvement

Distal, face only

Generalized

Progression

Slow

Rapid

Immunologic finding

Anticentromere antibody

Anti-Scl-70 antibody

Prognosis

Fair

Poor

Calcinosis

+++

+

Telangiectasia

+++

+

Renal failure

0

++

Pulmonary interstitial fibrosis

+

+++

CHAPTER 12

NEPHROLOGY Renal Basics

214

Acute Tubular Necrosis

224

GLOMERULAR FILTRATION RATE AND SURROGATES

214

Contrast Nephropathy

224

INTERPRETING A URINALYSIS

214

FRACTIONAL EXCRETION OF SODIUM

215

Chronic Kidney Disease

224

Hematuria

225

Electrolytes

216

SODIUM

216

Proteinuria

226

POTASSIUM

218

Nephrotic Syndrome

227

CALCIUM

219

Acid-Base Disorders

229

Renal Tubular Acidosis

230

Nephrolithiasis

231

Syndrome of Inappropriate Secretion of ADH

221

Acute Renal Failure

222

Acute Glomerulonephritis

223

213

CHAPTER 12

214

NEPHROLOGY

Renal Basics G LOM E R U LAR F I LTR ATI ON R ATE ( G F R ) AND S U R R OGATES ■

■

■

GFR is a marker of renal function defined by the amount of fluid entering Bowman’s space from the glomeruli per minute. It cannot be directly measured but is approximated using creatinine clearance (CrCl). CrCl is estimated by the Cockcroft-Gault equation, whereas GFR is estimated by the Modification of Diet in Renal Disease (MDRD) equation. CrCl generally overestimates GFR as creatinine is secreted into the tubule. Normal values are 100–130 mL/min/1.73 m2. Oliguria is generally defined as a urine volume of < 500 mL/day, or approximately 20 mL/hr. INT E R P R E TI NG A U R I NALYS I S ( U A)

Tables 12-1 and 12-2 offer guidelines for interpreting a UA.

TA B L E 12 - 1 .

Interpretation of UAs

TEST Proteinuria

INTERPRETATION A urine dip generally requires 100–150 mg/dL of protein to be 䊝; many dip tests can detect only albumin (not globulins or Bence Jones proteins). UA can detect both albumin and nonalbumin proteins, but there must be at least 1–10 mg of protein/dL for the UA to be 䊝.

Glucosuria

May indicate hyperglycemia; consider diabetes. May also indicate proximal tubule dysfunction, as in Fanconi’s.

Ketonuria

Occurs with starvation, poorly controlled diabetes (eg, DKA), and alcohol intoxication. Urine ketones can also be elevated following recent exercise and during pregnancy.

Hematuria/blood

A 䊝 value indicates myoglobin, hemoglobin, or RBCs in the urine.

Nitrite

Can become 䊝 with gram-䊞 bacteriuria.

Leukocyte esterase

Produced by WBCs; abnormal in urine; suggests a UTI.

pH

Alkalosis is most commonly associated with Proteus UTIs but may also be seen with some strains of Klebsiella, Pseudomonas, Providencia, and Staphylococcus. Acidosis with nephrolithiasis suggests uric acid or cystine stones. A pH of > 5.5 in the setting of metabolic acidosis suggests distal renal tubular acidosis (RTA). A low-sensitivity test.

Specific gravity

A rough estimate of urine osmolarity (Uosm).

Urobilinogen

Low sensitivity. ↑ urobilinogen occurs in hemolysis or hepatocellular disease; ↓ urobilinogen may suggest biliary obstruction.

Bilirubin

Bilirubin in the urine suggests a conjugated hyperbilirubinemia.

Epithelial cells

An excessive number of epithelial cells in the urine suggests a contaminated urine sample.

NEPHROLOGY

TA B L E 12 - 2 .

CHAPTER 12

215

Urine Sediment Analysis

FINDING

ASSOCIATION

Hyaline casts

A normal finding, but an ↑ amount, while nonspecific, suggests a prerenal condition.

RBC casts, dysmorphic

Glomerulonephritis.

RBCs Waxy casts

Chronic kidney disease.

WBC casts

Pyelonephritis or interstitial nephritis.

Eosinophils

Allergic interstitial nephritis.

Glomerular, “muddy

Acute tubular necrosis (ATN).

brown” casts RBCs

Indicates hematuria. The absence of RBCs when the dipstick is ⊕ for blood suggests hemoglobinuria from hemolysis or myoglobinuria from rhabdomyolysis.

WBCs

A finding of more than a few WBCs is always abnormal except when the sample is contaminated (eg, with epithelial cells). Causes include infection, nephrolithiasis, neoplasm, acute interstitial cystitis, prostatitis, acute interstitial nephritis, strictures, and glomerulonephropathy.

Crystals

See the discussion of nephrolithiasis.

Yeast, bacteria

Indicate infection if the sample is not contaminated (eg, with epithelial cells).

FRA C T I O N A L E X C R E T IO N O F S O D IU M ( F e Na ) ■

FeNa is calculated using measured plasma and urine levels of sodium and creatinine: FeNa = (UNa × PCr)/(UCr × PNa)

■ ■

■

■

The acronym “UP/UP” can be used to remember the FeNa equation. An FeNa of < 1% suggests a prerenal state such as CHF, dehydration, hepatorenal syndrome, or drug effects (eg, NSAIDs, ACEIs). An FeNa of > 2% suggests intrinsic renal disease such as ATN, acute interstitial nephritis, vasculitis, or anything causing renal ischemia. Note that FeNa should be used only in patients with oliguria (< 500 mL of urine per day).

216

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NEPHROLOGY

Electrolytes S ODI U M

Hyponatremia A 65-year-old man is brought to the ER because his family insists that he is “just not himself.” His wife thinks that he has been excessively thirsty lately, and she also notes a worsening cough but no fever. The man has a past medical history of smoking and CAD. A basic metabolic panel shows a serum sodium level of 115 mEq/L. What are the next steps in diagnosis? Basic steps in evaluating hyponatremia include assessing volume status and checking serum osmolality, urine osmolality, and urine sodium. Given this patient’s worsening cough, you might also consider a CXR, as this may be relevant in the setting of SIADH.

KEY FACT In pseudohyponatremia, measured serum sodium may be falsely ↓ by hyperlipidemia or hyperproteinemia.

Defined as a serum sodium level of < 135 mEq/L. SYMPTOMS ■

■

KEY FACT

Often asymptomatic, but may present with confusion, lethargy, muscle cramps, and nausea. When serum sodium is low or rapidly decreasing, hyponatremia may lead to cerebral edema that may result in seizures, status epilepticus, coma, or even death.

DIAGNOSIS No, you’re not an outstanding intern if you ↑ the patient’s sodium from 115 mEq/L to 135 mEq/L by the postcall morning. You may be able to bump hyponatremia to the bottom of your problem list, but central pontine myelinolysis will go to spot number one!

Assess volume status, and check serum osmolality, urine osmolality, and urine sodium (see Figure 12-1). TREATMENT ■ ■

■

Hypovolemic hyponatremia: Treat with NS or hypertonic (3%) NS. Euvolemic hyponatremia: If the patient is symptomatic, give hypertonic NS with furosemide. If asymptomatic, fluid restrict to 1 L/day. Note that overly rapid correction may result in central pontine myelinolysis (flaccid paralysis, dysarthria, dysphagia, and gait abnormalities). Maximum target correction should not exceed 8–10 mEq/L/day.

Hypernatremia

Defined as a serum sodium level of > 147 mEq/L. SYMPTOMS

Hyperpnea, weakness, restlessness, insomnia, altered mental status, coma. DIAGNOSIS ■ ■

Assess volume status, urine output, urine osmolality, and urine sodium. Hypernatremia from hypovolemia usually presents in the setting of dehydration, when the patient has limited access to free water. Uosm is usually > 700 mOsm/kg. Causes include ↑ insensible losses (burns, sweating, endotracheal intubation) and diarrhea.

NEPHROLOGY

Increased protein/lipids, not seen with new lab assays

CHAPTER 12

> 295

280–295 Sosm

217

Increased glucose, hypertonic infusion

Hypo-osmotic < 280

UNa < 10

UNa > 20

Hemorrhage Drains Skin GI

Diuretics Osmotic diuresis Salt wasting Adrenal insufficiency

Evaluation of hyponatremia.

FIGURE 12-1.

■

■

Hypervolemia: CHF Nephrotic syndrome Cirrhosis Renal failure

Euvolemia: Hypothyroidism Adrenal insufficiency Thiazides SIADH Polydipsia Beer potomania

Hypovolemia

Hypernatremia from ↑ total body sodium generally does not present with hypovolemia. Causes include excessive hydration with hypertonic fluids, dysfunction of central regulation, and mineralocorticoid excess (consider if the patient has hypokalemia and hypertension). Hypernatremia from renal losses (see Table 12-3) usually occurs in the setting of hypovolemia and a Uosm < 700 mOsm/kg. Consider the clinical context in the setting of the Uosm/Posm ratio to help determine the cause.

KEY FACT Hypernatremia often occurs with dehydration when a patient has no access to free water. Envision a salty desert.

TREATMENT ■

■

■

Always treat underlying causes (eg, DDAVP for central DI; a low-salt diet and thiazides for nephrogenic DI). Correct the free-water deficit with hypotonic saline, D5W, or oral water depending on the patient’s volume status. To prevent cerebral edema, do not correct hypernatremia at rate of > 12 mEq/L/day.

TA B L E 12 - 3 .

Causes of Hypernatremia 2° to Renal Losses

ETIOLOGY Osmotic diuresis

Causes: Mannitol, hyperglycemia, high-protein feeds, postobstructive

COMMENTS Uosm/Posm > 0.7.

diuresis. Central DI

Nephrogenic DI

The pituitary does not make ADH.

Uosm/Posm < 0.7.

Causes: Tumor, trauma, neurosurgery, infection.

Uosm should ↑ by 50% in response to DDAVP.

The kidneys are unresponsive to ADH.

Uosm/Posm < 0.7.

Causes: Renal failure, hypercalcemia, demeclocycline, lithium, sickle

Uosm should not respond to DDAVP challenge.

cell anemia.

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CHAPTER 12

NEPHROLOGY

POT AS S I U M

Hypokalemia

Defined as a serum potassium level of < 3.5 mEq/L. SYMPTOMS ■

■

May present with fatigue, muscle weakness or cramps, ileus, hyporeflexia, paresthesias, and flaccid paralysis if severe. ECG may show T-wave flattening, U waves (an additional wave after the T wave), ST-segment depression, and QT prolongation followed by AV block and subsequent cardiac arrest.

DIAGNOSIS ■ ■

KEY FACT The main determinant of urinary potassium wasting is urinary flow rate. The greater the urine volume production, the more potassium is wasted.

■

Order an ECG and check urine potassium. Urine potassium > 20 mEq/L: Usually indicates that the kidneys are wasting potassium. Acid-base status must be examined to further stratify the etiology. ■ Metabolic acidosis: Type I RTA (eg, amphotericin), lactic acidosis, or ketoacidosis. ■ Metabolic alkalosis: 1° or 2° hyperaldosteronism (check plasma renin activity and plasma aldosterone concentration), Cushing’s syndrome (check 24-hour urine cortisol), diuretics (loop or thiazide), vomiting, NG suction. ■ Variable pH: Gentamicin, platinum-containing chemotherapeutic agents, hypomagnesemia. Urine potassium < 20 mEq/L: Usually indicates a nonrenal source of hypokalemia. This could be from transcellular shift (eg, insulin, β2agonists, alkalosis, periodic paralysis) or from GI losses (eg, diarrhea, chronic laxative abuse).

TREATMENT ■ ■

■

Treat the underlying disorder. Provide oral and/or IV potassium repletion. Replete cautiously in patients with renal insufficiency Replace magnesium, as this deficiency makes potassium repletion more difficult.

Hyperkalemia A 55-year-old woman with a history of chronic renal insufficiency, likely 2° to hypertension and DM, is in the hospital receiving IV antibiotics for pyelonephritis. On admission, her baseline serum creatinine ↑ from 2.5 to 3.0 mg/dL. She is on her second day of antibiotics and has been afebrile with stable vital signs for the past 24 hours. She is feeling well. A basic metabolic panel this morning shows a serum potassium level of 5.8 mEq/L. You call the laboratory, and they state that the specimen was not hemolyzed. What do you do next? Get an ECG, as this may show serious signs of hyperkalemia. Next, follow the mnemonic C BIG K Drop. Start by administering calcium to stabilize the heart. Then give bicarbonate, insulin, and glucose for a fast-acting but short-lived response. Finally, you can give Kayexalate and furosemide to dispose of the excess potassium. Also make sure you remove any extra potassium from the patient’s diet and/or IV fluids.

NEPHROLOGY

CHAPTER 12

Defined as a serum potassium level of ≥ 5 mEq/L. Etiologies include the following: ■ ■ ■

■

Spurious: Hemolysis (can also ↑ with high platelets or WBCs). Excessive intake: Ingestion, iatrogenic. Renal: Renal failure, type IV RTA (see below), adrenal insufficiency (low mineralocorticoid state), drugs (spironolactone, ACEIs, TMP-SMX, digoxin overdose). Cellular release: Hyperkalemia during acidosis, cell lysis, retroperitoneal hemorrhage.

SYMPTOMS ■

■

Usually asymptomatic, but may present with muscle weakness and abdominal distention. ECG may show tall, peaked T waves and PR prolongation followed by loss of P waves and QRS widening that progress to sine waves, ventricular fibrillation, and cardiac arrest (see Figure 12-2).

DIAGNOSIS ■ ■ ■

Order a repeat blood draw unless suspicion is high. Obtain an ECG. Urine potassium levels can help determine the etiology of the hyperkalemia. ■ Urine potassium < 40 mEq/L: Usually indicates that the hyperkalemia is caused by ↓ potassium excretion by the kidneys. Causes include renal insufficiency, drugs (eg, spironolactone, triamterene, amiloride, ACEIs, TMP, NSAIDs), and mineralocorticoid deficiency (type IV RTA). A plasma renin activity and plasma aldosterone concentration should be ordered if a mineralocorticoid deficiency is suspected. ■ Urine potassium > 40 mEq/L: Usually points to a nonrenal etiology. Causes include cellular shifts resulting from tissue injury, tumor lysis, insulin deficiency, drugs (eg, succinylcholine, digitalis, arginine, α-blockers), and iatrogenic factors.

TREATMENT ■

■

■

Values > 6.5 mEq/L or ECG changes (especially PR prolongation or wide QRS) require emergent treatment. ■ Calcium gluconate (for cardiac cell membrane stabilization) should be given immediately to prevent arrhythmias, ■ Temporary treatment includes β2-agonists, insulin and glucose, and sodium bicarbonate. ■ Long-lasting elimination requires Kayexalate and a loop diuretic. Restrict dietary potassium and discontinue any medications that may be contributing to the hyperkalemia. Severe or symptomatic hyperkalemia, hyperkalemia refractory to the above management, or patients on chronic hemodialysis may require acute hemodialysis. C A L C IU M

Hypocalcemia ■ ■

Defined as a serum ionized calcium level of < 8.4 mg/dL. Correct for hypoalbuminemia. For every 1-mg/dL ↓ in albumin, ↑ the calcium level by 0.8 mg/dL. Alkalosis ↑ calcium binding to albumin.

219

MNEMONIC Treatment of hyperkalemia—

C BIG K Drop Calcium gluconate Bicarbonate Insulin Glucose Kayexalate Diuretic/Dialysis

QRS prolongation

Peaked T

PR prolongation Low P

FIGURE 12-2. Effects of hyperkalemia as seen on ECG.

CHAPTER 12

220

MNEMONIC

NEPHROLOGY

■

Causes of hypocalcemia—

HIPOCAL Hypoparathyroidism/hypomagnesemia Infection Pancreatitis Overload (rapid volume expansion) Chronic kidney disease Absorption abnormalities Loop diuretics

■

■

Etiologies include ↓ GI absorption (as found in hypoparathyroidism, pseudohypoparathyroidism, vitamin D deficiency, malabsorption, renal failure, critically ill patients, and hypomagnesemia), acute pancreatitis, rhabdomyolysis, tumor lysis, and diuretics. Don’t forget to check a calcium level after a total thyroidectomy. Sx: Paresthesias, tetany, lethargy, confusion, seizures, Trousseau’s sign, Chvostek’s sign, QT prolongation. Tx: Replace with calcium carbonate orally or with IV calcium gluconate.

Hypercalcemia

Defined as a serum calcium level of > 10.2 mg/dL. SYMPTOMS

May present with bones (fractures), stones (kidney stones), abdominal groans (anorexia, nausea, constipation), and psychiatric overtones (weakness, fatigue, altered mental status). Consider in patients with pancreatitis, refractory peptic ulcer disease, a personal or family history of kidney stones, or bone pain. DIAGNOSIS ■ ■

■

MNEMONIC Causes of hypercalcemia—

CHIMPANZEES Calcium supplementation Hyperparathyroidism Iatrogenic/Immobility Milk-alkali syndrome Paget’s disease Addison’s disease/Acromegaly Neoplasm Zollinger-Ellison syndrome Excess vitamin A Excess vitamin D Sarcoidosis

Inquire about diet and vitamin supplementation. Check calcium, phosphate, albumin, ionized calcium, and alkaline phosphatase. Also consider vitamin D levels, SPEP, TSH, and imaging. Hyperparathyroidism is a common cause of hypercalcemia, so check PTH and parathyroid hormone–related peptide (PTHrP) levels. To ensure the patient’s safety, order an ECG (may show a short QT interval). ■ Elevated PTH: Indicates that 1° hyperparathyroidism (eg, from adenoma, hyperplasia, carcinoma, or MEN 1/2) is the likely cause (see Chapter 5 for more details). Consider an ectopic PTH-producing tumor as well. ■ Normal or low PTH: ■ Indicates that the cause could be excessive calcium or vitamin D intake, granulomatous disease, sarcoidosis, malignancy (eg, hematologic, lymphoproliferative, multiple myeloma, bone metastases), milk-alkali syndrome, or Paget’s disease. ■ PTHrP secretion from cancer cells (often squamous cell carcinoma) can cause a paraneoplastic hypercalcemia. The elevated calcium suppresses the normal parathyroid gland, resulting in low PTH levels. ■ Testing options include phosphate, vitamin D, TSH, serum immunoelectrophoresis (for MGUS), alkaline phosphatase (for Paget’s), GGT (to determine the origin of the elevated alkaline phosphatase), spot urine calcium, spot urine creatinine, BUN/creatinine, and x-rays/bone scan (to look for lytic lesions).

NEPHROLOGY

CHAPTER 12

TREATMENT ■ ■

■

■

Identify and treat the underlying cause. For 1° hyperparathyroidism, parathyroidectomy is needed. In all other cases, additional treatment measures depend on the severity of the hypercalcemia. Possible interventions include the following: ■ Discontinue all drugs that can cause hypercalcemia (eg, thiazides). ■ Place the patient on a low-calcium diet. ■ Hydrate and use furosemide to ↑ calcium excretion and, if necessary, to prevent volume overload. Patients with symptomatic hypercalcemia or a serum calcium level > 14 mg/dL require IV bisphosphonates (eg, pamidronate) or calcitonin. However, each takes 12–24 hours to have an effect, and the therapeutic benefits of both may be short-lived. Hemodialysis is a last resort.

Syndrome of Inappropriate Secretion of ADH (SIADH) A major cause of hyponatremia due to ↑ ADH release without osmolalitydependent or volume-dependent physiologic stimuli. Causes include the following: ■

■

■ ■

Pulmonary: Small cell carcinoma, TB, pneumonia, pulmonary abscess. Consider ordering a CXR. CNS: Meningitis, brain abscess, head trauma. Consider ordering a head CT. Drugs: Clofibrate, chlorpropamide, phenothiazine, carbamazepine. Ectopic ADH production: Lymphoma, sarcoma, duodenal/pancreatic cancer.

DIFFERENTIAL

Hypothyroidism; consumption of too much water with not enough salt (psychogenic polydipsia, beer potomania). DIAGNOSIS ■ ■

Asymptomatic unless serum sodium becomes very low (< 120 mEq/L). Check plasma and urine osmolalities and sodium. Findings include Posm < 270 mOsm/kg; Uosm > 100 mOsm/kg; euvolemia; and normal renal, adrenal, and thyroid function. SIADH cannot be diagnosed in a hypovolemic patient regardless of plasma or urine osmolalities.

TREATMENT ■

■

Fluid restriction (free-water consumption < 1 L/day). If response is inadequate, add demeclocycline to antagonize ADH. Treat symptomatic hyponatremia with hypertonic saline (see the discussion of hyponatremia). Do not give patients with SIADH NS, as this can paradoxically worsen the hyponatremia.

MNEMONIC Causes of SIADH—

BCDE Breathing (pulmonary) CNS Drugs Ectopic

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Acute Renal Failure (ARF) A 65-year-old man who is otherwise healthy comes to your primary care clinic for a routine checkup after getting a set of labs. The patient’s serum creatinine is 1.8 mg/dL, up from 1.1 mg/dL three months ago. The patient states that he has been producing plenty of urine, maintaining that he goes to the bathroom every 20 minutes. He adds that his urine “mostly just dribbles out” and that he’s not sure if he is completely emptying his bladder, as he feels some fullness in his suprapubic region. On exam, you feel a suprapubic mass. What should you do next? Evaluate the patient for urinary retention, as this is likely the cause of his renal failure. Consider ordering a bladder scan, a straight catheterization, or placement of a Foley catheter. If the patient has a large postvoid residual, he should keep his Foley in place and be referred to urology. As this condition is most commonly 2° to BPH, consider starting α-blockers and 5α-reductase inhibitors.

A ↓ in GFR (usually corresponding to an ↑ in creatinine of 0.5 mg/dL or > 50% over the baseline value) occurring over a period of hours to days. Results in failure of the kidneys to excrete nitrogenous waste and to maintain fluid and electrolyte balance. Oliguria (defined as < 500 mL/day) is not required for ARF but should prompt one to test for it. SYMPTOMS/EXAM ■

■

Patients are often asymptomatic but may present with dyspnea, uremic symptoms (eg, anorexia, nausea, malaise, hyperpigmented skin, asterixis, pericarditis [listen for a friction rub]), and anemia. Examination should include checking BP, daily weights, and assessment of volume status. Other findings are specific to the etiology of the renal failure.

DIAGNOSIS KEY FACT An FeNa < 1% suggests prerenal failure.

ARF is categorized as prerenal, intrinsic, or postrenal (see Table 12-4). To determine the etiology, order electrolytes, BUN/creatinine, and a UA with micro and urine eosinophils, and calculate FeNa (see the discussion of renal basics). ■

■

Prerenal failure: Caused by ↓ renal perfusion. FeNa is usually < 1% and the BUN/creatinine ratio > 20. Can be due to anything that causes the kidneys to “see” less volume. ■ Listen for a renal artery bruit characteristic of renal artery stenosis. ■ If a bolus of isotonic fluids improves the BUN/creatinine ratio, prerenal failure due to shock is the likely cause, but make sure the patient is not in CHF before giving the bolus! Intrinsic failure: Can be vascular, glomerular, tubular (most common), or interstitial. Usually presents with hematuria, proteinuria, and/or casts on UA. ■ Glomerulonephritis presents with a nephritic syndrome (RBCs/RBC casts).

NEPHROLOGY

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223

Causes of Acute Renal Failure

PRERENAL Dehydration (anorexia, burns, GI losses) ACEIs, NSAIDs

INTRINSIC Interstitial: Acute interstitial nephritis (eg, penicillins, systemic infections)

POSTRENAL Ureteral stenosis: Papillary necrosis, stones, blood clot, retroperitoneal fibrosis

Renal artery stenosis

Glomerular: Nephritides

Bladder neck: Anticholinergics, tumor

All causes of shock (eg, cardiogenic,

Tubular: ATN (often drug induced, eg,

Prostate: BPH, cancer, prostatitis

hypovolemic) Hepatorenal syndrome Cardiomyopathies

aminoglycosides, radiocontrast) Vascular: Emboli, occlusion, vasculitis, renal vein thrombosis

Acute interstitial nephritis yields a UA with eosinophils, WBCs, and WBC casts. ■ ATN presents with an FeNa > 1% and a urine sediment with pigmented granular (“muddy brown”) casts and renal tubular epithelial cells. ■ Suspect a vascular cause in predisposed patients (eg, those with a hypercoagulable state) presenting with abdominal pain. Postrenal failure: Caused by urinary outflow obstructions in one or both ureters, the bladder neck, the urethra, or the prostate. Patients can present in fluid overload from urinary retention. ■ Determine a postvoid residual—ie, have the patient urinate, and then insert a Foley catheter to measure the urine remaining in the bladder. A postvoid residual of > 75 mL points to bladder outlet obstruction (from a large prostate, a high bladder neck, or a urethral stricture) or indicates that the bladder is unable to contract fully. ■ Renal ultrasound or CT scan can detect hydronephrosis. ■ Men should have a prostate exam in cases of postrenal failure. ■

■

TREATMENT

Treat the underlying cause and the sequelae. Protect the kidneys with the following interventions: ■

■ ■

■ ■ ■

■

Discontinue nephrotoxic medications, and ↓ any renally excreted medications in proportion to the GFR. Avoid contrast studies unless they are essential. To keep patients euvolemic, give IV fluids and, if absolutely necessary, furosemide (be careful to prevent further damage!). Volume expansion, however, may not shorten the duration of ATN. Initiate a low-potassium diet. Monitor and correct calcium, PO4, and potassium. If the pH is < 7.2, bicarbonate may be used to treat a nongap acidosis or to temporize an anion-gap metabolic acidosis (until dialysis). Dialyze if indicated (see the mnemonic AEIOU).

Acute Glomerulonephritis ■ ■

Relatively acute onset of hypertension, hematuria, edema, and oliguria. Dx: ■ UA shows microscopic hematuria with RBC casts and dysmorphic red cells. Proteinuria is usually present in subnephrotic ranges.

MNEMONIC Indications for emergent dialysis—

AEIOU Acidosis Electrolytes (hyperkalemia) Ingestion (of toxins) Overload (volume) Uremic symptoms (encephalopathy, pericarditis)

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Renal biopsy is the gold standard for diagnosis. Evaluation may also include checking complement levels, ANCA, ANA, anti-dsDNA, cryoglobulin, hepatitis B and C, anti-GBM antibodies, ASO, and blood cultures. Tx: Treat inflammatory disorders with steroids and cytotoxic agents. In cases 2° to systemic disease, treat the underlying disorder.

■ ■

■

Acute Tubular Necrosis (ATN) The most common form of intrinsic ARF. Usually caused by toxic or ischemic damage. Causes include the following: ■

■

■

Exogenous nephrotoxins: Chemotherapeutic agents (cisplatin, methotrexate) and other immunosuppressants (cyclosporine, tacrolimus), aminoglycosides, amphotericin B, cephalosporins, heavy metals, and radiocontrast dyes (effects can be minimized by hydration and oral N-acetylcysteine). Endogenous nephrotoxins: Hyperuricemia, rhabdomyolysis, massive intravascular hemolysis, Bence Jones proteins (from multiple myeloma). Ischemia: All causes of shock. ATN can therefore be a complication of prerenal ARF.

DIAGNOSIS

Check the same labs/studies as one would with other forms of ARF plus a serum CK and uric acid level. FeNa is usually > 1%, and routine UA shows a sediment with pigmented granular (“muddy brown”) casts and renal tubular epithelial cells. TREATMENT ■

■

Treat as per ARF. If the patient is ischemic, treat the underlying cause. If toxic, remove or minimize the toxin. With rhabdomyolysis, aggressively hydrate to keep urine output > 300 mL/ hr; the use of mannitol for diuresis and bicarbonate to alkalinize urine remains controversial.

Contrast Nephropathy ■

■

■

■

Characterized by an acute decline in GFR that occurs 24–48 hours after a patient receives IV radiocontrast. Risk factors include preexisting renal insufficiency, diabetes, ↓ effective arterial volume, a high volume of contrast, and concomitant nephrotoxic medications. Patients with an ↑ risk of developing contrast nephropathy should receive prophylaxis with IV fluids, sodium bicarbonate, and acetylcysteine. Tx: Treatment is supportive. Contrast nephropathy usually resolves in one week.

Chronic Kidney Disease (CKD) An irreversible or only partially reversible state in which the kidneys have lost the ability to regulate some combination of the body’s fluid state, electrolyte levels, and acid-base status. Erythropoiesis and vitamin D metabolism are often compromised as well.

NEPHROLOGY

CHAPTER 12

SYMPTOMS/EXAM ■

■

■

May be asymptomatic, or may present with a clinical picture that appears inconsistent with the severity of the disease. If mild or gradual, other organ systems may compensate (eg, hyperventilation to blow off CO2). As CKD worsens—ie, as GFR approaches zero—uremic and anemic symptoms worsen, and patients appear progressively more ill. Urine volume may remain normal despite marked changes in serum (elevation) or urine (reduction) electrolytes, urea nitrogen levels, and creatinine. Urine output will ↓ as CKD reaches a terminal stage.

DIAGNOSIS ■

■

■

A serum creatinine that is persistently > 1.4 mg/dL is generally considered diagnostic. Lower cutoffs are applied to patients with less muscle mass (often shorter or older patients), particularly women, and higher cutoffs to large, muscular patients (remember to examine the labs and the patient). Etiologies vary, and appropriate identification of the cause is critical to preventing disease progression. Most causes are similar to those of ARF and include the following: ■ ARF: Persistent ARF can lead to CKD. Identifying what caused the ARF remains important (see the earlier discussion). ■ Prerenal causes: Addison’s disease, CHF, cirrhosis. ■ Intrinsic renal disease: Diabetes, hypertension, drugs, glomerulonephritis, malignancy, hereditary renal disease, renal vascular disease. Diabetes and hypertension are the most common causes of CKD. ■ Postrenal causes: Includes anything that causes postrenal obstruction, such as kidney stones, compression of the ureters (eg, masses, scarring), neurogenic bladder, and an enlarged prostate. Note that high-protein diets, rhabdomyolysis, and certain medications (eg, cimetidine, TMP) can ↓ creatinine excretion, in which case serum creatinine may be high without renal impairment.

TREATMENT ■

■

■

■

■

Detect and treat any reversible causes. Follow the indications for dialysis as laid out in the discussion of ARF. For intrinsic renal disease, it is important to optimize the kidney in other respects—ie, to control hypertension, avoid nephrotoxic drugs, control blood glucose level, restrict protein intake, and control lipids. Patients should be placed on a renal diet to prevent a high potassium load. Long-term treatment often involves erythropoietin (if the patient is anemic), vitamin D, phosphate binders, and calcium. Bicarbonate may be used for severe acidosis. Prepare the patient for dialysis. Avoid IVs in the arm that will be used for AV shunts. The only definitive treatment for irreversible end-stage renal disease is transplantation.

Hematuria Defined as three or more RBCs/hpf on urine microscopy. Gross hematuria is present when blood is visible to the naked eye. DIFFERENTIAL

Pseudohematuria is defined as urine that gives the false impression of hematuria either grossly or by laboratory testing. It may result from certain drugs,

KEY FACT Urine volume may be completely normal in acute and chronic renal failure.

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KEY FACT Remember—true hematuria must have RBCs.

NEPHROLOGY

foods, or dyes that cause myoglobinuria, hemoglobinuria, or simple discoloration of urine. DIAGNOSIS ■

■

■

Patients with gross hematuria should have a UA to rule out UTI, nephrolithiasis (indicated by crystals on urine microscopy), and tubulointerstitial nephritis (indicated by urine WBCs, WBC casts, and/or eosinophils, though less common). If the UA shows RBC casts or the daily urinary protein is > 1 g, suspect a glomerular cause for the hematuria (see the discussion of nephritic syndrome below). First repeat the UA, as there are benign causes for isolated hematuria, such as vigorous exercise. If an infection is evident, treat the infection and then repeat the UA to confirm resolution of the hematuria with elimination of the infection. In all patients with confirmed hematuria, check PTT, PT, and platelets to determine if any coagulopathy is present. Male patients should undergo a prostate exam to look for BPH or prostatitis as a cause of the hematuria. Urine cytology can be sent if there is reason to suspect bladder cancer (eg, smoking, exposure to organic compounds). If the initial workup is 䊞 or hematuria persists despite treatment, proceed as follows: ■ Look for upper tract (renal and ureteral) causes of hematuria by ordering an IVP, a CT urogram, or a renal ultrasound to look for renal masses, polycystic kidneys, or hydronephrosis/hydroureter that may be 2° to nephrolithiasis. ■ If no upper tract cause can be found, cystoscopy can look for lower tract causes of hematuria, such as interstitial cystitis, or bladder cancer. ■ If the workup is still 䊞 and suspicion is high, a renal angiogram may be ordered to look for vascular causes (eg, renal vein thrombosis, varices, aneurysms, AVMs).

Proteinuria Urinary protein excretion of > 150 mg/24 hrs. Nephrotic syndrome consists of severe proteinuria that is defined as a daily urinary protein excretion of > 3.5 g (see the following section). Microalbuminuria is defined as a persistent daily urinary protein excretion of 30–300 mg in a patient with diabetes. Transient microalbuminuria can occur with infection, stress, and illness. SYMPTOMS/EXAM

Presentation is generally unremarkable unless the patient has nephroticrange proteinuria. In such instances, patients usually present with generalized edema and/or frothy urine. DIAGNOSIS

To ascertain the cause of proteinuria, it is important to know the quantity and type of protein involved. To determine this, proceed as follows (see also Table 12-5): ■

■

■

Obtain a 24-hour urine collection to quantify daily urinary protein excretion. If this is not possible, check a urine protein/creatinine ratio (normal is < 0.2; nephrotic syndrome is > 3.0). Check a UA, electrolytes, BUN/creatinine, urine protein electrophoresis, and serum total protein. Examine urine sediment. A benign appearance suggests benign causes, while red cells and casts suggest acute nephritic syndrome, and fat bodies

NEPHROLOGY

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227

Location of Renal Disease in Proteinuria

LOCATION Interstitial nephritis

URINE PROTEIN < 2 g/24 hrs

LAB FINDINGS

ETIOLOGIES

Routine UA shows WBCs, WBC

Infection, medications (NSAIDs, quinolones,

casts, and eosinophils.

sulfonamides, rifampin), connective tissue diseases (SLE, sarcoidosis, Sjögren’s syndrome).

Glomerular disease

Overflow proteinuria

■

> 2 g/24 hrs

< 2 g/24 hrs; mostly light-

Routine UA shows RBCs or RBC

See the discussion of nephritic and nephrotic

casts.

syndromes.

↑ serum protein.

Amyloid, multiple myeloma,

chain or low-molecular-weight

lymphoproliferative disease, hemoglobin,

proteins.

myoglobin.

point to nephrotic syndrome. (Note the difference between nephritic and nephrotic syndromes.) A UA significant only for protein in the absence of other signs of renal disease suggests benign proteinuria. Causes include pulmonary edema, CHF, fever, exercise, head injury, CVA, stress, orthostatic proteinuria, and idiopathic factors.

TREATMENT ■

Treat any underlying causes: Hyponatremia: Free water restriction. ■ Peripheral edema: Furosemide. ■ Diabetes with microalbuminuria or proteinuria: Treat diabetes and use ACEIs. Proteinuria itself does not require treatment. Patients in whom proteinuria persists for many years are at ↑ risk for renal failure. In these cases, consider a low-salt and low-saturated-fat diet, and limit protein intake to 1 g/kg/day. ■

■

Nephrotic Syndrome A mother brings her two-year-old boy to the clinic because his face seems swollen and he is heavier overall. The child recently had a URI, and you were able to reassure the parents over the phone. Although the child’s upper respiratory symptoms have improved, he has grown more fatigued. On exam, you note dependent edema, and you send some labs and a UA, which reveals 3+ protein. Light microscopy shows normal-appearing glomeruli, and biopsy reveals podocyte effacement. What is your diagnosis? Minimal change disease. The mother is only minimally impressed.

A syndrome of edema, hypoalbuminemia, and severe proteinuria that is defined as > 3.5 g of urinary protein/24 hrs. Patients may also have hyperlipidemia and hypercoagulability. Causes are summarized in Table 12-6.

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228

TA B L E 12 - 6 .

NEPHROLOGY

Causes of Nephrotic Syndrome

PATHOLOGY

DESCRIPTION

HISTORY/PE

LABS Light microscopy appears

Minimal change

Common in children;

Patients have a tendency

disease

idiopathic etiology.

toward infections and thrombotic events.

normal.

TREATMENT/ PROGNOSIS Steroids; excellent prognosis.

Electron microscopy shows fusion of epithelial foot processes with lipidladen renal cortices.

Focal segmental

Idiopathic, IV drug use,

The typical patient is a

Microscopic hematuria;

Prednisone, cytotoxic

glomerulosclerosis

HIV infection.

young African American

biopsy shows sclerosis in

therapy.

male with uncontrolled

capillary tufts.

hypertension. Membranous

The most common

Associated with HBV,

“Spike and dome”

Prednisone and cytotoxic

nephropathy

nephropathy in adult

syphilis, malaria, and

appearance due to

therapy for severe disease.

Caucasians; an immune

gold.

granular deposits of IgG and C3 at the basement

complex disease.

membrane. Diabetic nephropathy

Has two characteristic

Patients generally have

Thickened GBM; ↑

Tight control of blood

forms: diffuse

long-standing, poorly

mesangial matrix.

sugar; ACEIs.

hyalinization and nodular

controlled DM.

glomerulosclerosis (Kimmelstiel-Wilson lesions). Lupus nephritis

Classified as WHO types

Proteinuria or RBCs

Mesangial proliferation;

Prednisone and cytotoxic

I–V. Both nephrotic and

on UA may be found

subendothelial immune

therapy may reduce

nephritic. The severity

during evaluation of SLE

complex deposition.

disease progression.

of renal disease often

patients.

determines overall prognosis. Renal amyloidosis

1° (plasma cell dyscrasia)

Patients may have

Abdominal fat biopsy;

Prednisone and

and 2° (infectious or

multiple myeloma or a

seen with Congo red

melphalan. Bone marrow

inflammatory) are the

chronic inflammatory

stain; apple-green

transplantation may

most common.

disease (eg, RA, TB).

birefringence under

be used for multiple

polarized light.

myeloma.

Membranoproliferative

Can also be nephritic

Slow progression to renal

“Tram-track” double-

Corticosteroids and

nephropathy

syndrome. Type I is

failure.

layered basement

cytotoxic agents may help.

associated with HCV,

membrane. Type I has

cryoglobulinemia, SLE,

subendothelial deposits;

and subacute bacterial

type II involves a C3

endocarditis.

nephritic factor; all three types have ↓ C3.

(Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 487–488.)

NEPHROLOGY

CHAPTER 12

DIAGNOSIS ■

■

■

■

In addition to the labs ordered for the workup of proteinuria, order a lipid panel, and examine urine sediment (reveals fatty vacuoles in a Maltese cross pattern). To evaluate for nonrenal causes, check an ANA, a hepatitis panel, RPR, fasting glucose, a pregnancy test, and HIV status. It should be noted that serum sodium, calcium, thyroxine, and anion gaps are often low, while ESR is often elevated. Consider a renal biopsy if the etiology is still not evident from the initial studies. Roughly one-third of cases are caused by diabetes, amyloidosis, or SLE nephropathy. The remainder are usually due to one of four 1° renal diseases: minimal change disease, focal glomerulosclerosis, membranous nephropathy, or membranoproliferative glomerulonephritis. Since albumin, coagulation proteins (eg, proteins C and S), immunoglobulins, and binding proteins (especially for calcium, vitamin D, and transferrin) may all be lost, patients may be edematous, hypercoagulable, immune deficient, and deficient of vitamins, minerals, and iron.

TREATMENT ■

■

Treat as per proteinuria, except that patients with hyperlipidemia should be started on a statin. Patients who develop thrombosis require anticoagulation. Pneumovax is also recommended. Biopsy may be required to establish the diagnosis and to guide the treatment of underlying causes.

Acid-Base Disorders The algorithm for acid-base disorders is as follows: 1. Identify the primary disorder: a. Respiratory alkalosis: pH > 7.40, pCO2 < 40 b. Respiratory acidosis: pH < 7.40, pCO2 > 40 c. Metabolic alkalosis: pH > 7.40, HCO3 > 24 d. Metabolic acidosis: pH < 7.40, HCO3 < 24 2. Determine the anion gap (sodium minus HCO3 and chloride). If the anion gap is ≥ 20, then a metabolic acidosis exists. A normal anion gap is 12. 3. Determine the delta gap if there is a metabolic acidosis (anion gap minus 12 plus the patient’s HCO3). If the delta gap is > 30, then there is a concomitant metabolic alkalosis. If the delta gap is < 24, there is a concomitant metabolic acidosis. 4. Consider compensation, both metabolic and respiratory, and both acute and chronic. Figure 12-3 demonstrates a flow chart for evaluating acid-base disorders.

MNEMONIC Causes of gap acidosis—

MUDPILERS Methanol Uremia Diabetic ketoacidosis Paraldehyde INH, Iron toxicity Lactic acidosis Ethylene glycol Rhabdomyolysis Salicylates

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230

NEPHROLOGY

Check arterial pH

pH < 7.4 Acidosis

pH > 7.4 Alkalosis

PCO2 > 40 mmHg

PCO2 < 40 mmHg

Respiratory acidosis

Metabolic acidosis with compensation

PCO2 < 40 mmHg

Respiratory alkalosis —Hyperventilation —ASA ingestion (early)

Check anion gap Hypoventilation —Acute lung disease —Chronic lung disease —Opioids, narcotics, sedatives —Weakening of respiratory muscles

FIGURE 12-3.

↑ anion gap —Renal failure —Lactic acidosis —Ketoacidosis (DM) —ASA ingestion

PCO2 > 40 mmHg

Metabolic alkalosis with compensation —Vomiting —Diuretic use —Antacid use —Hyperaldosteronism

Normal anion gap (8–12 mEq/L) —Diarrhea —Glue sniffing —RTA —Hyperchloremia

Acid-base disorders.

Renal Tubular Acidosis (RTA) May occur 2° to renal or adrenal disease, or may be a 1° disease. Due to a net ↓ in either tubular hydrogen (H+) secretion or bicarbonate reabsorption that leads to a non-anion-gap metabolic acidosis. There are four types of RTA (see Table 12-7), but only three are clinically important. Type IV (distal) is the most common; type III is uncommon and is seen only in children. DIAGNOSIS

Usually asymptomatic. In distal RTA there are fewer urinary anions (mostly Cl–) than cations (Na+, K+), whereas in proximal RTA there is high urinary bicarbonate despite low serum bicarbonate.

NEPHROLOGY

T A B L E 1 2 - 7.

231

Types of Renal Tubular Acidosis

TYPE I (DISTAL) H+ secretion.

Defect

CHAPTER 12

TYPE II (PROXIMAL) HCO3– reabsorption.

TYPE IV (DISTAL) Aldosterone deficiency or resistance leads to defects in Na+ reabsorption, H+ and K+ excretion, and ↓ ammoniagenesis.

Serum K+

High or low.

Low.

High.

Urinary pH

> 5.3.

> 5.3 initially; < 5.3 once

< 5.3.

serum is acidic. Etiologies

Hereditary, amphotericin, collagen

Hereditary, carbonic anhydrase

Hyporeninemic hypoaldosteronism with DM;

(most

vascular disease (eg, scleroderma),

inhibitors, Fanconi’s syndrome,

hypertension, chronic interstitial nephritis.

common)

cirrhosis, nephrocalcinosis.

tenofovir.

Treatment

Potassium citrate.

Potassium citrate.

Furosemide, Kayexalate.

Complications

Nephrolithiasis.

Rickets, osteomalacia.

Hyperkalemia.

Nephrolithiasis A 38-year-old woman comes to the ER complaining of fevers and right flank pain. She says that the pain began two days ago but worsened today. She states that she is otherwise healthy. For medications, she says she takes only HAART therapy. You ask if she has HIV, and she says yes. On physical exam, she is found to have right CVA tenderness. A UA shows 20–50 RBCs/hpf and 20–50 WBCs/hpf. You order a CT scan, which reveals moderate right-sided hydronephrosis and a nondistended bladder. There is also some perinephric and periureteral stranding. Neither you nor the radiologist can visualize a stone. After viewing the CT scan, you return to the patient, and her BP has gone from 120/75 to 82/50. She is also tachycardic to the 150s, and her temperature is 40.1°C (104.2°F). What do you do? Fluid resuscitate this septic patient and initiate early goal-directed therapy. Send urine and blood cultures and start empiric antibiotics. Call urology for a presumed indinavir stone.

Stones most commonly occur in males in the third and fourth decades of life. Risk factors include a family history, low fluid intake, gout, status postcolectomy/ileostomy, chronic diarrhea, sarcoid, specific enzyme disorders, RTA, and hyperparathyroidism. Stones are most commonly composed of calcium oxalate but may also be calcium phosphate, struvite, uric acid, or cystine (see Table 12-8).

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TA B L E 12 - 8 .

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Types of Nephrolithiasis

TYPE

FREQUENCY

Calcium

83%

ETIOLOGY AND CHARACTERISTICS

TREATMENT

The most common causes are idiopathic hypercalciuria, elevated

Hydration, thiazide diuretics in the

oxalate/

urine uric acid 2° to diet, and 1° hyperparathyroidism. Alkaline urine.

setting of hypercalciuria, surgical

calcium

Radiopaque.

removal.

“Triple phosphate” stones. Associated with urease-producing

Hydration, treat UTI if present, surgical

(Mg-NH4-

organisms (eg, Proteus). Form staghorn calculi. Alkaline urine.

removal.

PO4)

Radiopaque.

phosphate Struvite

Uric acid

Cystine

9%

7%

1%

Associated with gout and high purine turnover states. Acidic urine

Hydration, alkalinize urine with citrate,

(pH < 5.5). Radiolucent on KUB, but seen on CT.

surgical removal.

Due to a defect in renal transport of certain amino acids (COLA—

Hydration, alkalinize urine,

Cystine, Ornithine, Lysine, and Arginine). Hexagonal crystals.

penicillamine, surgical removal.

Radiopaque. Indinavir

Rare

Patients will be on protease inhibitors for HIV. Stones consist of

Hydration, surgical removal.

precipitated indinavir. Radiolucent on KUB and CT. (Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 489.)

SYMPTOMS/EXAM

Presents with acute onset of severe, colicky flank pain that may radiate to the testes or vulva and may be associated with nausea and vomiting. Patients are unable to get comfortable and shift position frequently (vs. those with peritonitis, who remain still). DIAGNOSIS

Labs, examination, and imaging together make the diagnosis. ■

■

■

■

Gross or microscopic hematuria and an altered urine pH may be noted on UA. Check serum calcium, a CBC, and serum creatinine, and look for signs of UTI (which may be the cause of infection leading to struvite stones or 2° to obstruction from other stones). Tenderness may be present in the costovertebral areas or in either abdominal lower quadrant. It may be difficult to distinguish pain associated with nephrolithiasis from that originating in the ovaries, fallopian tubes, intestines, or gallbladder. Imaging is critical. A noncontrast abdominal CT scan is the primary means of diagnosis and can visualize all stones except indinavir stones. Additionally, a KUB can often detect radiopaque stones, and IVP can be used to detect stones that are radiolucent on KUB. These modalities are rarely used for the primary diagnosis of nephrolithiasis, but a KUB is often used to follow known radiopaque stones (see Figure 12-4). All urine should be strained, and if a stone is passed, it should be recovered and sent to the lab for analysis.

NEPHROLOGY

A

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233

B

Nephrolithiasis. (A) Transaxial CT without IV contrast shows a right ureteral calculus (arrowhead) with surrounding inflammatory changes of retroperitoneal fat. (B) AXR shows a left staghorn or struvite (Mg-NH4-PO4) stone filling the collecting system of the right kidney. (Image A reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. FIGURE 12-4.

9-31. Image B reproduced with permission from USMLERx.com.)

TREATMENT ■

■

■

Hydration and analgesia are the initial treatment; additional treatment is based on the size of the stone. ■ Stones < 5 mm almost always pass without surgical intervention. Typically 4–6 weeks of medical expulsion therapy is first attempted, consisting of α-blockers, pain control, and time. ■ Stones up to 3 cm in diameter can be treated with extracorporeal shock-wave lithotripsy (ESWL) or percutaneous nephrolithotomy. Stones may also be treated with ureteroscopy and percutaneous nephrolithotomy. ■ In cases where stones are 2° to hypercalciuria, thiazide therapy should be implemented. Patients who present with fever and an obstructing stone require immediate drainage of the kidney by way of ureteral stenting or nephrostomy tubes. Failure to treat in a timely fashion will result in urosepsis and possibly death. Preventive measures include hydration and a diet low in salt and animal protein. Additional prophylactic measures depend on stone composition and urine electrolyte profile.

KEY FACT The recommended diet for a patient with a calcium stone is a normalcalcium diet. Low-calcium and highcalcium diets can both exacerbate the problem! A diet low in animal protein is recommended for all kinds of stones.

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NEPHROLOGY

NO T E S

CHAPTER 13

NEUROLOGY Localization

236

Guillain-Barré Syndrome

247

Stroke

237

Myasthenia Gravis

248

Seizures

241

Vertigo

249

Brain Death

242

Epidural Hematoma

243

Subdural Hematoma

244

Spinal Cord Compression

244

Headache

246

PERIPHERAL VERTIGO

249

CENTRAL VERTIGO

249

Multiple Sclerosis

250

Muscular Dystrophy

252

Parkinson’s Disease

252

TENSION HEADACHE

246

Amyotrophic Lateral Sclerosis

253

MIGRAINE

246

Dementia

253

CLUSTER HEADACHE

247

Wernicke-Korsakoff Syndrome

255

235

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236

NEUROLOGY

Localization Localization involves determining where a lesion exists in the nervous system. It is the first step in the neurological thought process derived from the history and physical exam. You do not need to know detailed neuroanatomy in order to localize. The following is a list of the major locations for lesions and their associated patterns of findings. See Table 13-1 for a definition of upper motor neuron (UMN) and lower motor neuron (LMN) signs. ■

■

■

■

■

■

■

TA B L E 13 - 1 .

Muscle: Proximal limb weakness (eg, hip girdle muscles) in a symmetric pattern; no sensory loss; muscles may be tender. Neuromuscular junction: Fatigable weakness (ie, weakness that is exacerbated by repetition of movement); the face and proximal limbs are affected; symmetric pattern; no sensory loss. Peripheral nerve: Distal asymmetric or symmetric pattern; LMN signs; ↓ sensation in a patch innervated by nerve. Root: Shooting pain in a proximal or distal asymmetric pattern; weakness in movement corresponding to the root; LMN signs; dermatomal sensory change without spinal cord signs. Spinal cord: Sensory level (“band” with ↓ sensation below); bladder or bowel incontinence or retention; symmetric pattern; UMN signs below the level affected. Brain stem: Cranial nerve deficits; hemibody UMN signs; hemibody sensory changes; possible stupor or coma; crossed motor and sensory signs (eg, right face and left body). Cerebellum: Ipsilateral ataxia (distal limbs = cerebellar hemispheres; core body = vermis); nystagmus; dysmetria; breakdown of rapid alternating movements.

UMN vs. LMN Lesions

UMN LESIONS Anatomy

LMN LESIONS

Motor cortex → internal capsule → pons → medulla

Anterior horn cell → plexus → peripheral nerve (“PNS

(pyramidal decussation) → corticospinal tract (“CNS

lesions”).

lesions”). Paresis (muscle

Affects the upper extremity extensors more than the flexors,

Affects the distribution of the anterior horn cell, plexus,

weakness)

and the lower extremity flexors more than the extensors.

or peripheral nerve.

Tone

Spasticity.

Flaccidity.

Wasting

Absent.

Present.

DTRs

Hyperactive.

Hypoactive or absent.

Plantar reflexes

Upgoing (䊝 Babinski’s).

Downgoing (normal).

Fasciculations

Absent.

Present.

Examples

Strokes, TIA, brain tumors, head trauma, MS, epidural

Guillain-Barré syndrome, neuropathies, Bell’s palsy,

abscess.

herpes zoster, Lyme disease, cauda equina syndrome.

NEUROLOGY

■

■

Subcortical brain: Hemibody UMN signs; hemibody sensory changes; extrapyramidal signs (rigidity, bradykinesia, tremor); visual field cuts. Cortical brain: Cortical signs (aphasia → left hemisphere; neglect → right hemisphere, gaze deviation); UMN weakness that is not fully hemibody (eg, face and arm > leg); sensory changes that are not fully hemibody.

For practice in localization, www.lesionlocalizer.com is a useful preparation tool.

Stroke An 81-year-old woman with a history of hypertension presents with sudden onset of left-sided weakness. On exam, she displays left-sided neglect and left facial and arm paralysis with relative sparing of the left leg. Is this likely a large-vessel or a small-vessel stroke? Which vessel territory is affected? The woman is likely experiencing a large-vessel stroke involving the right MCA territory. This is supported by the neglect (a cortical sign) and sparing of the left leg, indicating preservation of the ACA territory and the MCA perforators to the internal capsule.

An acute onset of neurologic deficit referable to a cerebrovascular territory. Stroke is a clinical diagnosis that can be divided into two categories, ischemic and hemorrhagic, each of which consists of pathologic diagnoses facilitated by imaging. ■

Ischemic: Ischemic stroke: An infarction of CNS tissue that accounts for 85% of all strokes. It results from vessel obstruction caused by cerebral thrombosis (clot development at the site of obstruction) or cerebral embolism (clot development, usually in the heart or neck vessels, that migrates to the site of obstruction). Risk factors include untreated hypertension, atrial fibrillation (AF), diabetes, cigarette smoking, recent MI, valvular heart disease, carotid artery disease, TIA, OCP use, illicit drug use (eg, cocaine, amphetamines), and hyperlipidemia (see Figure 13-1). ■ Transient ischemic attack (TIA): A transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia without acute infarction. Typically lasts 10–60 minutes. The etiologies of TIA are the same as those of ischemic stroke, and therefore the same workup is required. Hemorrhagic: ■ Intracerebral hemorrhage (ICH): Focal bleeding from a blood vessel in the brain parenchyma. This usually results from rupture of an atherosclerotic small artery weakened by chronic hypertension (see Figure 13-2). ■ Subarachnoid hemorrhage (SAH): Sudden bleeding into the subarachnoid space. The most common cause is head trauma, although spontaneous bleeding is usually the result of a ruptured aneurysm (see Figure 13-3). ■

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KEY FACT Bell’s palsy involves damage to the facial nerve that leads to hemifacial weakness, diminished taste, hyperacusis, ↑ tearing, and variable hyperesthesia of the face.

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A

B

C

Acute ischemic stroke. Acute left hemiparesis in a 62-year-old woman. (A) Noncontrast transaxial head CT with loss of gray and white matter differentiation and asymmetrically decreased size of the right lateral ventricle in a right MCA distribution (indicating mass effect). (B) Transaxial diffusion-weighted MRI with reduced diffusion in the same distribution, consistent with an acute infarct. (C) Maximum-intensity projection of a transaxial time-of-flight MRA shows the cause: an abrupt occlusion of the proximal right MCA (arrow). Compare with the normal left MCA (arrowhead). (Reproduced with permission from USMLERx.com.)

FIGURE 13-1.

SYMPTOMS/EXAM ■

■

Ischemic strokes have an abrupt, dramatic onset of focal neurologic symptoms. By contrast, intracranial hemorrhagic strokes usually involve headache, vomiting, hypertension, and impaired consciousness, although a CT scan is needed to truly differentiate them from ischemic strokes.

C H

P T

Intracerebral hemorrhage. Transaxial image from a noncontrast head CT shows an intraparenchymal hemorrhage (H) and surrounding edema (arrows) centered in the left putamen, a common location for hypertensive hemorrhage. C, P, and T denote the normal contralateral caudate, putamen, and thalamus. (Reproduced with permission from Fauci AS et al. Harrison’s

FIGURE 13-2.

Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Fig. 364-17.)

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FIGURE 13-3. Subarachnoid hemorrhage. Transaxial noncontrast CT (left) showing SAH filling the basilar cisterns and sylvian fissures (straight arrows). The curved arrow shows the dilated temporal horns of the lateral ventricles/hydrocephalus. Coned-down images (right) from a catheter angiogram (A), a CT angiogram (B), and an MRA (C) show a saccular aneurysm arising from the anterior communicating artery (arrow). (Left image reproduced with permission from Tintinalli JE et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 6th ed. New York: McGraw-Hill, 2004, Fig. 237-4. Right image reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 36-6.)

■

Specific symptoms are as follows: Superior division MCA stroke: Contralateral hemiparesis that affects the face, hand, and arm; contralateral hemisensory deficit in the same distribution; ipsilateral gaze preference; facial droop. If the dominant hemisphere is affected, Broca’s aphasia results. ■ Inferior division MCA stroke: Contralateral homonymous hemianopia; neglect of the contralateral limbs; apraxia. If the dominant hemisphere is affected, Wernicke’s aphasia results. ■ ACA stroke: Leg paresis. ■ PCA stroke: Homonymous hemianopia with macular sparing; prosopagnosia (inability to recognize familiar faces). ■ Basilar artery stroke: Coma, cranial nerve palsies, “locked-in” syndrome. ■ Lacunar stroke: Pure motor or sensory deficit; dysarthria–clumsy hand syndrome; hemiparesis involving the face, arm, and leg. ■

DIFFERENTIAL

Seizure, brain tumor or abscess, subdural or epidural hematoma, hypo- or hyperglycemia, migraine, TIA.

KEY FACT Broca’s (expressive) aphasia involves nonfluent speech; good auditory comprehension; and poor repetition and naming.

KEY FACT Wernicke’s (receptive) aphasia involves fluent speech and poor auditory comprehension, repetition, and naming.

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DIAGNOSIS ■ ■

■

■

■ ■

Head CT without contrast to rule out bleed. MRI with diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) or CT perfusion: DWI shows dying tissue; PWI shows penumbra, or tissue at risk of dying. MRA or CT angiography: To evaluate vessels, including the carotids and circle of Willis. Transesophageal echocardiography (TEE): To evaluate for cardiac emboli and patent foramen ovale. Labs: CBC, electrolytes, coagulation studies, HbA1c, fasting lipids. Telemetry or ECG: To evaluate for AF.

TREATMENT ■

■ ■

■

■

Check airway, breathing, and circulation (ABCs); order a stat glucose. Keep NPO until intracranial hemorrhage has been ruled out and the patient has been assessed for dysphagia (aspiration risk). Admit to the ICU or to a telemetry-monitored bed. For ischemic stroke patients who are tPA candidates, proceed by keeping BP < 185/110. For patients with ischemic stroke who are not tPA candidates, allow permissive hypertension (> 160/> 80). For hemorrhagic stroke, lower systolic BP to < 160 unless intracranial pressure is very high. In hemorrhagic stroke, obtain an urgent neurosurgical evaluation for possible posterior craniotomy for cerebellar ICHs of > 3 cm or aneurysm clipping/coiling in SAH. If the head CT shows a normal or hypodense area consistent with acute ischemic stroke, consider the following: ■ Antiplatelet agents: ASA ↓ the incidence of a second event. Patients already on ASA may be given clopidogrel, ticlopidine, or dipyridamole. ■ Thrombolytics: IV recombinant tPA has strict inclusion and exclusion criteria. ■ Inclusion criteria include a symptom duration of < 4.5 hours, age > 18 years, a CT scan without hemorrhage, a diagnosis of ischemic stroke, and a measurable neurologic deficit. ■ Exclusion criteria include stroke or head trauma within the prior three months; a history of intracranial hemorrhage; major surgery within two weeks; acute MI within the past three months; LP within seven days; uncontrolled hypertension requiring aggressive therapy; pregnancy or lactation; and evidence of cerebral hemorrhage. ■ Patients with basilar artery thrombosis may receive intra-arterial tPA up to six hours after symptom onset.

PREVENTION ■

■ ■ ■

Antiplatelet therapy: ASA, ASA/dipyridamole (Aggrenox), or clopidogrel (Plavix). BP goals: Treat most patients to < 130/80. Lipid goals: Treat patients to an LDL of < 100 mg/dL. Other: ■ The HbA1c goal is < 7%. ■ Discontinue smoking. ■ Encourage physical activity. ■ If > 50% carotid stenosis is seen on angiography, consider carotid endarterectomy. ■ If AF is present or if the LVEF is ≤ 25%, consider warfarin.

NEUROLOGY

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Seizures Paroxysmal events due to neuronal discharges that are inappropriately excessive and hypersynchronous. SYMPTOMS ■

■

■

Partial seizures: Involve only part of the brain. There are two subtypes, both of which can progress to a generalized tonic-clonic (GTC) seizure. ■ Simple partial seizures: Acute onset of motor, sensory, autonomic, or psychiatric symptoms without alteration of consciousness. ■ Complex partial seizures: Acute onset of motor, sensory, autonomic, or psychiatric symptoms with transient alteration of consciousness. These seizures frequently begin with an aura. Generalized seizures: Arise at once from both cerebral hemispheres. There are four major subtypes: ■ GTC (“grand mal”) seizures: Acute onset of loss of consciousness accompanied by tonic contraction of the jaw, larynx, and extremity muscles for 10–20 seconds, followed by a clonic phase marked by periods of muscle relaxation for no more than one minute. Incontinence and confusion may occur in the postictal period. EEG shows generalized low-voltage activity followed by high-amplitude, polyspike discharges and then a spike-and-wave pattern. Generally there is also a postictal acidosis with a low HCO3, elevated serum CK, and elevated serum prolactin. ■ Absence (“petit mal”) seizures: Acute onset of brief lapses of consciousness with no loss of postural control and no postictal confusion. These seizures usually begin in childhood (4–8 years). EEG shows generalized spike-and-wave discharges at 3 Hz. ■ Atonic seizures: Acute onset of loss of postural muscle tone lasting 1–2 seconds with brief impairment of consciousness and no postictal confusion. ■ Myoclonic seizures: Acute onset of shocklike contraction of muscle groups. Status epilepticus: Continuous seizures or repetitive, discrete seizures with impaired consciousness in the interictal period. A medical emergency with up to a 20% mortality rate.

EXAM ■ ■

Fever suggests CNS infection or status epilepticus. Look for tongue biting, urinary incontinence, and meningeal signs (nuchal rigidity, ⊕ Brudzinski’s, ⊕ Kernig’s).

DIFFERENTIAL ■

■

■

■

ICH, acute or old stroke (particularly cortical), SAH, meningitis, head injury, subdural or epidural hematoma, migraines. Hyponatremia (or changes in magnesium, calcium, or glucose), EtOH withdrawal, cocaine or amphetamine intoxication. Medications associated with seizures include imipramine, meperidine, INH, metronidazole, bupropion, and fluoroquinolones. 1° CNS tumor or brain metastases.

KEY FACT Jacksonian march seizure activity presents as progressive jerking that spreads from one limb to the next.

KEY FACT Postictally, seizure patients may have a focal neurologic deficit that mimics a stroke (eg, Todd’s paralysis) and resolves within minutes to days.

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TA B L E 13 - 2 .

First-Line Drugs for the Prevention of Seizure

PARTIAL ONSETa

PRIMARY GENERALIZED

ABSENCE

Carbamazepine

Valproate

Ethosuximide

Lamotrigine

Lamotrigine

Valproate

MYOCLONIC, ATONIC Valproate

Phenytoin Valproate a

KEY FACT

DIAGNOSIS ■

Signs and symptoms of elevated ICP include headache on awakening, nausea/vomiting, drowsiness, diplopia, blurry vision, papilledema, and CN VI palsies.

Includes simple partial, complex partial, and secondarily generalized.

■

■

Labs: Order a CBC, electrolytes, glucose, magnesium, calcium, ammonia, an EtOH level, a toxicology screen, and an antiepileptic drug level if appropriate. EEG: To establish a baseline, localize the focus and confirm the diagnosis. If a focal deficit is present, get a CT or MRI of the brain. If CNS infection is suspected, get an LP—but only if there is no evidence of ↑ ICP.

TREATMENT ■

Acute: Check ABCs; intubation may be required to protect the airway. ■ Gently turn the patient onto his left side to prevent aspiration. Unless the patient is being intubated, do not put anything into his mouth (eg, tongue blade, fingers)! ■ Always check a glucose level, as hypoglycemia is a common cause of convulsions. If the patient is hypoglycemic, give IV thiamine and then glucose. If the glucose level is normal, give lorazepam 0.1 mg/kg in 2-mg increments each over 2–3 minutes up to 8 mg. ■ If the seizure continues, give fosphenytoin 15–20 mg/kg at a rate no faster than 150 mg/min. If the seizure persists, consider induction of coma with anesthetic (propofol, midazolam, phenobarbital). Chronic: Table 13-2 outlines pharmacotherapeutic options for the longterm prevention of seizures. ■

KEY FACT Most antiepileptic drugs are teratogenic. Rule out pregnancy before starting treatment.

■

Brain Death A state characterized by the absence of cerebral or brain stem function with maintenance of other organs through artificial means. Clinical criteria for the determination of brain death include the following: ■

KEY FACT Common causes of coma include ischemic brain injury, traumatic brain injury, and metabolic derangements (eg, profound hypoglycemia).

■

■ ■

■

A comatose state (unresponsiveness to verbal, tactile, or painful stimuli). Absent pupillary light, corneal, oculovestibular (tested by cold calorics), and gag reflexes. Absent motor responses to painful stimuli. Complete apnea denoted by no respirations at a PaCO2 of 60 mm Hg, or 20 mm Hg above normal values. Exclusion of sedative medications, hypothermia, hypotension, or metabolic derangements.

NEUROLOGY

DIAGNOSIS

■ ■ ■

For comatose patients, always rule out nonconvulsive status epilepticus with an EEG.

Radionuclide brain scanning EEG Cerebral angiography Transcranial Doppler measurements

Epidural Hematoma ■

■

■

■

A

243

KEY FACT

Auxiliary tests include the following: ■

CHAPTER 13

An accumulation of blood between the skull and the dura. It typically results from tearing of the middle meningeal artery 2° to head trauma. A true neurologic emergency. Sx/Exam: ■ The patient is initially unconscious from concussion resulting from head trauma. ■ The patient awakens and has a “lucid interval” in which the hematoma subclinically expands. ■ Lethargy and rapid neurologic deterioration follow, including evidence of herniation (hemiparesis and a fixed, dilated pupil). Dx: Head CT without contrast shows a biconvex, lens-shaped hyperdensity that respects cranial suture lines (see Figure 13-4A). Tx: Open craniotomy and evacuation of blood.

B

FIGURE 13-4. Acute epidural and acute subdural hematoma. (A) Noncontrast transaxial CT showing a right temporal acute epidural hematoma. Note the characteristic biconvex shape. (B) Noncontrast transaxial CT demonstrating a right acute holohemispheric subdural hematoma. Note the characteristic crescentic shape. (Image A reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 36-8. Image B reproduced with permission from Chen MY et al. Basic Radiology. New York: McGraw-Hill, 2004, Fig. 12-32.)

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Subdural Hematoma ■

■

■

■

An accumulation of blood between the arachnoid membrane and the dura. This typically results from blunt head trauma (commonly a fall) that leads to rupture of the bridging veins (common in the elderly and in alcoholics). Sx/Exam: Presents with headache, altered mental status, and possible hemiparesis. Dx: Head CT shows a crescent-shaped, concave hyperdensity that may have a less distinct border and does not cross the midline (see Figure 134B). Tx: Surgical evacuation of blood if symptoms are present or if the lesion is increasing in size.

Spinal Cord Compression A 58-year-old male-to-female transgender patient who has been treated with estrogen presents with an inability to walk or to urinate. Exam shows a distended bladder, ↓ rectal tone, weakness in the bilateral lower extremities, and bilateral ankle clonus. Where is the lesion, and what are the most likely etiologies? Given this patient’s bilateral weakness, spasticity, and bowel and bladder involvement, the lesion is likely in the spinal cord at the lumbar level or higher. The most likely etiologies are neoplastic, infectious, inflammatory, vascular, or structural (disk herniation). In this rare case, the etiology was a metastatic lesion at the thoracic level from a 1° breast cancer 2° to estrogen treatment.

KEY FACT Loss of anal reflex (“anal wink”) indicates a lesion in S2–S4.

A neurologic emergency! The approach is to evaluate for trauma (immobilize the neck if necessary), localize the lesion, image the spine, and call neurosurgery (see Figure 13-5). SYMPTOMS/EXAM ■

■

■

KEY FACT ■

Always look for a sensory level when considering a spinal cord process. The pinprick test is precise and reproducible.

Symptoms include back pain, bilateral weakness, paresthesias, and bladder/bowel incontinence or retention. Exam includes bilateral weakness, sensory level (by pinprick), hyperreflexia below the sensory level, saddle anesthesia, and loss of anal wink. These last two findings are common with conus medullaris and cauda equina involvement. Abrupt onset of radicular pain, flaccid weakness, sphincter dysfunction, and a sensory level could indicate cord infarction. Trauma to the neck should be suspected if there is trauma to the face and body. Signs of skull fracture include the following: ■ Battle’s sign (ecchymosis over the mastoid process). ■ Raccoon eyes (periorbital ecchymosis). ■ Hemotympanum and CSF rhinorrhea/otorrhea.

NEUROLOGY

A

B

FIGURE 13-5. Spinal cord compression. (A) Sagittal postcontrast MRI shows diskitis/ osteomyelitis (arrows) and a rim-enhancing epidural abscess (arrowhead) compressing the spinal cord. (B) Sagittal T2-weighted MRI in another patient shows a traumatic fracture at C6–C7 compressing the spinal cord. Note the abnormally high signal within the spinal cord (arrow). (Image A reproduced with permission from Tintinalli JE et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 6th ed. New York: McGraw-Hill, 2004, Fig. 305-5. Image B reproduced with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 36-12.)

DIFFERENTIAL

The etiologies of spinal cord compression include the following: ■ ■

■ ■ ■

Trauma: Motor vehicle accidents; sports-related injuries. Infection: Epidural abscess in IV drug users; spinal TB (Pott’s disease) in immunocompromised patients; vertebral osteomyelitis. Neoplasms: Metastases are most common. Degenerative disease: Cervical and lumbar disk herniations. Vascular: Infarction, epidural and subdural hematomas, and AVMs are rare.

DIAGNOSIS

Spinal MRI; CT or CT myelography for patients in whom MRI is contraindicated (eg, those with pacemakers). TREATMENT ■

Acute spinal cord injury: Methylprednisolone 30 mg/kg IV bolus. Wait 45 minutes; then give methylprednisolone in a 5.4-mg/kg/hr continuous infusion over the next 24 hours.

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■ ■ ■

Spinal tumor: Dexamethasone 100 mg IV bolus. Fractures, subluxations, and dislocations: Surgical reduction. Epidural abscess: Neurosurgical drainage and broad-spectrum antibiotics (a third-generation cephalosporin, vancomycin, and metronidazole).

Headache TE N S I ON HE ADAC HE

A chronic syndrome characterized by tight, bandlike pain bilaterally. KEY FACT SYMPTOMS/EXAM Headache danger signs include a change in frequency or severity, fever, neurologic signs, and new-onset headaches.

Presents with nonthrobbing, bilateral occipital head pain that is generally not associated with nausea, vomiting, photophobia, phonophobia, or aggravation with movement. Exam is usually normal. DIFFERENTIAL ■

KEY FACT

■ ■

Severe, sudden-onset headache should raise concern for a subarachnoid/ aneurysm rupture.

DIAGNOSIS

Obtain a CT scan under the following conditions: ■

KEY FACT Even if the head CT is 䊞, get an LP if there is a high suspicion for SAH. Fifteen percent of patients with an aneurysmal SAH have a 䊞 CT scan. LP will show high RBCs in all tubes and xanthochromia (yellow CSF).

Sinus tenderness: May point to sinusitis. Temporal artery tenderness: Associated with temporal arteritis. Cranial bruit: Rule out AVM.

■

■ ■ ■

If the headache is acute and extremely severe (“thunderclap headache”). If the headache is progressive over days to weeks, particularly if it is not similar to previous headaches. In the presence of focal neurologic signs. In the setting of papilledema. If the headache has a morning onset or awakens the patient from sleep.

TREATMENT

Treat with NSAIDs or acetaminophen. Relaxation techniques may be of benefit. MI G R AI NE

An episodic headache syndrome that is associated with sensitivity to light, sound, and movement and is often accompanied by nausea and vomiting. Its prevalence in the United States is 15% in women and 6% in men. Migraine has a familial predisposition, with > 50% of patients having an affected family member. SYMPTOMS/EXAM ■

■

Migraine without aura (“common migraine”): Recurrent headaches of 4–72 hours’ duration that are characterized by at least two of the following—unilateral, throbbing, severe enough in intensity to limit daily activity, and aggravated by movement—plus nausea/vomiting or photophobia/ phonophobia. Migraine with aura (“classic migraine”): Common migraine that also includes a preceding homonymous visual disturbance (eg, scintillations, blind spots), unilateral paresthesias, and, rarely, weakness.

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TREATMENT ■ ■

■

Identify and eliminate triggers. Treat according to severity: ■ Mild: NSAIDs plus an antiemetic such as metoclopramide. ■ Moderate: Abortive (triptans as soon as headache begins). ■ Severe: IV hydration, metoclopramide, dexamethasone, prochlorperazine, or ergotamine. Preventive therapy: TCAs, α-blockers, valproate, β-blockers. C L U S T E R H E A D A CH E

■

■ ■

■

A brief, severe, unilateral, periorbital, stabbing headache, with attacks occurring at the same hour each day and with periods of remission during the year. Affects men more than women; onset is at 20–30 years of age. Sx/Exam: Exam reveals ipsilateral lacrimation, conjunctival injection, Horner’s syndrome, and nasal congestion. Tx: Responds to 100% O2 or low-dose prednisone.

KEY FACT Horner’s syndrome presents with ipsilateral miosis (pupillary constriction), ipsilateral ptosis (eyelid droop), and ipsilateral anhidrosis (lack of sweating) of the face.

Guillain-Barré Syndrome (GBS) An acute polyradiculoneuropathy (root and peripheral nerve process) that usually has an autoimmune basis. It typically presents as an ascending motor paralysis with areflexia, autonomic involvement (eg, postural hypotension), and possible sensory symptoms. Seventy percent of patients have a recent history of respiratory or GI infection (particularly Campylobacter jejuni). SYMPTOMS/EXAM

Exam shows leg > arm weakness, facial weakness with difficulty handling secretions, absent reflexes, proprioception > pain/temperature sensation, postural hypotension, and respiratory failure. DIAGNOSIS ■

■

■ ■

GBS is a clinical diagnosis; it is supported by ancillary tests that are most effective at excluding mimics (eg, acute myelopathies, botulism, diphtheria, Lyme disease). LP: Typically shows ↑ protein with normal WBC levels (“albuminocytologic dissociation”), but often normal in the first 48 hours. CBC: May show an ↑ WBC count. Obtain an ESR and a Lyme titer. Nerve conduction study (NCS): May show evidence of demyelination.

TREATMENT ■ ■

■

Give IVIG or plasmapheresis as soon as possible. Measure vital capacity and maximum inspiratory force to monitor for respiratory compromise. Watch for autonomic instability, including hypotension, temperature dysregulation, and cardiac arrhythmias.

KEY FACT Absence of reflexes, ascending weakness, and recent infection— think GBS.

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Myasthenia Gravis (MG) A 31-year-old man complains that when he looks up to catch a baseball, he sees two balls and cannot make the catch. On exam, he displays ptosis and weakness in all extraocular muscles. Where is the lesion, and what is the likely diagnosis? How should the diagnosis be confirmed, and how should he be treated? The lesion is in the neuromuscular junction isolated to the eyes, and the likely diagnosis is ocular myasthenia gravis. Confirmatory tests include edrophonium (Tensilon) injection and an acetylcholine receptor antibody blood test. The patient should be treated with pyridostigmine 60 mg TID.

An autoimmune disorder in which antibodies attack the acetylcholine (ACh) receptor proteins at the neuromuscular junction. This causes weakness and fatigability of skeletal muscles. There is a bimodal distribution, with an earlier peak in the 30s–40s (women) and a late peak in the 70s–90s (men). SYMPTOMS/EXAM

KEY FACT

The main features are weakness and fatigability of muscles. The weakness may be worse at the end of the day or after exercise and may improve with rest. There is an ↑ in weakness with repeated use of the skeletal muscles (fatigability). Categorized as follows: ■

Neuromuscular blocking agents used during anesthesia can unmask or worsen MG, leading to prolonged postoperative weakness and ventilator dependence.

■

Ocular MG: Muscle weakness limited to the eyelids and extraocular muscles, with ptosis and/or diplopia. Fifty percent of patients go on to develop generalized MG. Generalized MG: Weakness may be seen in ocular, bulbar (dysarthria, dysphagia, fatigable chewing), facial (expressionless), limb, and respiratory muscles. Worsening respiratory muscle strength can lead to respiratory failure, or a “myasthenic crisis.”

DIFFERENTIAL

Lambert-Eaton myasthenic syndrome, botulism, drug-induced myasthenia, motor neuron diseases (eg, ALS), generalized fatigue, intracranial mass lesion, hyperthyroidism. DIAGNOSIS ■

Bedside tests: Edrophonium chloride (Tensilon) is an acetylcholinesterase inhibitor that prolongs the presence of ACh at the neuromuscular junction. A ⊕ test results in an immediate ↑ in the strength of affected muscles. ■ The ice pack test is the use of ice that improves ptosis in patients with MG. Immunologic assays for ACh receptor antibody; if seronegative, musclespecific kinase (MuSK) antibodies. Repetitive nerve stimulation: The nerve is stimulated and action potentials are measured in muscles. In MG, there is a rapid ↓ in the amplitude of action potentials. Single-fiber electromyography: This test measures single-muscle-fiber discharges. It is the most sensitive diagnostic test for MG. ■

■

■

■

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TREATMENT ■

■

■ ■

Symptomatic treatment: First-line treatment is an acetylcholinesterase inhibitor (pyridostigmine). Chronic immunomodulating agents: Corticosteroids, azathioprine, cyclosporine, mycophenolate mofetil. For myasthenic crisis: Plasmapheresis and/or IVIG. Surgery: Thymectomy.

Vertigo An illusion of movement of either the patient or his/her surroundings. Mimickers of vertigo include orthostatic hypotension, cardiac arrhythmia, and presyncope/syncope. Once a diagnosis of vertigo has been established, one must determine whether it is peripheral or central. P ER IP H E R A L V E R T I G O

A lesion of the vestibular apparatus of the inner ear or CN VIII. It is often intermittently severe, positional, and associated with auditory sensations (tinnitus, hearing loss) and postural unsteadiness. SYMPTOMS/EXAM

Nystagmus is rotary, unidirectional, and fatigable. Examine the external auditory canal for vesicles (herpes zoster or Ramsay Hunt syndrome). Use DixHallpike and head thrust maneuvers to evaluate for positional effects. Rule out cerebellar signs (ataxia, wide-based gait) and cranial neuropathies. DIFFERENTIAL ■ ■

■

■

■

Medication side effects: Furosemide, aminoglycosides, salicylates. Benign paroxysmal positional vertigo (BPPV): Episodic attacks of severe vertigo. Self-limited; probably caused by crystals floating inside the semicircular canals brushing against the sensory cilia. Labyrinthitis/neuronitis: Viral inflammation of CN VIII or the labyrinth; usually self-limited. Ménière’s disease: Overproduction of endolymph in the vestibular canals. Presents with the triad of vertigo, tinnitus, and hearing loss. Schwannoma: A mass compressing CN VIII, causing hearing loss and vertigo.

DIAGNOSIS

The history and exam should reveal the diagnosis. No imaging is needed, although an audiogram is necessary to rule out vestibular schwannoma. TREATMENT

Canalith repositioning (the Epley maneuver), physical therapy, antihistamines/benzodiazepines/scopolamine, possible surgery for schwannoma. C EN T R A L V E R T I G O

A lesion that affects the brain stem vestibular nuclei or their connections. It is usually acute onset, with symptoms independent of head positioning.

KEY FACT If there are episodic attacks of severe vertigo associated with head position, think of BPPV.

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SYMPTOMS/EXAM ■

■

Spontaneous nystagmus that cannot be suppressed with visual fixation; nystagmus that changes direction with gaze; purely vertical, horizontal, or torsional nystagmus; saccade dysmetria (overshoot and undershoot of gaze). Cranial nerve signs such as facial droop, dysarthria, and loss of corneal reflexes are also seen.

DIFFERENTIAL ■

■

■ ■

Brain stem stroke: Associated neurologic deficits seen include weakness, ataxia, and cranial nerve dysfunction. Cerebellar stroke: Associated neurologic deficits seen include midline and appendicular ataxia. Demyelination: MS. Neoplasm: Brain stem glioma.

DIAGNOSIS

Head CT without contrast; MRI of the brain with DWI. TREATMENT

In the setting of a posterior circulation stroke, careful monitoring is necessary for 24–48 hours followed by stroke workup.

Multiple Sclerosis (MS) A disease involving inflammation and destruction of the CNS myelin, likely from an autoimmune process. Young women are at higher risk, as are those who reside in northern latitudes. SYMPTOMS ■

■

Initial symptoms are varied. The most common are sensory loss, optic neuritis, weakness, paresthesias, diplopia, and ataxia. The four clinical courses of MS are relapsing-remitting, 2° progressive, 1° progressive, and progressive/relapsing.

EXAM

Some of the classic findings include the following: ■ ■

■

■

■

Hyperreflexia, weakness, and ataxia. Lhermitte’s sign: Radiating/shooting pain up or down the neck on flexion or extension. Optic neuritis: ↓ visual acuity; pain with eye movements; central scotoma; red desaturation. Afferent pupillary defect (Marcus Gunn pupil): The pupil paradoxically dilates to a light stimulus owing to delayed conduction. Internuclear ophthalmoplegia (MLF syndrome): The classic finding is bilateral weakness on adduction of the ipsilateral eye with nystagmus on abduction of the contralateral eye, together with incomplete or slow abduction of the ipsilateral eye on lateral gaze with complete preservation of convergence.

NEUROLOGY

A

B

C FIGURE 13-6. Multiple sclerosis. Transaxial T2-weighted MRI (A) and sagittal FLAIR image (B) showing multiple MS plaques (arrows) in the periventricular matter oriented radially from the corpus callosum (“Dawson’s fingers”). (C) Areas of demyelination of the white matter (arrows) in the frontal lobe of a 54-year-old man with multiple sclerosis. (Images A and B reproduced with permission from Ropper AH, Samuels MA. Adams & Victor’s Principles of Neurology, 9th ed. New York: McGraw-Hill, 2009, Fig. 36-1. Image C reproduced with permission from Waxman SG. Clinical Neuroanatomy, 26th ed. New York: McGraw-Hill, 2010, Fig. 25-9.)

DIAGNOSIS ■

■ ■

Brain MRI with gadolinium: Reveals multiple focal periventricular areas of ↑ signal, called Dawson’s fingers (see Figure 13-6). CSF: Shows ↑ protein (myelin basic protein, oligoclonal bands). Visual evoked potentials: Show delayed conduction.

TREATMENT ■ ■

■

■

Treat acute exacerbations with methylprednisolone/prednisone. Manage relapsing-remitting disease with prophylactic agents such as interferon-α1a/1b or glatiramer acetate. If there is poor response or intolerance to prophylactic agents, use natalizumab. Baclofen may be given for spasticity.

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252

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NEUROLOGY

Muscular Dystrophy A group of hereditary progressive muscle-based diseases. The most common form is Duchenne’s muscular dystrophy, which is X-linked and caused by a defect in the gene encoding the dystrophin protein. Patients usually present between ages 3 and 5 and then progress to being wheelchair bound in childhood and to death due to pulmonary complications in adolescence. SYMPTOMS/EXAM ■

■

■

Presents with toe walking, waddling gait, and inability to run or climb stairs. In attempting to rise to a standing from a supine position, patients use their arms to climb up their bodies (Gowers’ sign). Proximal and girdle muscle weakness and pseudohypertrophy of the calves are apparent on exam.

DIAGNOSIS ■ ■

Serum CK levels are elevated to 20–100 times normal. Genetic testing for the dystrophin gene mutation; muscle biopsy with immunohistochemistry.

TREATMENT

Prednisone slows disease progression by up to three years.

Parkinson’s Disease (PD) A 65-year-old man presents with tremor of the right hand and a voice that has become softer over the years. On exam, he is found to have hypophonia, a 4-Hz resting tremor, mild right-sided rigidity, and micrographia. Where is the lesion, and what is the likely etiology? What might be the pathologic findings at autopsy? The lesion is in the left basal ganglia, specifically the substantia nigra. The likely etiology is Parkinson’s disease with neuronal degeneration and Lewy bodies in the substantia nigra at autopsy.

A neurodegenerative disease clinically diagnosed by at least two out of four cardinal features: resting tremor, bradykinesia, muscular rigidity, and postural instability. It is due to ↓ dopaminergic transmission in the basal ganglia resulting from neuronal degeneration in the substantia nigra. PD affects one million people in the United States, with a peak age of onset in the early 60s. SYMPTOMS ■

■

■

Motor symptoms: Progressive slowness in dressing, walking, feeding, or writing; difficulty rising from a chair; hesitancy in initiating gait; frequent falls and loss of balance; loss of facial expression; smaller handwriting (micrographia). Nonmotor symptoms: Sleep disorders (restless legs and REM sleep behavior disorder); sensory abnormalities and pain; autonomic dysfunction. Neuropsychiatric symptoms: Depression, anxiety, cognitive impairment (including psychosis).

NEUROLOGY

EXAM

Exam reveals the following: ■

■

■

■

Resting tremor: A 4- to 6-Hz tremor, unilateral initially, with distal prominence and pill rolling. Bradykinesia: Slowness and paucity of movement with ↓ amplitudes. Patients have a slow blink rate and few facial expressions (masked facies). Rigidity: ↑ muscle tone that is present in all directions of movement may be cogwheel rigidity. Loss of postural reflexes: Patients cannot remain balanced if pushed from the front or from behind.

TREATMENT ■

■

■

■

Carbidopa/levodopa: The most effective treatment for PD. Carbidopa blocks the metabolism of levodopa in the periphery. Levodopa is an amino acid precursor to dopamine that crosses the blood-brain barrier. Dopamine agonists: These are direct agonists of the dopamine receptor and are effective as monotherapy or as adjuncts to carbidopa/levodopa. They include nonergot alkaloids (pramipexole, ropinirole) and ergot alkaloids (bromocriptine). Adjunctive therapy: MAO-B inhibitors (selegiline), COMT inhibitors (entacapone), amantidine, anticholinergics. Surgical: Deep brain stimulation in the subthalamus or pallidum; pallidotomy.

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253

MNEMONIC Key Parkinson’s signs—

PARKINSON’S Pill rolling Akinesia/bradykinesia Rigidity Kyphosis Instability Neck titubation Shuffling gait Oculogyric crisis Nose tap (eg, glabellar tap) Small writing

Amyotrophic Lateral Sclerosis (ALS) ■

■

■

■

A neurodegenerative, progressive motor neuron disease. The chief feature is the involvement of the LMNs and UMNs in a pure motor disorder (sensations are intact). There is a 2:1 male-to-female ratio with a peak occurrence between 55 and 75 years of age. Some 5–10% of cases are familial. Sx/Exam: ■ Patients have progressive muscular weakness, muscle wasting, spasticity, respiratory insufficiency, and possible dementia. ■ Exam reveals UMN signs (spasticity, weakness, ⊕ Babinski’s), LMN signs (muscle atrophy, fasciculations), and bulbar signs (dysarthria, dysphagia, tongue fasciculations). Dx: EMG shows widespread denervation. Muscle biopsy shows neurogenic atrophy. Tx: ALS is an incurable, progressive disease. Treatment with BiPAP and riluzole, which inhibits glutamate release, has been associated with modest improvement.

Dementia Progressive cognitive decline that interferes with the performance of the activities of daily living. Etiologies may be reversible (eg, alcoholism, vitamin deficiencies, endocrine deficiencies, chronic infections, head trauma, neoplastic disease, toxic disorders, psychiatric disorders) or nonreversible (eg, neurodegenerative disease). It is important to look for reversible causes, which are treatable.

KEY FACT Look for UMN and LMN signs with ALS.

254

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NEUROLOGY

SYMPTOMS ■ ■

Impairment of recent memory is typically the first sign. Subsequent manifestations include deficits in visuospatial ability (depth perception), language (speech or naming), calculation, or problem solving; behavioral and personality changes; and depression.

EXAM

Exam reveals cortical signs specific to each region: ■

■ ■

■

Frontal: Executive function breakdown, primitive reflexes, gait instability, personality changes. Temporal: Aphasia, memory, behavioral changes. Parietal: Calculation difficulties, left/right confusion, writing problems, inability to recognize fingers. Occipital: Simultagnosia (inability to synthesize full visual scenes), visual delusions.

DIFFERENTIAL ■

■

First consider reversible causes such as alcoholism, thyroid disease, vitamin deficiencies (B12), drug and medication intoxication, chronic infections (HIV, neurosyphilis), depression (“pseudodementia”), subdural hematoma, delirium, and normal pressure hydrocephalus. The major neurodegnerative diseases and their initial symptoms include the following: ■ Alzheimer’s disease: Memory loss. ■ Frontotemporal dementia: Apathy, poor judgment, language changes. ■ Diffuse Lewy body dementia: Visual hallucinations, REM sleep disorders, parkinsonism. ■ Creutzfeldt-Jakob disease: Myoclonus, ataxia, personality changes. ■ Vascular dementia: Falls, apathy, weakness. May be sudden stepwise in onset.

DIAGNOSIS ■

■ ■

■

Conduct a complete history and exam, a mini-mental status exam, and neuropsychological testing. Review medications. Check a CBC, electrolytes, B12, TSH, VDRL, HIV, and a urine toxicology screen. Obtain a CT and possibly an MRI of the brain.

TREATMENT ■

■

■

■

Reversible causes of dementia can be treated with alcohol rehabilitation, vitamin supplementation, a thyroid workup, antibiotics/antiretrovirals, antidepressants, neurosurgical treatment of structural lesions, and environmental interventions for delirium. Current therapies for Alzheimer’s disease are aimed at increasing CNS ACh levels. Acetylcholinesterase inhibitors include donepezil (Aricept), rivastigmine (Exelon), and galantamine (Reminyl). Memantine (Namenda) works as a glutamate receptor antagonist. Aricept may delay admission to a nursing home by roughly six months. Offer social support and assisted-living interventions.

NEUROLOGY

Wernicke-Korsakoff Syndrome ■

■

■ ■

A nutritional disorder of the nervous system caused by a deficiency in thiamine (vitamin B1), causing symmetrical lesions in the mammillary bodies. It is a syndrome complex consisting of Wernicke’s encephalopathy and Korsakoff amnesia, disorders that may be seen separately. Both disorders are preventable and may be reversed with thiamine repletion. Sx/Exam: ■ Wernicke’s encephalopathy: Characterized by the triad of ataxia, ophthalmoplegia, and confusion. ■ Korsakoff’s syndrome: Characterized by impaired short-term memory in an alert and responsive patient. There may or may not be confabulation, which is the unconscious filling of gaps in memory by imagined or untrue experiences. Dx: A clinical diagnosis. MRI may be used to rule out structural lesions. Tx: Wernicke-Korsakoff syndrome is a medical emergency. Treat with high-dose thiamine (up to 500 mg). Give thiamine before glucose, as administering glucose in the absence of thiamine may precipitate neuronal death.

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256

CHAPTER 13

NEUROLOGY

NO T E S

CHAPTER 14

OBSTETRICS Prenatal Care and Nutrition

258

Teratogens in Pregnancy

266

Prenatal Diagnostic Testing

259

Obstetric Complications of Pregnancy

268

TRIPLE-MARKER SCREEN/QUADRUPLE TEST (QUAD SCREEN)

259

INTRAUTERINE GROWTH RESTRICTION

268

AMNIOCENTESIS

259

OLIGOHYDRAMNIOS AND POLYHYDRAMNIOS

268

CHORIONIC VILLUS SAMPLING

259

RHESUS ISOIMMUNIZATION

268

260

THIRD-TRIMESTER BLEEDING

269

Tests of Fetal Well-Being NONSTRESS TEST

260

Abnormal Labor and Delivery

270

CONTRACTION STRESS TEST

260

PRETERM PREMATURE RUPTURE OF MEMBRANES

270

BIOPHYSICAL PROFILE

260

PRETERM LABOR

271

FETAL HEART RATE PATTERNS

261

FETAL MALPRESENTATION

271

261

SHOULDER DYSTOCIA

272

DIABETES MELLITUS

261

INDICATIONS FOR CESAREAN SECTION

272

PREECLAMPSIA/ECLAMPSIA

262

Medical Complications of Pregnancy

Spontaneous and Recurrent Abortion

273

HYPEREMESIS GRAVIDARUM

262

SPONTANEOUS ABORTION

273

GESTATIONAL TROPHOBLASTIC DISEASE

263

RECURRENT ABORTION

274

Peripartum Complications

264

POSTPARTUM HEMORRHAGE

264

SHEEHAN’S SYNDROME (POSTPARTUM HYPOPITUITARISM)

264

INTRAPARTUM AND POSTPARTUM FEVERS

265

MASTITIS

265

257

258

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OBSTETRICS

Prenatal Care and Nutrition All prenatal visits should document weight, BP, extremity edema, urine protein and glucose, fundal height (> 20 weeks), and fetal heart rate. Further recommendations are as follows: ■

■

■ ■

TA B L E 14 - 1 .

Weight gain: Average-size women should gain 25–35 lbs; obese women should gain less (15–25 lbs) and thin women more. Nutrition: Requirements for total calories, protein, iron, folate, calcium, and zinc should ↑. All patients should take prenatal vitamins. ■ Caloric intake: An additional 300 kcal/day is needed during pregnancy and 500 kcal/day during breast-feeding. ■ Folate: Supplement with 400 μg/day to ↓ the risk of neural tube defects (NTDs). Women with twin gestation or a prior history of a fetus with NTDs should receive 4 mg/day. ■ Iron: Supplement in the latter half of pregnancy to prevent anemia. ■ Calcium: Supplement in the later months of pregnancy and during breast-feeding. Smoking and alcohol cessation. Prenatal labs: See Table 14-1 for lab work that should be scheduled during pregnancy.

Prenatal Labs During Pregnancy

GESTATIONAL AGE (GA) Initial visit

LABS TO BE OBTAINED CBC, blood type, Rh antibody screen, UA with culture, Pap smear, cervical gonorrhea and chlamydia cultures, rubella antibody titer, hepatitis B surface antigen, syphilis screen, PPD, HIV. Toxoplasmosis and sickle cell screening for at-risk patients. Women with prior gestational diabetes or a family history (in a first-degree relative) should get early glucose testing.

6–11 weeks

Ultrasound to determine GA (more accurate than later scans).

15–19 weeks

Triple-marker screen/quadruple test (quad screen). Offer amniocentesis for those of advanced maternal age (≥ 35 years of age at delivery).

18–21 weeks

Screening ultrasound to survey fetal anatomy, placental location, and amniotic fluid.

26–28 weeks

One-hour glucose challenge test. If ≥ 140 mg/dL, follow with a three-hour glucose tolerance test. Repeat hemoglobin/ hematocrit.

28 weeks

RhoGAM injection for Rh-両 patients. Start fetal kick counting (the patient should count 10 fetal movements in < 1 hour).

35–37 weeks

Screen for group B streptococcus (GBS) with a rectovaginal swab. Repeat hemoglobin/hematocrit. Cervical gonorrhea and chlamydia cultures, RPR, and HIV (in at-risk patients). Assess fetal position with Leopold maneuvers and ultrasound.

OBSTETRICS

Prenatal Diagnostic Testing T RI P LE -M A R K E R S CR E E N / Q U A D RUP LE TE S T ( QU AD S C R E E N) ■ ■

■

■

Measured between 15 and 20 weeks’ gestation. Any maternal serum α-fetoprotein (MSAFP) result > 2.5 multiples of the mean (MoM) can signify an open NTD, an abdominal wall defect, multiple gestation, incorrect dating, fetal death, or placental abnormalities. The sensitivity for detecting chromosomal abnormalities (trisomies 18 and 21) can be ↑ through the addition of estriol and β-hCG (triple-marker screen) to MSAFP. See Table 14-2 for trends in the detection of genetic abnormalities. The addition of inhibin-A to the three markers above (quadruple test) will ↑ the sensitivity for Down syndrome. A M N IO C E N T E S I S

A 32-year-old G4P2 woman at 16 weeks’ gestation has an abnormal triple-marker screen that raises concern for trisomy 21. What is the next step? The next step depends on the patient’s desire to confirm the diagnosis. If the patient desires termination of pregnancy with a positive result, amniocentesis would be confirmatory.

■

■ ■

Performed primarily between 15 and 20 weeks’ gestation to detect possible genetic diseases or congenital malformations. Risks include fetal-maternal hemorrhage (1–2%) and fetal loss (0.5%). Amniocentesis is used: ■ In conjunction with an abnormal triple-marker screen/quadruple test. ■ In women > 35 years of age at the time of delivery. ■ In Rh-sensitized pregnancy to ascertain fetal blood type or to detect fetal hemolysis. ■ For the evaluation of fetal lung maturity in the third trimester. C H O R IO N I C V ILLU S S A M PLI N G

■

■

Performed to evaluate possible genetic diseases at an earlier time than is possible with amniocentesis, with comparable diagnostic accuracy. Done at 10–12 weeks’ gestation via transabdominal or transvaginal aspiration of chorionic villus tissue (a precursor of the placenta). Risks include fetal loss (1–5%) and an association with distal limb defects.

TA B L E 14 - 2 .

Detection of Genetic Abnormalities with the Triple-Marker Test

NEURAL TUBE DEFECT

TRISOMY 18

TRISOMY 21

MSAFP

↑

↓

↓

Estriol

Not used

↓

↓

β-hCG

Not used

↓

↑

CHAPTER 14

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CHAPTER 14

260

OBSTETRICS

Tests of Fetal Well-Being NONS TR E S S TE S T ( NS T) ■ ■

■

■

■

Fetal heart rate is monitored externally by Doppler. A normal response is an acceleration of ≥ 15 bpm above baseline lasting > 15 seconds. A normal or “reactive” test includes two such accelerations in a 20-minute period. An abnormal or “nonreactive” NST warrants a biophysical profile or a contraction stress test (see below). A nonreactive NST can be due to fetal sleep cycle, GA < 30 weeks, a fetal CNS anomaly, or maternal sedative or narcotic use. CON TR AC TI ON S TR E S S TE S T ( C S T)

■ ■

■

■

MNEMONIC When performing a BPP, remember to—

BIO P HYS I C AL P R OF I LE ( BP P )

Test the Baby, MAN!

■

Fetal Tone Fetal Breathing Fetal Movements Amniotic fluid volume Nonstress test

TA B L E 14 - 3 .

Used to assess uteroplacental dysfunction. Fetal heart rate is monitored during spontaneous or induced (nipple stimulation or pitocin) contractions. A normal or “negative” CST has no late decelerations and is highly predictive of fetal well-being. An abnormal or “positive” CST is defined by late decelerations in conjunction with at least 50% of contractions. A minimum of three contractions within a 10-minute period must be present for an adequate CST.

■ ■

■

Ultrasound is used to assess five parameters (see the mnemonic Test the Baby, MAN). A score of 2 (normal) or 0 (abnormal) is given to each of the parameters. A normal or “negative” test (a score of 8–10) is reassuring for fetal wellbeing. An abnormal or “positive” test (a score < 6) is worrisome for fetal compromise.

Fetal Heart Rate Patterns

TYPE OF DECELERATION Early

DESCRIPTION Deceleration begins and ends at approximately the same

COMMON CAUSE Fetal head compression (no fetal distress).

time as maternal contractions. Variable

Variable onset of abrupt (< 30-sec) slowing of fetal heart

Umbilical cord compression.

rate in association with contractions. The return is similarly abrupt in most situations. Late

Decelerations begin after onset of maternal contractions

Late decelerations indicate fetal hypoxia (fetal distress).

and persist until after the contractions are finished. The time

If late decelerations are repetitive and severe, immediate

from peak to nadir is > 30 sec.

delivery is necessary.

OBSTETRICS

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FE T A L H E A R T R A T E P A T T E R N S

Table 14-3 outlines different types of heart rate patterns seen in near-term and term fetuses.

Medical Complications of Pregnancy

KEY FACT

D I A B E T E S M E LLI T U S (D M )

The most common medical complication of pregnancy. See Table 14-4 for a comparison of pregestational and gestational DM.

TA B L E 14 - 4 .

An HbA1c > 6.5 prior to conception or during the first trimester will lead to a higher rate of fetal malformations.

Pregestational vs. Gestational Diabetes Mellitus

PREGESTATIONAL

GESTATIONAL

Definition

Diagnosed prior to pregnancy.

Diagnosed during pregnancy.

Risk factors

Family history; autoimmune disorders (type 1), obesity

Obesity, family history (in a first-degree relative), prior

(type 2).

history of DM in pregnancy.

Diagnosis

See above.

Diagnosed if the one-hour glucose test is ≥ 140 mg/dL and the follow-up three-hour glucose test has at least two ↑ levels.

Treatment

Strict control of blood glucose levels with diet, exercise, and insulin:

Labor

■

Fasting morning: < 90 mg/dL.

■

Two-hour postprandial: < 120 mg/dL.

Fingersticks every 1–2 hours while the patient is in active labor with dextrose infusion +/– an insulin drip to

Postpartum

ADA diet and regular exercise. If blood sugars are ↑ after one week, initiate insulin therapy. Glyburide can be considered.

Diet controlled (A1): Fingersticks on admission and every four hours in labor.

maintain tight glycemic control.

A2: Same as pregestational.

Continue glucose monitoring; the body’s insulin

Resume normal diet; no insulin is required.

requirements quickly ↓. Complications Fetus

Congenital malformations, stillbirth, macrosomia, IUGR, hypoglycemia, birth trauma.

Mother

Hypoglycemia, DKA, spontaneous abortion, polyhydramnios, preterm labor, worsening end-organ dysfunction, ↑ risk of preeclampsia.

Hypoglycemia from hyperinsulinemia; macrosomia; birth trauma. Perineal trauma from macrosomic infant; ↑ lifetime risk of developing DM.

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OBSTETRICS

PR E E C LAM P S I A/ E C LAM P S I A

A 32-year-old G1P0 at 34 weeks’ gestation with a diagnosis of preeclampsia presents with a refractory headache and nausea. She is found to have a BP of 208/112 and 3+ protein on urine dipstick. Her labs are pending. What is the next step? The patient is presenting with severe preeclampsia that raises concern for the development of eclampsia. You should administer antihypertensives and magnesium for seizure prophylaxis and prepare for emergent delivery.

Preeclampsia is characterized by hypertension and proteinuria and is thought to be due to ↓ organ perfusion 2° to vasospasm and endothelial activation. Risk factors include nulliparity, African American ethnicity, extremes of age, multiple gestations (ie, twins), renal disease, and chronic hypertension. Eclampsia is defined as seizures in a patient with preeclampsia. Preeclampsia is further distinguished as follows: ■

■

Mild: Systolic BP (SBP) > 140, diastolic BP (DBP) > 90, and 1+ on dipstick or > 300 mg on 24-hour urine. Severe: SBP > 160, DBP > 110, and 3+ on dipstick or > 5 g on 24-hour urine.

SYMPTOMS/EXAM

Table 14-5 outline differences in the presentation of mild preeclampsia, severe preeclampsia, and eclampsia. DIAGNOSIS ■

MNEMONIC ■

HELLP syndrome:

Hemolysis Elevated Liver enzymes Low Platelets

■

Check UA, 24-hour urine for protein and creatinine clearance, CBC, BUN, creatinine, uric acid, LFTs, PT/PTT, fibrinogen, and a toxicology screen. Determine the precise GA; consider amniocentesis to assess fetal lung maturity for mild preeclampsia. Diagnosis is based on clinical findings as described in Table 14-5.

TREATMENT

Definitive treatment is delivery. See Table 14-5 for management. HYP E R E M E S I S G R AVI DAR U M ■

■

■

■

■

Defined as refractory vomiting that leads to weight loss, poor weight gain, dehydration, ketosis from starvation, and metabolic alkalosis. Typically persists beyond 14–16 weeks’ gestation. Risk factors include nulliparity, multiple pregnancies, and trophoblastic disease. DDx: Rule out molar pregnancy, hepatitis, gallbladder disease, reflux, and gastroenteritis. Dx: Labs show hyponatremia and a hypokalemic, hypochloremic metabolic alkalosis. Ketonuria on UA suggests starvation ketosis. Tx: If there is evidence of weight loss, dehydration, or altered electrolytes, hospitalize and give antiemetics, IV hydration, and vitamin and electrolyte replacement. Advance the diet slowly and avoid fatty foods.

OBSTETRICS

TA B L E 14 - 5 .

exam

263

Mild and Severe Preeclampsia vs. Eclampsia

MILD PREECLAMPSIA Symptoms/

CHAPTER 14

SBP > 140 or DBP > 90 on ≥ 2 occasions. Proteinuria (> 300 mg/24 hrs or 1+ on urine dipstick).

SEVERE PREECLAMPSIA SBP > 160 or DBP > 110 on > 2 occasions.

ECLAMPSIA Seizures with the diagnosis of preeclampsia.

Proteinuria (> 5 g/24 hrs or > 3+ on urine dipstick). HELLP syndrome (see mnemonic). Oliguria (< 500 mL/24 hrs). Pulmonary edema.

Treatment

Deliver if near term, fetal lungs are mature, or preeclampsia worsens. If far from term, treat with bed rest and conservative management. Use of magnesium sulfate for seizure prophylaxis is controversial.

Magnesium sulfate for seizure prophylaxis. Hydralazine +/– labetalol for BP control. When stable, deliver. Postpartum: Continue magnesium sulfate for at least 12–24

Magnesium sulfate to control seizures. Monitor ABCs closely. When stable, deliver. Seizures may occur before delivery, during delivery, and up to six weeks postpartum.

hours after delivery. Watch for magnesium toxicity; treat lifethreatening toxicity with IV calcium gluconate. Complications

Fetal distress, stillbirth, placental

Same as with mild preeclampsia.

abruption, DIC, seizures, fetal/ maternal death, cerebral hemorrhage.

G ES T A T I O N A L T R O PH O B L A S T IC DI S E AS E

Can range from benign (eg, hydatidiform mole) to malignant (eg, choriocarcinoma). Hydatidiform mole accounts for approximately 80% of cases. SYMPTOMS/EXAM ■

■ ■

■ ■

Suspect in patients with first-trimester uterine bleeding and excessive nausea and vomiting. Look for patients with preeclampsia or eclampsia at < 24 weeks. Other findings include uterine size greater than dates and hyperthyroidism. No fetal heartbeat is detected. Pelvic exam may show enlarged ovaries and possible expulsion of grapelike molar clusters into the vagina or blood in the cervical os.

DIAGNOSIS ■ ■

■

β-hCG levels are markedly ↑ (usually > 100,000 mIU/dL). Pelvic ultrasound shows a “snowstorm” appearance with no gestational sac and no fetus or heart tones present. Obtain a CXR to look for metastases.

Fetal/maternal death.

264

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OBSTETRICS

TREATMENT

D&C. Carefully monitor β-hCG levels after D&C for possible progression to malignant disease. Pregnancy prevention (contraception) is needed for one year to ensure accurate monitoring of β-hCG levels. Treat malignant disease with chemotherapy and residual uterine disease with hysterectomy.

■ ■

■

■

Peripartum Complications KEY FACT POS TP AR TU M HE M OR R HAG E If postpartum uterine bleeding persists after conventional therapy, uterine/internal iliac artery ligation or hysterectomy can be lifesaving.

Defined as blood loss of > 500 mL during a vaginal delivery or > 1000 mL during a cesarean section occurring before, during, or after delivery of the placenta. Table 14-6 summarizes common causes. Complications include Sheehan’s syndrome (see below).

■

■

S HE E HAN’S S YNDR OM E ( P OS TP AR TU M HYP OP I TU I TAR ISM) ■

■

■

TA B L E 14 - 6 .

The most common cause of anterior pituitary insufficiency in adult females. It occurs 2° to pituitary ischemia, usually as a result of postpartum blood loss and hypotension. Sx/Exam: ■ The most common presenting symptom is failure to lactate as a result of ↓ prolactin levels. ■ Other symptoms include lethargy, anorexia, weight loss, amenorrhea, and loss of sexual hair, but these may not be recognized for many years. Tx: Lifelong hormone replacement therapy (corticosteroids, levothyroxine, estrogen and progesterone).

Common Causes of Postpartum Hemorrhage

UTERINE ATONY Risk factors

GENITAL TRACT TRAUMA

RETAINED PLACENTAL TISSUE

Uterine overdistention, exhausted

Precipitous delivery, operative vaginal

Placenta accreta/increta/percreta,

myometrium, uterine infection, grand

delivery, large infant, laceration.

placenta previa, prior C-section, curettage, accessory placental lobe,

multiparity.

retained membranes. Diagnosis

Palpation of a soft, enlarged, “boggy”

Inspection of the cervix, vagina, and

uterus.

vulva for lacerations or hematoma.

Inspection of the placenta and uterine cavity. Ultrasound to look for retained placenta.

Treatment

Vigorous bimanual massage. Oxytocin infusion. Methylergonovine if not hypertensive; PGF2a if not asthmatic; misoprostol.

Surgical repair of the defect.

Removal of remaining placental tissue.

OBSTETRICS

CHAPTER 14

I N T R A PA R T U M A N D P O S T P A R T U M F E VE R S

265

MNEMONIC

A 31-year-old healthy woman develops fevers (39.1°C/102.4°F) and shak-

The 7 W’s of postpartum fever:

ing chills eight hours following a C-section performed for fetal malposi-

Womb—endomyometritis Wind—atelectasis, pneumonia Water—UTI Walk—DVT, pulmonary embolism Wound—incision, lacerations Weaning—breast engorgement, mastitis,

tion. The baby is doing well, and the amniotic fluid at C-section is clear. What is the likely source of infection? The uterus (endometritis). This is a rapid postoperative presentation, making the standard causes of postoperative fever less likely.

breast abscess

Wonder drugs—drug fever ■ ■

Most commonly due to infections (see Table 14-7). Remember the mnemonic for the 7 W’s for the causes of postpartum fever. KEY FACT MA ST IT IS

■

■

■

■ ■

Cellulitis of the periglandular tissue in breast-feeding mothers, typically due to S aureus, occurring at about 2–4 weeks postpartum. Sx/Exam: Symptoms include breast pain and redness along with a high fever, chills, and flulike symptoms. Look for focal breast erythema, swelling, and tenderness. Fluctuance points to a breast abscess. DDx: Distinguish from simple breast engorgement, which can present as a swollen, firm, tender breast with low-grade fever and a breast abscess. Dx: Diagnosis includes breast milk cultures and CBC. Tx: Treat with dicloxacillin or erythromycin. Continue nursing or manually expressing milk to prevent milk stasis. Incision and drainage is necessary if an abscess is present.

T A B L E 1 4 - 7.

KEY FACT Contraindications to breast-feeding include HIV infection, active hepatitis, and certain drugs (eg, tetracycline, chloramphenicol, warfarin).

Common Infections During Labor and After Delivery

CHORIOAMNIONITIS Definition

The treatment of mastitis includes antibiotics and continued breast-feeding.

Infection of the chorion, amnion, and amniotic fluid,

ENDOMETRITIS Infection of the uterus, diagnosed after delivery.

diagnosed during labor. Risk factors

Prolonged rupture of membranes (ROM); multiple vaginal

C-section, prolonged ROM, multiple vaginal exams while

exams while being ruptured in labor.

being ruptured in labor.

Symptoms/

Fever with no other obvious source and one of the following:

Fever within 24 hours postpartum without an obvious

exam

■

Fetal or maternal tachycardia

■

Abdominal tenderness

■

Foul-smelling amniotic fluid

■

Leukocytosis

Diagnosis

Clinical; CBC with differential.

source.

Pelvic exam to rule out hematoma or retained membranes. CBC with differential, UA, urine culture, and blood cultures as indicated.

Treatment

Delivery of the fetus (chorioamnionitis is not an indication for cesarean delivery). Antibiotics until the patient is afebrile for 24 hours after delivery. Some practitioners stop antibiotics after delivery.

Antibiotics until the patient is afebrile for 24 hours (vaginal) or 48 hours (cesarean) after delivery

266

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OBSTETRICS

Teratogens in Pregnancy

KEY FACT ■

CT scans of the fetus should be avoided at all trimesters of pregnancy in light of concerns over increasing the risk of childhood cancer.

■

Radiation: Diagnostic and nuclear medicine studies have not been shown to pose any risk of fetal teratogenicity if overall exposure during pregnancy is < 5000 mrads. Table 14-8 outlines radiation exposure levels associated with such procedures. Medications: See Table 14-9 for safe and teratogenic medications during pregnancy.

TA B L E 14 - 9 .

Radiation Exposure Resulting from Common Radiologic Procedures

Safe vs. Teratogenic/Unsafe Medications During Pregnancy

TA B L E 14 - 8 .

RADIOLOGIC FILM Abdominal

EXPOSURE (mrad)

INDICATION Acne

SAFE TO USE Benzoyl peroxide.

CONTRAINDICATED Vitamin A and derivatives (eg, isotretinoin, etretinate) → heart and great vessel defects,

100

x-ray (one

craniofacial dysmorphism, and

view)

deafness.

Chest x-ray

0.02–0.07

Antibiotics

Penicillins, cephalosporin, macrolides.

(two views)

Tetracycline → discoloration of deciduous teeth. Quinolones → cartilage damage.

CT head/chest

< 1000

Sulfonamides late in pregnancy →

CT abdomen/

3500

Streptomycin → CN VIII damage/

kernicterus.

lumbar spine

ototoxicity.

MRI

0

Ultrasound

0

Bipolar disorder

Assess the risks and benefits of

Lithium → congenital heart

medications.

disease and Ebstein’s anomaly (also avoid if the mother is breastfeeding).

Cancer

Contrast solution

Alkylating agents can be used in

Folic acid antagonists →

the second and third trimesters.

abnormalities of the cranium.

Indigo carmine.

Methylene blue → jejunal and ileal atresia.

Depression

Assess risks vs. benefits; TCAs,

SSRIs may cause persistent

SSRIs.

pulmonary hypertension of the newborn, poor feeding, and/or jitteriness.

GERD

OTC antacids (calcium carbonate,

Alka-Seltzer (has aspirin).

milk of magnesia), ranitidine, cimetidine, omeprazole. Headache/

Acetaminophen, codeine,

migraine

caffeine.

Avoid aspirin in late pregnancy in light of the risk of bleeding to the mother and fetus at birth. Ergotamines have abortifacient potential and a theoretical risk of fetal vasoconstriction.

OBSTETRICS

TA B L E 14 - 9 .

Safe vs. Teratogenic/Unsafe Medications During Pregnancy (continued)

INDICATION Hypertension

SAFE TO USE

CONTRAINDICATED

Labetalol, hydralazine, nifedipine,

ACEIs and angiotensin receptor

methyldopa, clonidine.

blockers → fetal renal damage and oligohydramnios.

Hyperthyroidism

PTU.

Hypothyroidism

Levothyroxine.

Nausea/vomiting

Methimazole → aplasia cutis.

Pyridoxine (B6), doxylamine,

Thalidomide → limb reduction and

prochlorperazine,

malformation of the ear, kidney,

metoclopramide, ondansetron,

and heart.

granisetron, promethazine. Pain

Acetaminophen, menthol, topical

Avoid NSAIDs in late pregnancy

patches, morphine, hydrocodone,

for > 48 hours. When used over

propoxyphene, meperidine; these

a long period, will → premature

medications should not be used

closure of the ductus arteriosus.

continuously. Seizure

Use an anticonvulsant that

Phenytoin → dysmorphic

works best to control maternal

facies, microcephaly, mental

seizures. Monotherapy at the

retardation, hypoplasia of the

lowest dose is preferred.

nails and distal phalanges, and

Folate supplementation should be started three months prior to conception.

NTDs. Valproic acid → craniofacial defects and NTDs. Carbamazepine → craniofacial defects, mental retardation, and NTDs. Phenobarbital → cleft palate and cardiac defects. Trimethadione and paramethadione have strong teratogenic potential and → mental retardation, speech difficulty, and abnormal facies.

Thromboembolic

Heparin, low-molecular-weight

Warfarin → fetal nasal

disease

heparin. Warfarin must be used

hypoplasia and bony defects

in cases of highly thrombogenic

(chondrodysplasia).

artificial heart valves. URI

Guaifenesin (Robitussin), acetaminophen, diphenhydramine, loratadine (Claritin).

CHAPTER 14

267

268

CHAPTER 14

OBSTETRICS

Obstetric Complications of Pregnancy INT R AU TE R I NE G R OW TH R E S TR I C TI ON ( I U G R ) ■

■

■

OLI G OHYDR AM NI OS AND P OLYHYDR AM NI OS

KEY FACT Oligohydramnios almost always indicates the presence of a fetal abnormality.

Defined as an estimated fetal weight at or below the 10th percentile for GA. See Table 14-10 for common causes of IUGR. Sx/Exam: Suspect IUGR clinically if the difference between fundal height and GA is > 2 cm. Tx: Focus on prevention—eg, smoking cessation, BP control, and dietary changes. Order an ultrasound every 3–4 weeks to assess interval growth. Deliver once the pregnancy reaches term.

Table 14-11 contrasts oligohydramnios with polyhydramnios. RH E S U S ( R h) I S OI M M U NI ZATI ON

When fetal Rh-⊕ RBCs leak into Rh-両 maternal circulation, maternal antiRh IgG antibodies can form. These antibodies can cross the placenta and react with fetal Rh-⊕ RBCs, leading to fetal hemolysis (erythroblastosis fetalis). TREATMENT ■

Give RhoGAM to Rh-両 women: With prior delivery of an Rh-⊕ baby. ■ If the father is Rh ⊕, Rh status is unknown, or paternity is uncertain. ■ If the baby is Rh ⊕ at delivery. ■ If the woman has had ectopic pregnancies, abortions, amniocentesis or other traumatic procedures during pregnancy, vaginal bleeding, blood transfusions, or placental abruption. Sensitized Rh-両 women with titers > 1:16 should be closely monitored for evidence of fetal hemolysis with serial ultrasound and amniocentesis or middle cerebral artery Doppler velocimetry. In severe cases, intrauterine blood transfusion via the umbilical vein or preterm delivery is indicated. ■

■

■

TA B L E 14 - 10 .

Causes of IUGR

FETAL Chromosomal abnormalities: Trisomy 21 is most common, followed by trisomies 18 and 13. Infection: CMV is most common; then toxoplasmosis. Placental abnormalities, uterine abnormalities, multiple gestations.

MATERNAL Hypertension. Drugs: Cigarette smoking is most common; also alcohol, heroin, methamphetamines, and cocaine. SLE. Maternal thrombophilia. Malnutrition, malabsorption (eg, cystic fibrosis). Ethnic/genetic variation.

OBSTETRICS

TA B L E 14 - 11 .

CHAPTER 14

269

Oligohydramnios vs. Polyhydramnios

OLIGOHYDRAMNIOS

POLYHYDRAMNIOS

Definition

Amniotic fluid index (AFI) ≤ 5 cm on ultrasound.

AFI ≥ 25 cm on ultrasound.

Causes

Fetal urinary tract abnormalities (renal agenesis,

Normal pregnancy, uncontrolled maternal DM, multiple gestations, pulmonary abnormalities, fetal anomalies

polycystic kidneys, GU obstruction).

Diagnosis

Chronic uteroplacental insufficiency, ROM.

(duodenal atresia, tracheoesophageal fistula).

Ultrasound for anomalies.

Ultrasound for fetal anomalies; glucose testing for DM.

Rule out ROM with ferning test and Nitrazine paper. Treatment

Possible amnioinfusion during labor to prevent cord

Depends on the cause; therapeutic amniocentesis.

compression. Complications

Cord compression → fetal hypoxia.

Preterm labor, placental abruption, fetal malpresentation,

Musculoskeletal abnormalities (facial distortion, clubfoot).

cord prolapse.

Pulmonary hypoplasia, IUGR.

T H I R D -T R I M E S T E R B L E E D I N G

A 32-year-old G3P2 at 35 weeks’ gestation is brought to the ER by ambulance with severe abdominal pain following a motor vehicle accident. Her BP is 92/47 and her pulse is 135/min. Her exam is significant for a severely tender, asymmetric gravid uterus. Fetal monitoring is worrisome. What is the cause? Uterine rupture. The patient needs to go to the OR emergently for an exploratory laparotomy and a C-section.

■ ■

■

Describes any bleeding after 20 weeks’ gestation. The most common causes are placental abruption and placenta previa (see Table 14-12). Other causes of bleeding include bloody show, preterm/early labor, vasa previa, genital tract lesions, and trauma (eg, intercourse).

TA B L E 14 - 12 .

Common Causes of Third-Trimester Bleeding

PLACENTAL ABRUPTION Pathophysiology

PLACENTA PREVIA

Placental separation from the

Abnormal placental implantation

A complete rupture disrupts the

site of uterine implantation before

near or covering the os.

entire thickness of the uterine wall.

delivery of the fetus. Risk factors

UTERINE RUPTURE

Hypertension, abdominal/pelvic

Prior C-section, grand multiparity,

Prior uterine scar, trauma (eg,

trauma, tobacco or cocaine use,

multiple gestations, prior placenta

motor vehicle accident), uterine

uterine distention.

previa.

anomalies, grand multiparity. (continues)

270

TA B L E 14 - 12 .

CHAPTER 14

OBSTETRICS

Common Causes of Third-Trimester Bleeding (continued)

PLACENTAL ABRUPTION Symptoms

PLACENTA PREVIA Painless vaginal bleeding that ceases

Abdominal pain; vaginal bleeding

spontaneously with or without

that does not spontaneously cease.

uterine contractions.

Prolonged tightening of the abdomen coupled with prolonged

The first bleeding episode usually

contraction. Fetal distress.

UTERINE RUPTURE Severe abdominal pain, usually during labor, typically at the scar site. Change in the shape of the abdomen.

occurs in the second or third

Fetal distress.

trimester.

Loss of fetal station.

Usually no fetal distress. Diagnosis

Primarily clinical.

Ultrasound for placental position.

Primarily clinical; based on symptoms and fetal distress.

Ultrasound to look for retroplacental hemorrhage (low sensitivity). Treatment

Mild abruption or premature infant: Hospitalization, fetal

No cervical exams!

Immediate C-section with delivery

Stabilize patients with a premature

of the infant and repair of the

fetus.

monitoring, type and cross, bed

growth and resolution of previa.

Moderate to severe abruption: ABCs, type and cross, immediate

C-section for total or partial previa or if the patient/infant is in distress.

delivery. Complications

rupture.

Serial ultrasound to assess fetal

rest.

Hemorrhagic shock; DIC; fetal death

↑ risk of placenta accreta.

with severe abruption.

Persistent hemorrhage requiring

Fetal and maternal death.

hysterectomy.

Abnormal Labor and Delivery PR E TE R M P R E M ATU R E R U P TU R E OF M E M BR ANE S ( PPRO M)

A 26-year-old woman at 30 weeks’ gestation presents with PPROM without evidence of infection. What medication should be administered? Steroids for fetal lung maturation and prophylactic antibiotics for chorioamnionitis.

Defined as spontaneous ROM at < 37 weeks, prior to the onset of labor. Distinguished from premature rupture of membranes (PROM), which refers to loss of fluid at term prior to the onset of contractions. Risk factors include low socioeconomic status, young maternal age, smoking, and STDs. SYMPTOMS/EXAM ■

■

Sterile speculum exam shows pooling of amniotic fluid in the posterior vaginal vault. Look for cervical dilation.

OBSTETRICS

DIAGNOSIS ■ ■

■

Nitrazine paper test: Paper turns blue in alkaline amniotic fluid. Fern test: A ferning pattern is seen under the microscope after amniotic fluid dries on glass slide. Determine AFI by ultrasound to assess amniotic fluid volume.

TREATMENT ■

■

■

Obtain cultures and/or wet mounts to look for infectious causes. If signs of infection are present, assume amnionitis (maternal fever, fetal tachycardia, foul-smelling amniotic fluid). Give antibiotics (ampicillin +/– gentamicin) and induce labor regardless of GA. If no signs of infection are present and GA is 24–32 weeks, treat with antibiotics (ampicillin and erythromycin) to prolong pregnancy and steroids for fetal lung maturation +/– tocolytics. If no signs of infection are present and GA is ≥ 33 weeks, hospitalize and treat expectantly until labor begins, signs of infection are seen, or 34 weeks’ gestation is achieved. P RE T E R M LA B O R

Labor between 20 and 36 weeks’ gestation. SYMPTOMS/EXAM ■

■

■

Patients may complain of menstrual-like cramps, uterine contractions, low back pain, pelvic pressure, new vaginal discharge, or bleeding. Rule out cervical insufficiency (treated with cerclage if early enough) and preterm contractions (no cervical dilation). Can lead to fetal respiratory distress syndrome, intraventricular hemorrhage, retinopathy of prematurity, necrotizing enterocolitis, or fetal death.

DIAGNOSIS ■ ■

Obtain an ultrasound to verify GA, fetal presentation, and AFI. Look for regular uterine contractions (three or more contractions lasting 30 seconds each over a 30-minute period) coupled with a concurrent cervical change at < 37 weeks’ gestation.

TREATMENT ■ ■

■

Begin with hydration and bed rest. Unless contraindicated, administer steroids (to accelerate fetal lung maturity) +/– tocolytics. Give penicillin or ampicillin for GBS prophylaxis if preterm delivery is likely. FET A L M A LP R E S E N T A T IO N

Defined as any presentation other than cephalic (head down). Breech presentation is the most common fetal malpresentation (affects 3% of all pregnancies). DIAGNOSIS ■ ■

Perform Leopold maneuvers to identify fetal lie. Check by ultrasound if there is any doubt.

CHAPTER 14

271

272

CHAPTER 14

OBSTETRICS

TREATMENT ■

■

Follow: Up to 75% of cases spontaneously change to cephalic presentation by 38 weeks. External cephalic version can be attempted at 36–37 weeks’ gestation in the setting of persistent malpresentation. ■ Involves pressure applied to the maternal abdomen to turn the infant. ■ Risks of the procedure are placental abruption and cord compression; the infant must be monitored after the procedure, and consent must be obtained for emergent C-section. S HO U LDE R DYS TOC I A

Defined as difficult delivery due to entrapment of the fetal shoulder at the level of the pubic bone. Risk factors include the following: ■ ■

A prior history of a shoulder dystocia. Fetal macrosomia or inadequate pelvis.

DIAGNOSIS ■

■

A prolonged second stage of labor with retraction of the head (“turtle sign”) back into the vaginal canal after pushing. After delivery of the head, difficulty delivering the anterior shoulder without performing additional maneuvers.

TREATMENT

Flex and open the maternal hips (McRoberts maneuver), followed by suprapubic pressure. Most dystocias will be relieved with these two maneuvers: ■

■

Delivery of the posterior fetal arm or internal rotation of the fetal shoulders to lessen the shoulder diameter. Replacement of the fetal head into the vaginal canal, followed by cesarean section (Zavanelli maneuver). IND I C ATI ONS F OR C E S AR E AN S E C TI ON

Table 14-13 outlines the indications for C-section. TA B L E 14 - 13 .

Indications for Cesarean Section

MATERNAL FACTORS Prior C-section Active genital herpes infection Cervical carcinoma Maternal trauma/demise

FETAL AND MATERNAL FACTORS Cephalopelvic

FETAL FACTORS Fetal malposition

disproportion (the most

Fetal distress

common cause of 1°

Cord prolapse

C-section)

Erythroblastosis fetalis (Rh

Placenta previa/placental abruption Failed vaginal delivery

incompatibility)

OBSTETRICS

CHAPTER 14

273

Spontaneous and Recurrent Abortion S P O N T A N E O U S A B O R T I O N ( S A B)

Defined as nonelective termination of pregnancy at < 20 weeks’ gestation. Also known as “miscarriage.” Occurs in 10–15% of clinically recognizable pregnancies. SYMPTOMS/EXAM

Differentiate types of SABs on the basis of symptoms, cervical exam, and ultrasound (see Table 14-14). DIFFERENTIAL

Common causes of first-trimester bleeding include normal pregnancy (implantation bleeding), postcoital bleeding, ectopic pregnancy, vaginal or cervical lesions, pedunculated myomas or polyps, and extrusion of molar pregnancy.

TA B L E 14 - 14 .

Types of Spontaneous Abortions

TYPE Threatened abortion

SYMPTOMS Minimal bleeding +/– cramping.

CERVIX/ULTRASOUND Closed os; ⊕ gestational sac.

TREATMENT Expectant management; consider pelvic rest for several

Most cases are thought to be due to

weeks.

implantation bleed. No products of conception (POC) are expelled. Inevitable abortion

Cramping with bleeding.

Open os; normal ultrasound.

D&C.

Open os; normal ultrasound.

D&C.

Slight bleeding; pain has usually ceased.

Closed os; empty uterus on

None.

All POC are expelled.

ultrasound.

Often no symptoms.

Closed os; no fetal cardiac

Allow up to four weeks for

No POC are expelled.

activity; retained fetal tissue on

POC to pass; offer medical

ultrasound.

management with misoprostol

No POC are expelled. Incomplete abortion

Cramping with bleeding. Some POC are expelled.

Complete abortion

Missed abortion

or D&C. Septic abortion

Constitutional symptoms; malodorous discharge. Patients often have a recent history of therapeutic abortion; maternal mortality is 10–50%.

Cervical motion tenderness.

Monitor ABCs; D&C, IV antibiotics, supportive care.

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CHAPTER 14

KEY FACT

OBSTETRICS

TREATMENT ■

All women with potential SABs should receive RhoGAM if appropriate.

■

■

Hemodynamic monitoring for significant bleeding. Check β-hCG to confirm pregnancy and transvaginal ultrasound to establish GA and rule out ectopic pregnancies; assess fetal viability or check for remaining tissue in the setting of a completed abortion. Check blood type and antibody screen; give RhoGAM if appropriate. RE C U R R E NT ABOR TI ON

■

■

■

■

Defined as three or more consecutive pregnancy losses before 20 weeks’ gestation. Usually due to chromosomal or uterine abnormalities, but can also result from hormonal abnormalities, infection, or systemic disease. Dx: Based on clinical and lab findings. ■ Perform a pelvic exam (to look for anatomic abnormalities). ■ Check cervical cultures for chlamydia and gonorrhea. ■ Perform a maternal and paternal genetic analysis. ■ Obtain a hysterosalpingogram to look for uterine abnormalities. ■ Obtain TFTs, progesterone, lupus anticoagulant, and anticardiolipin antibody. Tx: Treatment is based on the diagnosis.

CHAPTER 15

GYNECOLOGY Abnormal Uterine Bleeding

276

Ectopic Pregnancy

281

Amenorrhea

277

Contraception

283

Dysmenorrhea

278

Infertility

284

Endometriosis

278

Menopause

284

Polycystic Ovarian Syndrome

279

Urinary Incontinence

285

Vulvovaginitis

280

Benign Breast Disorders

287

275

CHAPTER 15

276

GYNECOLOGY

KEY FACT

Abnormal Uterine Bleeding

Any woman > 35 years of age with unexplained bleeding needs an endometrial biopsy to rule out malignancy.

A 38-year-old woman has a history of bilateral tubal ligations five years ago. She presents to her gynecologist with intermittent and painless noncyclic vaginal bleeding of two months’ duration. She otherwise feels well and has a normal cervical exam. What is the next step? You must rule out endometrial cancer by performing an endometrial biopsy or a D&C (the gold standard).

MNEMONIC Causes of uterine bleeding—

MS. PDA Malignancy Systemic Postmenopausal Dysfunctional Anatomic

Abnormalities in the frequency, duration, volume, and/or timing of menstrual bleeding. Defined as follows: ■ ■ ■

Menorrhagia: Heavy or prolonged menstrual flow. Metrorrhagia: Bleeding between menses. Metromenorrhagia: Heavy bleeding at irregular intervals.

There are multiple causes of abnormal uterine bleeding (see Table 15-1 and the mnemonic MS. PDA). TA B L E 15 - 1 .

Types of Abnormal Uterine Bleeding

CATEGORY Malignancy

ETIOLOGY

DIAGNOSIS

Endometrial and cervical

Endometrial biopsy, Pap smear/

malignancies are most common,

cervical biopsy, D&C (gold

but malignancies may occur

standard).

anywhere along the genital tract. 1° bleeding disorders (eg, von

Coagulation profile, bleeding time,

Willebrand’s disease), endocrine

endocrine tests (FSH, LH, TSH,

abnormalities.

and prolactin).

Postmenopausal

Endometrial cancer, vaginal

By definition, occurs one or

bleeding

atrophy, exogenous hormones.

more years after menopause.

Systemic

Malignancy must be ruled out! Dysfunctional

A diagnosis of exclusion.

uterine bleeding

Ninety percent of cases are

(DUB)

due to unopposed estrogen

Other causes must be ruled out.

in anovulation that leads to proliferative endometrium; 10% of cases are ovulatory. Anatomic

Leiomyoma, adenomyosis, or

Pelvic ultrasound,

polyps.

sonohysterogram, hysteroscopy.

GYNECOLOGY

CHAPTER 15

277

EXAM/DIAGNOSIS ■

Determine if the bleeding is ovulatory or anovulatory. Ovulatory: ■ Characterized by midcycle bleeding or changes in menstrual flow. ■ Can present with premenstrual syndrome symptoms (weight gain, breast tenderness, dysmenorrhea). ■ Anovulatory: ■ Unpredictable bleeding patterns. ■ Excessive and prolonged bleeding due to unopposed estrogen on the endometrium. ■ Seen mostly in adolescent and perimenopausal women. ■ Associated with an ↑ risk of endometrial hyperplasia and cancer. Look for a cervical lesion on speculum exam or an enlarged uterus on bimanual exam. ■

■

TREATMENT ■ ■

■

Treat the underlying cause. Acute, profuse bleeding can be treated with high-dose IV estrogen, D&C, uterine artery embolization, or hysterectomy. DUB and anovulatory bleeding are treated with OCPs or NSAIDs.

Amenorrhea Defined as either 1° or 2° amenorrhea. ■

■

1° amenorrhea: Absence of menses and lack of 2° sexual characteristics by age 14 or absence of menses by age 16 with or without 2° sexual characteristics. Associated with gonadal failure, congenital abnormalities, and constitutional symptoms (see Figure 15-1). 2° amenorrhea: Absence of menses for three cycles or for six months with prior normal menses. Etiologies include pregnancy, anorexia nervosa, stress, strenuous exercise, intrauterine adhesions, chronic anovulation, hypothyroidism, and hyperprolactinemia (see Figure 15-2).

Uterus Yes

No

Patent vagina No

Yes Breasts

Imperforate hymen, transverse vaginal septum, or vaginal agenesis Yes

Work up as secondary amenorrhea

FIGURE 15-1.

Karyotype: testicular feminization, müllerian agenesis, 46,XY steroid enzyme defects, pure gonadal dysgenesis, or anorchia

No

Work up as progestin-negative secondary amenorrhea

Workup for patients with 1° amenorrhea. (Modified with permission from DeCherney

AH, Nathan L. Current Diagnosis & Treatment: Obstetrics & Gynecology, 10th ed. New York: McGraw-Hill, 2007, Fig. 56-2.)

KEY FACT Always rule out pregnancy in a patient with amenorrhea.

278

CHAPTER 15

GYNECOLOGY

Progestin challenge

Absence of withdrawal bleed

Rule out Asherman’s syndrome if necessary FSH

Over 40 mIU/mL

Under 40 mIU/mL

Ovarian failure

Severe hypothalamic dysfunction

FIGURE 15-2.

Presence of withdrawal bleed

Hirsute

Nonhirsute

Polycystic ovarian syndrome Rule out ovarian tumor Rule out adrenal tumor

Mild hypothalamic dysfunction

Workup for patients with 2° amenorrhea. (Modified with permission from DeCherney

AH, Nathan L. Current Diagnosis & Treatment: Obstetrics & Gynecology, 10th ed. New York: McGraw-Hill, 2007, Fig. 56-4.)

KEY FACT

DIAGNOSIS ■

Amenorrhea is a symptom, not a diagnosis.

■ ■

Check β-hCG to make sure the patient is not pregnant. 1° amenorrhea: See Figure 15-1. 2° amenorrhea: See Figure 15-2.

TREATMENT

Depends on the etiology; may include surgery or hormonal therapy +/– drug therapy.

Dysmenorrhea Defined as pain with menstrual periods that requires medication and prevents normal activity. It is divided into 1° and 2° dysmenorrhea. ■

■

1° dysmenorrhea: No clinically detectable pelvic pathology. Most likely due to ↑ uterine prostaglandin production. 2° dysmenorrhea: Menstrual pain due to pelvic pathology, most commonly endometriosis, adenomyosis, myomas, or PID.

Endometriosis Abnormal growth of endometrial tissue in locations other than the uterine lining, usually in the ovaries (called endometriomas or “chocolate cysts”), cul-de-sac, and broad ligament. Associated with premenstrual pelvic pain due to stimulation from estrogen and progesterone during the menstrual cycle. SYMPTOMS/EXAM ■ ■

Presents with pelvic pain, dysmenorrhea, dyspareunia, and infertility. On pelvic exam, patients may have tender nodularity along the uterosacral ligament +/– a fixed, retroflexed uterus or enlarged ovaries.

GYNECOLOGY

DIAGNOSIS

Diagnosis can be made by the history and physical, but the gold standard is direct visualization during laparoscopy with biopsy showing endometrial glands. TREATMENT

Treatment depends on the patient’s symptoms, age, desire for future fertility, and disease stage. ■

■

■

If the patient’s main complaint is infertility, operative laparoscopy should be performed to excise the endometriomas. If the patient’s main complaint is pain, the objective is to induce a state of anovulation: ■ For mild pain, first-line treatment is NSAIDs and/or continuous OCPs. ■ For moderate to severe pain, options include medical treatment to induce anovulation (GnRH agonists) or excision. Hysterectomy with bilateral oophorectomy is curative.

Polycystic Ovarian Syndrome (PCOS) A 23-year-old woman presents to her gynecologist because she has been unable to conceive despite having attempted to do so for two years. Her partner’s infertility workup has been 両. The patient was diagnosed with diabetes at age 14 but is otherwise healthy. On exam, she is found to be 5′2″ with a weight of 165 pounds, and she has acne. What would you expect to find on exam and imaging? The patient probably has PCOS. You would expect to find enlarged ovaries on bimanual exam and polycystic ovaries on ultrasound/CT scan.

The most common cause of female hirsutism (male-pattern hair growth). Typically affects adolescent women. The cause is unknown. SYMPTOMS

Look for an obese woman with hirsutism, oligo- or amenorrhea, infertility, acne, and diabetes or insulin resistance. EXAM ■

■

Exam may reveal hirsutism with no evidence of cortisol or adrenal androgen excess. Pelvic exam may reveal palpably enlarged ovaries.

DIAGNOSIS ■

■ ■

Two out of three of the following clinical signs must be present to diagnose PCOS: ■ Oligo- or anovulation. ■ Hyperandrogenism (acne, hirsutism, or elevated testosterone). ■ Polycystic ovaries. An ↑ LH/FSH ratio (> 2) is also characteristic. Perform a glucose tolerance test to evaluate for diabetes/hyperglycemia.

CHAPTER 15

279

280

CHAPTER 15

GYNECOLOGY

TREATMENT

Treat the specific symptoms: ■ ■ ■

Infertility: Induce ovulation with clomiphene and/or metformin. Hirsutism: Start combination OCPs to suppress ovarian steroidogenesis. Hyperglycemia/diabetes: Weight loss; hypoglycemic agents.

Vulvovaginitis A 19-year-old woman who is sexually active with multiple partners presents to your clinic with vaginal pruritus and ↑ discharge. A wet mount and KOH prep reveal no organisms. What organism is likely contributing to her vulvovaginitis? Chlamydia.

The most common outpatient gynecologic problem. Vulvovaginitis can be bacterial (bacterial vaginosis), fungal (Candida), or protozoal (Trichomonas vaginalis). Figure 15-3 depicts the histologic appearance of two common causes of vulvovaginitis. KEY FACT

SYMPTOMS/EXAM ■

Sexual abuse must be considered in any child with vulvovaginitis.

■

May present with ↑ vaginal discharge, a change in vaginal discharge odor, and/or vulvovaginal pruritus. Perform a complete examination of the vulva, vagina, and cervix. Look for vulvar edema, erythema, and discharge.

DIAGNOSIS/TREATMENT

Obtain swabs from the vagina to perform a wet mount and cultures for gonorrhea and chlamydia (see Table 15-2).

A

B

Causes of vaginitis. (A) Candidal vaginitis. Candida albicans organisms are evident on KOH wet mount. (B) Gardnerella vaginalis. Note the granular epithelial cells (“clue cells”) and indistinct cell margins. (Image A reproduced with permission from Wolff K, Johnson RA. FitzpatFIGURE 15-3.

rick’s Color Atlas & Synopsis of Clinical Dermatology, 6th ed. New York: McGraw-Hill, 2009: 720. Image B reproduced with permission from Kasper DL et al. Harrison’s Principles of Internal Medicine, 16th ed. New York: McGraw-Hill, 2005: 767.)

GYNECOLOGY

TA B L E 15 - 2 .

CHAPTER 15

281

Common Causes of Vulvovaginitis

BACTERIAL VAGINOSIS Exam

Can be unremarkable except for

YEAST (USUALLY CANDIDA) Erythema and irritation.

discharge. Discharge

Grayish or white, having a fishy odor;

TRICHOMONAS VAGINALIS The vagina and cervix may be swollen and red.

White, curdlike.

Yellow-green, malodorous.

Nothing.

Motile, flagellated protozoans.

⊕ “whiff test” (KOH placed on a

Pseudohyphae and spores (see Figure

Nothing.

slide leads to a fishy odor).

15-3).

Elevated (ie, > 7).

Normal or < 7.

Elevated or > 7.

Nonpregnant

Metronidazole.

Topical antifungal × 3–7 days or oral

Metronidazole.

Pregnant

Metronidazole.

Use only topical antifungals × 7 days.

pronounced after intercourse. Wet mount

Reveals > 20% of epithelial cells with indistinct cell margins (“clue cells”; see Figure 15-3).

KOH prep

pH Treatment

fluconazole × 1 dose. Metronidazole.

Ectopic Pregnancy A 28-year-old woman who found out that she was pregnant one week ago presents to the ER complaining of fevers and RLQ abdominal pain. Her exam is significant for RLQ tenderness and no cervical motion tenderness. What should be the next step? Abdominal ultrasound to look for an adnexal mass. It is too early to visualize an intrauterine gestational sac. Also, trend the patient’s β-hCG, as levels tend to rise less in ectopic as opposed to intrauterine pregnancies. It is also important to consider nongynecologic causes.

Defined as any pregnancy that is implanted outside the uterine cavity. The most common location is the fallopian tube (95%). Risk factors include a history of PID, prior ectopic pregnancy, tubal/pelvic surgery, DES exposure in utero leading to abnormal tubal development, and IUD use. SYMPTOMS/EXAM ■

■

■

Patients may complain of lower abdominal or pelvic pain as well as abnormal vaginal spotting or bleeding and amenorrhea. The abdomen may be tender to palpation. Bimanual exam may also reveal cervical motion tenderness and an adnexal mass. A ruptured ectopic may present with unstable vital signs, diffuse abdominal pain, rebound tenderness, and shock.

KEY FACT Any woman with abdominal pain needs a urine pregnancy test.

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GYNECOLOGY

DIFFERENTIAL

Spontaneous abortion, molar pregnancy, ruptured corpus luteum cyst, PID, ovarian torsion, appendicitis, pyelonephritis, diverticulitis, regional ileitis, ulcerative colitis. DIAGNOSIS ■

■

■

KEY FACT ↑ β-hCG in the absence of an intrauterine pregnancy on ultrasound is suspicious for an ectopic pregnancy.

■ ■

An ↑ β-hCG in the absence of an intrauterine pregnancy on ultrasound is highly suspicious for an ectopic pregnancy. Do an ultrasound to look for an intrauterine pregnancy, an adnexal mass, or free fluid (see Figure 15-4). The gestational sac may be visualized on: ■ Transvaginal ultrasound when β-hCG is approximately 1000–2000 mIU/mL, or at approximately 4–5 weeks’ GA. ■ Transabdominal ultrasound when β-hCG is > 1800–3600 mIU/mL. Fetal heart motion of the embryo can be seen after 5–6 weeks’ GA. Definitive diagnosis is made by laparoscopy, laparotomy, or ultrasound visualization of a pregnancy outside the uterus.

TREATMENT ■ ■

KEY FACT ■

All women with ectopic pregnancies should be typed and screened and given RhoGAM if Rh is 両.

■

For hemodynamically unstable patients, immediate surgery is required. For hemodynamically stable patients: ■ Follow serial β-hCG levels closely with or without ultrasound studies. ■ Methotrexate is used for small (< 3.5-cm), unruptured ectopic pregnancies in asymptomatic women until levels are undetectable. ■ Laparoscopy or laparotomy for removal of ectopic pregnancy. Expectant management is appropriate for stable, compliant patients with decreasing β-hCG levels or β-hCG < 200 mIU/mL, and if the risk of rupture is low. Prevention of ectopic pregnancies includes prevention and thorough treatment of STDs.

CM A

B

Normal intrauterine pregnancy and ectopic pregnancy. Transvaginal ultrasound showing (A) a normal intrauterine pregnancy with a gestational sac containing a yolk sac within the uterine cavity, and (B) a complex mass (CM)/ectopic pregnancy adjacent to an empty uterus. (Reproduced with permission from Tintinalli JE et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 6th ed. New York: McGraw-Hill, 2004, Figs. 113-15

FIGURE 15-4.

and 113-22.)

GYNECOLOGY

Contraception ORA L C O N T R A C E PT IV E S (O C Ps )

The long-term consequences of OCP use include a ↓ in ovarian and endometrial cancers, a ↓ incidence of breast disease (but not breast cancer), ↓ menstrual flow, and ↓ dysmenorrhea. OCP use also ↑ the risk of hypertension and stroke. Contraindications to OCP use include the following: ■ ■ ■ ■ ■ ■ ■

Pregnancy. Previous or active thromboembolic disease. Smoking in patients > 35 years of age. Undiagnosed genital bleeding. Estrogen-dependent neoplasms. Hepatocellular carcinoma. Acute liver dysfunction. OT H E R H O R M O N A L C O N T R A C E PTI VE S

Have fewer compliance issues than OCPs. Include the following: ■

■

■

■

Injectable (Depo-Provera): Administered intramuscularly every three months. Transdermal (Ortho Evra): A patch that is changed weekly for three weeks followed by a one-week holiday. Vaginal (NuvaRing): A vaginal ring that is removed after three weeks followed by a one-week holiday. Intrauterine (Mirena): See the discussion of IUDs below. I N T R A U T E R IN E D E V I CE S (I U D s )

A 36-year-old mother with a history of breast cancer presents to her gynecologist seeking a reliable, “hassle-free” birth control option. She has been in a long-term relationship with her husband. What method would you recommend? A copper IUD would be optimal for this patient, since she has a contraindication to using hormonal contraceptives and is not at high risk for contracting STDs.

Two types of IUDs are approved for use in the United States. Both are highly effective, with > 99% efficacy during the first year of use. ■

Levonorgestrel IUD (trade name Mirena): Lasts 5 years. ■ ↓ the amount of menstrual bleeding and dysmenorrhea; thus, a good choice for the treatment of menorrhagia. ■ Side effects: Irregular menstrual bleeding or amenorrhea. Copper IUD (trade name ParaGard): ■ Lasts 10 years. ■ Nonhormonal; a good choice for women who have contraindications to hormone treatment. ■ Side effects: Dysmenorrhea and ↑ menstrual bleeding. ■

■

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283

284

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GYNECOLOGY

E M E R G E NC Y C ONTR AC E P TI ON ■

■

Should be taken immediately after intercourse; can be taken up to five days afterward, but with decreasing effectiveness. Options include levonorgestrel +/– estradiol.

Infertility Defined as the inability of a couple to conceive after one year of unprotected intercourse. It affects 10–15% of couples. Causes include the following: ■

■

KEY FACT Endometriosis is the leading cause of female infertility, followed by PID. ■

Male dysfunction (35%): Defects in spermatogenesis (male factor); varicoceles. Female dysfunction (50%): ■ Uterine/tubal factors: Endometriosis or myomas that distort the endometrium or fallopian tubes, PID, congenital genital tract abnormalities. ■ Ovulatory dysfunction: Ovarian failure, prolactinoma. ■ Endocrine dysfunction: Thyroid/adrenal disease, PCOS. Unexplained infertility and rare problems (15%).

DIAGNOSIS ■ ■ ■ ■

Semen analysis to rule out male factors. Serum FSH/LH/TSH/prolactin to rule out endocrine dysfunction. Hysterosalpingography to rule out tubal and uterine cavity abnormalities. Basal body temperatures or ovulation kits to rule out ovulatory dysfunction.

TREATMENT ■ ■

■

■

Treat the underlying cause. Fertility rates in endometriosis can be improved through laparoscopic removal of implants outside the uterine cavity. Ovulation can be induced with clomiphene, but this can lead to ovarian hyperstimulation and multiple gestations. For refractory cases, assisted reproductive technologies such as in vitro fertilization can be used.

Menopause KEY FACT Premature menopause occurs before age 40 and is often due to idiopathic premature ovarian failure.

Cessation of menstruation for > 12 months. Average age of onset is 51. Surgical menopause occurs following removal or irradiation of the ovaries. Postmenopausal women are at ↑ risk for developing osteoporosis and heart disease. SYMPTOMS/EXAM ■

■

Patients may complain of menstrual irregularities, hot flashes, sweating, sleep disturbances, mood changes, ↓ libido, and vaginal dryness. Exam may reveal vaginal dryness, ↓ breast size, and genital tract atrophy.

GYNECOLOGY

CHAPTER 15

285

DIAGNOSIS ■ ■

Requires one year without menses with no other known cause. ↑↑ serum FSH (> 30 IU/L) is suggestive.

TREATMENT ■

■

■

■

Hormone therapy with estrogen (in woman without a uterus) or combined estrogen and progesterone (in woman with an intact uterus) can be used for short-term symptomatic relief. Absolute contraindications to hormone therapy include undiagnosed vaginal bleeding, active liver disease, recent MI, recent or active vascular thrombosis, and a history of endometrial or breast cancer. Alternatives to hormone therapy include the following: ■ Vasomotor instability: Venlafaxine and some SSRIs. ■ Vaginal atrophy: Vaginal lubricants or topical estrogens. ■ Osteoporosis: Calcium, vitamin D, calcitonin, bisphosphonates (alendronate), and selective estrogen receptor modulators (raloxifene). Unopposed estrogen (without progesterone therapy) can lead to endometrial hyperplasia and/or carcinoma.

KEY FACT Use the lowest possible dose of hormone therapy for the shortest duration to treat symptoms.

Urinary Incontinence A 43-year-old mother of four presents to her primary care physician complaining of urinary leakage that has occurred during her aerobics classes and when she coughs or lifts heavy objects. These symptoms started after the birth of her last child. She wants to avoid surgery if at all possible. What do you recommend? This patient has stress incontinence from a weakened pelvic floor. Kegel exercises can strengthen the pelvic floor and improve symptoms. Pessaries can also be used to prevent embarrassing leakage.

Involuntary loss of urine that is a social or hygienic problem. See Table 15-3 for an outline of stress, urge, and mixed incontinence. EXAM/DIAGNOSIS ■

■

■

■

Voiding diaries can help quantify the frequency and volume of urine lost, the circumstances of leakage (to diagnose stress or urge types of incontinence), voiding patterns, and the amount and type of fluid taken in. Patients with incontinence should have a screening neurologic exam to rule out neurologic causes. A standing cough stress test can be used to diagnose stress incontinence; cystometry can be used to diagnose urge incontinence. Urinary retention with overflow can be a cause of urinary incontinence and can be diagnosed with an elevated postvoid residual.

TREATMENT

Table 15-3 outlines treatment measures for urinary incontinence.

KEY FACT UTI must be ruled out in all women complaining of urinary incontinence.

286

CHAPTER 15

GYNECOLOGY

TA B L E 15 - 3 .

Types of Urinary Incontinence

STRESS INCONTINENCE History

Loss of urine with exertion (running) or straining (coughing, laughing).

URGE INCONTINENCE

MIXED

(DETRUSOR INSTABILITY)

INCONTINENCE

Loss of urine with strong

Stress and urge

desire to void. Often associated with urinary frequency and

incontinence present simultaneously.

urgency. Mechanism

Poor support or poor

Involuntary detrusor muscle

A combination of

function of the urethral

contractions.

both mechanisms.

Urethral hypermobility;

Idiopathic, neurologic

As for both

weakened urethral

(Alzheimer’s, diabetes, MS).

conditions.

Patient history.

Patient history.

As for both

Demonstrable leakage

Cystometry reveals

conditions.

sphincter. Etiology

closing mechanisms. Diagnosis

with stress (cough).

involuntary detrusor muscle contraction associated with urinary leakage.

Treatment

Pelvic floor

Behavior modification (eg,

Based on the

strengthening

limiting fluid intake;

patient’s worst

exercises (Kegel) +/–

avoiding caffeinated or

symptom; some

alcoholic beverages).

treatments

biofeedback, pessaries, weight loss, surgery to

Bladder training.

overlap (eg, Kegel

restore bladder neck

Medical therapy

exercises).

support.

(anticholinergic). Surgical therapy (sacral neurostimulators, intravesical Botox injections).

GYNECOLOGY

CHAPTER 15

KEY FACT

Benign Breast Disorders Include fibrocystic change (the most common), fibroadenoma, intraductal papilloma (a common cause of bloody nipple discharge), duct ectasia, fat necrosis, mastitis, and breast abscess. See Table 15-4 for a list of common examples.

TA B L E 15 - 4 .

changes

Always rule out a breast malignancy with a biopsy in anyone who is high risk.

Benign Breast Disease

DISEASE TYPE Fibrocystic

287

SYMPTOMS/EXAM Mild to moderate pain in the breasts

TREATMENT OCPs.

ASSOCIATED WITH CARCINOMA Patients are at ↑ risk of

+/– lumps premenstrually; multifocal,

breast cancer only in

bilateral nodularity.

the presence of cellular atypia.

Most common in women 20–50 years of

Cancer must be excluded in

age.

high-risk groups. Fibroadenoma

The most common tumor in menstruating women < 25 years of age. Presents as a small, firm, unilateral, nontender mass that is freely movable and slow growing. Ultrasound can be used to differentiate

Thirty percent will spontaneously disappear.

Risk is twice as high as that of control patients.

Removal is not necessary, but surgical excision is both diagnostic and curative. Biopsy if the patient is in a high-risk group. Recurrence is common.

from a cyst. Intraductal papilloma

Clear, bloody, or discolored fluid from a single duct opening. Milking of the breast shows drainage from one duct opening.

Mastitis

Drainage and surgical exploration of the duct.

Risk is twice as high as that of control patients.

A malignant process must always be excluded.

Seen in breast-feeding women; presents

Continued breast-feeding; NSAIDs and

as a hard, red, tender, swollen area of

antibiotics to cover common etiologies

breast accompanied by fever, myalgias, and

(staph, strep, E coli).

None.

general malaise. Abscess

Can develop if mastitis is inadequately

Needle aspiration or surgical drainage in

treated. Exam reveals a fluctuant mass

addition to antibiotics.

None.

accompanied by systemic symptoms similar to those seen in mastitis. Fat necrosis

Firm, tender, and ill defined with

Analgesia. An excisional biopsy may be

surrounding erythema; related to trauma/

done to rule out malignancy.

ischemia.

None.

288

CHAPTER 15

GYNECOLOGY

NO T E S

CHAPTER 16

PEDIATRICS Well-Child Care/Routine Health Screening

290

Cardiology

313

GROWTH AND DEVELOPMENT

290

VENTRICULAR SEPTAL DEFECT

313

PREVENTION OF ILLNESS

293

ATRIAL SEPTAL DEFECT

313

SAFETY

293

PATENT DUCTUS ARTERIOSUS

314

ANTICIPATORY GUIDANCE

294

TETRALOGY OF FALLOT

315

TRANSPOSITION OF THE GREAT ARTERIES

315

COARCTATION OF THE AORTA

316

Colic Neonatology

294 294 295

Gastroenterology

316

NEONATAL SEPSIS

296

PYLORIC STENOSIS

316

CONGENITAL TORCHES INFECTIONS

297

INTUSSUSCEPTION

317

CONGENITAL ANOMALIES

297

MALROTATION/VOLVULUS

318

JAUNDICE

297

MECKEL’S DIVERTICULUM

320

NECROTIZING ENTEROCOLITIS

320

RESPIRATORY DISTRESS

Dermatology NEONATAL RASHES ECZEMA

Endocrinology

301 301 301

303

CONGENITAL ADRENAL HYPERPLASIA

303

PRECOCIOUS PUBERTY

304

Infectious Disease FEVER WITHOUT A SOURCE

Immunology

305 305

306

IMMUNODEFICIENCY SYNDROMES

306

KAWASAKI DISEASE (MUCOCUTANEOUS LYMPH NODE SYNDROME)

309

Pulmonology

321

CROUP (LARYNGOTRACHEOBRONCHITIS)

321

EPIGLOTTITIS

323

PERTUSSIS

324

BRONCHIOLITIS

324

Neurology

325

FEBRILE SEIZURES

325

EPILEPSY SYNDROMES

325

Oncology

326

WILMS’ TUMOR

326

NEUROBLASTOMA

327

310

RETINOBLASTOMA

328

JUVENILE IDIOPATHIC ARTHRITIS

310

TUMOR LYSIS SYNDROME

328

REACTIVE ARTHRITIS

311

HENOCH-SCHÖNLEIN PURPURA

311

Rheumatology

Genetics COMMON GENETIC DISORDERS

329 329

289

290

CHAPTER 16

PEDIATRICS

Well-Child Care/Routine Health Screening Routine health screening includes the monitoring of growth and development, the prevention of illness, safety, and anticipatory guidance to help parents prepare for their child’s next steps. Routine screening should be conducted at the following intervals: ■

■

KEY FACT Commonly tested disorders on newborn screens: ■ Phenylketonuria ■ Congenital hypothyroidism ■ Galactosemia ■ Sickle cell disease ■ Biotinidase deficiency ■ Congenital adrenal hyperplasia ■ Maple syrup urine disease ■ Tyrosinemia ■ Cystic fibrosis (CF) ■ Medium-chain acyl-CoA dehydrogenase deficiency ■ Toxoplasmosis

■

■

■

■

■

Metabolic/genetic diseases: At one day of life, a state newborn screen is drawn. The exact tests conducted vary by state but typically include testing for disorders for which early identification and treatment would significantly improve morbidity and mortality for affected infants. Growth parameters/development/behavior: Screen at each visit—ie, at 2–4 weeks, 2 months, 4 months, 6 months, 9 months, 12 months, 15 months, 18 months, and 2 years. Then screen annually. Lead/anemia: Screen at 9–15 months in communities where more than one-third of the houses were built before 1950; where > 12% of one- and two-year-old children have been found to have elevated serum lead levels; or where limited information is available about the lead levels of the children in the community. Lead screening should be repeated at age two, especially in high-risk communities. Consider repeating anemia screening in menstruating adolescents and screening for anemia at six months in premature infants. BP: Screen with every medical exam starting at age three. Norms are based on sex, age, and height percentile. Vision and hearing screening: Conduct subjective testing at each visit; red-reflex testing at all infant visits; and objective hearing and vision screening at birth and annually starting at age three. TB: Conduct a risk assessment at each well-child check. PPD placement is appropriate for high-risk children. High-risk behaviors/STD screening: Screen at each adolescent visit (beginning at approximately 10–11 years of age). G RO W TH AND DE VE LOP M E NT

A concerned parent brings his 11-month-old son to see you because the child is smaller than his cousins, who are approximately the same age. The boy has been meeting his developmental milestones, and when you plot his height and weight, you find that his weight is in the 10th percentile and height in the 25th percentile. His physical exam is unremarkable. According to his past records, his height has been in the 25th percentile since birth, and his weight has been in the 10th to 25th percentile. What further evaluation should you consider? None; the boy’s growth is appropriate.

Failure to Thrive (FTT)

Although there is no consensus for the definition of FTT, criteria that are often used include the following: ■

■ ■

Weight less than the third to fifth percentile for gestation-corrected age and sex on growth charts on more than one occasion. Weight for height less than the 10th percentile. ↓ weight velocity with crossing of two major percentiles (90th, 75th, 50th, 25th, 10th, 5th) on the growth chart.

PEDIATRICS

■ ■

■

■

Daily weight gain less than expected for age. Failure to grow: Growth that is significantly slower than that of children of the same age. Height and weight are both slow (eg, growth hormone deficiency, genetic disease). Failure to gain weight: The child is or was previously able to maintain normal height velocity, but weight is disproportionately low or has “fallen off” the growth curve. Height velocity may subsequently slow if the child has been underweight for a prolonged period of time. Head circumference is the last to fall off the curve. Short stature: ■ Height less than the third percentile for age, with weight in the normal range. ■ ↓ height velocity with crossing of two major percentiles on the growth chart, with normal or ↑ weight gain for age.

SYMPTOMS/EXAM ■

■

■

■ ■ ■

Obtain a thorough feeding/nutrition history, and if possible, observe the parent or caretaker feeding the child. Ask about malabsorption, quality and frequency of stools, and/or systemic symptoms. Obtain a detailed social history (family stressors) and family history (CF, genetic diseases, HIV). Conduct formal development and behavioral testing. Plot height, weight, and head circumference since birth. Conduct a complete physical exam.

DIFFERENTIAL ■

■

■

Inadequate intake: The most common cause (ie, overdiluting formula). Often 2° to psychosocial issues, with no underlying medical condition. Other causes include mechanical problems such as cleft palate/nasal obstruction or sucking/swallowing dysfunction. Inadequate absorption or ↑ losses: Examples include malabsorption, infectious diarrhea, vomiting, biliary atresia, intestinal obstruction, necrotizing enterocolitis, and short gut. ↑ metabolic demand or ineffective utilization: Examples include inborn errors of metabolism, CF/lung disease, HIV/infection, endocrine disorders, and congenital heart disease.

DIAGNOSIS ■ ■

■

The H&P will dictate the extent of lab workup needed. First-line lab evaluation should include a CBC, electrolytes, BUN/creatinine, a lead level if appropriate, and a UA. If the child is severely malnourished, also evaluate albumin (to assess protein status), alkaline phosphatase, calcium, and phosphorus (to evaluate for rickets).

TREATMENT ■ ■

■

Treat the underlying cause. If the H&P does not suggest an organic cause, start a calorie count and consider nutritional supplementation. Hospitalization may be necessary for severe malnourishment or if there is concern for neglect.

CHAPTER 16

291

CHAPTER 16

292

PEDIATRICS

Developmental Milestones You are seeing an infant in clinic for a routine well-child checkup. The mother reports that the infant recently started crawling. In addition, she is reportedly saying “mama” and “dada” to everyone and waving “bye-bye.” If the infant is developmentally on target, how old should she be? Nine months.

Table 16-1 highlights major developmental milestones. Red flags include the following: ■ ■ ■

TA B L E 16 - 1 .

Developmental Milestones

AGE 2 months

Persistent primitive reflexes by six months. Handedness before one year. No pointing by 18 months.

GROSS MOTOR Lifts head/chest when

FINE MOTOR Tracks past midline.

LANGUAGE Alerts to sound; coos.

prone. 4–5 months

Rolls front to back and

Recognizes parent; social smile.

Grasps rattle.

back to front (5 months). 6 months

SOCIAL/COGNITIVE

Orients to voice; “ah-goo”;

Enjoys looking around;

razzes.

laughs.

Babbles.

Stranger anxiety.

Sits unassisted

Transfers objects; raking

(7 months).

grasp.

Crawls; pulls to stand.

Uses three-finger pincer

Says “mama/dada”

Waves “bye-bye”; plays pat-

grasp.

(nonspecific).

a-cake.

Cruises (11 months); walks

Uses two-finger pincer

Says “mama/dada”

Imitates actions.

alone.

grasp.

(specific).

15 months

Walks backward.

Uses cup.

Uses 4–6 words.

Temper tantrums.

18 months

Runs; kicks a ball.

Builds tower of 2–4 cubes.

Names common objects.

Copies parent in tasks (eg,

9–10 months

12 months

sweeping). 2 years

Walks up/down steps with

Builds tower of six cubes.

Uses two-word phrases.

help; jumps.

Follows two-step commands; removes clothes.

3 years

Rides tricycle; climbs stairs

Copies a circle; uses

Uses three-word

Brushes teeth with help;

with alternating feet (3–4

utensils.

sentences.

washes/dries hands.

Copies a cross.

Counts to 10.

Cooperative play.

years). 4 years

Hops.

(Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 402.)

PEDIATRICS

CHAPTER 16

PREVENTION OF ILLNESS

293

KEY FACT

Immunizations

Figure 16-1 summarizes the recommended timetable for childhood immunizations. Schedules may vary for children who are behind and require catchup immunizations.

The HPV vaccine is recommended for girls 11–12 years of age or for girls 13–26 years of age who have not previously been vaccinated as a catch-up.

SAFETY

General Principles ■

■

Car seats should be placed in the rear seat of the car, rear-facing, until the child weighs > 20 lbs and is > 1 year of age. Car seats should not be placed in seats with active air bags. Car seats have a finite useful life, and seats that are more than a few years old are not considered safe. The B-HEADSS interview (see mnemonic) can be used to gauge psychosocial risk.

KEY FACT All infants should go “back” to sleep (ie, sleep on their backs) to ↓ the risk of sudden infant death syndrome (SIDS).

Child Abuse MNEMONIC A three-month-old infant is brought to the pediatric ER with a broken left femur. Her parents explain that they had just left her alone for a minute when she rolled off the couch. In addition to x-rays of her leg, what other evaluation would you want to perform on this child? Three-month-old infants generally cannot roll on their own, and a fall from a couch should not result in a broken femur. You should thus order a skeletal survey and an ophthalmologic exam as well as a CBC, PT/PTT, AST, ALT, amylase, lipase, calcium, phosphorus, alkaline phosphatase, electrolytes, BUN/creatinine, and UA—in other words, you should perform a full workup for medical causes of

Use the B-HEADSS interview for adolescents:

Body image Home Education and Employment Activities Drugs Sexuality Suicidality/depression

unusual fractures in this age group, as well as for additional injuries that might be

Vaccine ▼

Age

▼

the result of abuse.

Birth HepB

Hepatitis B Rotavirus Diphtheria, Tetanus, Pertussis

1 month

2 4 6 12 15 18 19–23 months months months months months months months

HepB RV

RV

RV

DTaP

DTaP

DTaP

DTaP

Hib

Hib

Hib

Hib

PCV

PCV

PCV

PCV

Inactivated Poliovirus

IPV

IPV

Measles, Mumps, Rubella Varicella Hepatitis A Meningococcal FIGURE 16-1.

4–6 years

HepB

Pneumococcal

type b

2–3 years

DTaP

PPSV

IPV

IPV

MMR

MMR

Varicella

Varicella

HepA (2 doses)

Range of recommended ages for all children except certain high-risk groups

HepA Series MCV

Pediatric immunization timetable. (Reproduced from the Centers for Disease Control and Prevention, Atlanta, GA.)

Range of recommended ages for certain high-risk groups

CHAPTER 16

294

KEY FACT Consider nonaccidental trauma whenever the history of an injury is discordant with physical findings.

PEDIATRICS

Includes physical, sexual, and emotional abuse/neglect. Diagnosis is based on a history that is discordant with physical findings. SYMPTOMS/EXAM

Presentation may include the following: ■ ■ ■ ■

■ ■

■ ■

■

Multiple injuries in various stages of healing. Irritability/lethargy. Growth failure. Oddly situated bruises (not over bony prominences) or bruises on a child who is not yet mobile. Pattern injuries (cigarette/immersion burns). Skeletal trauma in the absence of a developmentally plausible mechanism (especially spiral fracture of long bones, multiple/old/posterior rib fractures, or corner fractures). Retinal hemorrhage in infants. Intracranial hemorrhage, especially in the absence of a plausible mechanism. Signs/symptoms of STDs or genital trauma in prepubertal children.

DIAGNOSIS ■

■

Laboratory evaluation: CBC, PT/PTT, AST, ALT, amylase, lipase, calcium, phosphorus, alkaline phosphatase, electrolytes, BUN/creatinine, and UA. Consider a toxicology screen if ingestion is suspected. Other: Skeletal survey, head CT, ophthalmologic exam.

TREATMENT ■

■

Physicians are mandated reporters of any suspected abuse or nonaccidental trauma and should immediately notify social services or Child Protective Services. Consider hospitalization to ensure the safety of the child. AN TI C I P ATOR Y G U I DANC E

Provide nutrition and sleep counseling as well as injury/violence prevention counseling at each health maintenance visit.

Colic

MNEMONIC The 5 S’s for soothing crying babies:

■

Swaddling Side/Stomach position (done under close supervision only)

Shushing sounds Swinging Sucking

■

Defined as severe, paroxysmal crying for > 3 hours a day, > 3 days a week for > 3 weeks in a healthy, well-fed infant. Usually peaks at around six weeks of life, with spontaneous resolution by 3–4 months. A diagnosis of exclusion. Tx: Treatment consists of providing reassurance and teaching parents soothing techniques such as the 5 S’s (see mnemonic).

Neonatology The specialty of pediatrics that concerns the care of infants from birth until they are ready to be discharged to home. A neonate is defined as an infant < 28 days old.

PEDIATRICS

CHAPTER 16

295

RE S PI R A T O R Y D I S T R E S S ■ ■

■

Common causes of neonatal respiratory distress are outlined in Table 16-2. Also consider sepsis, congenital heart disease (if O2 saturation fails to improve with supplemental oxygen), anatomic airway anomalies (eg, choanal atresia, in which an NG tube cannot be passed at birth), pneumothorax (especially in an infant who suddenly decompensates), neurologic abnormalities, and pneumonia. Dx/Tx: The diagnosis and treatment of common neonatal respiratory disorders are outlined in Table 16-2.

TA B L E 16 - 2 .

DISORDER

Common Neonatal Respiratory Disorders

DESCRIPTION

HISTORY

EXAM/CXR FINDINGS

TREATMENT

COMPLICATIONS

Respiratory

Surfactant deficiency

Usually occurs

↓ air movement;

Maternal antenatal steroids

Chronic lung

distress

leads to poor lung

in premature

CXR shows ↓

for prevention; surfactant

disease.

syndrome/

compliance and

infants.

lung volumes and

administration at the time of

hyaline

respiratory failure.

“ground-glass”

delivery; respiratory support.

membrane

appearance (see

disease

Figure 16-2A). Usually only a mild to

Transient

Retained fetal lung

Term or near-

CXR shows perihilar

tachypnea of

fluid leads to brief,

term infants;

streaking and fluid

moderate O2 requirement

the newborn

self-resolving, mild

nonasphyxiated;

in interlobar fissures.

for support.

respiratory distress. A

born following

diagnosis of exclusion.

short labor or

None.

often via C-section without labor. Meconium

Inhalation of meconium

Term infants;

Hypoxia; coarse

Nasopharyngeal suctioning

Pulmonary

aspiration

at or near the time of

meconium present

breath sounds;

at perineum; tracheal

hypertension.

syndrome

birth leads to aspiration

at the time of

CXR shows coarse,

suctioning at birth;

Suspect CF.

pneumonitis.

delivery.

irregular infiltrates,

ventilatory support and

hyperexpansion, and

antibiotics. Nitrous oxide

lobar consolidation.

if severe pulmonary hypertension.

Congenital

A defect in the

Severe respiratory

Scaphoid abdomen;

Immediate intubation,

Severe

diaphragmatic

diaphragm leads to

distress at birth;

CXR may show

ventilatory support, and

pulmonary

hernia

herniation of abdominal

may be diagnosed

bowel loops in the

surgical correction after

hypertension.

contents into the chest

by prenatal

chest (see Figure

stabilization. Patients may

Mortality is

cavity; limitation of

ultrasound.

16-2B).

require extracorporeal

25–40%.

lung growth leads to

membrane oxygenation

pulmonary hypoplasia.

(ECMO).

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A

B

Neonatal respiratory distress. (A) Frontal CXR in a neonate with RDS, showing diffuse fine granular (“ground-glass”) opacities and hypoaeration. (B) Frontal radiograph in a patient with congenital diaphragmatic hernia, demonstrating air-filled loops of bowel in the left chest and rightward displacement of mediastinal structures. (Image A reproduced with permission from USMLERx.com. Image B reproduced with permission FIGURE 16-2.

from Brunicardi FC et al. Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill, 2010, Fig. 39-3.)

NE ONATAL S E P S I S

You are taking advice calls for the pediatric urgent care clinic. A father calls in to report that his two-week-old daughter has a rectal temperature of 38.5°C (101.3°F). She was a term newborn who was delivered vaginally with no complications. She has been breast-feeding well and has been having six bowel movements daily with about 10 wet diapers. According to the father, the infant has no other symptoms. Her two-year-old sister has a cold, but the parents have been careful about having her wash her hands before going near the baby. What advice would you give this father? In a two-week-old infant, a temperature of 38°C requires a full sepsis workup, including a CBC, a blood culture, a UA and urine culture, and an LP. The baby should be admitted for IV antibiotics until culture results are back (usually for a minimum of 48 hours).

KEY FACT A fever in the first month of life is an indication for a full sepsis workup, admission, and IV antibiotics.

Serious bacterial infections are relatively common in infants < 2 months of age. The most frequent infections are UTIs, followed by bacterial sepsis, meningitis, and pneumonia. Risk factors include maternal group B strep (GBS) infection, rupture of membranes > 18 hours, maternal fever, chorioamnionitis, and premature labor. The most common pathogens are E coli, GBS, and other gram-両 rods. Listeria monocytogenes is rare but is a frequent topic on pediatric exams.

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SYMPTOMS/EXAM ■

■

Serious infections in neonates are often occult, meaning that the signs and symptoms of infection are difficult to see. A neonate who appears well may still have a serious infection. Temperature may be high, low, or variable, and the infant may or may not have additional abnormal vital signs. Septic infants often present with nonspecific signs such as poor feeding, rapid breathing, vomiting, or ↓ activity.

DIAGNOSIS

Evaluation should include a CBC, a blood culture, a UA and urine culture, and an LP for CSF culture. Consider a CXR. TREATMENT ■

Initial treatment: Begin IV ampicillin (to cover Listeria) + either gentamicin or a thirdgeneration cephalosporin such as cefotaxime. ■ If the child continues to appear ill after antibiotics have been started or has pleocytosis on CSF analysis, consider starting acyclovir and sending an HSV PCR of the CSF. Subsequent therapy: ■ If the cause of sepsis was a UTI, a renal ultrasound and VCUG may be obtained to evaluate the infant for hydronephrosis and vesicoureteral reflux. ■ If the infant had meningitis, follow-up hearing tests and developmental tests may be recommended. ■

■

KEY FACT Ceftriaxone displaces bilirubin and should not be used in neonates < 28 days.

PREVENTION

Screen the mother for GBS at 36 weeks, and treat with prophylactic antibiotics during delivery. C O N G E N I T A L T O R C H E S I N F E C T I ONS

Many congenital infections present with jaundice, hepatosplenomegaly, and thrombocytopenia. Table 16-3 outlines the diagnosis and treatment of each. C O N G E N I T A L A N O M A L IE S

Table 16-4 outlines the clinical presentation and treatment of common congenital anomalies and malformations. J A U N D IC E

Physiologic Jaundice SYMPTOMS/EXAM ■

Nearly all babies have some form of indirect (unconjugated) hyperbilirubinemia, commonly known as physiologic jaundice. This is because newborns have a higher bilirubin load (from RBC breakdown); their immature livers are unable to conjugate bilirubin well; they are not stooling and urinating frequently to excrete bilirubin; and their guts lack the bacterial components that facilitate bilirubin breakdown.

KEY FACT With Down syndrome, look for the “double bubble” sign of duodenal atresia.

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TA B L E 16 - 3 .

PEDIATRICS

ToRCHeS Infections

INFECTION

DESCRIPTION

Toxoplasmosis

Rubella

TREATMENT

PREVENTION

Hydrocephalus, seizures, chorioretinitis,

Pyrimethamine,

Avoid exposure to cats and cat feces during

intracranial calcifications, and ring-enhancing

sulfadiazine,

pregnancy; avoid raw/undercooked meat; treat

lesions on head CT.

spiramycin.

women with 1° infection.

“Blueberry muffin” rash, cataracts, hearing loss,

None.

Immunize mothers prior to pregnancy.

Ganciclovir.

Avoid exposure.

Acyclovir.

Perform a C-section if the mother has active

PDA and other cardiac defects, encephalitis. Cytomegalovirus

Petechial rash, periventricular calcifications,

(CMV)

microcephaly, chorioretinitis.

Herpes simplex

Skin, eye, and mouth vesicles; can progress to

(HSV)

severe CNS/systemic infection.

lesions at the time of delivery. The highest risk is from mothers with 1° infection.

Syphilis

Maculopapular skin rash on palms and soles,

Penicillin.

Treat seropositive mothers with penicillin.

lymphadenopathy, “snuffles,” osteitis.

TA B L E 16 - 4 .

Common Congenital Anomalies and Malformations

AGE AT LESION Cleft lip/palate

DESCRIPTION Abnormal ridge/division.

PRESENTATION Presents at birth.

SYMPTOMS/SIGNS Poor feeding; aspiration; severe, recurrent otitis

TREATMENT Surgical repair of the lip/palate.

media. May be associated with other anomalies. Tracheoesophageal

Four different types. Blind

Usually presents

Copious secretions, choking/

Suctioning of the pouch

fistula

esophageal pouch with fistula

in the first few

coughing with feeds, cyanosis,

with an NG tube; reflux

between the distal esophagus

hours of life, but

respiratory distress/aspiration.

precautions; supportive

and trachea is the most common.

other types can

care; surgical repair.

present later in infancy. Abdominal wall

Gastroschisis (the intestine

Presents

A visible defect.

defects

extrudes through the defect);

antenatally or at

Associated anomalies are

omphalocele (a membrane-

birth.

covered herniation of abdominal contents).

common in omphalocele but are rare in gastroschisis.

Coverage of abdominal contents with sterile dressing. NG decompressions, antibiotics, supportive care, and stabilization followed by 1° or staged closure.

PEDIATRICS

TA B L E 16 - 4 .

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299

Common Congenital Anomalies and Malformations (continued)

AGE AT LESION Intestinal atresias

DESCRIPTION Intestinal obstruction.

PRESENTATION Present

SYMPTOMS/SIGNS Abdominal distention, bilious

antenatally or at

vomiting, obstipation/

birth.

failure to pass meconium,

TREATMENT Surgical resection.

polyhydramnios. With Down syndrome, look for the characteristic “double bubble” sign of duodenal atresia (see Figure 16-3). Diagnose by rectal

Hirschsprung’s

Absence of ganglion cells in the

Presents at

Failure to pass meconium,

disease

colon leads to narrowing of the

infancy or usually

vomiting, abdominal

biopsy at the anal

aganglionic segment with dilation

within the first

distention, chronic

verge to look for

of the proximal normal colon.

two years of life.

constipation.

ganglion cells. A staged procedure with

Can be a short (75%) or long

an initial diverting

segment.

colostomy followed by resection when the infant is > 6 months of age. Neural tube

Includes anencephaly

Depends on the defect. Ranges

Risk ↓ with folate

defects

(incompatible with life) and

birth, but may

from incompatibility with life

ingestion during the first

spina bifida (myelomeningocele,

be detected

to hydrocephalus, paralysis,

trimester. Surgical repair.

prenatally.

and neurogenic bowel and

meningocele).

Presents at

Associated with ↑ maternal

bladder. Associated with an ↑ risk of latex allergy.

and amniotic fluid α-fetoprotein.

■

Physiologic jaundice usually presents within the first 36–48 hours of life and reaches peak total bilirubin levels of 10–15 mg/dL at 5–7 days of life. Visible jaundice starts at the head (or eyes) and travels down the body with increasing bilirubin levels.

DIFFERENTIAL ■

■

Initial bilirubin evaluation should include both total and direct bilirubin to establish whether direct or indirect hyperbilirubinemia is the problem. Jaundice is less likely to be physiologic if it is severe or prolonged, occurs within the first 24 hours of life, or is associated with an elevated direct (conjugated) component.

TREATMENT ■

↑ feeding: Most normal babies will be able to excrete bilirubin on their own with time, additional intake, and improved intestinal motility.

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Duodenal atresia. Note the characteristic “double-bubble” appearance of the duodenal bulb (1) and stomach (2) in a neonate with duodenal atresia presenting with bilious emesis. (Reproduced with permission from Brunicardi FC et al. Schwartz’s Principles of Surgery, 9th ed. New York:

FIGURE 16-3.

McGraw-Hill, 2010, Fig. 39-13.)

■

■ ■

UV phototherapy: Phototherapy is more likely to be necessary if the mother’s blood type is O negative or if the infant suffered birth trauma, is of Asian descent, was born preterm, or has a nonphysiologic form of jaundice. Phototherapy modifies the bilirubin molecule into a water-soluble form that can be more easily excreted. Exchange transfusion is indicated for severe jaundice. Follow total serum bilirubin at least daily while treating for hyperbilirubinemia.

Breast Milk Jaundice ■

■

■ ■

Breast milk contains an enzyme that further delays hepatic bilirubin conjugation and can prolong jaundice in newborns. Sx/Exam: Occurs in exclusively breast-fed infants. Jaundice presents after the first 3–5 days of life and peaks at two weeks of age. Total bilirubin levels may reach 19–20 mg/dL and may persist for 1–2 months. Dx: A diagnosis of exclusion. Tx: Rarely requires phototherapy. Once the diagnosis is made, breast-feeding should be encouraged, as the problem will go away on its own.

Pathologic Jaundice

Jaundice is considered pathologic if it is severe or prolonged, occurs within the first 24 hours of life, or is associated with an elevated direct (conjugated) bilirubin component. Very high levels of unconjugated bilirubin (> 30 mg/dL) can cross the blood-brain barrier and deposit in the basal ganglia, causing kernicterus, an irreversible, potentially fatal encephalopathy. ■

Causes of pathologic indirect hyperbilirubinemia include the following: Disorders that ↑ bilirubin production (hemolysis, sepsis, severe bruising/hematoma).

■

PEDIATRICS

Disorders that affect bilirubin conjugation (hepatic enzyme deficiencies, hepatic dysfunction). ■ Disorders that affect bilirubin excretion (intestinal obstruction, poor motility). Causes of pathologic direct hyperbilirubinemia include the following: ■ Intrahepatic: Biliary obstruction/atresia (most common), choledochal cysts, neonatal hepatitis, Dubin-Johnson syndrome, Rotor’s syndrome, Alagille syndrome, α1-antitrypsin deficiency, TPN cholestasis (affects premature infants on TPN). ■ Extrahepatic: Sepsis, UTIs, hypothyroidism, CF, inborn errors of metabolism, RBC abnormalities. ■

■

SYMPTOMS/EXAM ■

■

Look for hepatomegaly, acholic (white) stools, signs of anemia or sepsis, growth abnormalities, and congenital abnormalities. Kernicterus (usually caused by extremely high levels of indirect hyperbilirubinemia) presents with jaundice, lethargy, poor feeding, a high-pitched cry, hypertonicity, and seizures.

DIAGNOSIS ■

■

■

Order a CBC (to assess for anemia), a reticulocyte count, and a peripheral blood smear (to rule out hemolysis). A Coombs’ test can distinguish antibody-mediated disease (eg, ABO incompatibility) from non-immune-related disorders (eg, G6PD deficiency, hereditary spherocytosis). Additional testing should be guided by the patient’s H&P.

TREATMENT ■ ■

Phototherapy/exchange transfusion. Treat associated conditions (eg, hemolysis, sepsis, hypothyroidism, biliary obstruction).

Dermatology NE O N A T A L R A S H E S

The vast majority of skin findings in the neonatal period are benign. Nonetheless, they are often a cause for concern among new parents. Table 16-5 describes common neonatal rashes. E C Z EM A

A chronic inflammatory skin condition that affects nearly 20% of children in the United States. Onset is generally before age five. Also known as atopic dermatitis. SYMPTOMS/EXAM

Presents with dry, itchy, often erythematous skin. May be papular or excoriated in severe cases. In infants, it is usually found on the trunk, cheeks, and scalp. In older children, it is generally found on flexor surfaces and may include lichenified plaques.

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302

TA B L E 16 - 5 .

PEDIATRICS

Presentation and Treatment of Common Neonatal Rashes

RASH

PRESENTATION

Erythema

Erythematous macules and papules that progress to

toxicum

pustules (see Figure 16-4A). Lesions usually appear within

neonatorum

24–48 hours after birth and resolve in 5–7 days.

Transient

There are three types of lesions: (1) pustules with a

neonatal

nonerythematous base; (2) erythematous macules with a

pustular

surrounding scaly area; and (3) hyperpigmented macules.

melanosis

Lesions present at birth and resolve within weeks to

TREATMENT None.

None.

months. Neonatal

Papules and pustules appearing on the face and/or scalp

Gentle cleansing with soap and water; avoidance of oils and

acne

(see Figure 16-4B) at three weeks of age. Generally resolves

lotions. Ketoconazole or hydrocortisone may help speed

by four months.

resolution of lesions.

White papules composed of retained keratin and sebaceous

None.

Milia

material. Present at birth; usually found on the cheeks and nose. Resolves within the first few weeks of life. Miliaria

Vesicles, papules, or pustules caused by the accumulation

Provision of a cooler environment; loose clothing and cool

(crystallina,

of sweat beneath sweat ducts blocked by keratin. More

baths.

rubra,

common in warm climates and among infants in incubators.

pustulosa,

Usually appears during the first week of life.

profunda) Seborrheic

Erythema and greasy scales, usually on the face and scalp

dermatitis

(see Figure 16-4C). Resolves within weeks to months.

Application of emollient overnight followed by massage and shampooing with baby shampoo to loosen scales; use of a soft brush to remove scales. If gentle cleansing methods do not work, ketoconazole, selenium sulfide, or hydrocortisone may be tried.

TREATMENT

Treatment consists of the following steps: ■

■

■

■

■

Avoid triggers such as heat, perspiration, and dry climates. Triggers may also include specific foods such as eggs, nuts, chocolate, peanut butter, milk, and seafood. Maintain hydration by daily bathing followed by the application of thick creams (eg, Eucerin, Cetaphil) or ointments (eg, petroleum jelly, Aquaphor) to lock in the skin’s moisture. Control itching by using antihistamines such as diphenhydramine, hydroxyzine, and cyproheptadine. Cool baths may also help alleviate pruritus. Wet cotton dressings applied after bathing and emollients covered with dry, loose cotton dressings can further reduce pruritus. Treat inflammation with topical corticosteroids (hydrocortisone for mild inflammation; triamcinolone or fluocinolone for more severe cases). Other treatment measures for severe disease include antibiotics, systemic corticosteroids, topical or oral calcineurin inhibitors, and phototherapy. Aggressively treat superinfections (impetigo or cellulitis), as patients with eczema are more susceptible to bacterial, viral, and fungal skin infections.

PEDIATRICS

A

B

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303

C

Common neonatal rashes. (A) Erythema toxicum neonatorum. Erythematous macules are seen on the arm of a one-dayold newborn. (B) Neonatal acne. Tiny papulopustules are seen on the face of a three-week-old infant. (C) Seborrheic dermatitis. (Reproduced

FIGURE 16-4.

with permission from Wolff K et al. Fitzpatrick’s Dermatology in General Medicine, 7th ed. New York: McGraw-Hill, 2008, Figs. 106-3, 106-5, and 22-1.)

Endocrinology C O N G E N I T A L A D R E N A L H Y P E R PLAS I A ( C AH)

A 10-day-old male infant is brought to the urgent care clinic because his parents feel that he has been “acting funny.” On exam, you note that the infant has poor skin turgor and dry lips. He is lethargic and has a sunken fontanelle. You plot his height and weight and discover that he is down 10% from his birth weight despite frequent breast-feeding with a good latch. You order a set of electrolytes that reveal hyponatremia and hyperkalemia. In addition to a sepsis workup, which lab tests should you consider? You should order a 17-hydroxyprogesterone level and an androstenedione level. In addition, you would want to see newborn screening results looking for congenital adrenal hyperplasia.

A group of disorders caused by a defect in one or more of the enzymes required for cortisol synthesis. These defects lead to overproduction of the precursors in the pathway and to an excess of ACTH as the body attempts to stimulate the adrenal gland. The most common defect, which accounts for 90–95% of all cases, is in the 21-hydroxylase enzyme. Defects in 11β-hydroxylase and 17α-hydroxylase, as well as other enzymes in the pathway for adrenal steroid synthesis, are less common.

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SYMPTOMS/EXAM ■

Classic form: Has two variants, salt-losing and non-salt-losing CAH. Girls with either variant: Present as infants with ambiguous genitalia caused by excess androgen production in utero. ■ Boys with the salt-losing variant: Present in the first 1–2 weeks of life with hyponatremia, hyperkalemia, dehydration, and FTT. ■ Boys with the non-salt-losing variant: Present with early virilization, including the development of pubic hair, adult body odor, and a growth spurt at 2–4 years of age. Nonclassic form: Typically presents later with signs of excess androgen production such as hirsutism, acne, early pubarche, irregular menses, and premature closure of the physes. ■

■

TREATMENT ■

KEY FACT ■

Any illness can lead to an adrenal crisis in children with congenital adrenal hyperplasia. Glucocorticoid doses 2–3 times the maintenance dose should be administered promptly.

■

Glucocorticoid replacement with hydrocortisone (in infants and younger children) or with dexamethasone or prednisone (in older adolescents) to replace cortisol and suppress androgen production. Mineralocorticoid replacement with fludrocortisone to normalize sodium and potassium concentrations. Infants should be given supplemental sodium chloride, which can be tapered as they begin to eat table food. Monitoring: Serum levels of 17-hydroxyprogesterone (17-OHP) and androstenedione, as well as plasma renin activity, should be measured every three months in infants and every 4–12 months in children. In addition, bone-age films should be taken every six months. PR E C OC I OU S P U BE R TY

Defined as the development of 2° sex characteristics prior to age eight in girls and age nine in boys. The lower limit of normal for girls is somewhat controversial; some use seven years for Caucasian girls and six years for African American girls. Classified as follows: ■

■

Gonadotropin-dependent precocious puberty (GDPP): A result of early activation of the hypothalamic-pituitary-gonadal (HPG) axis. Development occurs in the proper sequence and over a normal interval but begins early. Roughly 80% of cases are idiopathic. Other possible etiologies include CNS lesions; therefore, GDPP patients require brain imaging (CT or MRI). Gonadotropin-independent precocious puberty (GIPP): Not due to early activation of the HPG axis but rather to the secretion of sex hormones from the adrenals or the gonads. ■ Possible causes in both boys and girls include exogenous estrogen, CAH, adrenal androgen-secreting tumors, pituitary gonadotropinsecreting tumors, and McCune-Albright syndrome (GIPP, café-au-lait spots, and fibrous dysplasia of bone). ■ For girls, additional causes include ovarian cysts and ovarian tumors such as Leydig cell/granulosa cell tumors and gonadoblastomas. ■ For boys, Leydig cell tumors, hCG-secreting germ cell tumors, and a rare disorder known as familial GIPP, in which a mutation in the LH receptor gene causes early Leydig cell maturation, are other possible causes.

PEDIATRICS

DIAGNOSIS ■ ■

Imaging: X-rays of the wrist to determine bone age. Labs: Serum estradiol or testosterone level; 17-OHP; basal and GnRHstimulated LH; dehydroepiandrosterone (DHEA).

TREATMENT ■

■

GDPP: GnRH agonists are the therapy of choice if the projected height or rate of development results in a decision to treat. GIPP: Does not respond to GnRH agonists; treatment depends on the etiology.

Infectious Disease FE V ER W IT H O U T A S O U R CE (F WS )

An 18-month-old girl who is up to date on all her immunizations is brought to urgent care with a temperature of 39.2°C (102.6°F). She is somewhat more irritable than usual but is consolable and otherwise well. Her physical exam is unremarkable. What workup, if any, should you perform in this child? Obtain a UA and urine culture. You should consider adding a CBC if the child has not received at least two doses of pneumococcal vaccine and if her temperature is > 39.5°C (103.1°F). If the child were really irritable or lethargic, an LP would be indicated.

Roughly 20% of children with a fever do not have signs or symptoms of a bacterial or viral infection on history or exam. FWS is a concern because it may represent an occult serious bacterial infection (SBI). The concern for SBI, and therefore the recommended workup for FWS, is age dependent: ■ ■

■

0–28 days: See the discussion of neonatal sepsis. 1–3 months: Obtain a CBC, a blood culture, and a UA and urine culture. Consider an LP if the infant is irritable or lethargic. Treat with empiric antibiotics (usually ceftriaxone) if the WBC is > 15 or < 5. 3–36 months: If the infant has been vaccinated and appears well, the risk of bacteremia and/or meningitis is low. Obtain a UA and urine culture if the infant is an uncircumcised boy < 1 year of age or a girl < 2 years of age, especially if the fever is > 39°C (102.2°F) or the child has presented with fever for > 48 hours. If the infant is unvaccinated, obtain a CBC and a blood culture. Obtain a blood culture and treat with ceftriaxone if the WBC count is > 15.

UTI is the most common bacterial cause of FWS. In infants < 3 months of age, uncircumcised boys are at highest risk. Among infants > 3 months of age, girls are at highest risk. Some guidelines recommend evaluation of the first febrile UTI in a child < 2 years of age with a renal ultrasound +/– VCUG to rule out structural renal disease or vesicoureteral reflux (see Figure 16-5). These disorders are most likely to occur in very young infants (< 3 months) and those with recurrent UTIs.

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306

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Vesicoureteral reflux. Frontal radiograph from a voiding cystourethrogram shows reflux to the left ureter and intrarenal collecting system with hydronephrosis. Note the absence of reflux on the normal right side. (Reproduced with permission from Doherty GM. Current Diagnosis & FIGURE 16-5.

Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010, Fig. 38-7.)

Immunology IM M U NODE F I C I E NC Y S YNDR OM E S

A two-year-old girl is brought in by her parents with a high fever and a cough of two days’ duration. She is hypoxic and in respiratory distress, and your exam is suggestive of a right lower lobe pneumonia, which is confirmed on CXR. You review her chart and note that the girl was hospitalized at 6 months for mastoiditis and was then hospitalized again at 15 months with a leftsided pneumonia that was complicated by an empyema and a ⊕ blood culture. You also note that her weight is less than the third percentile for age. Aside from the workup needed for her acute infection, what additional tests would you consider in this patient? It is unusual for a healthy child to have recurrent severe bacterial infections. The fact that each infection has been in a different location argues against an anatomic cause; therefore, a 1° immunodeficiency should be considered. A basic starting evaluation might include a CBC to screen for cellular immunodeficiencies or malignancy; immunoglobulin levels; antibody titers to organisms against which the patient has been vaccinated (including both protein antigens and polysaccharide antigens); and a CH50 to evaluate for complement deficiencies. Additional, more specific tests (eg, for HIV or CF) should be guided by the results of this initial evaluation.

Present as recurrent or severe infections. In general, the frequency is roughly 1 in 10,000. Table 16-6 outlines the clinical presentation, diagnosis, and treatment of common pediatric immunodeficiency disorders.

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TA B L E 16 - 6 .

307

Pediatric Immunodeficiency Disorders (continued)

DISORDER

DESCRIPTION

SYMPTOMS

DIAGNOSIS

TREATMENT

B-CELL DISORDERS Most common.

Present with recurrent

Quantitative Ig

Prophylactic antibiotics

URIs and bacteremia

levels (subclasses)

and IVIG.

with encapsulated

and specific antibody

organisms (pneumococcus,

responses.

Staphylococcus, H influenzae) after age six (when maternal antibodies taper). X-linked (Bruton’s

A profound B-cell

May present before age

agammaglobulinemia)

deficiency found only in

six. Patients are at risk for

Boys.

pseudomonal infection.

Common variable

Ig levels drop in the

Associated with an ↑ risk of

immunodeficiency

second and third

lymphoma and autoimmune

(CVID)

decades of life.

disease.

IgA deficiency (most

Low IgA.

common)

Usually asymptomatic. Recurrent infection may be seen.

T-CELL DISORDERS Viral infection, fungal

Absolute

infection, intracellular

lymphocyte count,

bacteria (broader range of

mitogen stimulation

infections). Present at 1–3

response, and delayed

months of age.

hypersensitivity skin testing.

Thymic aplasia

Patients are unable to

Tetany (due to hypocalcemia)

Consider thymus

(DiGeorge syndrome)

generate T cells owing to

in the first few days of life.

transplant instead of bone marrow transplant

lack of a thymus.

(BMT). Ataxia-telangiectasia

A DNA repair defect.

Oculocutaneous

BMT for severe disease;

telangiectasias and

IVIG for antibody

progressive cerebellar ataxia.

deficiency. (continues)

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TA B L E 16 - 6 .

PEDIATRICS

Pediatric Immunodeficiency Disorders (continued)

DISORDER

DESCRIPTION

SYMPTOMS

DIAGNOSIS

TREATMENT

COMBINED DISORDERS Absolute lymphocyte count and quantitative Ig levels. Severe combined

Severe lack of B and T

Frequent and severe bacterial

BMT or stem-cell

immunodeficiency

cells.

infections, chronic candidiasis,

transplant; IVIG for

and opportunistic infections.

antibody deficiency;

(SCID)

PCP prophylaxis. Wiskott-Aldrich

An X-linked disorder with

Eczema, ↑ IgE, ↑ IgA, ↓ IgM,

Supportive treatment:

syndrome

less severe B- and T-cell

and thrombocytopenia.

IVIG and aggressive antibiotics. Patients

dysfunction.

rarely survive to adulthood.

PHAGOCYTIC DISORDERS Commonly caused by

Absolute neutrophil

catalase-⊕ (S aureus) and

count; adhesion,

enteric gram-両 organisms.

chemotactic, phagocytic, and bactericidal assays.

Chronic granulomatous

An X-linked or autosomal

Chronic GI and GU infections;

A nitroblue

Daily TMP-SMX,

disease (CGD)

recessive disorder with

osteomyelitis, hepatitis.

tetrazolium test is

judicious use of

deficient superoxide

Anemia, lymphadenopathy,

diagnostic.

antibiotics, γ-interferon.

reduction by PMNs and

and hypergamma-

macrophages.

globulinemia.

Chédiak-Higashi

An autosomal recessive

Recurrent pyogenic skin

Blood smear shows

Aggressive treatment

syndrome

defect in neutrophil

and respiratory infections.

PMNs with giant

of bacterial infections;

chemotaxis.

Oculocutaneous albinism,

cytoplasmic

corticosteroids,

neuropathy, neutropenia.

granules.

splenectomy.

COMPLEMENT DISORDERS Recurrent sinopulmonary infections, bacteremia, and/or meningitis due to encapsulated organisms (S pneumoniae, H influenzae type b, Neisseria meningitidis).

PEDIATRICS

TA B L E 16 - 6 .

CHAPTER 16

309

Pediatric Immunodeficiency Disorders (continued)

DISORDER

DESCRIPTION

SYMPTOMS

DIAGNOSIS

TREATMENT

C1 esterase

An autosomal dominant

Presents in late childhood or

Measurement

Daily prophylactic

deficiency (hereditary

disorder with recurrent

early adolescence. Provoked

of complement

antifibrinolytic agents

angioneurotic edema)

angioedema lasting

by stress, trauma, or puberty/

components.

or danazol. Purified C1

21–72 hours.

menses. Can lead to life-

esterase and FFP prior

threatening airway edema.

to surgery.

Terminal complement

A deficiency of

Mild, recurrent

Total hemolytic

Meningococcal vaccine

deficiency (C5–C9)

components of the

infection by Neisseria

complement (CH50);

and appropriate

membrane attack

spp. (meningococcal or

assess the quantity

antibiotics.

complex (C5–C9).

gonococcal). Rarely, SLE or

and function of

Associated with

glomerulonephritis.

complement pathway

meningococcal and

components.

gonococcal infection. (Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 411–413.)

K A W A S A K I D I S E A S E (M U CO C U T ANE OU S LYM P H NODE S YNDR OM E )

A relatively common medium-vessel vasculitis of childhood that predisposes to coronary artery aneurysms and to the subsequent development of myocardial ischemia. More common in children < 5 years of age and among those of Asian, particularly Japanese, ethnicity.

MNEMONIC Kawasaki symptoms—

CRASH and BURN

SYMPTOMS/EXAM

Conjunctivitis (bilateral, nonpurulent) Rash (truncal) Adenopathy (at least one cervical node

Presents as an acute illness characterized by the symptoms outlined in the CRASH and BURN mnemonic.

Strawberry tongue (or any change in

DIAGNOSIS ■ ■ ■

■

A clinical diagnosis. Patients must have fever for > 5 days and meet 4–5 of the other criteria. Occasional findings include arthritis, excessive irritability, scrotal swelling, pericarditis, and gallbladder inflammation. Labs may reveal sterile pyuria, ↑ ESR/CRP, and thrombocytosis during the second week of illness.

TREATMENT ■

■

■

■

Give anti-inflammatory, high-dose ASA during the acute phase to ↓ the incidence of cardiac abnormalities. Administer IVIG to prevent coronary artery aneurysms and to preserve myocardial contractility (given as a single infusion within the first 7–10 days of illness; repeat if the patient is still febrile 24 hours later). During the convalescent phase, switch to low-dose ASA for its antiplatelet effect. Follow patients with regular echocardiography.

COMPLICATIONS

Myocarditis; pericarditis; coronary artery aneurysm predisposing to myocardial ischemia.

> 1 cm) oropharyngeal mucosa, including an injected pharynx or lip fissuring) Hand/foot swelling/desquamation BURN (fever for > 5 days)

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Rheumatology JU VE NI LE I DI OP ATHI C AR THR I TI S ( JI A)

Can be classified into three categories: systemic, pauciarticular, and polyarticular. Systemic JIA ■

■

■

KEY FACT Children with JIA are at risk for developing macrophage activation syndrome.

■

Sx/Exam: Patients present with intermittent fever, rash (classically described as macular and salmon-pink), lymphadenopathy, and arthritis (usually of the knees, wrists, and ankles, but can affect other joints as well). Affects boys and girls equally. Dx: ■ Patients are generally worked up for infectious processes and leukemia before a diagnosis is made. ■ WBC count, ESR, CRP, and platelets are elevated. ■ In order for the diagnosis of JIA to be made, the patient must have a daily fever for two weeks, typically above 38.5°C (101.3°F), and arthritis. Arthritis may develop after the initial fever and rash. Tx: ■ First line: NSAIDs. ■ Second line: Corticosteroids or methotrexate. ■ Other: Agents such as monoclonal antibodies to IL-1 or IL-6, thalidomide, IVIG, hydroxychloroquine, sulfasalazine, cyclosporine, and TNF inhibitors have been used with varying degrees of success. Cx: A typical course for a first episode of JIA may last 4–6 months. Some children will continue to have fever and rash for years. The long-term sequelae vary from none at all to severe destruction requiring joint replacement.

Pauciarticular JIA ■ ■

■

■

■

The most common form of JIA; affects girls more often than boys. Sx/Exam: Involves < 5 joints (generally large joints); usually presents at 2–3 years of age. Dx: ■ See above. ■ Patients are ANA ⊕. Tx: ■ First line: NSAIDs and/or glucocorticoids injected into affected joints. ■ Second line: Methotrexate, TNF inhibitors (rarely used). Cx: ■ Usually resolves within six months. ■ More than 50% of patients will not have relapses; however, severe destructive arthritis may occur. ■ Children with pauciarticular JIA are at risk for uveitis, so routine screening by an ophthalmologist should be done every 3–12 months depending on the age of onset and ANA status.

Polyarticular JIA ■

Involves > 4 joints; affects girls more often than boys. Age of onset is 2–5 years and 10–14 years.

PEDIATRICS

■

Dx: See above. ■ Patients may be ANA and/or RF ⊕. ■ Lab findings may include anemia, elevated ESR, and hypergammaglobulinemia. Tx: ■ NSAIDs are first line but are unlikely to yield long-term control when used as a single agent. ■ Disease-modifying antirheumatic drugs (DMARDs) such as methotrexate, leflunomide, sulfasalazine, TNF inhibitors, cyclosporine, azathioprine, rituximab, corticosteroids (systemic and injected), and gold compounds should be added early in the course of treatment. Cx: ■ The prognosis is generally better for RF-seronegative patients than for those who are seropositive. ■ RF-seronegative patients often respond to NSAID therapy, while seropositive patients require treatment with DMARDs. ■ Patients are at risk for uveitis and require screening by an ophthalmologist. ■

■

■

RE A C T IV E A R T H R I T I S

Formerly known as Reiter’s syndrome, reactive arthritis has three components: postinfectious arthritis, urethritis, and conjunctivitis. Typical pathogens include Campylobacter, Yersinia, Salmonella, Shigella, Chlamydia trachomatis, and possibly C difficile and C pneumoniae. Often, no pathogen is recovered. SYMPTOMS/EXAM ■

■

Usually affects the lower extremities asymmetrically, presenting as a monoor oligoarthritis. Onset occurs days to weeks after initial infection.

TREATMENT ■

■

NSAIDs are first line and may also afford relief from intra-articular glucocorticoid injections. If the patient is unresponsive to NSAIDs alone, consider adding a DMARD. H E N O C H -S C H Ö N LE I N P U R P U R A (HS P )

An eight-year-old boy presents to the ER with severe abdominal pain that began this morning. He has had four episodes of emesis over the past eight hours and reports that he continues to have nausea. While you are examining him, you note that he has a nonblanching, palpable erythematous rash on his legs and buttocks. His parents report that the rash was much worse last week. Additional history reveals that the boy was recently diagnosed with HenochSchönlein purpura. What is your concern, and which studies should you order? Intussusception should be a concern, for which you should order an abdominal ultrasound.

The most common small-vessel vasculitis of childhood. Usually affects children 3–15 years of age.

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312

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SYMPTOMS/EXAM ■

■

■

■

KEY FACT In cases of HSP with severe, intermittent abdominal pain, obtain an ultrasound to evaluate for intussusception (often ileoileal).

■

Presents with palpable purpura (see Figure 16-6), arthritis/arthralgia, abdominal pain, and glomerulonephritis. One-half to two-thirds of patients report having had a URI a few weeks before. Arthritis is usually oligoarthritis and migratory, affecting the large joints of the lower extremities more often than the upper extremities. If renal involvement occurs, it is usually seen within four weeks of presentation and is typically self-limited. Abdominal pain is a result of GI tract inflammation and may be treated with systemic corticosteroids if severe.

DIAGNOSIS

Diagnosis is usually clinical. In cases where the clinical presentation is not clear, a biopsy from the skin or kidney with evidence of IgA deposits confirms the diagnosis. TREATMENT

Acetaminophen or NSAIDs for pain control +/– glucocorticoids. COMPLICATIONS

Recurs in roughly one-third of cases, generally within four months of initial presentation. Recurrences are usually milder than the initial episode.

FIGURE 16-6.

Classic palpable purpura in Henoch-Schönlein purpura. (Reproduced with per-

mission from Wolff K, Johnson RA. Fitzpatrick’s Color Atlas & Synopsis of Clinical Dermatology, 6th ed. New York: McGraw-Hill, 2009, Fig. 14-35.)

PEDIATRICS

CHAPTER 16

MNEMONIC

Cardiology The incidence of congenital heart disease is approximately 1%. The most common congenital heart lesion is VSD, followed by ASD. The most common cyanotic lesion is transposition of the great arteries (TGA). V EN T R IC U L A R S E P T A L D E F E C T (VSD)

A hole in the ventricular septum. Can be membranous (least likely to close spontaneously), perimembranous, or muscular (most likely to close spontaneously). SYMPTOMS/EXAM ■ ■

■

■

■

May be asymptomatic at birth if the lesion is small. Cardiac exam may reveal a pansystolic, vibratory murmur at the left lower sternal border without radiation to the axillae. May become symptomatic between two and six months of age. Symptoms result from flow across the defect, usually from the left to the right ventricle. If the lesion is large, it may present with symptoms of CHF (shortness of breath, pulmonary edema), frequent respiratory infection, FTT, and exercise/feeding intolerance (sweating with feeds). Look for cardiomegaly and crackles on exam (signs of right heart failure).

313

Right-to-left shunts (causes of cyanotic congenital heart disease)—

The 5 T’s Truncus arteriosus (1 common artery off of both ventricles)

Transposition of the great arteries (2 vessels switched)

Tricuspid atresia (3 leaflets not well formed)

Tetralogy of Fallot (4 problems present) Total anomalous pulmonary venous return (5 words)

DIAGNOSIS ■ ■ ■

ECG shows RVH and LVH. CXR may show pulmonary edema. Echocardiography is definitive.

TREATMENT ■ ■ ■

Treat CHF if present. Follow small, asymptomatic VSDs annually. Surgically repair large or membranous VSDs to prevent later development of heart failure and pulmonary hypertension.

COMPLICATIONS

If left untreated, VSD may lead to irreversible Eisenmenger’s syndrome (pulmonary hypertension, RVH, and reversal of left-to-right shunt). A T R I A L S E PT A L D E F E CT ( A S D )

A hole in the atrial septum. SYMPTOMS/EXAM ■ ■

■

■

Typically asymptomatic until late childhood or early adulthood. Cardiac exam may reveal a systolic murmur at the left upper sternal border. A wide and fixed, split S2 and a heaving cardiac impulse at the left lower sternal border are characteristic signs. Progression to CHF and cyanosis may occur in the second to third decade of life and depends on the size of the lesion.

KEY FACT Patients with VSDs and ASDs no longer require prophylactic antibiotics prior to dental work. Patients who do require antibiotic prophylaxis include those with: ■ Unrepaired or incompletely repaired cyanotic CHD. ■ Repaired CHD with a residual defect at or adjacent to the site of a prosthetic patch or device. ■ Repaired CHD with prosthetic patches or devices within the first six months following the procedure.

314

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PEDIATRICS

DIAGNOSIS ■ ■ ■

ECG shows left-axis deviation. CXR shows cardiomegaly and ↑ pulmonary vascularity (if defect is large). Echocardiography is definitive.

TREATMENT

Treat CHF if present; follow small ASDs. Surgically repair large ASDs in patients with CHF, and repair before the third decade to prevent symptoms. COMPLICATIONS

Eisenmenger’s syndrome. PA TE NT DU C TU S AR TE R I OS U S ( P DA)

Failure of the ductus arteriosus (the connection between the pulmonary artery and aorta) to close in the first few days of life. Usually results in a leftto-right shunt (from aorta to pulmonary artery). Risk factors include prematurity, high altitude, and maternal first-trimester rubella infection. SYMPTOMS/EXAM ■ ■

■

Presentation ranges from asymptomatic to CHF. Cardiac exam may reveal a wide pulse pressure; a continuous “machinery” murmur at the left upper sternal border; and bounding peripheral pulses. A loud S2 is characteristic.

DIAGNOSIS

Echocardiography is definitive, showing shunt flow as well as left atrial and left ventricular enlargement. TREATMENT ■ ■

If diagnosed within days of birth, use indomethacin to close the PDA. Surgical repair is indicated if the infant is > 6–8 months of age or if indomethacin fails.

COMPLICATIONS ■

■

In the case of pulmonary hypertension of the newborn (such as in meconium aspiration syndrome), flow may be right to left across a PDA, resulting in persistent cyanosis/hypoxia. The reduction of pulmonary hypertension is required to reduce the right-to-left flow. Remember that some cyanotic heart lesions (eg, TGA) are dependent on a patent ductus, so do not close the PDA in such cases. To keep the ductus open in such ductal-dependent lesions, medication may be indicated until definitive repair can be performed. Alprostadil (a form of prostaglandin E) is usually used for this purpose.

PEDIATRICS

CHAPTER 16

T E T R A LO G Y O F F A L L O T

Consists of four lesions (see the mnemonic PROVe). SYMPTOMS/EXAM ■

■

■

■

Presentation ranges from acyanotic (“pink tet”) to profound cyanosis. Most patients have some cyanosis, depending on the severity of pulmonary stenosis and the relative right and left ventricular pressures (which determine the direction of flow across the VSD). Cyanotic “tet spells” may occur in a child who is crying or overheated. These children need to be calmed and given oxygen, and squatting or other measures can be used to ↑ systemic vascular resistance and restore left-to-right flow across the VSD. Cardiac exam may reveal a systolic ejection murmur at the left sternal border along with right ventricular lift. A single S2 is characteristic.

DIAGNOSIS ■ ■

Echocardiography is definitive. CXR shows a boot-shaped heart.

TREATMENT ■

■ ■

If a newborn infant with this condition is cyanotic, administer prostaglandin E to maintain the PDA. Surgical repair is necessary. Treat tet spells with O2, a squatting position, fluids, morphine, propranolol, and phenylephrine if severe. T RA N S P O S IT IO N O F T H E G R E A T AR TE R I E S ( TG A)

The aorta arises from the right ventricle and the pulmonary artery from the left ventricle. SYMPTOMS/EXAM ■ ■ ■

Presents with extreme cyanosis from birth. May have no murmur. A single, loud S2 is characteristic.

DIAGNOSIS ■ ■ ■

Echocardiography is definitive. CXR shows an “egg on a string.” An O2 saturation monitor on the right arm (measuring “preductal” saturation) will show a lower O2 saturation than one on the lower extremity (“postductal” saturation).

TREATMENT ■ ■

■

Administer prostaglandin E to maintain the PDA. If necessary, a “balloon septostomy” or Rashkind procedure may be performed to rupture the atrial septum in order to improve mixing of venous and arterial blood as well as to ensure that adequately saturated blood enters the aorta. Surgical repair is necessary.

315

MNEMONIC Anatomy of tetralogy of Fallot—

PROVe Pulmonary stenosis (RV outflow obstruction)

RVH Overriding aorta VSD

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PEDIATRICS

COA R C TATI ON OF THE AOR TA

You are on call in the nursery and are asked to evaluate a term male infant who has been doing well over the first 12 hours of life. You examine the infant and find him to be extremely irritable, diaphoretic, and pale with ↑ work of breathing. You listen to his chest and do not appreciate a murmur, and his lungs have a few crackles. You feel his pulses and note that his femoral pulses are difficult to palpate. What simple test can you perform quickly to confirm your suspected diagnosis? Four-limb blood pressures. His presentation suggests coarctation of the aorta, and higher blood pressure in the upper (vs. lower) extremities is consistent with this diagnosis.

Narrowing of the lumen of the aorta, leading to ↓ blood flow below the obstruction and ↑ flow above it. Risk factors include Turner’s syndrome and male gender; also associated with bicuspid aortic valve. SYMPTOMS/EXAM ■

■

■

Presents with dyspnea on exertion, syncope, and systemic hypoperfusion/ shock. Cardiac exam may reveal hypertension in the upper extremities and a lower BP in the lower extremities. ↓ femoral and distal lower extremity pulses are characteristic.

DIAGNOSIS ■ ■

Echocardiography or catheterization is definitive. CXR shows rib notching due to collateral circulation through the intercostal arteries.

TREATMENT ■ ■

Surgical repair or balloon angioplasty +/– stent placement. Patients require prophylactic antibiotics prior to dental work even after surgical repair.

COMPLICATIONS

Often recurs.

Gastroenterology PYL OR I C S TE NOS I S

Hypertrophy of the pylorus, leading to gastric outlet obstruction. SYMPTOMS/EXAM ■

■

■

Occurs at 3–4 weeks of life (range: two weeks to four months), predominantly in term, firstborn male infants. Presents with progressively projectile, nonbilious emesis that may lead to dehydration. Exam may reveal an olive-shaped mass in the epigastrium along with visible peristaltic waves.

PEDIATRICS

L GB

A

B

FIGURE 16-7. Hypertrophic pyloric stenosis. (A) Schematic representation of a hypertrophied pylorus. The arrow denotes protrusion of the pylorus into the duodenum. (B) Longitudinal ultrasound of the pylorus showing a thickened pyloric musculature (X’s) over a long pyloric channel length (plus signs). L = liver; GB = gallbladder. (Image A adapted with permission from Doherty GM. Current Diagnosis & Treatment: Surgery, 13th ed. New York: McGraw-Hill, 2010. Image B reproduced with permission from USMLERx.com.)

DIAGNOSIS ■

■

■

Electrolytes show hypochloremic, hypokalemic metabolic alkalosis 2° to emesis. Ultrasound is the gold standard and shows a hypertrophied pylorus (see Figure 16-7). Barium studies show a “string sign” (a narrow pylorus) or a pyloric beak.

TREATMENT ■ ■

First, correct dehydration and electrolyte abnormalities. Surgical repair consists of pyloromyotomy and is usually well tolerated. I N T U S S U S CE P T I O N

Telescoping of a bowel segment into itself (see Figure 16-8) may lead to edema, arterial occlusion, gut necrosis, and death. Intussusception is the most common cause of bowel obstruction in the first two years of life. It is usually idiopathic in children < 2 years of age and often has an identifiable “lead point” (eg, a lymph node) in children > 5 years of age. Ileocecal intussusception is the most common type, while ileoileal intussusception is likely due to a pathologic cause. SYMPTOMS/EXAM ■

■

■

The classic presentation is bouts of paroxysmal abdominal pain. The child is often completely comfortable between paroxysms. Vomiting and heme-⊕ stools may be seen. “Currant jelly” stool is a late finding. May also present with altered mental status (lethargy or even obtundation), and may be preceded by a viral illness. Abdominal exam may reveal a palpable, sausage-shaped mass.

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317

318

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PEDIATRICS

FIGURE 16-8.

Intussusception.

DIAGNOSIS ■

■

Abdominal ultrasound is generally part of the initial workup in suspected cases. An air-contrast enema or a water-soluble contrast enema is both diagnostic and therapeutic; however, abdominal ultrasound is usually performed prior to the enema.

TREATMENT ■ ■

Following reduction via enema, treat with supportive care. If reduction fails or if perforation is suspected, surgical intervention may be required.

COMPLICATIONS

Associated with HSP and CF. MA LR OTATI ON/ VOLVU LU S

Distinguished as follows: ■

■

Malrotation: Failure of normal embryologic rotation as the gut returns to the abdominal cavity (during the 10th week of gestation). Results in abnormal location of intestinal contents in the abdomen, as well as incomplete fixation to the posterior abdominal wall. May predispose to intestinal obstruction (by a tissue called “Ladd’s bands” that abnormally lies over the proximal duodenum in malrotation) or volvulus. Volvulus: A complication of malrotation in which the malrotated gut twists on the axis of the superior mesenteric artery, resulting in intestinal obstruction as well as ischemia.

PEDIATRICS

SYMPTOMS/EXAM ■

■

First three weeks of life: Volvulus presents as acute onset of bilious emesis, small bowel obstruction, or bowel necrosis. Later in infancy/early childhood: Malrotation may present as acute or intermittent intestinal obstruction, malabsorption, protein-losing enteropathy, or diarrhea.

DIAGNOSIS ■

■

Malrotation: An upper GI series shows the duodenojejunal junction on the right side of the spine (see Figure 16-9). Barium enema shows a mobile cecum that is not in the RLQ. Volvulus: Contrast studies show a “bird’s beak” where the gut is twisted.

TREATMENT ■

■

Volvulus is a surgical emergency because the gut may necrose as a result of SMA occlusion. Surgical repair is necessary in asymptomatic patients who are diagnosed with malrotation because of the risk of complications such as volvulus.

COMPLICATIONS ■

■

The 1° complication of volvulus is “short bowel syndrome,” which occurs when < 30 cm of short bowel is left. If a large segment of bowel is lost as a result of bowel ischemia or surgery, the condition may also lead to malnutrition, TPN dependence, and liver failure.

Stomach

Midgut malrotation. Frontal radiograph from an upper GI study shows a spiral pattern of duodenal and proximal jejunal loops in the right abdomen, consistent with midgut malrotation. The duodenal-jejunal junction should normally be to the left of the patient’s spine. (Reproduced with permission from USMLERx.com.) FIGURE 16-9.

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319

320

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PEDIATRICS

ME C K E L’S DI VE R TI C U LU M

A remnant of the omphalomesenteric duct that persists as an outpouching of the distal ileum. Can contain ectopic (usually gastric or pancreatic) mucosa. SYMPTOMS/EXAM MNEMONIC

■ ■

Meckel’s diverticulum rule of 2’s:

2 feet proximal to the ileocecal valve 2 types of ectopic tissue (gastric, pancreatic)

2% of the population 2 times the number of males as females Usually presents by age 2 About 2 inches long 2 cm in diameter

Often asymptomatic. Patients may present with painless rectal bleeding or intussusception (with Meckel’s as the lead point).

DIAGNOSIS ■

■

Order a technetium radionuclide scan (“Meckel scan”) to detect gastric mucosa. The gold standard is tissue obtained surgically.

TREATMENT ■ ■ ■

Stabilize the patient with IV fluids; transfuse if needed. Surgical exploration is indicated if the patient is symptomatic. Bowel resection may be required with resection of diverticula depending on the location and complexity of the lesion. NE C R OTI ZI NG E NTE R OC OLI TI S ( NE C )

You are on call in the NICU. A three-week-old infant born at 28 weeks’ gestation, who has been growing well and is at his goal PO/NG feeds, has a few episodes of emesis. His next stool is heme ⊕. In addition, his abdominal girth is up 2 cm from the previous shift. You obtain labs that include blood and stool cultures as well as supine and left lateral decubitus AXRs. Air in the bowel wall and portal venous system confirms your suspicions. What are the next steps in management? This is a case of necrotizing enterocolitis, which is an emergency! The patient should be made NPO, and intermittent NG suctioning should be started along with IV antibiotics (either piperacillin + tazobactam or ampicillin + gentamicin), TPN, and IV fluids. The pediatric surgical team should be consulted, as surgical intervention may be indicated if the patient deteriorates.

Intestinal necrosis occurring primarily in a watershed distribution. Constitutes the most common GI emergency in newborns. Risk factors include prematurity and congenital heart disease. SYMPTOMS/EXAM ■

■

Presents with abdominal distention, gastric retention, abdominal wall tenderness and discoloration, and bloody stools. Nonspecific symptoms include apnea, respiratory failure, lethargy, poor feeding, temperature instability, thrombocytopenia, hypoglycemia, and hypotension/shock.

DIAGNOSIS

AXR shows pneumatosis intestinalis and possibly portal venous gas and free intraperitoneal air (see Figure 16-10).

PEDIATRICS

Necrotizing enterocolitis. Short arrows highlight pneumatosis intestinalis on an abdominal radiograph of a patient with NEC. (Reproduced with permission from Brunicardi FC et al.

FIGURE 16-10.

Schwartz’s Principles of Surgery, 9th ed. New York: McGraw-Hill, 2010, Fig. 39-19.)

TREATMENT ■

■

Medical management with IV fluids (no enteral feeds) and antibiotics if the patient is hemodynamically stable and/or too small or sick to go to the OR. Surgical management (resection of necrotic bowel) is necessary in the setting of extensive disease and/or hemodynamic instability.

Pulmonology C R O U P (LA R Y N G O T R A CH E O B R O NCHI TI S )

An acute viral inflammatory disease of the larynx/subglottic space (see Table 16-7). Most common in children three months to three years of age. Commonly caused by parainfluenza virus (PIV) type 1, but may also be caused by other PIVs as well as by RSV, influenza, rubeola, adenovirus, and Mycoplasma pneumoniae. SYMPTOMS/EXAM ■ ■

■

Typically has a one- to two-day viral prodrome with URI symptoms. Also presents with low-grade fever, mild dyspnea, and inspiratory stridor that worsens with agitation and may improve with cool air or a warm shower. Listen for the characteristic barking cough.

DIAGNOSIS ■ ■

Based on clinical findings. A “steeple sign” formed by subglottic narrowing may be seen on frontal neck x-ray (see Figure 16-11).

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321

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322

T A B L E 1 6 - 7.

PEDIATRICS

Characteristics of Croup, Epiglottitis, and Tracheitis

TRACHEITIS

CROUP

EPIGLOTTITIS

Age group

3 months to 2 years

3 months to 3 years

3–7 years

Incidence in children

2%

88%

8%

Pathogen

Often S aureus

PIV

H influenzae

Onset

Prodrome (three days) leads to acute

Prodrome (1–7 days)

Rapid (4–12 hours)

presenting with stridor

decompensation (10 hours) Fever severity

Intermediate grade

Low grade

High grade

Associated symptoms

Variable respiratory distress

Barking cough, hoarseness

Muffled voice, drooling

Position preference

None

None

Seated, neck extended

Response to racemic

Slight improvement

Marked improvement

Slight improvement

Subglottic narrowing may be seen on lateral

“Steeple sign” on AP films

“Thumbprint sign” on lateral film

epinephrine Neck film findings

film (Adapted with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 417.)

Croup. The x-ray shows marked subglottic narrowing of the airway (arrow). (Reproduced with permission from Stone CK, Humphries RL. Current Diagnosis & Treatment: Emergency Medicine, 6th

FIGURE 16-11.

ed. New York: McGraw-Hill, 2008, Fig. 30-10A.)

PEDIATRICS

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323

TREATMENT ■

■

■

Mist therapy (for mild croup only); oral or IM/IV dexamethasone (for mild or moderate croup); nebulized racemic epinephrine if stridor is present at rest. Following the administration of racemic epinephrine, always give systemic dexamethasone, and observe for 2–3 hours before discharge. Hospitalize patients with stridor at rest or those needing > 1 dose of racemic epinephrine. E P I G L O T T IT IS

A serious and rapidly progressive infection of the epiglottis and contiguous structures that can lead to life-threatening airway obstruction. It is increasingly rare owing to the Hib vaccine and is now most commonly caused by S pneumoniae or S aureus. SYMPTOMS/EXAM ■

■

Maintain a high index of suspicion in children with sudden-onset high fever, dysphagia, drooling, a muffled voice, inspiratory retractions, cyanosis, and soft stridor. Patients may be in the “sniffing” position, with the neck hyperextended and the chin protruding. Such patients should be identified and stabilized rapidly, as the disease can quickly progress to complete airway obstruction and respiratory arrest.

DIAGNOSIS ■ ■

■

Diagnosis is based on the clinical picture. Do not attempt to examine the throat unless the patient is in the OR with an anesthesiologist present. Lateral neck films show the characteristic “thumbprint sign” of a swollen epiglottis obliterating the valleculae (see Figure 16-12).

Epiglottitis. The classic swollen epiglottis (“thumbprint sign”) and obstructed airway are seen on x-ray. (Reproduced with permission from Stone CK, Humphries RL. Current Diagnosis &

FIGURE 16-12.

Treatment: Emergency Medicine, 6th ed. New York: McGraw-Hill, 2008, Fig. 48-40.)

KEY FACT In epiglottitis, throat examination may cause laryngospasm and airway obstruction.

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PEDIATRICS

TREATMENT ■

■

Keep the patient calm, call anesthesia immediately, and transfer to the OR. If the patient is unstable, do not delay treatment by getting a neck film. Treat with endotracheal intubation and IV antibiotics. PE R TU S S I S

Commonly known as “whooping cough.” The causative agent is Bordetella pertussis or B parapertussis. SYMPTOMS/EXAM ■

The disease has three stages: Catarrhal: Presents with nasal congestion, sneezing, and low-grade fever. ■ Paroxysmal: Presents with intense coughing paroxysms followed by a “whoop” in young children. Neonates and infants may experience apnea after coughing fits. ■ Convalescent: Characterized by a chronic cough that may last for weeks (also known as “hundred-day cough”). Patients are no longer shedding the organism during this phase. Children may have posttussive emesis associated with coughing fits. ■

■

DIAGNOSIS

Diagnosed by a nasopharyngeal swab that is ⊕ by PCR or culture for B pertussis. TREATMENT

Treatment with erythromycin or azithromycin is recommended if the diagnosis is made before the convalescent phase, when the patient is still contagious. BRO NC HI OLI TI S

The most common lower respiratory illness in childhood, and a leading cause of hospitalization in infants and young children. Peak incidence is at 2–8 months of age, during October through March. Symptoms are due to virally induced inflammation of the small airways, resulting in edema, mucous plugging, and sloughing of epithelial cells, which lead in turn to bronchiolar obstruction. SYMPTOMS/EXAM

Infants present with fever, nasal congestion, and varying degrees of hypoxia, tachypnea, retractions, and a characteristic loud, rhonchorous, coarse wheezing on lung exam. DIAGNOSIS ■

■

■

Diagnosis is clinical, based on the characteristic age, history, and exam findings. A nasopharyngeal swab may be ⊕ by PCR for RSV, the most common viral cause of bronchiolitis. CXR shows a nonspecific bilateral, perihilar infiltrate as well as hyperinflation and peribronchial cuffing.

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325

TREATMENT ■ ■

■

Supportive care; fluids and O2 as needed. Patients may or may not respond to albuterol, racemic epinephrine, and/or systemic corticosteroids. Use of these medications is not routinely recommended. Ribavirin can be used in immunocompromised patients and/or in severe cases. Endotracheal intubation is indicated for respiratory failure.

Neurology FE B R ILE S E IZ U R E S

Benign, self-limited seizures that occur in children six months to six years of age at the onset of a febrile illness. A ⊕ family history is common. Febrile seizures may be divided into simple or complex: ■

■

Simple: A generalized seizure characterized by a short duration (< 15 minutes), one seizure per 24-hour period, and a quick return to normal function with no residual focal neurologic deficit. Complex: A seizure associated with a febrile illness that does not meet the above criteria. The seizure may be focal; may be longer in duration (> 15 minutes); may recur in a 24-hour period; or may result in incomplete or slow return to normal neurologic status.

DIAGNOSIS/TREATMENT ■

■

■

■

■

Simple: No further evaluation is necessary beyond performing an ageappropriate evaluation and treatment for the source of the fever in infants and young children. Complex: Depending on the history, the severity of the seizure, and the patient’s exam findings, consider performing laboratory or radiologic workup for other etiologies of seizure, such as electrolyte abnormalities, toxic ingestion, sepsis, CNS infection, or CNS trauma. Strongly consider LP in patients < 12 months of age with complex febrile seizure as well as in any child who has focal neurologic deficits before or after the seizure. EEG and MRI are not routinely recommended for children with febrile seizures. They may be considered on an outpatient basis in a child with a complex febrile seizure, especially a focal seizure or one resulting in prolonged neurologic defects. Family education and anticipatory guidance are essential. Although febrile seizures are benign, 30–50% of children with a febrile seizure will have another one before they outgrow the syndrome. Febrile seizures cannot be prevented with the use of antipyretics, and anticonvulsants are not routinely recommended. EPILEPSY SYNDROMES

Table 16-8 outlines the presentation and treatment of common epilepsy syndromes affecting the pediatric population.

KEY FACT Hypsarrhythmia on EEG is characterized by slow, high-amplitude waves with random spikes that originate in all cortical areas with no identified pattern or rhythm.

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326

TA B L E 16 - 8 .

PEDIATRICS

Common Pediatric Epilepsy Syndromes

SYNDROME Absence

SYMPTOMS/EXAM

DIAGNOSIS

Multiple, brief staring episodes.

A generalized, 3-Hz, spike-and-wave

seizures

TREATMENT Ethosuximide.

pattern on EEG.

Infantile

Affects infants < 1 year of age, presenting with

Hypsarrhythmia on EEG.

spasms (West

“jackknife” spasms and psychomotor arrest/

Associated with tuberous sclerosis.

syndrome)

developmental regression.

Lennox-Gastaut

The first seizure occurs between one and seven

An atypical spike-and-wave pattern,

syndrome

years of age. Presents with multiple, progressive,

primarily in the frontal region, on

difficult-to-treat seizure types, including

EEG.

generalized tonic-clonic seizures (GTCS) and

Progressive mental retardation.

drop attacks.

Associated with refractory infantile

ACTH.

No effective treatment.

spasms and tuberous sclerosis. Juvenile

Affects healthy adolescents, presenting with

May have a genetic basis; patients

Easily treated with a

myoclonic

myoclonic jerks or GTCS in the early-morning

often have a ⊕ family history.

variety of antiepileptic

epilepsy

hours/upon awakening.

Benign partial

Affects healthy children, presenting with partial

Classic interictal spikes from the

Seizures usually disappear

epilepsy

seizures during wakefulness (oral, vocal, upper

centrotemporal (rolandic) region.

by adolescence.

medications.

extremity symptoms). May spread to GTCS during sleep. Landau-Kleffner

Those affected are developmentally normal

A bilateral temporal spike and sharp

Antiepileptic medications

syndrome

children who lose language ability between

waves on EEG.

may improve the long-

three and six years of age. Often confused with

term prognosis but cannot

autism.

reverse language loss.

(Data from Hay WW et al. Current Pediatric Diagnosis & Treatment, 18th ed. New York: McGraw-Hill, 2007: 721–725.)

Oncology Hematologic malignancies (leukemia and lymphoma) are the most common form of malignancy in children. Solid tumors in pediatrics most commonly occur in the CNS, bone, and kidneys. These topics are covered in Chapter 9. WI LM S ’ TU M OR

An embryonal tumor of renal origin. Wilms’ tumor is the most common renal tumor in children and is usually seen in those 1–4 years of age. Risk factors include a ⊕ family history, neurofibromatosis, aniridia (WAGR syndrome), Beckwith-Wiedemann syndrome, and congenital GU anomalies (eg, DenysDrash syndrome).

PEDIATRICS

SYMPTOMS/EXAM ■

■ ■

Patients may have abdominal pain or may present with a painless abdominal or flank mass. Hematuria and hypertension are commonly seen. Systemic symptoms include weight loss, nausea, emesis, bone pain, dysuria, and polyuria.

DIAGNOSIS ■ ■

■

Initially, an abdominal CT or ultrasound should be obtained. CXR, chest CT, CBC, LFTs, and BUN/creatinine can be used to assess severity and spread. Excisional biopsy to confirm.

TREATMENT ■

■ ■

Transabdominal nephrectomy followed by postoperative chemotherapy (vincristine/dactinomycin). Flank irradiation is of benefit in some cases. The prognosis is usually good but depends on staging and tumor histology. NE U R O B L A S T O M A

A tumor of neural crest cell origin that most commonly affects children < 5 years of age; the most common solid tumor during infancy. Risk factors include neurofibromatosis, tuberous sclerosis, pheochromocytoma, and Hirschsprung’s disease. SYMPTOMS/EXAM ■ ■

■

Lesions can appear anywhere in the body (eg, the skin or skull). Presentations include abdominal mass/distention/hepatomegaly, anorexia, weight loss, respiratory distress, fatigue, fever, diarrhea, irritability, or neuromuscular symptoms (if paraspinal). Other symptoms include leg edema, hypertension, and periorbital bruising (“raccoon eyes”).

DIAGNOSIS ■

■

■

Definitive diagnosis is based on a tumor tissue sample with or without elevated urine catecholamines (VMA and HVA) or on metastases to bone marrow with elevated urine catecholamines. The initial workup generally includes a CBC, electrolytes, LDH, ferritin, LFTs, a coagulation screen, urine catecholamines, and BUN/creatinine. For staging and assessing severity, obtain bilateral iliac crest bone marrow biopsies, an abdominal CT or MRI, a CXR, bone radiographs, and a technetium radionuclide scan or 131I-metaiodobenzylguanidine (MIBG) scan.

TREATMENT ■ ■

■ ■

Localized tumors are usually cured with excision. Chemotherapy includes cyclophosphamide, carboplatin or cisplatin, etoposide or teniposide, vincristine, and doxorubicin. Radiation can be used as an adjunct. The prognosis is improved if the diagnosis is made before one year of age. Staging is based on the International Neuroblastoma Staging System.

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327

328

CHAPTER 16

PEDIATRICS

RE T I NOBLAS TOM A

The most common intraocular malignancy in children; usually diagnosed before age two. One-quarter of cases are bilateral. SYMPTOMS/EXAM ■ ■

■

Usually presents with leukocoria and/or strabismus. Can be sporadic or inherited; the inherited form is associated with an ↑ risk of developing additional malignancies, including osteogenic sarcoma, soft tissue sarcomas, and malignant melanoma. Generally begins to metastasize within six months, so early diagnosis is critical.

DIAGNOSIS

Diagnosis is made by indirect ophthalmoscopic exam (with dilated pupils) TREATMENT ■ ■

■

Determined by the size and location of the tumor. Treatment options include enucleation, external beam radiation therapy, radioactive plaque therapy (125I brachytherapy), cryotherapy with laser photocoagulation, and chemotherapy. The chemotherapy regimen of vincristine, carboplatin, and etoposide is also used for chemoreduction of large tumors prior to other therapies. TU M OR LYS I S S YNDR OM E ( TLS )

A group of metabolic disturbances that may follow the initiation of cancer therapy. Most often associated with high-grade lymphomas or ALL. TLS is an oncologic emergency! SYMPTOMS/EXAM ■

■ ■

Tumor cell lysis results in severe hyperkalemia, hyperphosphatemia, and large amounts of serum nucleic acids, which lead to hyperuricemia. Hypocalcemia is also present 2° to calcium phosphate deposition. The condition can quickly lead to renal failure. In addition to renal failure, clinical manifestations may include seizure, cardiac arrhythmia, or sudden death.

TREATMENT ■

■

The most effective treatment is to prevent the syndrome from occurring by providing adequate IV hydration, urinary alkalinization using sodium bicarbonate and/or acetazolamide, and uric acid reduction using allopurinol or rasburicase (the drug of choice if uric acid levels are high prior to initiation of chemotherapy). If laboratory or clinical TLS as defined by the Cairo-Bishop criteria does develop: ■ Give rasburicase (if not already given with induction). ■ Correct electrolyte abnormalities using phosphate binders, calcium gluconate, sodium polystyrene sulfonate, insulin, and sodium bicarbonate. ■ Consider dialysis if abnormalities are severe or do not respond to therapies.

PEDIATRICS

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329

MNEMONIC

Genetics

Mnemonic for trisomies: C O M M O N G E N E T IC D IS O R D E R S

Down syndrome: Drinking age/ trisomy 21. Edwards’ syndrome: Election age/ trisomy 18. Patau’s syndrome: Puberty/trisomy 13.

Table 16-9 outlines the presentation and diagnosis of genetic syndromes.

TA B L E 16 - 9 .

Common Genetic Syndromes (continued)

SYNDROME

SYMPTOMS

EXAM

DIAGNOSIS

PROGNOSIS

Trisomy 21 (incidence

Hypotonia,

Mental retardation,

Karyotype, baseline

Fifty percent of those

1:600)

brachycephalic head,

cardiac defects, thyroid

echocardiogram, TFTs,

with congenital heart

slanted palpebral

disease, Gl atresias,

LFTs, CBC.

defects survive to 30

fissures, dysplasia of the

atlantoaxial instability,

years; 80% of those

midphalanx of the fifth

leukemia.

without such defects

finger, single transverse

survive to 30 years.

palmar (simian) crease.

Most who reach age 40 develop Alzheimer’s disease.

Trisomy 18 (incidence

Clenched hand/

Profound mental

Karyotype with

Fifty percent die by one

1:4000; 3:1 female

overlapping fingers,

retardation in survivors.

fluorescence in situ

week and 90% by one

predominance)

intrauterine growth

hybridization (FISH)

year.

retardation, cardiac

analysis.

defects, rocker-bottom feet. Trisomy 13 (incidence

CNS malformations,

Profound mental

Karyotype with FISH

Forty-four percent die

1:12,000)

polydactyly, seizures,

retardation in survivors.

analysis.

within one month; > 70% die by one year.

deafness, sloping forehead, aplasia cutis, cleft lip/cleft palate, microphthalmia/eye defects, cardiac defects. 22q11 syndrome

Congenital heart disease,

Mild to moderate

FISH analysis for 22q11.2

Parents should be tested

(DiGeorge syndrome,

palatal abnormalities,

mental retardation.

deletion. Serum calcium,

for being carriers of the

velocardiofacial

prominent/squared

Most have speech and

absolute lymphocyte

deletion.

syndrome, Shprintzen

nose, thymic hypoplasia/

language delay, learning

count, renal ultrasound,

syndrome, conotruncal

immune deficiency,

disabilities, and feeding

baseline echocardiogram.

anomaly face

absent parathyroid

difficulties. Psychosis.

syndrome) (incidence

glands/hypocalcemia.

1:4000) (continues)

CHAPTER 16

330

TA B L E 16 - 9 .

PEDIATRICS

Common Genetic Syndromes (continued)

SYNDROME

SYMPTOMS

EXAM

DIAGNOSIS

PROGNOSIS

Turner’s syndrome

Short female with

Mental retardation,

Karyotype for diagnosis.

Infertility; normal life

(45,XO) (incidence

shield chest, wide-

gonadal dysgenesis,

Baseline echocardiogram,

span.

1:10,000)

spaced nipples, webbed

renal anomalies, cardiac

renal ultrasound, BP,

neck, and congenital

defects (coarctation of

hearing screen.

lymphedema.

the aorta), hearing loss.

Fragile X syndrome

Boys present with

Mild to profound mental

DNA analysis shows

(incidence 1:1500

macrocephaly, large ears,

retardation, autism.

expansion of a CGG

males)

macroorchidism, and tall

nucleotide repeat in the

stature. Girls may have

FMR1 gene. The size of

only learning disabilities.

the repeat correlates with

Normal life span.

disease severity. Marfan’s syndrome

Tall stature, low upper-

Slit-lamp examination,

With treatment/corrective

(incidence 1:10,000)

to-lower-segment ratio,

echocardiography,

surgery of aortic root

arachnodactyly, joint

genetic evaluation.

dilation, patients have a

laxity, scoliosis, pectus

Diagnosis is made

normal life span.

excavatum or carinatum,

clinically.

Normal intelligence.

lens dislocation, retinal detachment, dilation of the aortic root, mitral valve prolapse, lumbosacral dural ectasia, high-arched palate. (Data from Hay WW et al. Current Pediatric Diagnosis & Treatment, 18th ed. New York: McGraw-Hill, 2007: 721–725.)

CHAPTER 17

PSYCHIATRY Diagnostic and Statistical Manual of Mental Disorders

332

Personality Disorders

332

Anxiety Disorders

332

GENERALIZED ANXIETY DISORDER

332

OBSESSIVE-COMPULSIVE DISORDER

334

PANIC DISORDER

334

Sleep Disorders

343

1° INSOMNIA

343

NARCOLEPSY

343

SLEEP APNEA

344

CIRCADIAN RHYTHM SLEEP DISORDER

344

Substance-Related Disorders

344

SUBSTANCE ABUSE/DEPENDENCE

344

PHOBIAS

335

POSTTRAUMATIC STRESS DISORDER

336

ALCOHOLISM

346

337

Eating Disorders

347

Cognitive Disorders

337

ANOREXIA NERVOSA

347

DEMENTIA

338

BULIMIA NERVOSA

347

DEPRESSION AND ANXIETY DUE TO A GENERAL MEDICAL CONDITION

338

Childhood Disorders

348

DELIRIUM

Mood (Affective) Disorders MAJOR DEPRESSIVE DISORDER BIPOLAR DISORDER

Psychotic Disorders

338

AUTISM SPECTRUM DISORDERS

348

338

DISRUPTIVE BEHAVIORAL DISORDERS

348

339

ATTENTION-DEFICIT HYPERACTIVITY DISORDER

349

340

SCHIZOPHRENIA

340

DISSOCIATIVE IDENTITY DISORDER

342

DISSOCIATIVE FUGUE

342

Somatoform Disorders

342

SOMATIZATION DISORDER

342

CONVERSION DISORDER

342

OTHER CAUSES OF LEARNING IMPAIRMENT

349

ENURESIS

349

Psychiatric Emergencies

349

SUICIDE RISK ASSESSMENT

349

NEUROLEPTIC MALIGNANT SYNDROME

350

SEROTONIN SYNDROME

350

Pharmacotherapy ANXIOLYTICS AND SEDATIVE-HYPNOTICS

351 351

HYPOCHONDRIASIS

342

PAIN DISORDER

343

ANTIDEPRESSANTS

351

343

ANTIPSYCHOTICS

353

MOOD STABILIZERS

354

BODY DYSMORPHIC DISORDER

Volitional/Intentional Disorders

343

FACTITIOUS DISORDER

343

MALINGERING

343

331

332

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PSYCHIATRY

Diagnostic and Statistical Manual of Mental Disorders (DSM) Psychiatric disorders affect (but do not always limit) a person’s ability to handle daily living and/or social or occupational situations. The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM) provides diagnostic criteria for mental disorders. The sixth edition, DSM-IV-TR, was released in the year 2000. MNEMONIC Characteristics of personality disorders—

The DSM organizes psychiatric diagnoses into five levels, or axes, relating to different aspects of disorder or disability: ■

MEDIC

■

Maladaptive Enduring Deviate from cultural norms Inflexible Cause impairment in social or

■ ■ ■

occupational functioning

KEY FACT To differentiate between schizoid and schizotypal, remember that schizOIDs feel like “Oh, I Don’t care.”

Axis I: Clinical disorders. Axis II: Personality disorders, mental disorders. Axis III: General medical conditions. Axis IV: Psychosocial/environmental problems. Axis V: Global assessment of functioning (GAF).

Personality Disorders Defined as enduring patterns of inner experience and behavior that deviate from cultural standards; are pervasive and inflexible; begin in adolescence or early adulthood; are stable and predictable over time; and lead to distress or impairment (see Table 17-1). In some cases, however (eg, OCPD), personality disorders are more annoying to others than to the person they affect. Treat with psychotherapy; pharmacotherapy is generally used only if psychiatric comorbidities exist.

Anxiety Disorders G E NE R ALI ZE D ANX I E TY DI S OR DE R ( G AD)

Lifetime prevalence is 5%; the male-to-female ratio is 1:2. Clinical diagnosis is usually made in the early 20s. SYMPTOMS ■

■

Characterized by excessive and pervasive worry about a number of activities or events that leads to significant impairment or distress. Patients may seek medical care for somatic complaints.

DIFFERENTIAL

Substance-induced anxiety disorder, anxiety disorder due to a general medical condition (eg, hyperthyroidism), panic disorder, OCD, depression, social phobia, hypochondriasis, somatization disorder.

PSYCHIATRY

TA B L E 17- 1 .

CLUSTER Cluster A:

CHAPTER 17

333

Signs and Symptoms of Personality Disorders

DISORDERS

CHARACTERISTICS

CLINICAL DILEMMA/STRATEGIES

Paranoid

Distrustful and suspicious; interpret others’ motives

Patients are suspicious and distrustful of doctors

Schizoid

Isolated, detached “loners.” Have restricted

“weird”

as malevolent. Litigious. emotional expression. Schizotypal

Odd behavior/appearance. Exhibit cognitive or

and rarely seek medical attention. Be clear, honest, noncontrolling, and nondefensive. Avoid humor. Maintain emotional distance.

perceptual distortions (eg, magical thinking, ideas of reference). Cluster B:

Borderline

Unstable mood/relationships and feelings of emptiness. Impulsive. Have a history of suicidal

“wild”

ideation or self-harm. Histrionic

Excessively emotional and attention seeking. Sexually provocative.

Narcissistic

Grandiose; need admiration; have sense of

Antisocial

Violate the rights of others, social norms, and laws.

Patients change the rules, demand attention, and feel they are special. Will manipulate staff and doctor (“splitting”). Be firm: Stick to the treatment plan. Be fair: Do not be punitive or derogatory. Be consistent: Do not change the rules.

entitlement. Lack empathy. Impulsive; lack remorse. May have a criminal history. Begins in childhood as conduct disorder. Cluster C: “worried and wimpy”

Obsessive-

Preoccupied with perfectionism, order, and control. Miserly. Have inflexible morals and values.

compulsive Avoidant

Socially inhibited; sensitive to rejection. Have fear of being disliked or ridiculed.

Dependent

Submissive, clingy, need to be taken care of. Have difficulty making decisions. Feel helpless.

Patients are controlling and may sabotage their treatment. Words may be inconsistent with actions. Avoid power struggles. Give clear recommendations, but do not push patients into decisions.

DIAGNOSIS

Diagnostic criteria are as follows: ■ ■

Anxiety/worry on most days for at least six months. Three or more somatic symptoms, including restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance.

TREATMENT ■

■

■

Pharmacologic therapy includes venlafaxine, SSRIs, benzodiazepines, and buspirone; second-line treatment with TCAs is appropriate if other antidepressants are ineffective or are not tolerated. Benzodiazepines offer acute relief, but tolerance and dependence may result from their use. Use them as a bridge to chronic treatment with SSRIs, as above. Psychotherapy and relaxation training are important adjuncts.

334

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OBS E S S I VE -C OM P U LS I VE DI S OR DE R ( OC D)

A 30-year-old high school guidance counselor presents to her dermatologist for irritation of her hands. She states that she washes her hands under hot water about 20 times a day and uses a variety of alcohol-based hand sanitizer products to avoid picking up germs. What is the most likely origin of her dermatitis? Obsessive-compulsive disorder.

Lifetime prevalence is 2–3%. Typically presents in late adolescence or early adulthood, and can lead to severe functional impairment. SYMPTOMS ■

■

Obsessions are persistent, intrusive thoughts, impulses, or images that lead to anxiety/distress and interfere with daily life. Common themes are contamination and fear of harm to oneself or to others. Compulsions are conscious, repetitive behaviors (eg, hand washing) or mental acts (eg, counting) that patients feel driven to perform to neutralize anxiety from obsessions.

KEY FACT DIFFERENTIAL In general, OCD is ego dystonic, whereas OCPD is ego syntonic.

OCPD, other anxiety disorders, Tourette’s syndrome (multiple motor and vocal tics), depression, schizophrenia, medical conditions (eg, brain tumor, temporal lobe epilepsy, group A β-hemolytic streptococcal infection). DIAGNOSIS

Patients recognize that their obsessions and/or compulsions are excessive, unreasonable productions of their own minds (rather than thought insertion). Nonetheless, their behaviors cause marked distress and are time-consuming (take > 1 hour/day). TREATMENT

Pharmacotherapy (eg, SSRIs, clomipramine, fluvoxamine) and behavioral therapy (eg, exposure and response prevention). PA NI C DI S OR DE R

More common in women, with a mean age of onset of 25. Lifetime prevalence is 1.5–3.5%. Often accompanied by agoraphobia (30–50% of cases), a fear of being in places or situations from which escape is difficult; of being outside the home alone; or of being in public places (see the discussion of phobias). SYMPTOMS

Presents as panic attacks—discrete periods of intense fear or discomfort in which at least four of the following symptoms develop abruptly and peak within 10 minutes: palpitations, sweating, trembling, shortness of breath,

PSYCHIATRY

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335

chest pain, nausea, dizziness, numbness, depersonalization, or fear of losing control. DIFFERENTIAL

Medical conditions (eg, angina, hyperthyroidism, hypoglycemia), substanceinduced anxiety disorder, other anxiety disorders. DIAGNOSIS

Recurrent, unexpected panic attacks followed by at least one month of worry about and/or behavioral change to avoid subsequent attacks. TREATMENT ■ ■

■

Behavioral therapy. Pharmacotherapy includes SSRIs, either alone or in combination with benzodiazepines. TCAs or MAOIs should be used only if SSRIs are not tolerated or are ineffective. Benzodiazepines (eg, alprazolam, clonazepam) are effective for immediate relief but have abuse potential. PHOBIAS

The three categories of phobia are agoraphobia, social phobia, and specific phobia. Lifetime prevalence is 10%. SYMPTOMS ■

■

Phobias are persistent, excessive, or unreasonable fear and/or avoidance of an object or situation that leads to significant distress or impairment. Exposure to the object or stimulus may precipitate panic attacks.

DIFFERENTIAL

Other anxiety disorders, depression, avoidant and schizoid personality disorders, schizophrenia, appropriate fear, normal shyness. DIAGNOSIS ■

■

■ ■

Social phobia is characterized by unreasonable, marked, and persistent fear of scrutiny and embarrassment in social or performance situations (also referred to as social anxiety disorder). It usually begins in adolescence. Specific phobia is immediately cued by an object or a situation (eg, spiders, animals, heights). It usually begins in childhood. In adults, the duration is six or more months. As in OCD, symptoms interrupt the patient’s life, and patients recognize that their fears are excessive.

TREATMENT ■

■

Cognitive-behavioral therapy (CBT) and pharmacotherapy (eg, SSRIs, benzodiazepines, β-blockers) are effective for social phobias. Behavioral therapy that uses exposure and desensitization is best for specific phobia.

KEY FACT Cognitive-behavioral therapy is a type of therapy that helps patients learn new ways to cope by: ■ Identifying automatic thoughts, or “cognitive distortions.” ■ Testing the automatic thoughts. ■ Identifying and testing the validity of maladaptive assumptions. ■ Strategizing on alternative ways to deal with problems.

336

CHAPTER 17

PSYCHIATRY

POS TTR AU M ATI C S TR E S S DI S OR DE R ( P TS D)

A 22-year-old war refugee presents to establish care at a local free clinic. She is soft-spoken and gives only brief responses to questions despite being fluent in English. The physician is unable to conduct a pelvic exam because of her obvious physical and emotional discomfort. The patient hesitantly admits to having vivid nightmares and flashbacks of the war. What psychiatric diagnosis should be considered in this patient? Posttraumatic stress disorder.

Results from exposure to a traumatic event that involved actual or threatened death or serious injury and evoked intense fear, helplessness, or horror. The lifetime prevalence is 8%. SYMPTOMS ■

■

■ ■

Examples of traumatic events include war, torture, natural disasters, assault, rape, and serious accidents. Patients with PTSD may have experienced the trauma personally, or they may have witnessed the event in a way that leads them to feel personally threatened, helpless, and horrified (eg, a child witnessing a parent being assaulted). Nightmares and flashbacks are common. Watch for survival guilt, personality change, substance abuse, depression, and suicide.

DIFFERENTIAL ■

■

■

Acute stress disorder: Symptoms are the same as or similar to those of PTSD but last < 1 month, occur within one month of a trauma, and are primarily dissociative. Adjustment disorder with anxiety: Emotional or behavioral symptoms occurring within three months of a stressor and lasting < 6 months. Other: Depression, OCD, acute intoxication or withdrawal, factitious disorders, malingering, borderline personality disorder.

DIAGNOSIS KEY FACT Victims of human trafficking may present with symptoms similar to those of PTSD.

Symptoms persist for > 1 month and include the following: ■ ■

■

Reexperiencing of the event (eg, nightmares, flashbacks). Avoidance of trauma-related stimuli or numbing of general responsiveness. Hyperarousal (eg, hypervigilance, exaggerated startle, irritability, difficulty falling or staying asleep).

TREATMENT ■

■

■

Pharmacotherapy includes first-line treatment with SSRIs; if SSRIs are not tolerated or are ineffective, use TCAs or MAOIs. Second-generation antipsychotics (eg, risperidone, olanzapine, quetiapine), anticonvulsants (eg, divalproex, topiramate), α2-adrenergic agonists (clonidine), or β-blockers (propranolol) may be helpful for some patients. CBT and group therapy are also effective.

PSYCHIATRY

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337

Cognitive Disorders D E L I R IU M

Delirium is common in hospitalized medical or surgical patients (15–70%) and is a medical, not psychiatric, disorder. However, since delirium may mimic psychosis, psychiatrists are often consulted on this problem. Risk factors include advanced age, hospitalization, medications (benzodiazepines, anticholinergics, opioids), starting multiple new medications at once, preexisting cognitive deficits, electrolyte abnormalities, malnutrition, hypoxia, a windowless ICU environment, infections, vision or hearing deficits, and severe illness. SYMPTOMS ■

Characterized by the following: Disturbance of consciousness and/or perception. ■ Altered cognition (memory, orientation, language)—eg, diminished attention span, impaired short-term memory, or unclear speech. ■ Acute onset. ■ A history suggesting a probable medical cause of delirium. Symptoms “wax and wane” during the day and feature lucid intervals. ■

■

DIFFERENTIAL

In contrast to delirium, dementia usually has an insidious onset; includes chronic memory and executive function deficits; and is characterized by symptoms that tend not to fluctuate during the day (see Table 17-2). DIAGNOSIS ■

The number of potential causes of delirium is extensive. First evaluate for recent medication changes, hypoglycemia, hepatic encephalopathy, or UTI.

TA B L E 17- 2 .

Delirium vs. Dementia

DELIRIUM Course

Functionality

DEMENTIA

Acute (abrupt onset), lasting hours to days; usually

Chronic (progressive degradation), lasting months to

reversible.

years; usually irreversible.

Fluctuating ability to focus and shift attention. Clouded

Alert. Intact consciousness.

consciousness. Cognition

Similar to dementia, but more likely to include perceptual

Disrupted memory, orientation, and language.

disturbances (hallucinations) and paranoia.

Hallucinations are present in about 30% of those with advanced disease.

Causes

Evidence of a general medical condition causing the

Insidious processes such as Alzheimer’s disease,

problem (seizures, postictal state, infections, thyroid

Huntington’s disease, vascular dementia, AIDS dementia,

disorders, UTI, vitamin deficiencies); substances (eg,

and major depressive disorder in the elderly.

cocaine, opioids, PCP); head trauma, kidney disease, sleep deprivation.

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Workup may include a CBC, electrolytes, BUN/creatinine, glucose, LFTs, UA, urine toxicology, vitamin B12/folate, TSH, RPR, HIV, blood culture, serum calcium/phosphorus/magnesium, pulse oximetry, ABGs, CSF, or serum drug screening.

TREATMENT ■ ■

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Treat the underlying medical condition. Minimize or discontinue delirium-inducing drugs (eg, benzodiazepines, anticholinergics), and simplify medication regimens if possible. Recommend reorientation techniques (eg, clocks or wall calendars), and provide an environment that will facilitate healthy sleep/wake cycles. Pharmacotherapy may be beneficial and includes low-dose antipsychotics (haloperidol, risperidone, olanzapine, quetiapine), usually for short-term use. Physical restraints may be necessary to prevent physical harm to self/ others. DE M E NTI A

General deterioration of function 2° to chronic, progressive cognitive decline with intact attention and consciousness. Most common among the elderly (those > 85 years of age), and most often caused by Alzheimer’s disease (50%) or multi-infarct dementia (25%). Refer to the Dementia section of Chapter 13 for further detail. DE P R E S S I ON AND ANX I E TY DU E TO A G E NE R AL M EDICAL CO N DITIO N ■

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Depression can be 2° to drug intoxication (alcohol or sedative-hypnotics; antihypertensives such as methyldopa, clonidine, and propranolol) or to stroke, hypothyroidism, MS, or SLE. Anxiety may be caused by drugs (caffeine, sympathomimetics, steroids), endocrinopathies (pheochromocytoma, hypercortisolism, hyperthyroidism, hyperparathyroidism), metabolic disorders (hypoxemia, hypercalcemia, hypoglycemia), or SLE.

Mood (Affective) Disorders MA JOR DE P R E S S I VE DI S OR DE R ( M DD)

Untreated episodes of MDD can last for four or more months, and the risk of recurrence is 50% after only one episode. The average age of onset is in the mid-20s; lifetime prevalence is 10–25% for females (the highest risk is in the childbearing years) and 5–12% for males. The male-to-female ratio is 1:2. MDD is often associated with a life stressor, and up to 15% of those affected die by suicide. SYMPTOMS

Diagnosis requires depressed mood or anhedonia (loss of interest or pleasure) and at least five of the following symptoms during a two-week period: ■ ■ ■

Insomnia or hypersomnia. Feelings of worthlessness or excessive guilt. Fatigue or loss of energy.

PSYCHIATRY

■ ■ ■ ■

↓ ability to concentrate, or indecisiveness. Significant weight loss or weight gain, or change in appetite. Psychomotor agitation or retardation. Recurrent thoughts of death or suicide.

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MNEMONIC Symptoms of depression—

SIG E CAPS DIFFERENTIAL ■

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Dysthymia: A milder, chronic depressed state of two or more years’ duration. Bereavement: Does not involve severe impairment or suicidality; usually improves within two months, but can last up to a year. Symptoms may vary on the basis of cultural norms. For example, visual and auditory hallucinations (such as thinking the deceased is still alive) are common and can be considered normal. Similarly, feelings of grief around anniversaries and other special events beyond the one-year period are also quite common. Adjustment disorder with depressed mood: Has fewer symptoms; occurs within three months of a stressor; lasts < 6 months. Other: Substance-induced mood disorder (eg, illicit drugs, β-blockers, OCPs); mood disorder due to a medical condition (eg, hypothyroidism, ACA stroke); dementia.

Sleep (↓/↑) Interest (↓) Guilt Energy (↓) Concentration Appetite (↓/↑) Psychomotor agitation or retardation Suicidal ideation

KEY FACT Cognitive decline is a common sign of major depressive disorder in the elderly (“pseudodementia”).

DIAGNOSIS

Symptoms last two or more weeks and must lead to significant dysfunction or impairment. TREATMENT ■

Pharmacotherapy: The effectiveness of antidepressants is similar between and within classes (50–70% of patients), and these drugs take at least 3–4 weeks to have an effect. Thus, the selection of an antidepressant should be based on side effect profiles, the safety and tolerability of side effects, patient preference, cost, and the patient’s previous response to specific antidepressants. ■ Continue treatment for six or more months. Avoid abrupt discontinuation of medications even if the patient “feels better”; instead, taper over 6–12 months unless the patient has had adverse side effects (eg, ↑ thoughts of suicide). Electroconvulsive therapy (ECT): ■ Safe and effective. ■ Best for refractory or catatonic depression, but may also be used for acute mania or acute psychosis and when the patient refuses to eat or drink (eg, severely depressed elderly) or is suicidally depressed. ■ Adverse effects include postictal confusion, arrhythmias, headache, and retrograde amnesia (inability to recall memories prior to the event). ■ Relative contraindications include intracranial mass, aneurysm, and recent MI/stroke. Pregnancy is not a contraindication. Psychotherapy: Psychotherapy combined with antidepressants is more effective than either modality alone.

KEY FACT

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B I P O L A R D IS O R D E R

A family history of bipolar illness significantly ↑ risk. Prevalence is 1%. The male-to-female ratio is 1:1, but women more often seek treatment. Symptoms usually appear around age 20, and the number of cycles actually ↑ with age. About 10–15% of those affected die by suicide.

Severe MDD can present with psychotic symptoms, in which case an antipsychotic in addition to an antidepressant may be temporarily required.

KEY FACT Seasonal affective disorder (SAD), which is typified by fall/winter depression, is treated with bright-light therapy (phototherapy).

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SYMPTOMS ■

A manic episode is defined as follows: One week of an abnormally and persistently elevated (“euphoric”), expansive, or irritable mood. ■ At least three of the following (four if the mood is irritable), as remembered by the mnemonic DIGS FAR: ■ Distractibility ■ Insomnia (↓ need for sleep) ■ Grandiosity (inflated self-esteem) ■ Pressured Speech ■ Flight of ideas (racing thoughts) ■ Psychomotor Agitation/↑ goal-directed Activity ■ Recklessness/pursuit of pleasurable but Risky behaviors (eg, gambling, sexual indiscretions) A mixed episode must meet the criteria for both manic and depressive episodes for one week or more. Mania and mixed episodes are considered psychiatric emergencies 2° to impaired judgment and the risk of hurting oneself or others. ■

KEY FACT Catatonia may be observed in both schizophrenia and mood disorders. Of the latter, it is more often associated with mania than depression.

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DIFFERENTIAL ■

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Hypomania: Features no marked functional impairment or psychosis. Symptoms last for four days or less. Does not require hospitalization. Cyclothymic disorder: Chronic cycles of mild depression (dysthymia) and hypomania for two or more years. Effectively a milder form of bipolar II disorder. Other: Substance-induced mood disorder, schizophrenia, schizoaffective disorder, personality disorders, medical conditions (eg, temporal lobe epilepsy, hyperthyroidism), ADHD.

DIAGNOSIS ■

■

Bipolar I disorder: Diagnosis is made after just one mixed or manic episode. Depressive episodes are common but are not required for diagnosis. Bipolar II disorder: Characterized by at least one hypomanic (rather than manic) episode alternating with at least one major depressive episode.

TREATMENT KEY FACT Screen for bipolar disorder before starting antidepressants, as they can induce acute mania or psychosis in bipolar patients.

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Acute mania: Lithium, anticonvulsants, antipsychotics, benzodiazepines, ECT. Bipolar depression: Mood stabilizers (lithium or lamotrigine are first line) +/– antidepressants. Monotherapy with an antidepressant is not recommended. If the patient does not respond to first-line treatment, the next step may include adding lamotrigine (if started with lithium), bupropion, or SSRIs. In severe cases, consider ECT.

Psychotic Disorders S CH I ZOP HR E NI A

Thought to be related to dysregulation of dopamine (↑ in the limbic system and ↓ in the frontal cortex). Lifetime prevalence is 1%. Family history ↑ risk, and an ↑ incidence is seen in those born during winter/early spring. Peak onset is 18–25 years for men and 25–35 years (and perimenopausally)

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for women. Few patients have a complete recovery. As with other psychiatric disorders, social/occupational dysfunction can be significant. There is a high incidence of substance abuse, and > 75% of patients smoke cigarettes. The suicide rate is 10%. SYMPTOMS

At least two of the following are required for one or more months, with continuous signs for six or more months: ■

■

Positive symptoms: Bizarre delusions, hallucinations, disorganized thoughts/speech/behavior. Hallucinations are usually auditory (eg, running commentary/monologues or conversations between two voices) but may also be visual, tactile, or, rarely, olfactory. Negative symptoms: Affective flattening, avolition, apathy, alogia.

KEY FACT A bizarre delusion is defined as an absurd, totally implausible, fixed false belief that is not shared by other members of that society/culture— eg, the conviction that aliens from another planet have implanted electrodes into one’s brain.

DIFFERENTIAL ■

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Brief psychotic disorder: Symptoms are of < 1 month’s duration; onset often follows a psychosocial stressor. Associated with a better prognosis. (Postpartum psychosis can last up to three months.) Schizophreniform disorder: Diagnostic criteria are the same as those for schizophrenia, but symptoms have a duration of 1–6 months. Schizoaffective disorder: Mood symptoms are present for a significant portion of the illness, but psychotic symptoms have been present without a mood episode. Delusional disorder: Nonbizarre delusions for one or more months in the absence of other psychotic symptoms; often chronic. Other: Mood disorder with psychotic features (contrast with schizoaffective disorder); substance-induced psychosis (eg, amphetamines) or drug withdrawal (eg, alcoholic hallucinosis); psychosis due to a general medical condition (eg, brain tumor); delirium or dementia; shared psychotic disorder.

DIAGNOSIS

There are several subtypes of schizophrenia, classified by their predominant symptoms: ■

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Paranoid: Marked by delusions and hallucinations. Carries the best prognosis. Disorganized (hebephrenic): Characterized by disinhibition and poor contact with reality. Carries the worst prognosis. Catatonic: Involves a marked ↑ or ↓ in speech and motor function. Rare (10–15% of cases). Residual: Entails eventual loss of positive symptoms but persistence of negative ones in long-term, untreated schizophrenics. Undifferentiated: A constellation of symptoms that is too inconsistent to be classified according to the above subtypes.

TREATMENT

Antipsychotic medications (neuroleptics). Hospitalize when the patient is a danger to himself/herself or to others. Psychosocial treatments, individual supportive psychotherapy, and family therapy help prevent relapse.

KEY FACT Negative symptoms are harder to treat.

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DI S S OC I ATI VE I DE NTI TY DI S OR DE R

A condition in which a person presents with two or more distinct personalities (aka “alters”). Each of these identities interprets and interacts with the world differently—eg, they may be of different ages, levels of intelligence, or even genders. The individual usually claims no memory when the other identities take over but sometimes reports internal quarreling between the “alters.” Often associated with severe and prolonged abuse and/or neglect in childhood. Comorbid PTSD is common. Formerly known as multiple personality disorder. DI S S OC I ATI VE F U G U E

Temporary amnesia for one’s own identity, typically lasting hours to days, and usually precipitated by acute stressors. Classically, the affected individual is found after having traveled to a different city or state and having established a new identity. Upon recovery, he or she is amnestic for the fugue episode as well as for the original stressor that caused it. Like other dissociative disorders, fugue cannot be attributed to ingestion of illicit substances or other psychiatric conditions such as delirium.

Somatoform Disorders S OM ATI ZATI ON DI S OR DE R

Chronic pain symptoms in four or more sites/organ systems that are not intentionally produced and cannot be explained by a general medical condition. Onset is before age 30, and the condition is much more prevalent in women. CON VE R S I ON DI S OR DE R ■

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Presents with sensory symptoms, motor deficits, or “psychogenic seizures” that are not intentionally produced and cannot be explained by an organic etiology. Relation to a stressful event suggests association with psychological factors (eg, complete right arm paralysis after a fight). Symptoms usually subside spontaneously. HYP OC HONDR I AS I S

An 18-year-old student presents to the ER with a chief complaint of dyspareunia. Although she reports having experienced a bicycle accident approximately one year ago, she has had multiple diagnostic workups that have always been negative. She is now particularly concerned that she has contracted an STD and does not appear relieved when the physician states that her exam and blood work are normal. What diagnosis should be considered in this patient? Hypochondriasis.

PSYCHIATRY

Preoccupation over > 6 months with fear of having a serious disease based on misinterpretation of symptoms (rather than delusions). Patients usually recognize that their concerns are excessive, but they are not reassured by negative medical evaluations. Men and women are affected equally. P A I N D IS O R D E R ■

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Pain intensity or a pain profile that is inconsistent with physiologic processes. More common in women than in men, with a peak onset at 40–50 years of age. Sx/Exam: Symptoms are exacerbated by or related to psychological factors, especially depression. Tx: Treat with physical therapy, psychotherapy, and antidepressants. Analgesics rarely provide relief. B O D Y D Y S M O R PH IC D IS O R D E R

Preoccupation with an imagined defect in appearance. Multiple visits to surgeons and dermatologists are common. Slightly more common in women than in men. Associated with depression. Treat with SSRIs.

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KEY FACT Medical students are prone to thinking that they have the symptoms of whatever disease they are studying. It has been suggested that this is nosophobia, or fear of contracting disease, rather than true hypochondriasis.

KEY FACT Fibromyalgia, a pain disorder that features chronic pain and allodynia, is often accompanied by other psychiatric comorbidities. It is treated with antidepressants, muscle relaxants, anticonvulsants (eg, pregabalin), and dopamine agonists (eg, ropinirole).

Volitional/Intentional Disorders Unlike somatoform disorders, which have no conscious mechanism or motivation for symptoms, volitional disorders feature a conscious mechanism for illness (eg, self-harm, intentional ingestion of toxins) and a 1° or 2° gain. FA C T I T I O U S D IS O R D E R ■

■

Symptoms are intentionally caused or exaggerated for 1° gain (eg, assuming a sick role), although patients do not understand why they do this (ie, unconscious motivation). The disorder is more common in men and among health care workers. MA L I N G E R I N G

Feigning of symptoms for anticipated external (2°) gain (eg, money, food, shelter).

Sleep Disorders 1 ° I N S O M N IA

Significant difficulty falling or staying asleep. Affects up to one-third of the general population. The disorder cannot be attributed to physical or mental conditions but is often precipitated by anxiety. Symptoms occur three or more times a week for at least one month. NA R CO LE P S Y

Has a prevalence of approximately 0.16%, and usually presents before age 30.

KEY FACT Munchausen’s syndrome refers to repeated episodes of factitious disorders (either the same or new complaints). The sufferer feels a deep psychological need to play the role of patient and feels comforted by assuming such a role.

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KEY FACT HypnaGOgic hallucinations occur when you GO to sleep. HypnoPOMPic hallucinations occur when you awaken and “PUMP” yourself up for the day.

PSYCHIATRY

May be familial. Often associated with mood disorders, substance abuse, and GAD. SYMPTOMS ■

■

KEY FACT Cataplexy is sudden loss of muscle tone leading to collapse, usually in the setting of strong emotions or excitement. It is treated with SSRIs.

Presents with excessive daytime sleepiness and daytime sleep attacks characterized by ↓ REM sleep latency. Symptoms occur daily for three or more months. May involve hypnagogic (just before sleep) or hypnopompic (just before awakening) hallucinations.

TREATMENT

Amphetamines (methylphenidate) or nonamphetamine stimulants (modafinil). S LE E P AP NE A

Disturbances to the normal sleep cycle 2° to airflow obstruction +/– pauses in respiratory effort, leading to excessive daytime somnolence. Both central (CSA) and obstructive sleep apnea (OSA) can be diagnosed via polysomnography (a sleep study), but OSA is strongly associated with snoring and is usually observed in obese men. Therapy usually includes continuous positive airway pressure (CPAP) while sleeping and treatment of underlying/associated medical problems (eg, heart failure, obesity). CI R C ADI AN R HYTHM S LE E P DI S OR DE R

Discrepancy between when the patient would like to sleep and when he or she actually does so. Often 2° to jet lag or shift work.

Substance-Related Disorders S U BS TANC E ABU S E / DE P E NDE NC E

KEY FACT Exercise caution when diagnosing mood disorders in patients who are acutely intoxicated/impaired.

The lifetime prevalence of substance abuse is approximately 20%. The lifetime prevalence of using one or more illicit substances in the United States is roughly 40%. Comorbid psychiatric disorders are common. SYMPTOMS

The signs, symptoms, and physical findings of acute intoxication and withdrawal are outlined in Table 17-3. KEY FACT DIAGNOSIS Dependence ≈ abuse + tolerance and/ or withdrawal.

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Check urine and serum toxicology. Offer HIV testing; check LFTs and consider hepatitis testing. Diagnostic criteria: ■ Individuals display maladaptive patterns of behavior (ie, reliance on substances) to cope with stressors, leading to clinically significant impairment and, in general, to an overall worsening of the situation. ■ Substance abuse (one or more criteria in one year): Failure to meet obligations, substance use during hazardous activities, substancerelated legal problems, or continued use despite social problems.

PSYCHIATRY

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Substance dependence (three or more criteria in one year): Tolerance, ↑ use, desire to ↓ use, withdrawal, spending a significant amount of time obtaining the substance, disinterest in other activities.

TA B L E 17- 3 .

Signs and Symptoms of Intoxication and Withdrawal

DRUG Alcohol

INTOXICATION

WITHDRAWAL

Disinhibition/impaired judgment, emotional lability, slurred speech, ataxia,

Tremor, tachycardia, hypertension,

aggression, hallucinations, hypoglycemia, blackouts (retrograde amnesia),

malaise, nausea, seizures, DTs, agitation,

coma.

hallucinations. May be life-threatening and require hospitalization.

Opioids

Euphoria leading to apathy, CNS depression, nausea, vomiting,

Anxiety, insomnia, anorexia, diaphoresis,

constipation, pupillary constriction, seizures, respiratory depression (life-

dilated pupils, fever, rhinorrhea,

threatening in overdose).

piloerection, nausea, stomach cramps,

Naloxone/naltrexone will block opioid receptors and reverse effects

diarrhea, yawning, myalgias. Extremely

(beware of the antagonist clearing before the opioid, particularly with

uncomfortable, but rarely life-

long-acting opioids such as methadone).

threatening.

Amphetamines,

Psychomotor agitation, impaired judgment, tachycardia, pupillary dilation,

Post-use “crash” with hypersomnolence,

cocaine

fever, diaphoresis, hypertension, paranoia, angina, arrhythmias, seizures,

dysphoria/nightmares, depression,

hallucinations, sudden death. Treat with haloperidol for severe agitation

malaise, severe craving, suicidality.

and symptom-targeted medications. Phencyclidine

Belligerence, psychosis, violence, impulsiveness, psychomotor agitation,

Recurrence of intoxication symptoms

hydrochloride

fever, tachycardia, vertical/horizontal nystagmus, ataxia, seizures,

due to reabsorption in the Gl tract;

(PCP)

delirium.

sudden onset of severe, random

Give benzodiazepines or haloperidol for severe symptoms; otherwise

violence.

reassure. LSD

—

Marked anxiety or depression, delusions, visual hallucinations, flashbacks, pupillary dilation. Give benzodiazepines or traditional antipsychotics for severe symptoms.

Marijuana (THC)

—

Euphoria, slowed sense of time, impaired judgment, “heightened senses,” social withdrawal, ↑ appetite, dry mouth, diaphoresis, conjunctival injection, hallucinations, anxiety, paranoia, tachycardia, hypertension, amotivational syndrome.

Barbiturates

Low safety margin; respiratory depression.

Anxiety, seizures, delirium, lifethreatening cardiovascular collapse.

Benzodiazepines

Caffeine

Nicotine

Interactions with alcohol, amnesia, ataxia, somnolence, mild respiratory

Rebound anxiety, seizures, tremor,

depression.

insomnia, hypertension, tachycardia.

Restlessness, insomnia, diuresis, muscle twitching, arrhythmias,

Headache, lethargy, depression, weight

psychomotor agitation.

gain, irritability, craving.

Restlessness, insomnia, anxiety, arrhythmias.

Irritability, headache, anxiety, weight gain, craving.

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MNEMONIC CAGE questions: 1. Have you ever felt the need to Cut down on your drinking? 2. Have you ever felt Annoyed by criticism of your drinking? 3. Have you ever felt Guilty about your drinking? 4. Have you ever had a morning Eye opener? More than one “yes” on the CAGE questionnaire makes alcohol abuse likely.

PSYCHIATRY

TREATMENT

Group therapy, Narcotics Anonymous, recovery housing. Hospitalization may be necessary for acute withdrawal. Consider methadone maintenance for opiate dependence. ALC OHOLI S M

The lifetime prevalence of alcohol abuse is roughly 10% in women and approximately 20% in men. The lifetime prevalence of alcohol dependence is 3–5% in women and 10% in men. Evidence of a problem usually begins to surface between 21 and 34 years of age. Family history ↑ risk. Common causes of death include suicide, cancer, heart disease, and hepatic disease. DIAGNOSIS ■ ■

KEY FACT Alcoholism can toAST your liver.

■

Screen with the CAGE questionnaire. Monitor vital signs for tachycardia and elevated BP associated with withdrawal; look for stigmata of liver disease such as palmar erythema or spider angiomata. Labs may reveal macrocytosis and an elevated AST and GGT.

TREATMENT ■

■

KEY FACT ■

DTs are a medical emergency with an untreated mortality rate of 20%. Give IV lorazepam.

■

Rule out medical complications; correct electrolyte abnormalities and hydrate. Start a benzodiazepine taper (eg, chlordiazepoxide, lorazepam) for withdrawal symptoms—ie, the CIWA protocol. Give multivitamins and folic acid; administer thiamine before glucose to prevent Wernicke’s encephalopathy. Individual or group counseling, Alcoholics Anonymous, disulfiram, naltrexone, or acamprosate may be of benefit.

COMPLICATIONS ■

KEY FACT Alcohol use is related to 50% of all homicides and automobile fatalities.

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GI bleeding (eg, gastritis, varices, Mallory-Weiss tears), pancreatitis, liver disease, delirium tremens (DTs), alcohol-induced psychosis, peripheral neuropathy, cerebellar degeneration. Wernicke’s encephalopathy: Acute and usually reversible ataxia accompanied by confusion and ophthalmoplegia. Korsakoff’s syndrome: A chronic and often irreversible condition marked by anterograde amnesia +/– confabulation.

PSYCHIATRY

Eating Disorders ANOREXIA NERVOSA

A 15-year-old boy presents to his family doctor for a routine well-child exam. The father is concerned that his son has been eating poorly ever since he and his wife filed for divorce. The son, for his part, states that he has been trying to exercise more and eat less so that he can make the basketball team at school. The boy’s growth curve reveals a drop from the 50th to the 15th percentile for weight. What psychiatric diagnoses should be considered? Depression and anorexia nervosa. (Although eating disorders are much less common in males, the diagnosis should still be considered in male patients.)

Females account for 90% of cases. Peak incidences are at age 14 and age 18. Risk factors include family history, higher socioeconomic status (SES), poor self-esteem, psychiatric comorbidities (eg, major depression, OCD, anxiety), and body-conscious careers/activities such as modeling, ballet, and wrestling. Mortality from suicide or medical complications is 10%. SYMPTOMS

Classified as restricting type (excessive dieting or exercising) or binge-eating/ purging type (vomiting, laxatives, diuretics). Presents with the following: ■

■ ■ ■

Refusal to maintain normal body weight (ie, the patient is < 85% of ideal body weight). Intense fear of weight gain. Distorted body image. Amenorrhea (three missed cycles).

DIAGNOSIS ■

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Measure height and weight. Check CBC, electrolytes, TSH/free T4, and an ECG. Look for lanugo (fine body hair), dry skin, lethargy, bradycardia, hypotension, and peripheral edema.

TREATMENT

Patients often deny the health risks of their behavior. Monitor caloric intake and focus on slow weight gain. Individual, family, and group psychotherapy are crucial. SSRIs (fluoxetine) have been used successfully, but avoid bupropion in light of the risk of seizure. BULIMIA NERVOSA

Affects 1–3% of young adult females. The prognosis is more favorable than that of anorexia nervosa. Associated with an ↑ frequency of affective disorders, substance abuse, and borderline personality disorder.

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SYMPTOMS

Patients have normal weight or are overweight but engage in the following behaviors twice a week for three or more months: ■ ■

Binge eating with a sense of lack of self-control. Compensatory behavior to prevent weight gain (eg, self-induced vomiting, laxatives, diuretics, overexercise).

DIAGNOSIS ■

■

The same as that for anorexia nervosa. Look for poor dentition, enlarged parotid glands, scars on the dorsal hand surfaces (from finger-induced vomiting), electrolyte imbalances, and metabolic alkalosis. In contrast to anorexia nervosa, patients are typically distressed about their symptoms and behaviors and are consequently easier to treat.

TREATMENT

Restore the patient’s nutritional status and electrolytes and then rebuild his/ her weight. CBT is the most effective treatment. Antidepressants are useful even in nondepressed patients, but avoid bupropion in light of its seizure risk.

Childhood Disorders AU T I S M S P E C TR U M DI S OR DE R S

More common in males, and symptoms usually appear before age three. Subtypes include the following: ■

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Autism: Characterized by delayed and aberrant communication (language); cognitive dysfunction; abnormal social interaction; and restricted, repetitive, and stereotyped patterns of behavior, interests, and activities. Asperger’s disorder: Similar to autistic disorder, but involves normal language and cognition. Rett’s disorder: A neurodegenerative disorder that affects girls only. It is marked by normal development until five months of age followed by deceleration of head circumference, stereotyped hand movements (wringing, hand washing), loss of social engagement, poor gait and truncal movements, severely impaired language development, severe psychomotor retardation, and an ↑ risk of seizure. Childhood disintegrative disorder: Severe developmental regression after > 2 years of normal social/motor/language development. DI S R U P TI VE BE HAVI OR AL DI S OR DE R S

KEY FACT Conduct disorder is diagnosed in Children and can eventually lead to inCarceration. Adults suffer from Antisocial personality disorder.

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Oppositional defiant disorder: A negative, hostile, and defiant attitude toward authority figures of six or more months’ duration. May lead to conduct disorder. Conduct disorder: A disorder in which a patient repeatedly and significantly violates societal norms and the rights of others (eg, bullies, tortures animals, steals/destroys property) for one or more years. Considered a precursor to antisocial personality disorder.

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A T T EN T IO N -D E F I CI T H Y P E R A CT IVITY DI S OR DE R ( ADHD) ■ ■

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The most common childhood psychiatric disorder. Sx/Exam: Involves six or more symptoms of either inattention (eg, easy distractibility, difficulty following instructions/finishing tasks, tendency to make careless mistakes) or hyperactivity/impulsivity (eg, interrupts others/has difficulty waiting) in two or more settings (school, work, home). Causes impairment before seven years of age. Dx: Although parents often immediately think of this diagnosis, first consider physical and social factors that may contribute to the problem (eg, the child has poor vision and can’t see the chalkboard). Tx: Initial treatment generally includes behavior modification. Pharmacologic approaches include psychostimulant (eg, amphetamines, methylphenidate) or nonstimulant medications (eg, bupropion, atomoxetine, SSRIs, α2-agonists). OT H E R CA U S E S O F LE A R N I N G I MPAI R M E NT

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Learning disabilities: Weaker academic performance than expected for age, intelligence, and education. May involve specific deficits such as dyslexia or more general problems with understanding and processing new information. Tend to occur more frequently in males and in those of lower SES, and may have a familial pattern. As with ADHD, consider physical and social factors prior to making a diagnosis. Mental retardation: Global deficits in intellectual and adaptive/social function. Eighty-five percent of cases are mild, with an IQ between 50 and 70. Associated with chromosomal abnormalities, congenital infections, teratogens, and inborn errors of metabolism. Tourette’s syndrome: Multiple motor and vocal tics such as blinking, grimacing, or grunting that occur many times a day for > 1 year and cause functional impairment. Associated with ADHD, learning disorders, and OCD. Treated with dopamine receptor antagonists (eg, haloperidol, pimozide), clonidine, behavioral therapy, and counseling. Stimulants can worsen or precipitate tics. E N U R E S IS

Enuresis (bed-wetting) is not a clinical disorder until a child is > 5 years of age (the child may not feel/understand neurologic impulses until then). It should initially be treated with behavioral therapy (eg, bed alarms); imipramine should be reserved for refractory cases.

Psychiatric Emergencies S U I C ID E R IS K A S S E S S M E N T ■

The eighth leading overall cause of death in the United States. Risk factors include the following: ■ Gender: Men complete suicide three times more often than do women, whereas women attempt suicide three times more frequently. Men also prefer more violent methods (eg, hanging, firearms, jumping from high places) as opposed to overdose.

KEY FACT Approximately 50% of patients diagnosed in childhood continue to have ADHD into adulthood.

KEY FACT Fetal alcohol syndrome is the numberone preventable cause of mental retardation; Down syndrome is the number-one cause overall.

KEY FACT Tourette’s syndrome is often depicted in popular media as including coprolalia (the repetition of obscene words), but this tic is found in only 10–30% of cases.

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Age: Those > 75 years of age account for 25% of completed suicides. Suicide is also the third leading cause of death in 15- to 24-year-olds, after homicides and accidents. ■ Ethnicity: Two-thirds of completed suicides are Caucasian males. ■ Psychiatric illness: MDD, bipolar disorder, psychotic disorder, substance abuse or dependence. ■ Other risk factors: Include unemployment or job dissatisfaction; chronic, debilitating illness; a history of prior suicide attempts; and a family history of suicide. Protective factors include religious affiliation or civic groups, married status, and parenthood. ■

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A life-threatening complication of antipsychotic treatment. May also be precipitated in patients with Parkinson’s disease following the abrupt withdrawal of the dopamine precursor levodopa. Mortality is 10–20%. SYMPTOMS ■ ■

■

■

Can occur at any time during the course of treatment. Presents with muscular rigidity and dystonia, akinesia, mutism, obtundation, and agitation. Autonomic symptoms include high fever, diaphoresis, hypertensive episodes, and tachycardia. Look for extremely elevated CK and elevated liver enzymes. May progress to rhabdomyolysis and/or renal dysfunction.

TREATMENT

Stop the offending medication; give dantrolene, bromocriptine, or amantadine. S E R OTONI N S YNDR OM E

Caused by the use of MAOIs with SSRIs or MAOIs with venlafaxine. Less commonly, it may involve SSRIs with lithium, SSRIs with levodopa, or SSRIs with an atypical antipsychotic. SYMPTOMS ■ ■

Presents with delirium, agitation, tachycardia, diaphoresis, and diarrhea. Exam reveals myoclonus and hyperreflexia. In severe cases, patients may present with hyperthermia, seizures, rhabdomyolysis, renal failure, cardiac arrhythmias, and DIC.

TREATMENT

Stop the offending medications; give supportive care. Administer a serotonin antagonist or cyproheptadine.

PSYCHIATRY

CHAPTER 17

Pharmacotherapy A N X IO L Y T I CS A N D S E D A T IV E -H YP NOTI C S

Benzodiazepines ■

■

■

Applications: Used for anxiety, alcohol withdrawal, insomnia, anesthesia, seizures, and muscle spasms. Have rapid onset of action; augment sedation and respiratory depression from other CNS depressants (eg, alcohol). Where possible, use on a short-term basis only (eg, no more than 2–3 months) or occasionally PRN. Interactions: P-450 inhibitors (eg, cimetidine, fluoxetine) ↑ levels; carbamazepine and rifampin ↓ levels. Relative contraindications: Disadvantages include a risk of abuse, tolerance, dependence, and withdrawal. May also induce delirium in elderly and/or critically ill patients. Avoid in patients who are at high risk for falling.

Buspirone ■ ■

■

Mechanism of action: A 5-HT1A partial agonist. Applications: Used for GAD and chronic anxiety; for the augmentation of depression or OCD therapy; and for patients with a history of substance abuse. May also be used when sedation poses a potential risk. Unlike benzodiazepines, it has no anticonvulsant or muscle-relaxant properties. Also characterized by few side effects and no tolerance, dependence, or withdrawal. Relative contraindications: Has slow onset of action and lower efficacy than benzodiazepines. Should not be used with MAOIs. Not effective as a PRN anxiolytic (chronic ↑ in 5-HT are anxiolytic, but acute ↑ cause anxiety).

Antihistamines

Used for the short-term management of insomnia and for preoperative sedation. Zolpidem

A nonbenzodiazepine used for insomnia. ↓ sleep latency and ↑ total sleep time. Has rapid onset; withdrawal is rare. A N T ID E PR E S S A N T S

A 29-year-old attorney is being treated for depression. He blushingly admits that since starting SSRIs, he has noticed diminished interest in sex and difficulty maintaining an erection. What other antidepressant medications should be considered to prevent these sexual side effects? Bupropion or mirtazapine.

KEY FACT Diazepam is longer-acting than lorazepam.

351

352

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PSYCHIATRY

Selective Serotonin Reuptake Inhibitors (SSRIs) KEY FACT

■

■

Use of antidepressant medications during pregnancy carries the risk of abstinence syndrome and pulmonary hypertension in the neonate. However, untreated depression carries the risk of low birth weight.

■ ■

Include fluoxetine, sertraline, paroxetine, citalopram, escitalopram, and fluvoxamine. Applications: First-line therapy for depression and many anxiety disorders. Well tolerated, effective, and relatively safe in overdose. Interactions: Can ↑ warfarin levels because of P-450 interactions. Side effects: Sexual dysfunction, nausea, diarrhea, anorexia, headache, anxiety, tremor, sleep disturbance.

Atypical Antidepressants ■

Bupropion: Mechanism of action: Dopamine reuptake inhibition. Metabolite weakly blocks norepinephrine (NE) reuptake. ■ Applications: Constitutes first-line therapy for depression and smoking cessation. Effective for patients who have had sexual side effects from other antidepressants. ■ Side effects: Common side effects include anxiety, agitation, and insomnia. Can worsen tics. Also lowers seizure threshold, especially in the setting of rapid or large dose increases or immediate-release preparations. Not associated with weight gain. ■ Relative contraindications: A history of seizure disorder, eating disorders, or head trauma. Venlafaxine: ■ Mechanism of action: The main action is 5-HT and NE reuptake inhibition. ■ Applications: Used for major depression and GAD. Has a more rapid response than SSRIs. ■ Side effects: Adverse effects include diastolic hypertension (monitor BP), insomnia, nervousness, sedation, sexual dysfunction, anticholinergic effects, and nausea. Mirtazapine: ■ Mechanism of action: An α2-antagonist that enhances NE and 5-HT. Does not affect the P-450 system. More effective as part of dual therapy. ■ Side effects: Sedation (worse in lower doses) and weight gain. Has little effect on sexual function. Trazodone: ■ Mechanism of action: Primarily inhibits 5-HT reuptake. At lower doses, may be helpful in insomnia. ■ Side effects: Sedation, priapism. ■

■

KEY FACT Duloxetine has a profile similar to that of venlafaxine but has a smaller effect on blood pressure. ■

KEY FACT Antidepressants are the preferred longterm treatment for anxiety, but they can be anxiogenic initially. Bupropion, in particular, should not be used with anxiety disorders.

KEY FACT

■

Tricyclic Antidepressants (TCAs) ■

TCAs may be lethal in an overdose.

KEY FACT

■ ■

TCA toxicity: ■ Trembling (convulsions) ■ Coma ■ Arrhythmias

■

Include nortriptyline, desipramine, imipramine, amitriptyline, clomipramine, and doxepin. TCAs are considered to be second-line agents owing to their relatively poor side effect profile compared with the newer antidepressants, along with the risk of dysrhythmias, and even death, from an overdose. Mechanism of action: Block the reuptake of NE and serotonin. Applications: Useful for chronic pain and migraines. OCD responds to clomipramine. Interactions: Levels ↑ when used with SSRIs because of P-450 competition. Also interact with ranitidine and warfarin.

PSYCHIATRY

■

Side effects: Anticholinergic: Dry mouth, blurry vision, constipation, urinary retention. ■ Cardiac: Orthostatic hypotension; cardiac conduction delays with prolonged PR and QRS intervals. TCAs are contraindicated in patients with a history of heart block and in those at high risk of suicide. Obtain a baseline ECG prior to initiating therapy, and use with caution in the elderly. ■ Other: Sedation, weight gain.

CHAPTER 17

KEY FACT

■

Ingestion of fermented foods (eg, aged cheeses, red wine, beer) can precipitate a hypertensive crisis in patients taking MAOIs.

MNEMONIC

Monoamine Oxidase Inhibitors (MAOIs) ■

■

Include phenelzine, selegiline, and tranylcypromine. MAOIs are also considered to be second-line agents owing to their relatively poor side effect profile compared to the newer antidepressants. Side effects: ■ Common side effects include orthostatic hypotension, insomnia, weight gain, edema, and sexual dysfunction. ■ May lead to tyramine-induced hypertensive crisis. Dietary restrictions include aged cheeses, sour cream, yogurt, pickled herring, cured meats, and certain alcoholic beverages such as chianti. ■ Potentially fatal serotonin syndrome can occur if MAOIs are combined with SSRIs, TCAs, meperidine, fentanyl, or indirect sympathomimetics (eg, those found in OTC cold remedies).

353

Side effects of MAOIs–

The 6 H’s Hepatocellular jaundice/necrosis Hypotension (postural) Headache Hyperreflexia Hallucinations Hypomania

KEY FACT A N T IP S Y C H O T IC S

First-Generation (“Typical”) Antipsychotics ■ ■

■

Mechanism of action: Act through dopamine receptor blockade. Applications: Used for psychotic disorders and acute agitation. Cheap and effective. Include the following: ■ High-potency agents (haloperidol, fluphenazine): ↓ only positive symptoms of psychosis. Associated with more extrapyramidal symptoms (EPS). ■ Low-potency agents (thioridazine, chlorpromazine): Associated with more sedation, anticholinergic effects, and hypotension. Side effects: Key side effects include the following: ■ EPS: Result from excessive cholinergic effect (see Table 17-4). ■ Hyperprolactinemia (amenorrhea, gynecomastia, galactorrhea). ■ Anticholinergic effects (dry mouth, blurry vision, urinary retention, constipation). ■ Neuroleptic malignant syndrome. ■ Other: Cardiac arrhythmias, weight gain, sedation.

Second-Generation (“Atypical”) Antipsychotics ■ ■

Mechanism of action: Act through 5-HT2 and dopamine antagonism. Applications: Currently first-line therapy for schizophrenia. Benefits are fewer EPS and anticholinergic effects than first-generation agents. ■ Risperidone, olanzapine, quetiapine, ziprasidone, and aripiprazole are commonly used. ■ Clozapine is second-line therapy and is used for treatment-refractory patients.

“Activating” antidepressants: bupropion, venlafaxine, and SSRIs and MAOIs in general.

KEY FACT “Sedating” antidepressants: trazodone, mirtazapine, and amitriptyline.

KEY FACT “Augmentation” strategies for antidepressants: 1. Lithium (with TCA) 2. Triiodothyronine (with TCA or SSRI) 3. Mirtazapine 4. Aripiprazole (with SSRI) 5. Buspirone 6. Bupropion

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CHAPTER 17

KEY FACT

PSYCHIATRY

TA B L E 17- 4 .

Extrapyramidal Symptoms and Treatment

SYMPTOM

Evolution of EPS— ■ 4 hours: Acute dystonia ■ 4 days: Akinesia ■ 4 weeks: Akathisia ■ 4 months: Tardive dyskinesia

TREATMENT

Acute

Involuntary muscle

Give an anticholinergic (benztropine)

dystonia

contraction or spasm (eg,

or diphenhydramine. To prevent, give

torticollis, oculogyric crisis).

prophylactic benztropine with an

More common in young men.

antipsychotic.

Pseudoparkinsonism (eg,

Give an anticholinergic (benztropine) or a

shuffling gait, cogwheel

dopamine agonist (amantadine). ↓ the dose

rigidity).

of neuroleptic or discontinue (if tolerated).

Subjective/objective

↓ neuroleptic and try β-blockers

restlessness.

(propranolol). Benzodiazepines or

Dyskinesia

KEY FACT Metoclopramide is actually a more common cause of tardive dyskinesia than antipsychotics.

DESCRIPTION

Akathisia

anticholinergics may help. Tardive

Stereotypic oral-facial

Discontinue or ↓ dose of neuroleptic,

dyskinesia

movements. Likely from

attempt treatment with more appropriate

dopamine receptor

drugs, and consider changing neuroleptic

sensitization. Often

(eg, changing to clozapine or risperidone).

irreversible (50%). More

Treat symptoms with β-blockers or

common in older women.

benzodiazepines. Giving anticholinergics or decreasing neuroleptics may initially worsen tardive dyskinesia.

■

Side effects: May cause sedation, weight gain, anticholinergic effects, and QT prolongation. Obtain baseline values, and monitor the patient’s weight, lipid profile, and glucose levels. ■ Olanzapine carries the risk of diabetogenesis. ■ Common side effects of clozapine include sedation, constipation, weight gain, and sialorrhea (drooling). Clozapine may also cause agranulocytosis and seizures (requires weekly CBCs during the first six months followed by biweekly monitoring). ■

MO OD S TABI LI ZE R S

KEY FACT When using lithium, monitor renal and thyroid function. Chronic use can lead to hypothyroidism and nephrotoxicity.

Lithium ■

■

KEY FACT Lithium toxicity treatment may include hemodialysis.

Applications: Used for long-term maintenance or prophylaxis of bipolar disorder. Effective in mania and in augmenting antidepressants in depression and OCD. ↓ suicidal behavior/risk in bipolar disorder. Has a narrow therapeutic index and requires monitoring of serum levels. Side effects: ■ Include thirst, polyuria, fine tremor, weight gain, diarrhea, nausea, acne, and hypothyroidism. ■ Lithium toxicity presents with a coarse tremor, ataxia, vomiting, confusion, seizures, and arrhythmias. ■ Teratogenic.

PSYCHIATRY

CHAPTER 17

355

Valproic Acid ■

■

Applications: First-line agent for acute mania and bipolar disorder; effective in rapid cyclers (those with four or more episodes per year). Side effects: ■ Sedation, weight gain, hair loss, tremor, ataxia, GI distress. ■ Pancreatitis, thrombocytopenia, and fatal hepatotoxicity are uncommon. Do not use in patients with hepatitis or cirrhosis. ■ Monitor platelets, LFTs, and serum drug levels. ■ Teratogenic.

Carbamazepine ■ ■

Applications: Second-line agent for acute mania and bipolar disorder. Side effects: ■ Common side effects include nausea, sedation, rash, and ataxia. ■ Rare side effects include hepatic toxicity, SIADH (leading to hyponatremia), bone marrow suppression (leading to life-threatening dyscrasias such as aplastic anemia), and Stevens-Johnson syndrome. ■ Monitor blood counts, transaminases, and electrolytes. Drug interactions complicate its use (eg, cannot be used with MAOIs). ■ Teratogenic.

KEY FACT Lamotrigine or lithium may be used as first-line agents for bipolar depression.

Other Anticonvulsants ■ ■ ■ ■

Include oxcarbazepine, lamotrigine, gabapentin, and topiramate. Efficacy is not well documented. Do not require blood level monitoring and do not cause weight gain. Lamotrigine is associated with Stevens-Johnson syndrome and toxic epidermal necrolysis.

KEY FACT The bioavailability of gabapentin actually ↓ with larger doses.

356

CHAPTER 17

PSYCHIATRY

NO T E S

CHAPTER 18

PULMONARY Pulmonary Function Tests

358

Pulmonary Embolism

366

Hypoxia and Hypoxemia

359

Acute Respiratory Distress Syndrome

368

Asthma

359

Solitary Pulmonary Nodule

369

Chronic Obstructive Pulmonary Disease

361

Sarcoidosis

370

Pleural Effusion

363

Obstructive Sleep Apnea

371

Pneumothorax

365

Bronchiolitis

371

366

Cystic Fibrosis

372

TENSION PNEUMOTHORAX

357

358

CHAPTER 18

PULMONARY

Pulmonary Function Tests (PFTs) The two measurements most often used in pulmonary function testing are FEV1 (forced expiratory volume in one second) and FVC (forced vital capacity). Findings are categorized as follows: ■

KEY FACT ■

Asthma, while obstructive in nature, is a reversible condition. It usually has a normal DLCO because the alveoli are unaffected. By contrast, COPD is characterized by a ↓ DLCO because some alveoli are destroyed and unavailable for gas diffusion.

Obstructive pattern (eg, COPD, chronic bronchitis, bronchiectasis, asthma): ■ An FEV1/FVC ratio of < 70% (the normal ratio in adults is generally > 75%). ■ Total lung capacity (TLC) will be ↑ in some obstructive processes, such as COPD, whereas it may be normal or ↑ in asthma. ■ The severity of FEV1 is used to grade obstructive airway diseases. Restrictive pattern (eg, obesity, kyphosis, inflammatory/fibrosing lung disease, interstitial lung disease): ■ While FEV1 and FVC will each be low, the FEV1/FVC ratio will be normal or ↑. ■ TLC will be ↓ in restrictive processes. ■ An FVC of < 80% is suggestive of restriction when the FEV1/FVC ratio is normal.

Table 18-1 outlines PFT findings in the setting of common lung conditions. TA B L E 18 - 1 .

PFTs in Common Settings

Asthma COPD Fibrotic disease Extrathoracic restriction a

FEV1/FVC

TLC

DLCOa

Normal/↓

Normal/↑

Normal/↑

↓

↑

↓

Normal/↑

↓

↓

Normal

↓

Normal

DLCO, defined as the diffusing capacity of carbon monoxide, measures the gas exchange capacity of the capillary-alveolar interface.

PULMONARY

CHAPTER 18

359

Hypoxia and Hypoxemia Defined as a room-air O2 saturation of < 88% or a PaO2 of < 55 mm Hg on ABG measurement or evidence of cor pulmonale. Think about the cause of hypoxia in order to determine the next step: ■

Ventilation-perfusion (V/Q) mismatch: Examples include asthma, COPD, nonmassive pulmonary embolus (PE), and pneumonia. ■ Responds to O2. ■ Associated with an ↑ alveolar-arterial oxygen (A-a) gradient. Hypoventilation: ■ Commonly due to oversedation from medications. ■ Responds to O2. ■ Characterized by a normal A-a gradient. Decreased diffusion: ■ Think about interstitial or parenchymal lung diseases. ■ Responds to O2. ■ Characterized by an ↑ A-a gradient. ■ Associated with a very low DLCO. High altitude: ■ Responds to O2. ■ Characterized by a normal A-a gradient. Shunt physiology: ■ Think about acute respiratory distress syndrome, significant lobar pneumonia, patent foramen ovale, or patent ductus arteriosus. ■ Typically does not respond to O2. ■ Characterized by an ↑ A-a gradient. ■

■

■

■

■

TREATMENT

Always treat hypoxic patients with adequate amounts of O2 to maintain saturations of > 90% or a PaO2 of > 60 mm Hg. Definitive treatment entails reversing the underlying cause of the hypoxia.

Asthma A patient with a history of asthma that was previously controlled with once-monthly albuterol states that he has been using his albuterol inhaler 4–5 times a week but denies any nighttime symptoms. How would you adjust his treatment regimen? Add a low-dose inhaled corticosteroid, as the patient now has mild persistent asthma.

Asthma is defined as chronic inflammation of the airways. Patients may be atopic (the classic triad is eczema, wheezing, and seasonal rhinitis).

KEY FACT Hypoxia due to shunt physiology will not correct with supplemental O2.

KEY FACT Hypoxia can lead to apnea in infants, so be sure to use supplemental O2 to maintain O2 saturations.

KEY FACT Think of methemoglobinemia in a patient with a low O2 saturation on pulse oximetry but a normal PaO2 on ABG. Treatment is with methylene blue.

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CHAPTER 18

PULMONARY

SYMPTOMS ■

■

Look for intermittent wheezing, coughing, chest tightness, or shortness of breath. Symptoms may be seasonal or may occur following exposure to triggers (eg, URIs, dust, pet dander, cold air) or with exercise.

EXAM ■

■

KEY FACT Think of GERD in a patient with chronic cough that worsens when the patient lies supine.

Determine the severity of the attack by assessing mental status, the ability to speak in full sentences, the presence of cyanosis, use of accessory muscles, and, of course, vital signs. O2 saturation monitoring is not adequate, as ventilation is more important than oxygenation. Look for wheezing or rhonchi along with a prolonged expiratory phase. Patients with severe exacerbations may have ↓ wheezing. These patients will need prompt assessment of their gas exchange (with ABG analysis) along with aggressive treatment.

DIFFERENTIAL ■

■

Not all that wheezes is asthma! Rule out foreign body aspiration, laryngeal spasm or irritation, GERD, and CHF. In patients with chronic cough, think about asthma as well as allergic rhinitis, postnasal drip, or GERD. PFTs can help differentiate asthma from COPD and chronic bronchitis (see below), although there are overlapping findings.

KEY FACT DIAGNOSIS A 両 methacholine challenge generally excludes asthma.

■

■

KEY FACT Inhaled corticosteroids are safe for use in pregnancy.

TREATMENT ■ ■

KEY FACT Be sure to check an ABG in any patient with an asthma exacerbation. A normal PCO2 suggests that the patient is tiring out and is about to crash.

CXR may show hyperinflation (suggesting air trapping) but can also be normal. Definitive diagnosis is made by demonstration of obstruction on PFTs: ■ Reversibility with bronchodilators as defined by an ↑ in FEV1 or FVC by 12% and at least 200 mL. ■ Methacholine challenge testing in a monitored setting can be used to confirm the diagnosis.

Chronic asthma: See Table 18-2. Acute asthma exacerbations: Recognizing the severity of the attack and instituting the correct therapy are the keys to treatment. ■ Initiate short-acting β-agonist (albuterol) therapy (nebulizer or MDI). ■ Administer a systemic corticosteroid such as methylprednisolone or prednisone. ■ Begin inhaled corticosteroids as well. ■ Follow patients closely with peak flows, and tailor therapy to the response. ■ Chronic antibiotics (without evidence of infection), anticholinergics, cromolyn, and leukotriene antagonists are generally not useful in this setting.

CHAPTER 18

PULMONARY

TA B L E 18 - 2 .

361

Medications for the Treatment of Chronic Asthma

TYPE Severe persistent

SYMPTOMS (DAY/NIGHT) Continual

FEV1 ≤ 60%

Frequent

MEDICATIONS High-dose inhaled corticosteroids + long-acting inhaled β-agonists. Possible PO steroids. PRN short-acting bronchodilator.

Moderate

Daily

persistent

> 1 night/week

Mild persistent

> 2/week but < 1/day

60–80%

PRN short-acting bronchodilator. ≥ 80%

> 2 nights/month Mild intermittent

≤ 2 days/week ≤ 2 nights/month

Low- to medium-dose inhaled corticosteroids + long-acting inhaled β-agonists.

Low-dose inhaled corticosteroids. PRN short-acting bronchodilator.

≥ 80%

No daily medications. PRN short-acting bronchodilator.

(Reproduced with permission from Le T et al. First Aid for the USMLE Step 2 CK, 7th ed. New York: McGraw-Hill, 2010: 458.)

Chronic Obstructive Pulmonary Disease (COPD) You order PFTs for a patient with worsening shortness of breath. Which of the following values would be consistent with a diagnosis of COPD? (A) Low FEV1, low FVC, low FEV1/FVC, high TLC, low DLCO. (B) Low FEV1, low FVC, high FEV1/FVC, low TLC, low DLCO. The answer is A. Choice B describes a restrictive pattern.

A combination of emphysema and chronic bronchitis, COPD generally involves the destruction of lung parenchyma. This results in ↓ elastic recoil, which in turn leads to air trapping. TLC ↑ as a result of a rise in the residual volume. Chronic bronchitis is defined as chronic productive cough for three or more months in each of two successive years. SYMPTOMS

Look for cough, dyspnea, wheezing, and a history of smoking. Dyspnea is usually progressive. In advanced disease, weight loss may be seen. EXAM ■

■

Emphysema (“pink puffer”): ↓ breath sounds, minimal cough, dyspnea, pursed-lip breathing, hypercarbia/hypoxia late, barrel chest. Chronic bronchitis (“blue bloater”): Rhonchi; productive cough; cyanosis, but with mild dyspnea; hypercarbia/hypoxia early. Patients are frequently overweight with peripheral edema.

362

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PULMONARY

■ ■

■ ■ ■

KEY FACT Think α1-antitrypsin deficiency in young patients with COPD and bullae.

KEY FACT

■

■ ■

TREATMENT ■

Chronic COPD: The mainstays of treatment are inhaled β-agonists (albuterol) and anticholinergics (ipratropium). ■ O2 therapy is indicated for patients with an O2 saturation of < 88% or a PaO2 of < 55 mm Hg or a PaO2 of 55–60 mm Hg and evidence of cor pulmonale. It is also indicated with desaturations of < 88% during exercise or at night. ■ Smoking cessation and O2 therapy have been proven to ↓ mortality in COPD. ■ Inhaled corticosteroids do not play a major role unless PFTs reveal significant reversible airway disease. ■ Remember to vaccinate COPD patients against influenza (yearly) and pneumococcal pneumonia (at least once). Acute COPD exacerbations: ■ Defined as ↑ dyspnea or a change in cough or sputum production. ■ Check a CXR to look for causes of the exacerbation (pneumonia, CHF). ■ Administer O2 to maintain a saturation of 90–95% (no need to go higher!). ■

Only O2 therapy and smoking cessation have been unequivocally shown to improve survival in patients with COPD.

KEY FACT Don’t forget—empiric antibiotics are indicated for acute COPD exacerbations!

Clubbing is generally not present in COPD. Patients may also have evidence of cor pulmonale (right heart failure from pulmonary hypertension). PFTs may suggest the diagnosis in patients who smoke. FEV1/FVC is < 70% and FEV1 < 80% of predicted. The condition is not reversible with bronchodilators. DLCO tends to be low in emphysema and mildly reduced in chronic bronchitis. TLC is ↑. CXR shows hyperlucent, hyperinflated lungs with flat diaphragms and a narrow cardiac silhouette (see Figure 18-1).

■

A

B

FIGURE 18-1. Chronic obstructive pulmonary disease. Note the hyperinflated and hyperlucent lungs, flat diaphragms, increased AP diameter, narrow mediastinum, and large upper lobe bullae on AP (A) and lateral (B) CXR. (Reproduced with permission from Stobo JD et al. The Principles and Practice of Medicine, 23rd ed. Stamford, CT: Appleton & Lange, 1996: 135.)

PULMONARY

■

■

■

■

Start patients on an inhaled β-agonist (albuterol) and anticholinergics (ipratropium). Systemic corticosteroids (prednisone) may ↓ the length of hospital stay but should be tapered over 3–14 days. Empiric antibiotics with coverage of Streptococcus, H influenzae, and Moraxella (eg, amoxicillin, TMP-SMX, doxycycline, azithromycin, clarithromycin) are indicated in an acute setting. Spirometry in an acute setting is not helpful in guiding therapy.

Pleural Effusion A 33-year-old man presents with cough, night sweats, and pleuritic chest pain. A CXR shows a left pleural effusion. A PPD test results in 16 mm of induration. Thoracentesis yields the following lab results: glucose 50, LDH 340, pleural fluid protein 4.6, and serum protein 3.0 mg/dL. A sputum culture for acid-fast bacilli (AFB) is 両. What is your next step? This patient has an exudative pleural effusion with suspected TB. A pleural biopsy is needed to confirm the diagnosis despite the fact that the patient’s sputum culture was 両 for AFB.

Effusions are characterized as either transudative or exudative on the basis of their composition. SYMPTOMS/EXAM ■

■

A

Patients are usually short of breath and may complain of pleuritic chest pain. Some may be asymptomatic or have symptoms of an underlying process (eg, CHF, pneumonia, cancer). Exam reveals ↓ breath sounds, dullness to percussion, and ↓ tactile fremitus on the side with the effusion (see Figure 18-2).

B

FIGURE 18-2. Pleural effusion. PA (A) and lateral (B) CXRs show blunting of the right costophrenic sulcus (arrows). (Reproduced with permission from USMLERx.com.)

CHAPTER 18

363

KEY FACT Always treat hypoxic patients with O2. CO2 retention won’t kill the patient, but hypoxia will.

364

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PULMONARY

TA B L E 18 - 3 .

Thoracentesis Findings in Transudative vs. Exudative Pleural Effusions

Transudative

PLEURAL/SERUM

PLEURAL/SERUM

PROTEIN (RATIO)

LDH (RATIO)

PLEURAL LDH

< 0.5 and

< 0.6 and

< 200

> 0.5 or

> 0.6 or

> 200

Exudative

DIAGNOSIS ■ ■

KEY FACT Thoracentesis is indicated for any effusion > 10 mm thick (or about 100 mL) on decubitus CXR.

Thoracentesis. Obtain the following assays on the pleural fluid to aid in management: Gram stain and culture, AFB, glucose, triglycerides, cell count with differential, and pH. Serum total protein and LDH values will also be needed (see Table 18-3). ■ If the fluid is transudative, no further workup is needed; focus on treating the underlying cause (eg, diuresing the patient). ■ If the fluid is exudative, refer to Table 18-4 to help determine the cause.

TREATMENT ■

KEY FACT Consider a pleural biopsy if you suspect TB. Send the fluid for cytology if you suspect malignancy.

■

If the decubitus CXR shows an effusion > 10 mm thick (or about 100 mL), always do a thoracentesis. This may be both therapeutic (to relieve dyspnea) and diagnostic. Indications for a chest tube (any one of these) are as follows: ■ A pleural WBC count > 100,000 or frank pus, or gram-⊕ fluid. ■ Glucose < 40 mg/dL. ■ pH < 7.0.

COMPLICATIONS ■

■

An untreated pleural effusion in the setting of pneumonia may become infected and turn into an empyema. Over time, exudative effusions may become loculated and require drainage by video-assisted thoracoscopy (VATS) or surgical decortication.

TA B L E 18 - 4 .

Assays for Exudative Fluid and Their Differential Diagnosis

PLEURAL ASSAY

VALUE

DIFFERENTIAL

Glucose

< 60

Empyema or parapneumonia, TB, RA, malignancy.

WBCs

> 10,000

Empyema or parapneumonia, RA, malignancy.

RBCs

> 100,000

Gross blood—think of trauma, PE.

Lymphocytes

TB, sarcoid, malignancy, chylothorax.

PMNs

Empyema, PE.

Eosinophils

Bleeding, pneumothorax.

pH

< 7.20

Complicated effusion or empyema.

Triglycerides

> 150

Diagnostic of chylothorax.

Cellular differential

PULMONARY

■

CHAPTER 18

365

The principal complications of thoracentesis include pneumothorax and bleeding (remember, the neurovascular bundle runs along the inferior side of the rib).

Pneumothorax Defined as air that becomes trapped in the pleural space. This can be traumatic, spontaneous, or iatrogenic. Spontaneous pneumothorax can be due to underlying lung pathology such as COPD or CF. SYMPTOMS/EXAM ■

■

Look for patients who develop acute shortness of breath and pleuritic chest pain. Look for tachypnea, ↓ tactile fremitus, ↓ breath sounds, tympany on percussion on the side involved, and tracheal deviation toward the affected side.

KEY FACT Suspect pneumothorax with shortness of breath and chest pain plus underlying COPD, CF, chest procedures (eg, central lines), or trauma. A 1° pneumothorax may be encountered in young adults with a tall, thin body habitus.

DIAGNOSIS

CXR will reveal the diagnosis. Look for a distinct lack of lung markings within the pneumothorax along with collapse of the lung on that side (see Figure 18-3). Tracheal deviation away from the side of the pneumothorax suggests tension pneumothorax. TREATMENT ■

■

■ ■

KEY FACT The differential for shortness of breath/ chest pain includes pneumothorax, MI, PE, pleuritis, and aortic dissection.

Insertion of a chest tube is required in patients with a pneumothorax of > 30%. Smaller pneumothoraces may be managed simply with supplemental O2 and observation. Treat pain with morphine and NSAIDs. For patients with recurrent pneumothorax, consider pleurodesis.

A

B

Pneumothorax. (A) Small right pneumothorax. (B) Right tension pneumothorax with collapse of the right lung and shifting of mediastinal structures to the left. Arrows denote pleural reflections. (Reproduced with permission from USMLERx.com.)

FIGURE 18-3.

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PULMONARY

TE N S I ON P NE U M OTHOR AX

A 34-year-old man with COPD comes to the ER with sudden-onset shortness of breath that requires high levels of supplemental O2. Physical exam reveals ↓ breath sounds on the left side and a trachea deviated to the right. What is your next step? Needle decompression for presumed left-sided tension pneumothorax.

■

■

KEY FACT ■

A tension pneumothorax is an emergency! If you suspect this, don’t wait for imaging; insert a needle to decompress the chest.

■

In this emergent complication of pneumothorax, defects in the chest wall act as a one-way valve. This allows air to be drawn into the pleural space and become trapped. The result is rapid decompensation, hypotension, and circulatory collapse leading to shock. Common scenarios in which to think of tension pneumothorax include penetrating trauma, positive-pressure ventilation, and COPD. Dx: Diagnostic clues include those of a pneumothorax along with tachycardia, hypotension, ↑ O2 requirements, and ↑ JVP. The trachea deviates away from the side with tension. Tx: If you suspect that the patient has a tension pneumothorax, don’t wait for imaging! Insert a needle to decompress the chest and then insert a chest tube.

Pulmonary Embolism (PE) A 72-year-old patient who was admitted to the hospital for a hemorrhagic stroke develops shortness of breath, and imaging reveals a pulmonary embolus as well as a left lower extremity DVT. How do you proceed? Place an IVC filter.

Remember Virchow’s triad when thinking of risk factors for venous thromboembolism (VTE): ■ ■ ■

Stasis: Immobility, CHF, obesity, ↑ JVP. Endothelial injury: Trauma, surgery, recent fracture, prior DVT. Hypercoagulable state: Pregnancy, OCP use, coagulation disorders, malignancy, burns.

KEY FACT SYMPTOMS Consider PE in any hospitalized patient who has dyspnea.

Think about PE or DVT in any patient with risk factors and complaints of leg pain or swelling, acute-onset chest pain (especially pleuritic), shortness of breath, or syncope. EXAM

Findings on exam include tachypnea, tachycardia, cyanosis, a loud P2 or S2, ↑ JVP, and signs of right heart failure. Patients may occasionally have hemoptysis or a low-grade fever. DIFFERENTIAL

Most signs and symptoms of PE are nonspecific, so be sure to think about other entities that can present this way, including acute MI, pneumonia, CHF, and aortic dissection.

PULMONARY

DIAGNOSIS

See Figure 18-4 for a diagnostic algorithm. Initial assessment should include the following: ■ ■

■

■

■

ABGs may show a 1° respiratory alkalosis and an ↑ A-a gradient. CXR findings may include the following: ■ Normal (most common!). ■ A wedge-shaped infarct (Hampton’s hump). ■ Oligemia in the affected lobe (Westermark’s sign). ■ Pleural effusion. ECG may reveal an S wave in lead I, a Q wave in lead III, and T-wave inversion in lead III (not very sensitive or specific). The pretest probability of PE will help determine the diagnostic utility of the V/Q scan. ■ If either the pretest probability or the V/Q scan results are intermediate, some type of confirmatory testing will be needed. ■ V/Q scans are also preferred in patients for whom CT angiography has relative contraindications (eg, renal insufficiency, pregnancy). In a nonhospitalized patient, a 両 D-dimer assay, when combined with some form of imaging, may help rule out DVT with good negative predictive value.

Clinical suspicion of pulmonary thromboembolism

Ventilation/perfusion lung scan

Normal

Low or indeterminate probability

High probability

Pulmonary thromboembolism excluded

Testing for DVT

Treatment

FIGURE 18-4.

Positive

Negative

Treatment

Pulmonary arteriogram or serial nonivasive testing for deep vein thrombosis

Positive

Negative

Treatment

Pulmonary thromboembolism excluded

Diagnostic approach to pulmonary embolism. (Modified with permission from Tier-

ney LM et al. Current Medical Diagnosis & Treatment: 2005. New York: McGraw-Hill, 2005: 281.)

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368

CHAPTER 18

KEY FACT The most common ECG finding in pulmonary embolism is sinus tachycardia.

PULMONARY

■

■

CT angiography has largely replaced V/Q scanning except in patients with renal insufficiency or dye allergy. It may also be useful as a confirmatory test when the V/Q scan is indeterminate. Pulmonary angiography can be considered for the diagnosis of PE and may be needed if other testing is intermediate. (It is now rarely necessary.)

TREATMENT ■

Treat VTE patients with anticoagulation. Initially use IV heparin or low-molecular-weight heparin. ■ Patients who are not anticoagulated adequately within 24 hours have a high rate of recurrence. ■ Patients should then be transitioned to warfarin therapy with a goal INR of 2.0–3.0. In patients with documented large central PEs (saddle PEs) and hypotension or shock, consider administering tPA along with heparin. The duration of anticoagulation therapy will vary with risk factors: ■ For patients with a first event and reversible or time-limited risk factors (eg, surgery, pregnancy), treat for at least 3–6 months. ■ Consider lifelong anticoagulation in patients with chronic risk factors (malignancy, paraplegia, recurrent DVTs, or PEs). In patients who cannot safely be anticoagulated, an IVC filter may be useful. Although these filters can ↓ the risk of PE, they are associated with a higher risk of recurrent DVT. ■

■

KEY FACT Don’ t forget to order DVT prophylaxis for all of your hospitalized patients!

■

Acute Respiratory Distress Syndrome (ARDS) ARDS is a common problem in the ICU and is a significant cause of mortality. It can be 2° to a range of underlying conditions, all with a similar end result of widespread inflammation in the lung parenchyma with leaking of fluid into the alveolar spaces, leading to (noncardiogenic) pulmonary edema and alveolar damage. Common etiologies are as follows: ■ ■

Direct: Pneumonia, aspiration. Indirect: Sepsis (most common), transfusions, pancreatitis, trauma.

SYMPTOMS/EXAM

Look for a patient with risk factors, usually in an ICU setting. Patients will have an acute onset of hypoxia and will be difficult to oxygenate. Intubation is required to maintain an acceptable PaO2. DIAGNOSIS ■

KEY FACT Think of ARDS in a patient with a PaO2/FiO2 ratio < 200, diffuse infiltrates, and normal cardiac function.

■

Patients will be hypoxic despite maximal O2 therapy and typically have diffuse bilateral pulmonary infiltrates with pulmonary edema on CXR without evidence of volume overload (eg, normal capillary wedge pressure) (see Figure 18-5). Look at the PaO2/FiO2 ratio (ratio of the arterial O2 level on ABG divided by the fraction of inhaled O2 the patient is on). A ratio of < 200 is consistent with ARDS.

TREATMENT ■

■

Patients typically require intubation and mechanical ventilation for the management of hypoxia. Low tidal volumes (6 mL/kg) and associated permissive hypercapnia (ie, letting the PCO2 rise) lead to a ↓↓ risk of barotrauma.

PULMONARY

A

CHAPTER 18

369

B

FIGURE 18-5. Acute respiratory distress syndrome. (A) Frontal CXR showing patchy areas of airspace consolidation in a patient with ARDS. (B) Transaxial CT showing groundglass opacity anteriorly and consolidations dependently in a patient with exudative-phase ARDS. (Reproduced with permission from Fauci AS et al. Harrison’s Principles of Internal Medicine, 17th ed. New York: McGraw-Hill, 2008, Figs. 262-2 and 262-4.)

■

■

Positive end-expiratory pressure (PEEP) is used to improve oxygenation and thus ↓ the FiO2 requirement and associated O2 toxicity. Look for the underlying cause and focus treatment on that as you are stabilizing the patient and treating hypoxia.

KEY FACT Remember—use low tidal volumes and PEEP for the treatment of ARDS.

Solitary Pulmonary Nodule (SPN) A chest CT of a 61-year-old patient with no smoking history reveals a noncalcified 1.7-cm nodule. What is your next step? Compare the CT scan with an old CXR.

Defined as a radiodense lesion seen on chest imaging that is < 3 cm in diameter and is not associated with infiltrates, adenopathy, or atelectasis. Most SPNs are detected on routine CXR in patients who are otherwise asymptomatic. SYMPTOMS/EXAM ■

■

Benign processes include histoplasmosis, coccidioidomycosis, TB, and hamartoma. Characteristics and risk factors include the following: ■ Very fast or no growth on serial imaging two years apart. ■ A diffuse, dense and central, popcorn-like, or concentric “target” calcification pattern. ■ Occurrence in patients who are lifelong nonsmokers, are < 30 years of age, and have no history of malignancy. Malignant lesions include lung cancer or metastases. Risk factors include the following: ■ Size > 2 cm. ■ Spiculation (ie, ragged edges). ■ Upper lobe location. ■ Occurence in patients who are smokers, are > 40 years of age, or have a prior diagnosis of cancer.

KEY FACT The appearance of “popcorn” calcification within an SPN likely represents a benign hamartoma.

KEY FACT Benign characteristics of SPN: ■ “Bull’s-eye” calcification ■ “Popcorn” calcification ■ “Satellite nodule” Malignant characteristics of SPN: ■ “Sunburst” pattern ■ Spiculation

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370

PULMONARY

DIAGNOSIS/TREATMENT ■

■

■

Start by examining old radiographs to determine age and change in size. Lesions with > 1 malignant feature should be further evaluated with CT imaging. If imaging points to a malignancy, biopsy tissue via bronchoscopy, needle aspiration, or VATS. If there is a low probability of malignancy, evaluate with serial CXRs or CTs every three months for one year and then every six months for one year. Surgery is the procedure of choice, particularly thoracoscopy or thoracotomy if the patient is a surgical candidate.

Sarcoidosis A 46-year-old African American woman comes in to your office with chronic dyspnea and a mild cough with clear sputum. Physical exam reveals raised, painful lesions on her legs. Laboratory studies show a serum calcium level of 9.6 mg/dL, and her CXR shows hilar adenopathy. What will

MNEMONIC

confirm the diagnosis of sarcoidosis? An endobronchial biopsy revealing a noncaseating granuloma is confirmatory.

Features of sarcoidosis—

A biopsy specimen of erythema nodosum will not show granulomatous involve-

GRUELING Granulomas Rheumatoid arthritis Uveitis Erythema nodosum Lymphadenitis Interstitial fibrosis Negative PPD Gammaglobulinemia

ment and is not diagnostically helpful.

An idiopathic illness characterized by the formation of noncaseating granulomas in various organs. Most patients have pulmonary involvement. SYMPTOMS/EXAM

Typical features include fever, cough, malaise, weight loss, dyspnea, and arthritis, particularly of the knees and ankles. DIFFERENTIAL

Sarcoidosis is a diagnosis of exclusion, so be sure to rule out other diseases that present similarly, such as TB, lymphoma, fungal infection, idiopathic pulmonary fibrosis, HIV, and berylliosis. DIAGNOSIS ■ ■

■

Look for bilateral hilar lymphadenopathy on CXR and/or infiltrates. PFTs will show a restrictive or mixed restrictive-obstructive pattern. Patients may also have hypercalcemia. Tissue biopsy will show noncaseating granulomas without organisms.

TREATMENT

Therapy includes systemic corticosteroids such as prednisone. Gear other medications toward the control of symptoms such as coughing or wheezing.

PULMONARY

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371

Obstructive Sleep Apnea (OSA) Characterized by recurrent episodes of upper airway collapse during sleep that lead to intermittent hypoxia and recurrent arousals. SYMPTOMS

Patients and their bed partners may complain about snoring. Patients may also have excessive daytime sleepiness, neurocognitive impairment, morning headache, unrefreshing sleep, or impotence. They may report choking or gasping during sleep and may have witnessed apnea episodes at home. EXAM

Patients are typically obese and hypertensive. They may also have a large neck circumference. Look for micrognathia/retrognathia, a large tongue, or large tonsils. Patients with severe OSA may have peripheral edema. DIFFERENTIAL

Rule out other causes of excessive daytime sleepiness, including obesity hypoventilation syndrome, narcolepsy, and restless leg syndrome. DIAGNOSIS

Overnight polysomnography (sleep study) is the gold standard for diagnosis. Severity is measured by the apnea-hypopnea index (AHI), defined as the number of apneas and/or hypopneas per hour of sleep. An AHI of > 5 is diagnostic of OSA. TREATMENT

Encourage weight loss. The most effective treatment is with continuous positive airway pressure (CPAP) to keep the airways open during sleep. Surgery such as uvulopalatopharyngoplasty (UPPP) is effective in 40–50% of cases. COMPLICATIONS

Patients with OSA are at ↑ risk of motor vehicle accidents as well as for the development of hypertension, left ventricular dysfunction, pulmonary hypertension, and insulin resistance.

Bronchiolitis Involves inflammation in smaller airways; occurs most often in infants from two months to one year of age. RSV accounts for the vast majority of cases. Other viral causes include adenovirus, influenza, and parainfluenza. SYMPTOMS

Patients are typically infants. Symptoms begin as those of a URI (sore throat, runny nose) and progress over the next 3–7 days to lower respiratory symptoms (cough, wheezing). EXAM

Patients may have cough, fever, tachypnea, and intercostal retractions. Look for cyanosis, expiratory wheezing, and crackles.

KEY FACT Overnight polysomnography (sleep study) is the gold standard for the diagnosis of obstructive sleep apnea. An AHI of > 5 is diagnostic.

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DIAGNOSIS ■

■

KEY FACT

TREATMENT ■

Intubate infants with ↑ PCO2 levels or ↑ O2 requirements.

Look for hyperinflation of the lungs on CXR with flattening of the diaphragms and mild interstitial infiltrates. RSV may be diagnosed with ELISA or a fluorescent antibody test.

■ ■

Supplemental O2 (oxygen tent). Aerosolized albuterol. In cases of RSV, use ribavirin for patients with severe disease or underlying cardiac or pulmonary problems.

Cystic Fibrosis (CF) An autosomal recessive disorder with mutations located in the CFTR gene, leading to abnormal transfer of sodium and chloride. Multiple exocrine glands and cilia in various organs become dysfunctional. The most common genetic disease in the United States and among Caucasians, affecting 1 in 3200. SYMPTOMS ■

■

A

Patients typically present in childhood or adolescence. Look for patients with recurrent pulmonary infections, sinusitis, bronchiectasis, infertility, or pancreatic insufficiency (diabetes, malabsorption, steatorrhea). Infants may present with meconium ileus or intussusception.

B

Cystic fibrosis. (A) Frontal CXR showing central cystic bronchiectasis (arrow) in a patient with CF. (B) Transaxial CT image showing cystic bronchiectasis (red arrow), with some bronchi containing impacted mucus (yellow arrow). (Reproduced with permission from

FIGURE 18-6. USMLERx.com.)

PULMONARY

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373

EXAM ■ ■

■

Patients may have short stature and nasal polyps. Lung exam often reveals wheezing, crackles, or squeaks. Clubbing may be present. Hyperinflation is seen early, followed by peribronchial cuffing, mucous plugging, and bronchiectasis (see Figure 18-6).

DIAGNOSIS ■

■

Diagnosis is made with a sweat chloride test of > 60 mEq/L (must be confirmed on two different days). Genetic testing can confirm the presence of many of the genetic mutations.

TREATMENT ■

■

■

■

Manage the disease with attention to nutrition, chest physiotherapy, bronchodilators, pancreatic enzymes, mucolytics (DNase), and stool softeners (fiber). Patients need supplemental fat-soluble vitamins (A, D, E, K) to address fat malabsorption. Chronic and chronic intermittent oral antibiotics (azithromycin) or inhaled antibiotics (tobramycin) may also be beneficial. Pseudomonas aeruginosa is common; therapies are tailored to treat the infecting organism. In severe end-stage pulmonary disease, bilateral lung transplantation should be considered, as it is the only definitive treatment.

COMPLICATIONS

Associated with both pseudomonal and staphylococcal infections.

KEY FACT In patients with cystic fibrosis with signs of pulmonary infection, think Pseudomonas and/or Staphylococcus.

374

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NO T E S

CHAPTER 19

HIGH-YIELD CCS CASES How to Use This Section

377

CASE 31

406

Headache

380

CASE 32

408

380

CASE 33

408

CASE 2

380

CASE 34

410

CASE 3

380

CASE 35

410

CASE 4

382

CASE 5

382

CASE 36

412

384

CASE 37

412

384

CASE 38

412

CASE 7

384

CASE 39

414

CASE 8

386

CASE 40

414

CASE 9

386

CASE 41

416

CASE 10

388

CASE 42

416

CASE 11

388

CASE 43

418

390

CASE 44

418

CASE 45

418

CASE 46

420

CASE 47

420

CASE 48

420

CASE 1

Altered Mental Status/Loss of Consciousness CASE 6

CASE 12

Fatigue/Weakness

390

CASE 13

390

CASE 14

392

Abdominal Pain

412

CASE 15

392

CASE 16

392

CASE 49

422

CASE 17

394

CASE 50

422

CASE 51

424

CASE 52

424

Cough/Shortness of Breath

394

CASE 18

394

CASE 19

394

CASE 20

396

CASE 53

426

CASE 21

396

CASE 54

426

CASE 22

398

CASE 55

426

CASE 23

398

CASE 56

428

CASE 24

400

CASE 57

428

CASE 25

400

CASE 58

428

CASE 26

402

CASE 59

430

CASE 27

402

Chest Pain CASE 28

Constipation/Diarrhea

Gl Bleeding

426

430

404

CASE 60

430

404

CASE 61

432

CASE 29

404

CASE 62

432

CASE 30

406

CASE 63

434

375

Hematuria

434

CASE 82

448

CASE 64

434

CASE 83

450

CASE 65

434

CASE 84

450

CASE 66

436

CASE 85

452

436

CASE 86

452

Other Urinary Symptoms

Child with Fever

454

CASE 67

436

CASE 68

436

CASE 87

454

CASE 69

438

CASE 88

454

CASE 70

438

CASE 89

456

Amenorrhea

440

CASE 90

456

CASE 71

440

CASE 72

440

CASE 91

458

CASE 73

442

CASE 92

458

442

CASE 93

460

CASE 94

460

Vaginal Bleeding

Fever

458

CASE 74

442

CASE 75

444

CASE 76

444

CASE 95

462

CASE 77

444

CASE 96

462

446

CASE 97

462

CASE 98

464

CASE 99

464

CASE 100

464

Musculoskeletal Pain CASE 78

446

CASE 79

446

CASE 80

448

CASE 81

448

376

Outpatient Potpourri

462

HIGH-YIELD CCS CASES

How to Use This Section In this section are 100 minicases reflecting the types of clinical situations encountered on the actual CCS. Each case consists of columns that start on the left-hand page and end on the right-hand page with the Final Diagnosis. As you read each column, ask yourself what you should do and/or think next (see Table 19-1). If no results are given for a test, assume that is normal. To get the most out of these minicases, we strongly recommend that you do at least a few of the CCS cases on the USMLE CD-ROM (or from the USMLE Web site) to get a feel for the case flow and key decision points. This will allow you to place the minicases in context. Happy studying!

CHAPTER 19

377

CHAPTER 19

378

TA B L E 19 - 1 .

HIGH-YIELD CCS CASES

Approaching the CCS Minicases

WHEN READING . . . History

ASK YOURSELF . . . What should I be looking for on VS and PE? Do I need to stabilize the patient or perform an emergency procedure before conducting a PE?

Physical exam

What are the most likely diagnoses that explain the patient’s presentation?

Differential

What are the initial diagnostic tests and treatment that should be done? Does the patient need to be transferred to another location (eg, from the ER to the ICU)? Does the clock need to be advanced?

Initial management

What additional workup and management should occur? Can the patient be discharged or transferred to another setting?

Continuing management

What should be done in follow-up, including long-term disease management, health maintenance, and patient counseling? Should any treatment or monitoring be stopped?

Follow-up

What is the final diagnosis?

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H E A D A CH E

CASE 1 HX 21 yo F presents with a severe headache. She has a history of throbbing left temporal

PE VS: T 37°C (99.2°F), P 70, BP 120/80, RR 15, O2 sat 100% room air

DDX ■

Cluster headache

■

Intracranial neoplasm

pain that lasts for 2–3 hours. Before these

Gen: NAD

■

Migraine (complicated)

episodes start, she sees flashes of light in

Lungs: WNL

■

Partial seizure

her right visual field and feels weakness and

CV: WNL

■

Pseudotumor cerebri

numbness on the right side of her body for

Abd: WNL

■

Tension headache

a few minutes. The headaches are often

Ext: WNL

■

Trigeminal neuralgia

associated with nausea and vomiting. She

Neuro: WNL

has a family history of migraine.

CASE 2 HX

PE

DDX

29 yo F presents with daily episodes of

VS: Afebrile, P 70, BP 120/80, RR 15

■

Cluster headache

bilateral bandlike throbbing pain in her

Gen: NAD

■

Intracranial neoplasm

frontal-occipital region that last between

Lungs: WNL

■

Meningitis

30 minutes and a few hours. She usually

CV: WNL

■

Migraine headache

experiences these episodes when she is

Abd: WNL

■

Pseudotumor cerebri

either tired or under stress. She denies any

Ext: WNL

■

Sinusitis

associated nausea, vomiting, phonophobia,

Neuro: WNL

■

Tension headache

photophobia, or aura. She also feels pain and stiffness in her neck and shoulder.

CASE 3 HX 65 yo F presents with a severe intermittent headache in the right temporal lobe together

PE VS: T 37°C (99°F), P 85, BP 140/85, RR 18, O2 sat 100% room air

DDX ■

Cluster headache

■

Glaucoma Intracranial neoplasm

with blurred vision in her right eye and pain

Gen: NAD

■

in her jaw during mastication.

HEENT: Tenderness on temporal artery

■

Meningitis

■

Migraine

Neck: No rigidity

■

Temporal arteritis (giant cell arteritis)

Lungs: WNL

■

Tension headache

CV: WNL

■

Trigeminal neuralgia

palpation

Abd: WNL Ext: WNL Neuro: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

381

F/U

Emergency room W/U

■

Follow up in one month

■

Prophylactic therapy if the migraine

■

CT–head

■

CBC

recurs—eg, β-blockers, antidepressants

■

Chem 8

(SSRIs, TCAs), anticonvulsants (valproic

■

ESR

acid, gabapentin), calcium channel blockers

Rx ■

IV normal saline

■

IV promethazine, prochlorperazine, or

■

ASA, NSAIDs, or acetaminophen

metoclopramide

■

Caffeine

■

IM sumatriptan (if the patient does not improve) Final Dx: Migraine (complicated)

INITIAL MGMT

CONTINUING MGMT

F/U

Office W/U ■

CBC with differential

■

Chem 8

■

ESR

■

Follow up in one month

■

Relaxation exercises

Rx ■

Cold compresses

■

Acetaminophen

■

NSAIDs

Final Dx: Tension headache

INITIAL MGMT Emergency room STAT

CONTINUING MGMT

F/U

Ward W/U

■

IV normal saline

■

Ophthalmology consult

■

Prednisone

■

Temporal artery biopsy: ⊕ for temporal

Emergency room W/U

■

Discharge home

■

Continue low-dose maintenance prednisone

arteritis

■

ESR in two weeks

■

ESR every morning

■

Adequate dietary calcium and vitamin D if

Screen for polymyalgia rheumatica

■

CBC

■

Chem 8

■

■

CT—head: 䊞

Rx

■

CXR: 䊞

■

■

ESR: ↑↑

■

CRP: ↑↑

steroids are to be used chronically

Continue prednisone until ESR normalizes; then taper

Final Dx: Temporal arteritis (giant cell arteritis)

382

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 4 HX 25 yo M presents with a high fever, severe headache, and photophobia.

PE VS: T 39°C (103°F), P 95, BP 150/85, RR 18,

DDX ■

Encephalitis

■

Intracranial or epidural abscess

Gen: Moderate distress

■

Meningitis

Neck: Nuchal rigidity

■

Migraine

Lungs: WNL

■

Sinusitis

CV: WNL

■

Subarachnoid hemorrhage

O2 sat 100% room air

Abd: WNL Ext: WNL Neuro: ⊕ Kernig’s and Brudzinski’s signs

CASE 5 HX 60 yo M with a past medical history of hypertension presents with severe headache,

PE VS: T 37°C (99.3°F), P 100, BP 220/120, RR 20, O2 sat 95% room air

DDX ■

Cluster headache

■

Intracranial hemorrhage Intracranial neoplasm

nausea, and vomiting. The patient states that

Gen: Severe distress

■

he stopped taking his metoprolol because

HEENT: Funduscopy reveals papilledema

■

Malignant hypertension

he thought that he did not need it anymore.

Lungs: WNL

■

Migraine

CV: WNL

■

Partial seizure

Abd: WNL Ext: WNL Neuro: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

F/U ■

Improved within 48 hours

■

IV normal saline

■

CSF culture: ⊕ for S pneumoniae

■

Discharge home

■

Blood culture

■

Blood culture: 䊞

■

Follow up in one month

■

CT—head

Rx

■

Ceftriaxone and vancomycin

■

■

LP-CSF: ↑ WBCs, ↑ protein, ↓ CSF/blood

383

Continue ceftriaxone + vancomycin + steroids

glucose ratio, gram-⊕ cocci, ↑ opening pressure ■

IV dexamethasone

Emergency room W/U ■

CBC: ↑ WBC count

■

Chem 8

■

CT—head: 䊞

■

CXR: 䊞

Rx ■

Acetaminophen Final Dx: Bacterial meningitis

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

F/U ■

Transfer to the floor

■

O2

■

Continuous cardiac monitoring

■

Counsel patient re medication compliance

■

IV labetalol

■

Lipid profile

■

Discharge home

■

BP in both arms

■

Echocardiography: EF < 45%

■

Follow up in one week

■

CT—head: White matter changes

Rx

consistent with hypertension

■

■

ECG: LVH

■

CXR

Emergency room W/U ■

Cardiac/BP monitoring

■

CPK-MB, troponin × 3: 䊞

■

CBC

■

Chem 8

■

UA

Labetalol or metoprolol if good control previously

■

ACEIs (low EF)

■

HCTZ

Final Dx: Hypertensive emergency

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CHAPTER 19

HIGH-YIELD CCS CASES

A L T E RE D M EN T AL S TA TU S / LO S S OF CONS C I OU S NE S S

CASE 6 HX

PE

DDX

84 yo F brought in by her son complains of

VS: P 90, BP 120/60, RR 12

■

Alzheimer’s disease

forgetfulness (eg, forgets phone numbers,

Gen: NAD

■

B12 deficiency

loses her way home) along with difficulty

Lungs: WNL

■

Chronic subdural hematoma

performing some of her daily activities

CV: WNL

■

Depression

(eg, bathing, dressing, managing money,

Abd: WNL

■

Hypothyroidism

answering the phone). The problem has

Ext: WNL

■

Intracranial tumor

gradually progressed over the past few years.

Neuro: On mini-mental status exam, patient

■

Neurosyphilis

cannot recall objects, follow three-step

■

Pressure hydrocephalus

commands, or spell “world” backward;

■

Vascular dementia

cranial nerves intact; strength and sensation intact

CASE 7 HX

PE

DDX

79 yo M is brought in by his family

VS: P 92, BP 144/86, RR 14

■

Alzheimer’s disease

complaining of a seven-week history of

Gen: NAD

■

B12 deficiency

difficulty walking accompanied by memory

Lungs: WNL

■

Chronic subdural hematoma

loss and urinary incontinence. Since then he

CV: WNL

■

Frontal lobe syndromes

has had ↑ difficulty with memory and more

Abd: WNL

■

Huntington’s disease

frequent episodes of incontinence.

Ext: WNL

■

Intracranial tumor

Neuro: Difficulty with both recent and

■

Meningitis

immediate recall on mini-mental status

■

Normal pressure hydrocephalus

exam; spasticity and hyperreflexia in upper

■

Parkinson’s disease

and lower extremities; problem initiating

■

Vascular dementia

gait (gait is shuffling, broad-based, and slow)

HIGH-YIELD CCS CASES

INITIAL MGMT

CHAPTER 19

CONTINUING MGMT

Office W/U

F/U ■

Patient counseling

■

CBC

■

Support group

■

Chem 14

■

Advance directives

■

TSH

■

Family counseling

■

Serum B12

■

Serum folic acid

■

VDRL/RPR

■

CT—head

385

Rx ■

Donepezil

Final Dx: Alzheimer’s disease

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Advance directives

■

CBC

■

Neurosurgery consult

■

Family counseling

■

Chem 8

■

Neurology consult

■

Supportive care

■

LFTs

■

Ventriculoperitoneal shunt

■

TSH

■

CT—head: Enlarged lateral ventricles with no prominence of cortical sulci

■

LP

■

Serum B12

■

Serum folic acid

Final Dx: Normal pressure hydrocephalus

CHAPTER 19

386

HIGH-YIELD CCS CASES

CASE 8 HX

PE

The on-call physician is called to see a 46 yo

VS: T 37°C (99°F), P 133, BP 146/89, RR 22,

M patient because of seizures. The patient was admitted to the surgical ward two days ago, after emergency trauma surgery. The

O2 sat 92% room air Gen: Sweating; cigarette burns on hands; multiple tattoos and rings

nurse reports that the patient was anxious,

Chest: WNL

agitated, irritable, and tachycardic last night.

Abd: Hepatomegaly

Later on, the nurse noted nausea, diarrhea,

Ext: Evidence of recent surgery

sweating, and insomnia. The patient had

Neuro: Tremor, confusion, delirium, clouded

tremors, startle response, and hallucinations

sensorium, and evidence of peripheral

earlier tonight.

neuropathy

DDX ■

Alcohol withdrawal

■

Amphetamine psychosis

■

Delirium

■

Sedative withdrawal

■

SLE

CASE 9 HX

PE

DDX

24 yo M is brought to the ER in a drowsy

VS: T 37°C (98.2°F), P 90, BP 120/80, RR 12

■

Alcohol withdrawal

state. His wife reports that he was working

Gen: NAD

■

Cardioembolic stroke

at home when he suddenly stiffened, fell

Lungs: WNL

■

Frontal lobe epilepsy

backward, and lost consciousness. While he

CV: WNL

■

Migraine headache

was lying on the ground, he was noted to

Abd: WNL

■

Psychiatric conditions

have no respiration for about one minute,

Ext: WNL

■

Seizures

followed by jerking of all four limbs for

Neuro: In a state of confusion and lethargy

■

Syncope

but oriented; no focal neurologic deficits

■

Vascular conditions

about five minutes. He was unconscious for another five minutes.

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Ward W/U

CONTINUING MGMT Ward W/U

■

Follow up in four weeks

■

Patient counseling

hypomagnesemia

■

Smoking cessation

CBC: MCV 110 fL

■

Chem 8: Hypokalemia, hypomagnesemia

■

Urine toxicology: WNL

Rx

■

LFTs: GGT 40 U/L

■

■

CT—head: Cerebral atrophy, no subdural hematoma

Rx ■

Thiamine before IV D5W NS

■

Pyridoxine

■

Folic acid

■

IV diazepam

■

Atenolol

■

Replete K and Mg

■

F/U

Chem 8: Corrected hypokalemia,

■

387

■

Dietary supplements

IV normal saline

■

Addiction unit consult

■

IV diazepam

■

Social work consult

■

Atenolol

■

Naltrexone (for maintenance therapy if indicated)

Final Dx: Alcohol withdrawal

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Follow up in 3–4 weeks

■

CBC

■

Continue IV

■

Patient counseling

■

Chem 8

■

O2

■

Family counseling

■

LFTs

Rx

■

Advise patient to use seat belts

■

ABG

■

■

Advise patient not to drive

■

Serum calcium, magnesium, phosphate

■

ECG

■

EEG

■

CT—head

■

MRI—brain

■

UA

■

Urine toxicology

Neurology consult

Final Dx: Grand mal seizure (complex tonic-clonic seizure)

388

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 10 HX

PE

DDX

72 yo M is brought to the ER complaining

VS: T 37°C (98.1°F), P 35, BP 114/54, RR 15

■

Aortic stenosis

of syncope. He underwent a coronary artery

Gen: NAD

■

Asystole

bypass graft (CABG) three years ago. He

Lungs: WNL

■

Dilated cardiomyopathy

reports fatigue and dizziness over the past

CV: Irregular S1 and S2, bradycardia

■

Heart block

five days. The patient’s fall was broken by his

Abd: WNL

■

MI

wife, and as a result he has no head trauma.

Ext: WNL

■

Myocarditis

His wife reports loss of consciousness of

Neuro: Alert and oriented; CN II–XII intact;

■

Myopathies

■

Restrictive cardiomyopathy

■

Vasodepressor/vasovagal response

about three minutes’ duration. Prior to

5/5 motor strength in all extremities

the syncopal episode, the patient recalls a prodrome of lightheadedness. His medications include propranolol, digoxin, and diltiazem.

CASE 11 HX 25 yo F with no significant past medical history is brought to the ER after having

PE VS: T 38°C (99.8°F), P 50, BP 110/50, RR 9, O2 sat 92% room air

been found unresponsive with an empty

Gen: Drowsy

bottle lying next to her.

HEENT: Pinpoint pupils Lungs: WNL CV: Bradycardia Abd: WNL Ext: WNL Neuro: Opens eyes to painful stimuli Limited PE with ABCs

DDX ■

Acetaminophen overdose

■

Narcotic overdose

■

TCA overdose

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT ICU W/U

F/U ■

Cardiac rehabilitation program

■

IV normal saline

■

Continuous cardiac monitoring

■

Smoking cessation

■

CBC

■

ECG

■

Counsel patient to limit alcohol intake

■

Chem 8

■

Lipid profile

■

Counsel patient not to drive

■

LFTs

■

Echocardiography

■

Low-fat, low-sodium diet

■

ECG: Third-degree AV block

Rx

■

Cardiac enzymes

■

Lipid-lowering agents

■

Serum troponin I

■

Cardiology consult

■

Serum calcium, magnesium, phosphate

■

Cardiac catheterization, angiocardiography

■

CXR

■

Permanent cardiac pacemaker

■

UA

■

O2

■

Continuous cardiac monitoring

389

Rx ■

Temporary transvenous cardiac pacemaker

■

Withhold AV nodal agents Final Dx: Complete heart block

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

■

Suction airway

■

Gastric lavage: Pill fragments

■

Fingerstick blood sugar

■

Continuous monitoring: Patient started to

■

IV normal saline

■

IV naloxone: Patient responded

Rx

■

Dextrose 50%

■

IV naloxone: Patient responded

■

IV thiamine

■

Psychiatry consult

■

ABG

■

Suicide precautions

F/U ■

Monitor for at least 24 hours

become drowsy again (monitor events)

Emergency room W/U ■

CBC

■

ECG

■

Urine pregnancy

■

Urine toxicology

■

UA

■

Serum acetaminophen, salicylate

■

INR

■

Serum lactate

■

CXR, PA Final Dx: Narcotic overdose

CHAPTER 19

390

HIGH-YIELD CCS CASES

CASE 12 HX 60 yo M was found unconscious by his wife, who called the paramedics. She left him

PE VS: T 38°C (101°F), P 110, BP 95/45, RR 35, O2 sat 89% on 100% face mask

in bed at 7 A.M. to go to her volunteer job.

Gen: Acute distress; shallow, rapid breathing

When she returned for lunch at 1 P.M., she

HEENT: Dilated pupils

found an empty bottle of amitriptyline next

Lungs: WNL

to him. When paramedics arrived, he was

CV: Tachycardia

noted to be in respiratory distress and was

Abd: WNL

transferred to the ER.

Neuro: Opens eyes to painful stimuli

DDX ■

Anticholinergic toxicity

■

TCA intoxication

Limited PE

FA T I G UE/ W E AK N E S S

CASE 13 HX 68 yo M presents following a 20-minute episode of slurred speech, right facial

PE VS: T 37°C (98°F), P 75, BP 150/90, RR 16, O2 sat 100% room air

DDX ■

Intracranial tumor

■

Seizure

drooping and numbness, and weakness of

Gen: NAD

■

Stroke

the right hand. His symptoms had totally

Neck: Right carotid bruit

■

Subdural or epidural hematoma

resolved by the time he got to the ER. He

Lungs: WNL

■

TIA

has a history of hypertension, diabetes

CV: WNL

mellitus, and heavy smoking.

Abd: WNL Ext: WNL Neuro: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT ■

Intubate

CONTINUING MGMT

F/U

ICU W/U ■

Emergency room W/U

391

■

Psychiatry consult

Continuous monitoring of urine output q 1 h

■

Cardiac/BP monitoring

■

Continuous BP monitoring

■

Chem 14

■

Continuous cardiac monitoring

■

CBC

■

Neuro check

■

ABG

Rx

■

Serum lactate

■

■

Serum osmolality

■

■

Blood ketones

■

Urine toxicology: ⊕ for TCAs

■

ECG: Widened QRS

■

Serum magnesium

■

CXR, PA

■

Cardiac enzymes

■

CT—head

Cardiology consult Lidocaine for TCA-induced ventricular arrhythmias

■

IV magnesium sulfate, one time

Rx ■

IV D5W 0.9 NS

■

Thiamine

■

Central line placement

■

NG tube gastric lavage

■

Activated charcoal

■

IV bicarbonate Final Dx: Tricyclic antidepressant (TCA) intoxication

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

F/U ■

Counsel patient re smoking cessation,

■

Assess ABCs

■

Repeat neurologic exam

■

O2

■

Continuous cardiac monitoring

■

Treat hypertension

■

Blood glucose

■

BP monitoring

■

Treat diabetes

■

IV normal saline

■

Telemetry

■

Diabetic diet

■

CT—head

■

Lipid profile, HbAlc

■

Diabetic teaching

■

Echocardiography: EF 60%

■

Treat cholesterol

■

Carotid duplex: > 75% stenosis in right

■

Low-fat, low-sodium diet

Emergency room W/U ■

Continuous cardiac monitoring

■

BP monitoring

■

ECG

Rx

■

CBC

■

■

Chem 8

■

■

CXR

■

PT/PTT, INR

■

Neurology consult

exercise

carotid artery Vascular surgery consult Patient is scheduled for elective carotid endarterectomy ■

ASA

Rx ■

ASA Final Dx: Transient ischemic attack (TIA)

392

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 14 HX 40 yo F presents with numbness, lower extremity weakness, and difficulty walking.

PE VS: Afebrile, P I15, BP 130/80 with orthostatic changes, RR 16

DDX ■

Conversion disorder

■

Guillain-Barré syndrome Myasthenia gravis

She reports having had a URI approximately

Gen: NAD

■

two weeks ago. She says that her weakness

Lungs: WNL

■

Paraneoplastic neuropathy

started from her lower limbs to her hip and

CV: WNL

■

Poliomyelitis

then progressed to her upper limbs. She also

Ext: WNL

■

Polymyositis

complains of lightheadedness on standing

Neuro: Loss of motor strength in lower

and shortness of breath.

limbs; absent DTRs in patella and Achilles tendon; sensation intact

CASE 15 HX

PE

DDX

40 yo F presents with fatigue, weight gain,

VS: T 36°C (97°F), BP 100/60, HR 60

■

Anemia

sleepiness, cold intolerance, constipation,

Gen: Obese

■

Depression

and dry skin.

Skin: Dry

■

Diabetes

HEENT: Scar on neck from previous

■

Hypothyroidism

thyroidectomy Lungs: WNL CV: WNL Neuro: Delayed relaxation of DTRs

CASE 16 HX

PE

DDX

16 yo M complains of myalgia, fatigue, and

VS: T 38°C (101°F), P 85, BP 125/80, RR 18

■

CMV

sore throat. He also reports loss of appetite

Gen: Maculopapular rash

■

Hepatitis

and nausea but no vomiting. He reports that

HEENT: Posterior and auricular

■

Infectious mononucleosis

his girlfriend recently had similar symptoms

lymphadenopathy and pharyngitis with

■

1° HIV infection

that lasted a few weeks.

diffuse exudates and petechiae at junction

■

Streptococcal pharyngitis

of hard and soft palates

■

Toxoplasmosis

Lungs: WNL CV: WNL Abd: Soft, nontender; mild hepatosplenomegaly Ext: WNL Neuro: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward Rx

F/U ■

Follow up in 3–4 weeks

■

CBC

■

Immunoglobulins

■

Patient counseling

■

Chem 8

■

Plasmapheresis

■

Family counseling

■

TSH

■

Rehabilitative medicine consult

■

Advise patient to use seat belts

■

ESR

■

Neurology consult

■

CRP

■

Immunology consult

■

RF

■

Spirometry

■

VDRL

■

Serum B12

■

Serum folic acid

■

ECG

■

Serum CPK

■

CXR

■

LP: ↑ CSF protein

■

HIV testing, ELISA

393

Final Dx: Guillain-Barré syndrome

INITIAL MGMT

CONTINUING MGMT

Office W/U

F/U ■

■

CBC

■

Chem 14

■

TSH: ↑

■

FT4: ↓

■

ECG

■

Lipid profile

■

Depression index

Check TSH after one month

Rx ■

Thyroxine Final Dx: Hypothyroidism

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U ■

Follow up in two weeks with CBC

■

CBC: ↑ WBC count

■

Advise patient to rest at home

■

Peripheral smear: Atypical lymphocytes

■

Advise patient to avoid sports

■

Chem 14: ↑ SGOT and SGPT

■

ESR

■

CRP

■

Mono test: ⊕

■

Serum EBV titer: ↑, rapid strep

Rx ■

Acetaminophen or NSAIDs

■

Hydrate; patient counseling

Final Dx: Infectious mononucleosis

394

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 17 HX

PE

DDX

40 yo F complains of feeling tired, hopeless,

VS: P 70, BP 120/60, RR 12

■

Adjustment disorder

and worthless. She also reports depressed

Gen: NAD

■

Anemia

mood, inability to sleep, and impaired

Lungs: WNL

■

Anxiety

concentration. She has been missing work.

CV: WNL

■

Cancer

She denies any suicidal thoughts or attempts

Abd: WNL

■

Chronic fatigue syndrome

and denies having hallucinations. She has no

Ext: WNL

■

Dementia

history of alcohol or drug abuse and has not

Neuro: WNL

■

Depression

lost a loved one within the last 12 months.

■

Fibromyalgia

She is married and has one child and a

■

Hypothyroidism

supportive husband.

C O UG H /S H O R T N E S S O F B R E AT H

CASE 18 HX 2 yo M is brought in by his mother because of sudden-onset shortness of breath and cough. He had a URI four days ago. Earlier in the day he was playing with peanuts with his brother. His immunizations are up to date.

PE VS: T 37°C (98°F), P 110, BP 80/50, RR 38, O2 sat 99% room air Gen: Respiratory distress; using accessory

DDX ■

Angioedema

■

Asthma

■

Croup

muscles

■

Epiglottitis

HEENT: WNL

■

Foreign-body aspiration

Neck: WNL

■

Laryngitis

Lungs: Inspiratory stridor; ↓ breath sounds in

■

Peritonsillar abscess

■

Pneumonia

■

Retropharyngeal abscess

right lower base CV: Tachycardia Abd: WNL

CASE 19 HX

PE

DDX

75 yo F presents with chest pain and

VS: Afebrile, BP 120/75, HR 100, RR 24

■

CHF

shortness of breath. She reports having

Gen: Respiratory distress

■

Lung cancer

fallen five days ago and has a long cast for

HEENT: WNL

■

MI

her femoral fracture.

Lungs: Rales, wheezing, ↓ breath sounds in

■

Pericarditis

left lower lung

■

Pneumothorax

CV: Loud P2 and splitting of S2

■

Pulmonary embolism

Abd: WNL

■

Syncope

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Office W/U

395

F/U ■

Follow up in one week

■

CBC

■

Supportive psychotherapy

■

Chem 14

■

Exercise program

■

TSH

■

Patient counseling

■

Urine/serum toxicology

Rx ■

Suicide contract

■

SSRI (eg, sertraline) or

■

SNRI (eg, mirtazapine)

■

Psychiatry consult Final Dx: Major depression

INITIAL MGMT

CONTINUING MGMT

Emergency room STAT ■

F/U ■

Follow up in two weeks

CXR, PA and lateral

■

XR—neck

■

Bronchoscopy: Foreign body is removed and patient improves

Rx ■

Consider IV methylprednisolone before removal of the foreign body

Final Dx: Foreign-body aspiration

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Follow up in two weeks with PT/INR

■

IV normal saline

■

Continuous cardiac and BP monitoring

■

Chest physical therapy

■

NPO

■

Pulmonary medicine consult

■

Warfarin

■

CBC

■

PT/PTT, INR

■

Rehabilitative medicine consult

■

Chem 14

Rx

■

ABG: Hypoxia and hypocapnia

■

■

CXR: Left lower lobe atelectasis, Hampton’s humps

■

Discontinue heparin two days after INR is therapeutic

■

Warfarin

CT—chest: Pulmonary embolism

■

ECG

■

DVT U/S: Venous DVT

■

Heparin IV and warfarin Final Dx: Pulmonary embolism

396

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 20 HX 5 yo M is brought to the ER with a harsh barking cough. He has a history of URIs with coryza, nasal congestion, and sore throat. His symptoms have been present for about a week.

PE VS: T 38°C (101°F), BP 110/65, HR 100,

DDX ■

Bacterial tracheitis

■

Croup

■

Diphtheria

■

Epiglottitis

HEENT: WNL

■

Measles

Lungs: Stridor, hoarseness, barking cough

■

Peritonsillar abscess

CV: WNL

■

Retropharyngeal abscess

RR 22 Gen: Pallor and mild respiratory distress with intercostal retraction and nasal flaring

Abd: WNL

CASE 21 HX

PE

DDX

75 yo M presents with shortness of breath

VS: Afebrile, BP 130/85, HR 90, RR 15

■

Lung cancer

on exertion along with cough and blood-

Gen: WNL

■

Lymphoma

streaked sputum. He reports progressive

Chest: Barrel-shaped chest, gynecomastia

■

Sarcoidosis

malaise and weight loss together with loss

Lungs: Rales, wheezing, ↓ breath sounds,

■

Tuberculosis

of appetite over the past six months. He smokes 40 packs of cigarettes per year.

dullness on percussion in left upper lung CV: WNL Abd: Mild tenderness in RUQ with mild hepatomegaly Ext: Finger clubbing; dark-colored, pruritic rash on both forearms

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward Rx

■

O2

■

Humidified air

■

CBC

■

Epinephrine

■

Chem 8

■

Dexamethasone

■

Throat culture

■

XR—neck: Subglottic narrowing

397

F/U ■

Follow up in one month

■

Family counseling

Final Dx: Croup

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

F/U ■

Smoking cessation

■

CBC: ↓ hemoglobin

■

PFTs

■

Patient counseling

■

Chem 8

■

Oncology consult

■

Family counseling

■

LFTs: ↑ transaminase

■

Surgery consult

■

■

ABG

■

Dietary consult

■

ESR: ↑

■

Bronchoscopy with biopsy

■

CXR: Infiltrate and nodules in upper left

■

CT—abdomen and pelvis

lobe

■

CT—head

■

Sputum cytology: Adenocarcinoma

■

Antiemetic medication

■

Sputum culture

■

PPD: 䊞

■

CT—chest: Left upper lobe mass

Follow up in 3–4 weeks with CXR and CBC

■

Counsel patient to limit alcohol intake

Final Dx: Lung cancer

398

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 22 HX 60 yo M presents with ↑ dyspnea, sputum

PE VS: T 38°C (100.6°F), P 90, BP 130/70,

DDX ■

Bronchitis

production, and a change in the color of his

RR 28, O2 sat 92% on 2-L NC

■

CHF

sputum to yellow over the past three days.

Gen: Moderate respiratory distress

■

COPD exacerbation

He is a smoker with a history of COPD.

Lungs: Rhonchi at left lower base; diffuse

■

Lung cancer

■

Pneumonia

■

URI

wheezing CV: WNL Abd: WNL Ext: WNL

CASE 23 HX

PE

DDX

50 yo Mexican immigrant M presents

VS: T 38°C (100°F), BP 130/85, HR 90, RR 22

■

Bronchiectasis

with cough productive of bloody sputum

Gen: Pallor

■

Fungal lung infection

accompanied by night sweats, weight loss,

Lungs: ↓ breath sounds in upper lobes of

■

Lung cancer

■

Lymphoma

CV: WNL

■

Sarcoidosis

Abd: WNL

■

TB

■

Vasculitis

and fatigue of three months’ duration.

both lungs

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

399

F/U ■

Taper prednisone over the next two weeks

■

O2

■

Peak flow: 300 L/min

■

Smoking cessation

■

IV normal saline

■

FEV1: 2 L

■

■

IV steroids

■

■

Albuterol by nebulizer

■

Ipratropium by nebulizer

■

■

Sputum culture

Rx

■

Blood culture

■

Change to PO levofloxacin

■

Change to PO prednisone

Emergency room W/U ■

CBC: ↑ WBC count

■

CXR: Left lower lobe infiltrate

■

ECG

■

ABG

■

Peak flow: < 200 L/min

■

Sputum Gram stain: Gram-⊕ cocci

■

Chem 8

Sputum culture: ⊕ for S pneumoniae

Consider pneumococcal vaccine and flu shot

sensitive to levofloxacin Blood culture: 䊞

Rx ■

Third-generation cephalosporin + azithromycin vs. levofloxacin or gatifloxacin IV Final Dx: Chronic obstructive pulmonary disease (COPD) exacerbation/pneumonia

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

CXR: Infiltrate/nodules in upper lobes

■

■

AFB sputum/culture × 3 days: ⊕ stain

Rx

■

Sputum Gram stain and culture

■

■

PPD: 16 mm

■

CBC

■

Chem 14

■

HIV testing

■

CT—chest: Infiltrates and cavity consistent

■

F/U ■

Social worker consult

Sputum culture and smear at three months

■

LFTs

INH + rifampin + pyrazinamide +

■

Ophthalmology consult

ethambutol

■

Family education

Vitamin B6

■

Family PPD placement

■

Report case to the local public health department

with TB Rx ■

Respiratory isolation

■

Transfer to the ward Final Dx: Tuberculosis (TB)

400

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 24 HX 55 yo M presents with cough that is exacerbated when he lies down at night

PE VS: P 70, BP 120/70, RR 28, O2 sat 86% room air

DDX ■

CHF

■

COPD exacerbation MI

and improves when he props his head up

Gen: Moderate respiratory distress

■

on three pillows. He also reports worsening

Neck: JVD

■

Pericardial tamponade

exertional dyspnea for the past two months

Lungs: Bibasilar crackles

■

Pulmonary embolism

(he now has dyspnea at rest). He has had a

CV: S1/S2/S3 RRR, 3/6 systolic murmur at

■

Pulmonary fibrosis

■

Renal failure

25-pound weight gain since his symptoms

apex

began. His past medical history is significant

Abd: WNL

for hypertension, an MI five years ago,

Ext: +2 bilateral pitting edema

hyperlipidemia, and smoking.

CASE 25 HX 5 yo F presents with shortness of breath. She has a history of recurrent pulmonary infection and fatty, foul-smelling stool. She has also shown failure to thrive and has a history of meconium ileus.

PE VS: T 38°C (101°F), BP 110/65, HR 110, RR 24 Gen: Pallor, mild respiratory distress, low weight and height for age, dry skin HEENT: Nasal polyps Lungs: Barrel-shaped chest, rales, dullness and ↓ breath sounds over lower lung fields CV: WNL Abd: Abdominal distention, hepatosplenomegaly

DDX ■

Asthma

■

Cystic fibrosis

■

Failure to thrive

■

Malabsorption syndrome

■

Sinusitis

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT

F/U

Ward W/U

■

O2

■

■

IV

■

Lipid profile

■

IV furosemide

■

Echocardiography: Hypokinesia in anterior

■

CXR: Pulmonary edema

■

ECG: Old Q wave in anterior leads

Emergency room W/U

■

401

TSH

■

Cardiac rehabilitation

■

Counsel patient re smoking cessation, hypertension, exercise, relaxation, and lipids

wall; EF 20%

■

Chem 8: K 3.7

■

Rx

Follow up in one week Refer to cardiology; with ischemic cardiomyopathy and EF < 30%,

■

Cardiac/BP monitoring

■

Fluid restriction

patients may benefit from an automatic

■

CPK-MB, troponin q 8 h

■

Lisinopril

implantable cardiac defibrillator (AICD)

■

CBC

■

Atorvastatin

■

Chem 8: K 3.4

■

ASA

■

Serum calcium, magnesium, phosphate

■

Digoxin

■

Spironolactone

Rx ■

IV KCl

■

Change IV furosemide

■

Daily weight

■

Restart β-blockers (when euvolemic)

■

Discontinue any β-blockers

■

SQ heparin

■

Low-fat, low-sodium diet Final Dx: Congestive heart failure (CHF) exacerbation

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Follow up in two months

■

CBC: ↓ hemoglobin

■

PFTs

■

Chest physical therapy

■

Chem 8: ↑ sugar, ↓ albumin

■

Sweat chloride test: ⊕

■

Regular multiple vitamins

■

ABG: Hypoxia

■

Pancreatic enzymes

■

Influenza vaccine

■

CXR: Hyperinflation

■

24-hour fecal fat

■

Pneumococcal vaccine

■

Sputum Gram stain and culture

■

Dietary consult

■

Family counseling

■

O2

■

Genetics consult

■

Cystic fibrosis specialist

■

Pulmonary medicine, pediatrics consults

Rx ■

IV normal saline

■

O2

■

IV piperacillin

■

Albuterol, inhalation Final Dx: Cystic fibrosis (CF)

402

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 26 HX 65 yo F with a history of hypertension and diabetes mellitus presents with LUQ pain

PE VS: T 38°C (101°F), P 105, BP 130/75, RR 22, O2 sat 95% room air

DDX ■

Bronchitis

■

Infectious mononucleosis Lung abscess

accompanied by fever and a productive

Gen: NAD

■

cough with purulent yellow sputum.

Neck: WNL

■

Lung cancer

Lungs: ↓ breath sounds and rhonchi on left

■

Pneumonia

■

Pyelonephritis

■

Spleen abscess

side CV: Tachycardia Abd: Tenderness in LUQ

CASE 27 HX 25 yo HIV-⊕ M presents with shortness of breath, malaise, dry cough, fatigue, and fever.

PE VS: T 38°C (101°F), BP 110/65, HR 110,

DDX ■

CMV

■

Interstitial pneumonia

■

Kaposi’s sarcoma

■

Legionellosis

HEENT: Oral thrush

■

Mycobacterium avium–intracellulare

Lungs: Intercostal reaction; rales and ↓

■

Pneumocystis jiroveci pneumonia

■

TB

RR 24 Gen: Pallor, mild respiratory distress, generalized lymphadenopathy

breath sounds over both lung fields CV: WNL Abd: Soft, nontender; hepatosplenomegaly Ext: Reddish maculopapular rash

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

F/U

Ward W/U

Office W/U

Sputum culture: ⊕ for S pneumoniae

■

CBC: ↑ WBC count

■

■

Chem 8

Rx

■

UA

■

IV normal saline

■

Sputum Gram stain: Gram-⊕ cocci

■

PO levofloxacin

■

Sputum culture: Pending

■

Chest physiotherapy

■

CXR: Left lower lobe infiltrate

■

Acetaminophen

■

U/S—abdomen

■

SQ heparin

403

■

Discharge home

■

Continue PO levofloxacin × 14 days

Final Dx: Pneumonia

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U

Office W/U

■

Regular follow-up visits

■

CBC

■

LFTs

■

LFTs

■

CD4: 200

■

VDRL

■

Influenza vaccine

■

Chem 8

■

Anti-HCV

■

Pneumococcal vaccine

■

ABG: Hypoxia

■

HBsAg

■

Counsel patient re safe sex practices

■

Sputum Gram stain and culture

■

Anti-HBc

■

HIV support group

■

Sputum AFB smear

■

Serum Toxoplasma serology

■

Patient counseling

■

Bronchial washings—Pneumocystis stain

Rx

■

Family counseling

(bronchoscopy is a prerequisite along with

■

thoracic surgery consult): ⊕

TMP-SMX or pentamidine (if patient cannot tolerate TMP-SMX)

■

CXR: Bilateral interstitial infiltrate

■

Prednisone

■

PPD: 䊞

■

Begin highly active antiretroviral therapy (HAART) Final Dx: Pneumocystis jiroveci pneumonia (PCP)

404

CHAPTER 19

HIGH-YIELD CCS CASES

C H E ST PA I N

CASE 28 HX 40 yo F presents with sudden onset of 8/10 substernal chest pain that began at rest, has

PE VS: P 80, BP 130/60, RR 14, O2 sat 99% room air

DDX ■

Angina

■

Aortic dissection

lasted for 20 minutes, and radiates to the

Gen: Moderate distress

■

Costochondritis

jaw. The pain is accompanied by nausea. The

Lungs: WNL

■

GERD

patient has a prior history of hypertension,

CV: WNL

■

MI

hyperlipidemia, and smoking.

Abd: WNL

■

Pericarditis

Ext: WNL

■

Pneumothorax

■

Pulmonary embolism

CASE 29 HX 58 yo M was working in his office 30 minutes ago when he suddenly developed

PE VS: P 123, BP 101/64, RR 28, O2 sat 91% room air

DDX ■

Angina

■

Aortic dissection

right-sided chest discomfort and shortness

Gen: Cyanosis, severe respiratory distress

■

Asthma exacerbation

of breath. He has a prior history of asthma

Trachea: Deviated to left

■

Pneumothorax

and emphysema.

Lungs: No breath sounds on right side with

■

Pulmonary embolism

■

Tension pneumothorax

hyperresonance on percussion CV: Tachycardia; apical impulse displaced to the left Abd: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

■

O2

■

ECG

■

Chewable aspirin

■

Lipid profile

■

SL nitroglycerin

■

TSH

■

IV normal saline

■

■

IV morphine

■

■

ECG: T-wave inversions

Rx

Emergency room W/U

405

F/U ■

Cardiac rehabilitation

■

Counsel patient re smoking cessation, hypertension, exercise, relaxation, and lipids

Echocardiography: 60%

■

Advise patient to rest at home

Stress test: ⊕

■

Low-fat, low-sodium diet

■

Enoxaparin

■

Cardiac/BP monitoring

■

ASA

■

CPK-MB, troponin q 8 h: 䊞

■

Clopidogrel

■

CBC

■

β-blocker (atenolol)

■

Chem 14

■

ACEI (enalapril)

■

PT/PTT

■

Atorvastatin

■

CXR

■

Cardiology consult

■

Cardiac catheterization Final Dx: Unstable angina

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

■

IV normal saline

■

Thoracic surgery consult

■

O2

■

CXR: Inflated right lung

■

Needle thoracostomy

Rx

■

Chest tube

■

Morphine

■

CXR: Collapsed right lung, mediastinal shift

■

Chest tube to water seal and vacuum

to left ■

F/U Ward ■

Pleurodesis if indicated

device

IV morphine

Emergency room W/U ■

Cardiac/BP monitoring

■

ECG: Sinus tachycardia

■

CBC

■

Chem 14

■

PT/PTT Final Dx: Tension pneumothorax

406

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 30 HX 34 yo F presents with stabbing retrosternal chest pain that radiates to the back. The

PE VS: T 37°C (99.2°F), P 80, BP 130/70, RR 16, O2 sat 98% room air

DDX ■

Angina/MI

■

Aortic dissection Costochondritis

pain improves when she leans forward and

Gen: NAD

■

worsens with deep inspiration. She had a

Neck: WNL

■

Esophageal rupture

URI one week ago.

Lungs: WNL

■

GERD

CV: S1/S2, pericardial friction rub

■

Pericarditis

Abd: WNL

■

Pneumothorax

Ext: WNL

■

Pulmonary embolism

CASE 31 HX

PE

DDX

48 yo F presents with palpitations and

VS: P 113, BP 145/85, RR 20

■

Anxiety

anxiety. She reports that she feels hot and

Gen: Mild respiratory distress, dehydration,

■

Atrial fibrillation

has to run the air conditioner all the time.

sweaty palms and face, warm skin, hand

■

Early menopause

She also reports hand tremors. She has lost

tremor

■

Hyperthyroidism

■

Mitral valve prolapse

■

Panic attack

■

Withdrawal syndrome

10 pounds over the past few months despite her good appetite.

HEENT: Exophthalmos with lid lag, generalized thyromegaly, thyroid bruit Lungs: WNL CV: Tachycardia Abd: WNL Ext: Edema over the tibia bilaterally

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

Continuous cardiac and BP monitoring

■

■

Stat ECG: Diffuse ST elevation, PR

■

depression

Discontinue continuous monitoring

407

F/U ■

Discharge home

■

Follow up in two weeks

Echocardiography: Minimal pericardial effusion

■

CPK-MB, troponin × 3

Rx

■

CBC

■

Reassure patient

■

Chem 8

■

ASA

■

CXR: No cardiomegaly

■

ESR

Rx ■

ASA or NSAIDs

■

Start IV

■

O2 Final Dx: Pericarditis

INITIAL MGMT Office W/U ■

CBC

■

BMP

■

Thyroid studies (T4, T3RU, T3, TSH): ↑ T3/T4,

■

Serum thyroid autoantibodies: ⊕

■

ECG

■

CXR

■

Nuclear scan—thyroid: ↑ uptake

CONTINUING MGMT Office W/U ■

Endocrinology consult

F/U ■

Check thyroid studies in one month

■

Patient counseling

↓ TSH

Rx ■

Propranolol

■

Methimazole

■

PTU Final Dx: Hyperthyroidism

408

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 32 HX 65 yo M presents with sudden onset of

PE VS: T 36°C (97°F), BP 195/110 right arm,

DDX ■

Aortic dissection

severe tearing anterior chest pain that

160/80 left arm, HR 100, RR 30, O2 sat

■

MI

radiates to the back. He is anxious and

Pericarditis Pulmonary embolism

98% room air

■

diaphoretic. He has a history of long-

Gen: Acute distress

■

standing hypertension.

Lungs: WNL CV: Tachycardia, S4, diastolic decrescendo heard best at left sternal border Abd: WNL Ext: Unequal pulse in both arms Limited PE

CASE 33 HX 34 yo F is brought to the ER after a car accident. She is gasping for air and

PE VS: Afebrile, BP 100/50, HR 115, RR 22, pulsus paradoxus

DDX ■

Aortic dissection

■

Cardiogenic shock MI

complains of weakness, chest pain, and

Gen: Confusion, cyanosis, respiratory distress

■

dizziness.

Neck: ↑ JVP, engorged neck veins,

■

Pericardial tamponade

■

Pericarditis

Lungs: WNL

■

Pneumothorax

CV: Muffled heart sounds, ↓ PMI

■

Pulmonary embolism

Kussmaul’s sign

Abd: WNL Ext: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

■

ASA

■

Continuous cardiac and BP monitoring

■

O2

■

Blood type and cross-match

■

IV normal saline

■

PT/PTT, INR

■

SL nitroglycerin

Rx

■

CXR: Widened mediastinum

■

Continuing IV β-blockers

■

IV β-blockers

■

Emergent surgery

■

ECG: LVH

■

IV morphine

409

F/U ■

Diet and lifestyle modifications

■

Lipid/BP management

Emergency room W/U ■

Cardiac/BP monitoring

■

CPK-MB, troponin × 3: 䊞

■

CBC

■

Chem 8

■

TEE: Aortic dissection type A or

■

CT—chest with IV contrast: Aortic dissection

Rx ■

Thoracic surgery consult Final Dx: Aortic dissection

INITIAL MGMT Emergency room W/U

CONTINUING MGMT ICU W/U

F/U ■

CXR

■

O2

■

Continuous cardiac and BP monitoring

■

Echocardiography

■

IV normal saline

■

ECG

■

Patient counseling

■

NPO

■

Echocardiography

■

Pulse oximetry

■

CXR

■

ECG: Tachycardia, low voltage, nonspecific

■

Cardiac surgery consult

ST- and T-wave changes

■

ABG

■

CPK-MB

Rx

■

CBC

■

NPO to liquid

■

Chem 8

■

O2

■

ABG

■

Follow up in two weeks

■

Coagulation profile

■

Blood type and cross-match

■

CXR: Cardiomegaly

■

Echocardiography: Tamponade

■

Pericardiocentesis Final Dx: Pericardial tamponade

410

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 34 HX

PE

DDX

28 yo F presents with palpitations, chest

VS: P 90, BP 125/75, RR 20

■

Anxiety

pain, nausea, and dizziness that last for

Gen: Mild respiratory distress, dehydration,

■

Asthma attack

■

Atrial fibrillation

almost 5–6 minutes. She has had several

sweating, cold hands

attacks over the past few weeks. During

HEENT: WNL

■

Early menopause

these episodes, she becomes diaphoretic

Lungs: WNL

■

Hyperthyroidism

and occasionally has diarrhea. In the course

CV: WNL

■

Hyperventilation

of some of her attacks, she describes feeling

Abd: WNL

■

Hypoglycemia

as if she might die.

Ext: WNL

■

Mitral valve prolapse

■

Panic attack

■

Pheochromocytoma

■

Pulmonary embolus

■

Substance abuse

CASE 35 HX

PE

DDX

32 yo F presents with occasional

VS: P 90–200 (variable), BP 125/75, RR 20

■

Anxiety

palpitations, chest pain, and dizziness. She

Gen: Mild cyanosis

■

Atrial fibrillation

also reports shortness of breath and chest

HEENT: WNL

■

Hyperthyroidism

tightness during her attacks.

Lungs: Bibasilar crackles

■

Hyperventilation

CV: Irregularly irregular, tachycardia

■

Mitral valve prolapse

Abd: WNL

■

Panic attack

Ext: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Office W/U

411

F/U ■

Outpatient follow-up in four weeks

■

CBC

■

Psychiatry consult

■

Chem 8

■

Patient counseling

■

UA

■

Behavioral modification program

■

Urine toxicology: 䊞

■

Relaxation exercises

■

TFTs

■

ECG

■

CXR

Rx ■

Reassure patient

■

Benzodiazepines (eg, alprazolam, lorazepam, clonazepam) or

■

SSRIs Final Dx: Panic attack

INITIAL MGMT Emergency room W/U

CONTINUING MGMT ICU W/U

■

IV normal saline

■

ECG

■

O2

■

Continuous cardiac monitoring

■

CBC

■

Continuous BP monitoring

■

Chem 8

■

Warfarin

■

TFTs

■

ASA

■

ECG: Atrial fibrillation

■

CXR: Pulmonary vascular congestion

■

Echocardiography: Enlarged left atrium

F/U ■

Follow up in two weeks

■

Patient counseling

Rx ■

Synchronous cardioversion

■

Amiodarone (give prior to DC cardioversion if possible)

■

Propranolol

■

Heparin Final Dx: Atrial fibrillation

412

CHAPTER 19

HIGH-YIELD CCS CASES

A B D O M IN A L P AI N

CASE 36 HX

PE

DDX

38 yo M presents with RUQ abdominal pain

VS: T 36°C (96°F), BP 130/85, HR 110, RR 22

■

Gastroenteritis

of 48 hours’ duration. The pain radiates to

Gen: In pain

■

Nephrolithiasis

his right groin and scrotal area and comes in

Lungs: WNL

■

Pancreatitis

waves of severe intensity that prevent him

CV: Tachycardia

■

Perforated duodenal ulcer

from finding a comfortable resting position.

Abd: Soft, nontender, no distention,

■

Retrocecal appendicitis

tenderness in right flank, no peritoneal signs, normal BS Rectal exam: WNL, guaiac 䊞

CASE 37 HX

PE

DDX

60 yo M presents with generalized

VS: T 37°C (99.2°F), P 90, BP 120/60, RR 18

■

weakness, left flank discomfort, nausea, and

Gen: NAD

■

Renal abscess

constipation of two weeks’ duration. He has

Lungs: WNL

■

Renal cell carcinoma

lost 20 pounds over the past four months.

CV: WNL

Colorectal cancer

Abd: ↓ BS, left flank tenderness with deep palpation Rectal exam: WNL Ext: WNL Neuro: WNL

CASE 38 HX 32 yo F presents with two days of progressive flank pain, urinary frequency,

PE VS: T 39.1°C (102°F), BP 130/85, HR 86, RR 18

DDX ■

Acute cervicitis

■

Acute cystitis

and a burning sensation during urination.

Gen: Mild discomfort with exam

■

Acute PID

She also reports associated fever and

Lungs: WNL

■

Acute pyelonephritis

shaking chills.

CV: Tachycardia

■

Acute urethritis

Abd: ⊕ BS, mild suprapubic tenderness, no

■

Ectopic pregnancy

■

Nephrolithiasis

peritoneal signs Back: Mild CVA tenderness on the left Pelvic: WNL Rectal exam: WNL, guaiac 䊞

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

F/U

■

Serum calcium, magnesium, phosphate

■

↑ fluid intake

CBC: Normal WBC count

■

Serum uric acid

■

Follow up in four weeks

■

Chem 8

■

Urine strain

■

Patient counseling

■

Serum amylase, lipase

■

Stone analysis: Calcium oxalate

■

Counsel patient to limit alcohol intake

■

UA: Microscopic hematuria

■

Counsel patient to limit caffeine intake

■

Urine culture

■

Smoking cessation

■

KUB: Radiopaque 3-mm stone

■

CT—kidney: Stone visualized in distal

Emergency room W/U ■

413

ureter Rx ■

Analgesia: Narcotics and NSAIDs

■

Counsel patient re oral hydration Final Dx: Nephrolithiasis

INITIAL MGMT

CONTINUING MGMT

F/U

Ward W/U

Office W/U ■

CBC: Hemoglobin 9.0

■

Intact PTH: ↓

■

Chem 14: Ca 15, BUN 40, creatinine 2.0

■

Chem 7: Ca 10, BUN 20, creatinine 1.5

■

UA: ⊕ for RBCs

■

CT—abdomen and chest: Left renal mass

■

CXR

■

Renal mass biopsy

■

U/S—complete abdominal: Left renal mass

■

Bone scan

■

Admit to ward

■

CT—head

■

Ferritin, TIBC, serum iron

Rx ■

IV normal saline

Rx

■

Bisphosphonate (pamidronate)

■

Oncology consult

■

Surgery consult Final Dx: Renal cell carcinoma

INITIAL MGMT Office W/U ■

CBC: ↑ WBC count

■

CONTINUING MGMT Office W/U Urine culture: ⊕ for E coli

F/U ■

Follow up in 3–5 days

■

Patient counseling

Chem 8

■

Counsel patient re medication compliance

■

UA: WBC, bacteria, nitrite ⊕

■

Counsel patient to limit alcohol intake

■

Urine culture: Pending

■

Urinary β-hCG: 䊞

■

U/S—renal

■

Rx ■

Ciprofloxacin (fluoroquinolone)

Final Dx: Pyelonephritis

414

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 39 HX

PE

DDX

10 yo African-American M presents with

VS: T 38°C (99.8°F), P 90, BP 110/50, RR 14

■

Autoimmune hemolytic anemia

sudden onset of jaundice, dark-colored

Gen: NAD

■

DIC

urine, back pain, and fatigue. He was started

Skin: Jaundice

■

G6PD deficiency

on TMP-SMX for an ear infection a few

HEENT: Icterus, pallor

■

Sickle cell anemia

days ago. He has a family history of blood

Lungs: WNL

■

Spherocytosis

disorders.

CV: WNL

■

Thalassemias

Abd: WNL

■

TTP

Ext: WNL

CASE 40 HX 58 yo alcoholic M presents with a one-day history of sharp epigastric pain that radiates to his back. He is nauseated and has vomited several times. He also complains of

PE VS: T 38.2°C (101°F), BP 138/68, HR 110, RR 22 Gen: WD/WN but agitated, lying on bed with knees drawn up

DDX ■

Acute cholecystitis

■

Acute gastritis

■

Acute pancreatitis

■

Aortic dissection

anorexia. The patient reports heavy alcohol

Lungs: ↓ breath sounds over left lower lung

■

Cholelithiasis

use over the past 2–3 days. He has no

CV: Tachycardia

■

Intestinal perforation

previous history of peptic ulcer disease.

Abd: Tender and distended with ↓ BS

■

MI

■

Perforated duodenal ulcers

■

Pneumonia

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT Ward W/U

Office W/U

F/U ■

Discharge home

CBC stat and q 12 h: ↓↓ hemoglobin, ↓↓

■

Reticulocyte count: Elevated

■

Follow up in two months

hematocrit

■

LDH: ↑

■

Educate patient/family

■

Peripheral smear: Bite cells, fragment cells

■

Haptoglobin: ↓

■

Chem 14: ↑ indirect bilirubin

■

UA: Hemoglobinuria

■

PT/PTT, INR

■

■

Rx ■

415

G6PD assay: Consistent with G6PD deficiency

Discontinue TMP-SMX

■

Type and cross two units of packed RBCs

Rx ■

Start IV

■

IV normal saline

■

Transfuse two units of packed RBCs Final Dx: G6PD deficiency

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

IV normal saline

■

NPO

■

■

Monitor, continue BP cuff

■

■

NG tube suction

■

ECG: No evidence of ischemia

■

PT/PTT

■

CBC

■

CT—abdomen

■

Chem 14

■

Surgery consult

■

Serum amylase, lipase: ↑

■

GI consult

■

ABG

■

Advance diet as tolerated

■

O2

■

Pulse oximetry

■

LFTs

■

Serum calcium

■

AXR, upright

■

CXR

■ ■

F/U ■

Follow up in seven days

Monitor, continue BP cuff

■

Patient counseling

Continue NPO

■

Counsel patient to cease alcohol intake

U/S—liver, gallbladder and bile duct,

■

Smoking cessation

pancreas

Rx ■

NG tube

■

IV meperidine Final Dx: Acute pancreatitis

416

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 41 HX 1-day-old M born at home is brought to the ER because of bilious vomiting, irritability,

PE VS: T 38°C (100°F), P 170, BP 69/44, RR 43, O2 sat 89% room air

DDX ■

Duodenal web

■

Intestinal atresia Malrotation with volvulus

poor feeding, lethargy, and an acute episode

Skin: Evidence of poor perfusion

■

of rectal bleeding.

Chest: WNL

■

Meconium plug/ileus

CV: WNL

■

Necrotizing enterocolitis

Abd: Distention; evidence of intestinal obstruction Limited PE

CASE 42 HX 21-month-old M is brought to the ER because of intermittent abdominal pain that

PE VS: T 38.5°C (101°F), P 157, BP 81/59, RR 35, O2 sat 93% room air

DDX ■

Intoxication

■

Intussusception Metabolic disease

causes him to become still while drawing

Skin: No evidence of purpura

■

up his legs. He also presents with irritability

Chest: WNL

■

Neurologic disease

and vomiting that initially was clear but then

CV: WNL

■

Small bowel obstruction

became bilious. The child seemed lethargic

Abd: Soft and mildly tender; examination of

■

Volvulus

between the pain episodes. In the ER, the child passes some dark red stool.

RUQ fails to identify presence of bowel; ill-defined mass in the RUQ Limited PE

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT ■

IV normal saline

CONTINUING MGMT Ward W/U ■

Upper GI series: Bird’s beak, corkscrew

417

F/U ■

Follow up in 48 hours

■

Family counseling

appearance of proximal jejunum

■

O2

■

ABG: Metabolic acidosis

Emergency room W/U

■

Barium enema: Cecum in RUQ

Rx

■

CBC: ↑ WBC count, mildly ↓ hemoglobin

■

NG tube suction

■

Chem 8

■

IV normal saline

■

AXR: Airless rectum; large gastric bubble

■

CXR: No evidence of diaphragmatic hernia

Rx ■

NG tube suction

■

IV bicarbonate (to correct acidosis if pH < 7.0)

■

Pediatric surgery consult Final Dx: Malrotation with volvulus

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

■

IV normal saline

■

AXR: Gastric bubble; no air-fluid levels

■

O2

■

ABG: Derangements being resolved

Emergency room W/U

■

Follow up in 48 hours

■

Family counseling

Rx

CBC: ↑ WBC count

■

D/C NG tube suction

■

Chem 14

■

IV normal saline

■

ABG: Metabolic acidosis

■

Advance diet

■

AXR: Distended bowel with air-fluid levels;

■

U/S—abdomen: Compatible with

■

F/U

mass in right abdomen intussusception Rx ■

NG tube suction

■

Barium enema: Coiled-spring appearance; disorder is relieved by air insufflation

■

Pediatric surgery consult Final Dx: Intussusception

418

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 43 HX 27-month-old M presents to the ER with seizures, irritability, anorexia, altered sleep

PE VS: T 37°C (99°F), P 129, BP 89/61, RR 20, O2 sat 92% room air

DDX ■

Lead toxicity

■

Metabolic disease

■

Neurologic disease

patterns, emotional lability, and vomiting. His

Neuro: Lethargy, ataxia, seizures. Remainder

mother states that the family has been living

of physical examination is noncontributory

■

Nonmetal intoxication

for about a year in an old, poorly maintained

(except for some conjunctival pallor)

■

Other heavy metal toxicity

building that has only recently begun to undergo renovation. Since she was laid off at the battery plant, the family has been considering moving out of town.

CASE 44 HX 7-day-old alert M presents to a clinic with jaundice that started two days ago. The baby

PE VS: T 37°C (99°F), P 129, BP 80/51, RR 29, O2 sat 94% room air

DDX ■

Breast-feeding jaundice

■

Hereditary spherocytosis

was born at term via an uneventful vaginal

PE: WNL except for jaundice

■

Physiologic hyperbilirubinemia

delivery and started breast-feeding after

Neuro: WNL

■

Unconjugated hyperbilirubinemia

some delay. The mother states that she took

(Gilbert’s/Crigler-Najjar)

the baby to the doctor’s office at that time and that the baby’s bilirubin was 14 mg/dL. The mother does not take any drugs. She is very concerned that the baby’s jaundice is not improving and asks if the baby has kernicterus.

CASE 45 HX 31 yo M comes to the office complaining of midepigastric pain that usually begins 1–2

PE VS: T 37.1°C (99°F), BP 130/75, HR 100, RR 16

DDX ■

Acute gastritis

■

Diverticulitis

hours after eating and sometimes awakens

Gen: Pallor, no distress

■

GERD

him at night. He also has occasional

Lungs: WNL

■

Mesenteric ischemia

indigestion. He is taking an antacid for his

CV: WNL

■

Pancreatic disease

problem. He denies melena or hematemesis.

Abd: Epigastric tenderness

■

Peptic ulcer disease

Rectal exam: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT

F/U

Ward Rx

■

Follow up in seven days

CBC: Hemoglobin 9 g/dL, MCV 75, blood

■

IV normal saline

■

Family counseling

smear reveals coarse basophilic stippling

■

Serum lead

■

Lead paint assay in home

in RBCs

■

IM EDTA (if necessary)

■

Chem 8

■

Family counseling

■

Serum lead: 80 μg/dL

■

■

UA: Glycosuria

■

Free erythrocyte protoporphyrin: ↑

■

Serum toxicology: ↑ lead levels

419

Rx ■

IV normal saline

■

IM EDTA Final Dx: Lead intoxication with encephalopathy

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

■

CBC: WNL, smear WNL

■

Direct Coombs’ test: Noncontributory

levels ↓ on cessation of breast-feeding;

■

Serum bilirubin: ↑ indirect bilirubin

levels ↑ again when breast-feeding

■

TSH: WNL

■

Breast-feeding suppression test: Bilirubin

F/U ■

Follow up in seven days

■

Family counseling

restarted Rx ■ ■

Continue breast feedings Consider phototherapy (if bilirubin levels do not ↓)

Final Dx: Breast-feeding neonatal jaundice

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U ■

Follow up in four weeks; patient reports

■

CBC

that he is feeling better (if symptoms

■

Chem 8

persist or if H pylori is still present, may

■

Serum amylase, lipase

proceed to endoscopy)

■

Serum H pylori antibody

■

Patient counseling

■

Stool H pylori antibody

■

Counsel patient to limit alcohol intake

■

Smoking cessation

Rx ■

Proton pump inhibitor

■

Clarithromycin (Biaxin)

■

Metronidazole Final Dx: Gastritis (H pylori infection)

420

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 46 HX

PE

DDX

45 yo M presents with a six-week history

VS: T 37°C (98°F), BP 130/70, HR 90, RR 16

■

Cholangiocarcinoma

of jaundice, pale stools, tea-colored urine,

Gen: Jaundice

■

Colon/stomach cancer with metastases

and epigastric pain that radiates to the back.

Lungs: WNL

He also reports that he has bilateral lower

CV: WNL

extremity swelling.

Abd: Palpable epigastric mass

in the porta hepatis region causing biliary obstruction ■

Pancreatic cancer

Ext: Lower extremity swelling with pain on dorsiflexion of ankle

CASE 47 HX

PE

DDX

60 yo F G0 presents with a two-month

VS: T 36°C (97°F), BP 140/60, HR 90, RR 23

■

CHF

history of ↑ abdominal girth, ↓ appetite, and

Gen: Pallor

■

Liver cirrhosis

early satiety. She also has mild shortness of

Breast: WNL

■

Ovarian cancer

breath.

Lungs: WNL CV: WNL Abd: Distended, nontender, normal BS, no palpable hepatosplenomegaly Pelvic: Solid right adnexal mass Rectal exam: Solid right adnexal mass; no involvement of rectovaginal septum

CASE 48 HX

PE

DDX

32 yo F presents with sudden onset of left

VS: T 37°C (99°F), P 90, BP 120/50, RR 14

■

Ectopic pregnancy

lower abdominal pain that radiates to the

Gen: Moderate distress 2° to pain

■

Ovarian torsion

scapula and back and is associated with

Lungs: WNL

■

PID

vaginal bleeding. Her last menstrual period

CV: WNL

■

Ruptured ovarian cyst

was five weeks ago. She has a history of

Abd: RLQ tenderness, rebound, and guarding

pelvic inflammatory disease and unprotected

Pelvic: Slightly enlarged uterus with small

intercourse.

amount of dark bloody discharge from cervix; right adnexal tenderness

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT

421

F/U

Ward Rx

■

CBC

■

■

Chem 14

■

■

Bilirubin, ALT, AST, alkaline phosphatase

■

CT—abdomen: Large necrotic pancreatic

■

ERCP/EUS: Biopsy to obtain histology

Medical oncology consult; palliative care Surgery is not an option owing to advanced disease

mass in head

Final Dx: Pancreatic cancer

INITIAL MGMT Office W/U

CONTINUING MGMT Ward Rx

F/U ■

Carboplatin

■

CBC

■

Blood type and cross-match

■

CA-125

■

Chem 14

■

PT/PTT, INR

■

CBC

■

CA-125: 900

■

Exploratory laparotomy

■

Chem 14

■

CT—abdomen and pelvis: 10- × 12-cm

■

TAH-BSO, laparotomy

right complex ovarian cyst; severe ascites

■

Staging, laparotomy

■

CXR: Right moderate pleural effusion

■

ECG

■

Pap smear

■

Mammogram

■

Colonoscopy

■

Gynecology consult

Final Dx: Ovarian cancer

INITIAL MGMT Emergency room W/U

CONTINUING MGMT

F/U

■

Blood type and cross-match

■

Counsel patient on contraception

■

Urinary β-hCG: ⊕

■

PT/PTT, INR

■

Counsel patient re safe sex practices

■

Quantitative serum β-hCG: 2500

■

Gynecology consult

■

CBC

■

Laparoscopy

■

Chem 8

■

Rh IgG (RhoGAM) if Rh-䊞

■

Cervical Gram stain and G&C culture

■

U/S—transvaginal: 2-cm right adnexal mass, no intrauterine pregnancy, free fluid in cul-de-sac

Rx ■

IV normal saline Final Dx: Ectopic pregnancy

422

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 49 HX 74 yo M presents with LLQ abdominal pain, fever, and chills for the past three days.

PE VS: T 38°C (101°F), BP 130/85, HR 100, RR 22

DDX ■

Crohn’s disease

■

Diverticular abscess Diverticulitis

He also reports recent-onset episodes of

Gen: Pallor, diaphoresis

■

alternating diarrhea and constipation. He

Lungs: WNL

■

Gastroenteritis

consumes a low-fiber, high-fat diet.

CV: Tachycardia

■

Ulcerative colitis

Abd: LLQ tenderness, no peritoneal signs, sluggish BS Rectal exam: Guaiac 䊞

CASE 50 HX 41 yo F presents with sudden-onset RUQ abdominal pain of six hours’ duration. She

PE VS: T 39.0°C (102°F), BP 130/82, HR 80, RR 16

DDX ■

Acute appendicitis

■

Acute cholangitis

also reports nausea and emesis. The pain

Gen: WD, slightly obese, moderate distress

■

Acute cholecystitis

started after lunch and has become more

Lungs: WNL

■

Acute hepatitis

severe and constant. She reports that the

CV: WNL

■

Acute pancreatitis

pain is exacerbated by deep breathing and

Abd: Obesity, tenderness and guarding to

■

Acute peptic ulcer disease with or without

that it radiates to her shoulder. She had a similar attack almost one year ago. She is taking OCPs and has three children.

palpation on RUQ, ⊕ Murphy’s sign, ↓ BS Rectal exam: WNL, guaiac 䊞

perforation ■

Biliary atresia

■

Cardiac ischemia

■

Cholelithiasis

■

Fitz-Hugh–Curtis syndrome (gonococcal perihepatitis)

■

Gastritis

■

Renal colic

■

Right-sided pneumonia

■

Small bowel obstruction

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

CBC: ↑ WBC count

■

Urine culture: Pending

■

Chem 14

■

Blood culture: Pending

■

Serum amylase, lipase

Rx

■

UA

■

■

Urine culture: Pending

■

Surgery consult

■

Blood culture: Pending

■

Metronidazole + ciprofloxacin × 7–10 days

■

Stool culture and sensitivity

■

Discharge home in 3–4 days

■

Stool for ova and parasites

■

CXR

■

KUB

■

CT—abdomen: Diverticulitis

423

F/U ■

High-fiber diet

■

Colonoscopy four weeks after recovery

NPO or clear liquid diet

Rx ■

NPO

■

IV normal saline

■

IV metronidazole + ciprofloxacin Final Dx: Diverticulitis

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Follow up in two weeks

■

IV normal saline

■

Blood type and cross-match

■

Patient counseling

■

NPO

■

PT/PTT, INR

■

Counsel patient to limit alcohol intake

■

Monitor, continue BP cuff

■

Surgery consult for cholecystectomy

■

ECG

■

Vitals q 4 h

■

CBC

■

CBC next day Chem 8 next day

■

Chem 14

■

■

Serum amylase, lipase

Rx

■

LFTs

■

NPO → advance diet as tolerated

■

Blood/urine cultures

■

Continue antibiotic therapy

■

AXR/CXR

■

Pregnancy test—urine

■

U/S—abdomen: Gallstones with gallbladder edema

Rx ■

IM prochlorperazine

■

IV morphine

■

IV cefuroxime Final Dx: Acute cholecystitis

424

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 51 HX

PE

DDX

24 yo F presents with bilateral lower

VS: T 38°C (100.4°F), P 90, BP 110/50, RR 14

■

Dysmenorrhea

abdominal pain that started with the first

Gen: Moderate distress 2° to pain

■

Endometriosis

day of her menstrual period. The pain is

Lungs: WNL

■

PID

associated with fever and a thick, greenish-

CV: WNL

■

Pyelonephritis

yellow vaginal discharge. She has had

Abd: Diffuse tenderness (greatest in the

■

Vaginitis

unprotected sex with multiple sexual

lower quadrants), no rebound, no distention, ↓ BS

partners.

Pelvic: Purulent, bloody discharge from cervix; cervical motion and bilateral adnexal tenderness Rectal exam: WNL Ext: WNL

CASE 52 HX

PE

DDX

25 yo M is brought to the ER because of

VS: T 37°C (98°F), P 120, BP 100/60, RR 25

■

Acute intestinal obstruction

abdominal pain and ↓ appetite for four days.

Gen: Moderate distress

■

Alcoholic ketoacidosis

This episode was preceded by ↑ urinary

Skin: Poor skin turgor

■

Appendicitis

frequency, nausea, and vomiting.

HEENT: Dry mucous membranes, “fruity

■

DKA

breath”

■

Drug intoxication

Lungs: WNL

■

Gastroenteritis

CV: Tachycardia

■

Pancreatitis

Abd: Generalized tenderness

■

Pyelonephritis

Ext: WNL Neuro: WNL Limited PE

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

Urinary β-hCG: 䊞

■

■

CBC: ↑ WBC count

Rx

■

Chem 14

■

■

Cervical Gram stain and G&C culture

Cervical culture: N gonorrhoeae

425

F/U ■

Counsel patient re safe sex practices

■

Treat partners

Discontinue IV ceftriaxone when symptoms improve (usually in 24–48 hours)

■

U/S—pelvis

■

UA and urine culture

■

Switch to doxycycline or clindamycin

Rx ■

IV normal saline

■

IV ceftriaxone + PO doxycycline or PO azithromycin

■

Acetaminophen Final Dx: Pelvic inflammatory disease (PID)

INITIAL MGMT Emergency room STAT ■ ■

CONTINUING MGMT ICU W/U

■

Diabetic diet

Continuous monitoring

■

Diabetic teaching

Random glucose q 1 h

■

HbAlc q 3 months

■

Follow up in two weeks in the office

Glucometer: 480 mg/dL

■

IV normal saline

■ ■

Chem 8 q 4 h: ↓ K, glucose < 250

Emergency room W/U

F/U

■

Continuous monitoring

Rx

■

Diabetic foot care

■

Chem 14: Normal K, normal Na, ↑ anion

■

Switch IV fluid to D5W

■

Ophthalmology consult

gap

■

IV potassium

■

Lipid profile

■

CBC: ↑ WBC count

■

SQ insulin NPH

■

Instruct patient in home sugar monitoring

■

Serum amylase, lipase

■

SQ insulin regular

■

Home sugar monitoring, glucometer

■

UA and urine culture: ⊕ glucose,

■

Discontinue IV insulin two hours after

⊕ ketone

starting long-acting insulin (NPH or

■

Urine/serum toxicology

Lantus)

■

Phosphate: ↓

■

ECG

■

ABG: Metabolic acidosis (pH = 7.1)

■

Quantitative serum ketones: ↑

■

Serum osmolality: Normal

■

CXR/AXR

Rx ■

IV regular insulin, continue

■

Phosphate therapy Final Dx: Diabetic ketoacidosis (DKA)

426

CHAPTER 19

HIGH-YIELD CCS CASES

C O N ST I PA TI O N / DI AR RH E A

CASE 53 HX 67 yo M presents with constipation, ↓ stool caliber, and blood in his stool for the past

PE VS: P 85, BP 140/85, RR 14, O2 sat 98% room air

DDX ■

Angiodysplasia

■

Colorectal cancer

eight months. He also reports unintentional

Gen: NAD

■

Diverticulosis

weight loss. He is on a low-fiber diet and has

HEENT: Pale conjunctivae

■

GI parasitic infection (ascariasis, giardiasis)

a family history of colon cancer.

Lungs: WNL

■

Hemorrhoids

CV: WNL

■

Hypothyroidism

Abd: WNL

■

Inflammatory bowel disease

Pelvic: WNL

■

Irritable bowel syndrome

Rectal exam: Hemoccult ⊕

CASE 54 HX

PE

DDX

28 yo M presents with diffuse abdominal

VS: T 37°C (99°F), BP 130/65, HR 70, RR 14

■

Crohn’s disease

pain, loose stools, perianal pain, mild fever,

Gen: NAD

■

Diverticulitis

and weight loss over the past four weeks. He

Lungs: WNL

■

Gastroenteritis

denies any history of travel or recent use of

CV: WNL

■

Infectious colitis

antibiotics.

Abd: WNL

■

Irritable bowel syndrome

Rectal exam: Perianal skin tags,

■

Ischemic colitis

■

Lactose intolerance

■

Pseudomembranous colitis

■

Small bowel lymphoma

■

Ulcerative colitis

hemoccult ⊕

CASE 55 HX

PE

DDX

30 yo F presents with periumbilical crampy

VS: Afebrile, P 85, BP 130/65, RR 14

■

Celiac disease

pain of six months’ duration. The pain

Gen: NAD

■

Chronic pancreatitis

never awakens her from sleep. It is relieved

Lungs: WNL

■

Colorectal cancer

by defecation and worsens when she is

CV: WNL

■

Crohn’s disease

upset. She has alternating constipation and

Abd: WNL

■

Diverticulosis

diarrhea but no nausea, vomiting, weight

Pelvic: WNL

■

Endometriosis

loss, or anorexia.

Rectal exam: Guaiac 䊞

■

GI parasitic infection (ascariasis, giardiasis)

■

Hypothyroidism

■

Inflammatory bowel disease

■

Irritable bowel syndrome

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT

427

F/U

Office W/U

■

CBC: ↓ hematocrit, ↓ MCV

■

GI consult

■

Chem 8: Normal

■

Colonoscopy: Polyp with adenocarcinoma

■

Ferritin: ↓

■

CT—abdomen and pelvis with contrast

■

Serum iron: ↓

■

CEA

■

TIBC: ↑

Rx

■

TSH: Normal

■

Iron sulfate

■

Stool for ova and parasites

■

General surgery consult

■

ESR: Normal

■

Plan partial colectomy

■

Stool guaiac: ⊕ Final Dx: Colorectal cancer

INITIAL MGMT

CONTINUING MGMT

Office W/U

F/U ■

■

CBC

■

Chem 14

■

Serum amylase, lipase

■

Stool for ova and parasites

■

Stool C difficile

■

Follow up in two weeks Counsel patient re medication compliance and adherence

■

AXR

■

Colonoscopy: Crohn’s disease

Rx ■

5-ASA

■

Metronidazole (for perianal abscess or fistula) Final Dx: Crohn’s disease

INITIAL MGMT Office W/U ■

CBC

■

Chem 14

■

TSH

■

Stool for ova and parasites

■

Stool for WBCs

■

Stool culture and sensitivity

■

Transglutaminase antibody

CONTINUING MGMT

F/U ■

Follow up in four weeks

■

Call with questions

Rx ■

Educate patient

■

Reassurance

■

High-fiber diet

■

Lactose-free diet Final Dx: Irritable bowel syndrome

428

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 56 HX

PE

DDX

8 yo M is brought to the clinic by his mother

VS: T 37°C (98°F), BP 110/65, HR 90, RR 16

■

Bacterial gastroenteritis

for intermittent diarrhea alternating with

Gen: Pale and dry mucosal membranes; lack

■

Celiac disease Food allergy

of growth

■

cramping abdominal pain. His mother also

Lungs: WNL

■

Giardiasis

reports that he has had progressive anorexia.

CV: WNL

■

Protein intolerance

Abd: WNL

■

Viral gastroenteritis

constipation together with vomiting and

Ext: Muscle wasting, especially in gluteal area

CASE 57 HX 28 yo M reports intermittent episodes of vomiting and diarrhea along with cramping

PE VS: T 39°C (101.9°F), BP 135/85, HR 100, RR 22

DDX ■

Campylobacter infection

■

Cholera

abdominal pain for the past two days. He

Gen: Mild dehydration

■

C difficile colitis

describes his stool as watery. He returned

Lungs: WNL

■

Crohn’s disease

from Mexico three days ago.

CV: WNL

■

Gastroenteritis

Abd: Mild tenderness, no peritoneal signs,

■

Giardiasis

■

Salmonellosis

■

Shigellosis

hyperactive BS Rectal exam: WNL, guaiac 䊞

CASE 58 HX 40 yo F presents with fever, anorexia, nausea, profuse and watery diarrhea, and

PE VS: T 38°C (100.4°F), BP 100/50, HR 100, RR 22, orthostatic hypotension

DDX ■

Amebiasis

■

Food poisoning

diffuse abdominal pain. Last week she was

Gen: WNL

■

Gastroenteritis

on antibiotics for a UTI.

Lungs: WNL

■

Giardiasis

CV: Tachycardia

■

Hepatitis A

Abd: Diffuse tenderness, no peritoneal signs,

■

Infectious diarrhea (bacterial, viral,

⊕ BS

Rectal exam: Guaiac ⊕

parasitic, protozoal) ■

Inflammatory bowel disease

■

Pseudomembranous (C difficile) colitis

■

Traveler’s diarrhea

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U

Ward W/U

■

Follow up in one week

■

CBC

■

CXR: Normal

■

Patient counseling

■

Chem 14

■

KUB: Normal

■

Pneumococcal vaccine

■

UA

■

CT—abdomen: Normal

■

Stool for ova and parasites

■ D

■

Stool occult blood

■

Stool Gram stain

■

Stool fat stain

■

Barium enema

■

■

CT—abdomen

Rx

■

Ferritin

■

Gluten-free diet

■

Serum folate

■

Prednisone

■

Serum B12

■

Vitamin D

■

Calcium

■ ■

Serum endomysial antibody: ⊕ titers

429

-xylose tolerance test: Carbohydrate

malabsorption ■

Peroral duodenal biopsy: Villi are atrophic or absent Dietary consult

Serum transglutaminase antibody: ⊕ titers Final Dx: Celiac disease

INITIAL MGMT Emergency room W/U

CONTINUING MGMT

F/U

Emergency room W/U

■

Stool culture: ⊕ for E coli

■

CBC

■

■

Chem 14

■

■

Stool culture

■

Fecal leukocyte stain

Rx

■

Stool for C difficile

■

Oral hydration

■

Stool Gram stain

■

Ciprofloxacin

■

Stool for ova and parasites

■

Stool occult blood

■

Stool fat stain

■

UA and urine culture

Follow up in one week

■

Patient counseling

Stool Gram stain: ⊕ for gram-䊞 rods and

■

Counsel patient to limit alcohol intake

↑ leukocytes

■

Smoking cessation

Final Dx: Gastroenteritis

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

Stool culture

■

■

Stool Giardia antigen

Rx

■

Stool for ova and parasites

■

■

Stool WBCs: ⊕

■

Stool for C difficile: ⊕

■

CBC: ↑ WBC count

■

Chem 14

F/U ■

Counsel patient re oral hydration

No orthostatic hypotension Send home on metronidazole (when diarrhea improves); no Lomotil/Imodium

Rx ■

IV normal saline

■

Metronidazole Final Dx: Pseudomembranous (C difficile) colitis

430

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 59 HX 33 yo M presents with foul-smelling, watery diarrhea together with diffuse abdominal

PE VS: T 37°C (98°F), BP 110/50, HR 85, RR 22, no orthostatic hypotension

DDX ■

Amebiasis

■

Food poisoning Gastroenteritis

cramps and bloating that began yesterday.

Gen: WNL

■

He also vomited once. He was recently in

Lungs: WNL

■

Giardiasis

Mexico.

CV: WNL

■

Hepatitis A

Abd: No tenderness, no peritoneal signs,

■

active BS

Infectious diarrhea (bacterial, viral, parasitic, protozoal)

Rectal exam: Guaiac 䊞

■

Inflammatory bowel disease

■

Pseudomembranous (C difficile) colitis

■

Traveler’s diarrhea

G I B LE E DI N G

CASE 60 HX 38 yo M presents with intermittent

PE VS: T 37°C (98.9°F), BP 90/65, HR 110,

DDX ■

Duodenal ulcers

hematemesis of two weeks’ duration. He

RR 24

■

Esophageal tear

has a history of epigastric pain for almost

Gen: Pallor

■

Gastric carcinoma

two years that occasionally worsens when

Lungs: WNL

■

Gastric ulcer

he eats food or drinks milk. He also reports

CV: WNL

■

Portal hypertension

melena of three weeks’ duration. His social

Abd: No tenderness, no peritoneal signs,

history is significant for alcohol and tobacco use.

normal BS Rectal exam: WNL, guaiac ⊕ Limited PE

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Office W/U ■

431

F/U ■

Counsel patient re oral hydration

Stool culture

■

Stool Giardia antigen: ⊕

■

Stool for ova and parasites

■

Stool WBCs

■

Stool for C difficile

■

CBC

■

Chem 8

Rx ■

Metronidazole Final Dx: Giardiasis

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

■

Follow up in one week

CBC q 4 h until hematocrit is stable; then

■

Patient counseling

frequency can be ↓

■

Counsel patient to cease alcohol intake

■

Smoking cessation

■

Dietary consult

■

IV normal saline

■

O2

■

Orthostatic vitals: Drop on standing

Rx

■

Type and cross-match

■

Emergency room W/U

■

■

F/U

GI consult Combination therapy with epinephrine injection followed by thermal coagulation

■

CBC: Hematocrit 24

■

Chem 14

■

Octreotide for varices

■

Upper GI series: Gastric antral lesion with

■

Advance diet

adherent clot

■

Ranitidine

■

PT/PTT, INR

■

Pantoprazole

■

CXR

■

Transfer to wards if patient remains stable

■

ECG

■

H pylori serology and eradication if ⊕

Rx ■

NPO

■

NG tube, iced saline lavage: Clears with 1 L of normal saline

■

IV pantoprazole

■

IV cimetidine Final Dx: Bleeding gastric ulcer

432

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 61 HX 67 yo F presents with acute crampy abdominal pain, weakness, and black stool.

PE VS: T 37°C (98.9°F), BP 90/65, HR 100, RR 24

DDX ■

Adenocarcinoma of the colon

■

Crohn’s disease Diverticular bleed

She reports diffuse abdominal pain of three

Gen: Mild dehydration

■

months’ duration. Eating worsens the pain.

Lungs: WNL

■

Infectious colitis

She has had a five-pound weight loss over

CV: WNL

■

Ischemic colitis

the last three months.

Abd: Tender and mildly distended; no rigidity

■

Peptic ulcer disease

■

Ulcerative colitis

or rebound tenderness Rectal exam: WNL, guaiac ⊕ Limited PE

CASE 62 HX

PE

DDX

30 yo M presents with loose, watery stools

VS: T 37°C (99°F), BP 130/65, HR 70, RR 14

■

Crohn’s disease

that are streaked with blood and mucus. He

Gen: NAD

■

Diverticulitis

has also had colicky abdominal pain and

Lungs: WNL

■

Gastroenteritis

weight loss over the past three weeks. He

CV: WNL

■

Infectious colitis

denies any history of travel, radiation, or

Abd: WNL

■

Internal hemorrhoid

recent medication use (antibiotics, NSAIDs).

Rectal exam: Blood-stained stool

■

Ischemic colitis

■

Pseudomembranous colitis

■

Radiation colitis

■

Ulcerative colitis

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT Ward W/U

■

IV normal saline

■

■

O2

Rx

Emergency room W/U ■

CBC

Hemoglobin and hematocrit q 4 h

Smoking cessation

■

Dietary consult

and/or bleeding

■

LDH: ↑

■

PT/PTT

■

CXR

■

ECG

■

Blood type and cross-match

Counsel patient to cease alcohol intake

Monitor carefully for persistent fever, leukocytosis, peritoneal irritation, diarrhea,

AXR

Patient counseling

■

■

Chem 14

CT—abdomen: Pneumatosis coli

Follow up in four weeks

■

■

Serum amylase: Normal

■

■

Advance diet

■

■

F/U

■

■

433

Rx ■

NPO

■

Surgery consult (for bowel resection)

■

Broad-spectrum antibiotics

■

NG tube suction Final Dx: Ischemic colitis

INITIAL MGMT Office W/U ■

CBC: Mild anemia

■

Chem 14

■

Serum amylase, lipase

■

Stool culture and sensitivity

■

Stool for ova and parasites

■

Stool WBCs

■

PT/PTT

■

Flexible sigmoidoscopy and rectal biopsy:

CONTINUING MGMT

F/U ■

Follow up in two weeks

■

Counsel patient re medication compliance and adherence

Consistent with ulcerative colitis involving rectum and distal sigmoid colon Rx ■

IV steroids (for attack) or

■

5-ASA enema/suppositories

■

Sulfasalazine Final Dx: Ulcerative colitis

434

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 63 HX

PE

DDX

58 yo M presents with painless bright red

VS: T 37°C (98°F), BP 130/85, HR 90, RR 20

■

Colon cancer

blood in his stool. He reports that his diet is

Gen: Pallor, diaphoresis

■

Crohn’s disease

low in fiber.

Lungs: WNL

■

Diverticulitis

CV: WNL

■

Diverticulosis

Abd: Soft, nontender, no peritoneal signs,

■

Ulcerative colitis

⊕ BS Rectal exam: Bloody stool

H E M A T UR I A

CASE 64 HX

PE

DDX

71 yo Asian M presents with a three-month

VS: T 37°C (98.5°F), P 76, BP 140/75, RR 14

■

Disk herniation

history of low back pain that is 3/6 in

Gen: NAD

■

Lumbar muscle strain

severity and steady with no radiation. He has

Neck: WNL

■

Muscular spasm

BPH and denies any history of trauma.

Back: Tenderness along lumbar spine (L4,

■

Osteoporosis

■

Prostate cancer

Lungs: WNL

■

Sciatic irritation

CV: WNL

■

Spinal stenosis

Abd: WNL

■

Tumor in the vertebral canal

L5)

Rectal exam: Irregular, enlarged prostate; hemoccult 䊞 Ext: WNL Neuro: WNL

CASE 65 HX

PE

DDX

40 yo M complains of a slow-onset dull pain

VS: T 37°C (98°F), P 98, BP 150/95, RR 18

■

Polycystic kidney disease

in his left flank and blood in his urine. His

Gen: WD/WN

■

Renal cell carcinoma

father died of a stroke.

HEENT: WNL

■

Renal dysplasia

Lungs: WNL

■

Simple renal cysts

CV: WNL (no pericardial rub)

■

Tuberous sclerosis

Abd: Palpable, nontender mass on both

■

Wilms’ tumor

flanks Ext: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

435

F/U ■

Follow up in four weeks

Colonoscopy: Diverticulosis, no other

■

Patient counseling

source

■

Counsel patient to cease alcohol intake

■

Smoking cessation

NPO → clear liquid diet

■

Dietary consult

■

Surgery consult

■

High-fiber diet

■

GI consult

■

NPO

■

IV normal saline

■

CBC: ↓ hemoglobin

Rx

■

Chem 14

■

■

PT/PTT

■

Serum amylase, lipase

■

UA

■

CXR

■

CT—abdomen: Diverticulosis

■

Final Dx: Diverticulosis

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

■

CBC

■

Bone scan: Diffuse metastases

■

Chem 14

■

Prostate biopsy: Adenocarcinoma

■

UA: Hematuria

■

CT—abdomen and pelvis: ⊕ for lymphatic

■

ESR: ↑

F/U ■

Patient counseling

involvement above aortic bifurcation

■

PSA: ↑↑

Rx

■

XR—back: Metastatic lesions in L4 and L5

■

■

CT—lumbar spine: Mets to L4 and L5

■

Urology consult

■

Echo—rectal: Multinodular enlarged

■

Radiation oncology consult

Flutamide (antiandrogen therapy) or

prostate ■

Prostate biopsy: Pending

Rx ■

Acetaminophen

■

Morphine or codeine if pain persists Final Dx: Prostate cancer

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

F/U ■

CBC

■

Chem 8

of renal insufficiency)—creatinine

■

Patient counseling

■

UA: Hematuria

> 2 mg/dL

■

Counsel patient to cease alcohol intake

■

U/S—renal or CT—abdomen: Bilateral renal

Urology consult (for nephrectomy, cyst

■

Smoking cessation

decompression, or unroofing)

■

Dietary consult

■

CT—head: No berry aneurysms

■

Low-sodium diet

■

Counsel patient to avoid sports

cysts, enlarged kidneys, no liver cysts Rx ■

■

■

Nephrology consult (to look for evidence

Follow up in eight weeks with blood

■

testing and ultrasound

ACEIs (eg, captopril, enalapril, lisinopril) Final Dx: Polycystic kidney disease

436

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 66 HX 10 yo M presents with tea-colored urine and periorbital edema. He had a fever and sore

PE VS: T 36°C (97.5°F), BP 140/85, HR 88, RR 18

DDX ■

Cryoglobulinemia

■

IgA nephropathy Membranoproliferative glomerulonephritis

throat one week ago. He also complains of

Gen: Periorbital edema, pallor

■

malaise, weakness, and anorexia.

Lungs: WNL

■

CV: WNL

Poststreptococcal glomerulonephritis (PSGN)

Abd: WNL Ext: Edema around ankles

OT H ER UR I N AR Y S Y M PT O MS

CASE 67 HX

PE

DDX

70 yo M complains of waking up 4–5 times

VS: T 37°C (98.5°F), P 78, BP 140/85, RR 14

■

Benign prostatic hypertrophy

a night to urinate. He also has urgency, a

Gen: NAD

■

Bladder cancer

weak stream, and dribbling, and he needs

Neck: WNL

■

Bladder stones

to strain to initiate urination. He denies any

Lungs: WNL

■

Bladder trauma

weight loss, fatigue, or bone pain. He also

CV: WNL

■

Chronic pelvic pain

has a sensation of incomplete evacuation of

Abd: WNL

■

Cystitis

urine from the bladder.

Rectal exam: Enlarged, nodular, nontender,

■

Neurogenic bladder

■

Prostate cancer

■

Prostatitis

■

Urethral strictures

■

UTI

rubbery prostate gland Ext: WNL

CASE 68 HX

PE

DDX

39 yo M complains of sudden-onset fever

VS: T 37.3°C (99°F), P 65, BP 101/64, RR 16

■

Acute cystitis

and chills, urgency and burning on urination,

Gen: No acute distress

■

Anal fistulas and fissures

and perineal pain. His symptoms started

Lungs: WNL

■

Epididymitis

after he underwent urethral dilation for

CV: WNL

■

Obstructive calculus

stricture.

Abd: Suprapubic tenderness

■

Orchitis

GU: Genitalia WNL

■

Prostatitis

Rectal exam: Asymmetrically swollen, firm,

■

Pyelonephritis

■

Reiter’s syndrome

■

Urethritis

markedly tender, hot prostate

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Office W/U

■

CBC

■

U/S—renal

■

Chem 8

■

Throat culture: ⊕

■

UA: Hematuria, proteinuria, RBC casts

Rx

■

24-hour urine protein: Proteinuria

■

■

ASO titer: Normal

■

Throat culture: Pending

■

Total serum complement: ↓

437

F/U ■

Follow up in three weeks with UA and periodic BP monitoring

■

Family counseling

■

Dietary consult

Furosemide

■

Low-sodium diet

■

Captopril

■

Restrict fluid intake

■

Nephrology consult

Rx Furosemide Captopril Penicillin Final Dx: Acute glomerulonephritis (PSGN)

INITIAL MGMT

CONTINUING MGMT Office W/U

Office W/U ■

CBC

■

Urology consult

■

BMP: Creatinine

■

Urodynamic studies

■

UA

■

Urine culture

■

U/S—prostate

■

ESR

■

Total serum PSA

■

Residual urinary volume

F/U ■

Follow up in six months with digital rectal examination and PSA

■

Patient counseling

■

Dietary consult

Rx ■

Finasteride

■

Prazosin (selective short-acting α-blockers) Final Dx: Benign prostatic hypertrophy (BPH)

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

F/U ■

Follow up in four weeks

■

UA

■

Urology consult

■

Patient counseling

■

Urine Gram stain and culture

■

Cystoscopy

■

Counsel patient to cease alcohol intake

■

CBC

■

Smoking cessation

■

Chem 8

■

Counsel patient re safe sex practices

■

VDRL

■

Treat sexual partner

Rx ■

TMP-SMX or fluoroquinolone

Final Dx: Prostatitis

438

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 69 HX 21 yo M complains of a burning sensation

PE VS: T 37.3°C (98.9°F), P 65, BP 101/64,

DDX ■

Acute cystitis

during urination and urethral discharge. He

RR 14

■

Epididymitis

recently began having unprotected sex with

Gen: NAD

■

Foreign body

a new partner. He denies urinary frequency,

Lungs: WNL

■

Nephrolithiasis

urgency, fever, chills, sweats, or nausea.

CV: WNL

■

Orchitis

Abd: Mild suprapubic tenderness

■

Prostatitis

GU: Erythema of urethral meatus, no penile

■

Pyelonephritis

■

Reiter’s syndrome

■

Urethritis

lesions, pus expressed from urethra

CASE 70 HX

PE

DDX

20 yo F presents with a two-day history of

VS: P 65, BP 101/64, RR 16

■

Acute cystitis

dysuria, ↑ urinary frequency, and suprapubic

Gen: NAD

■

Nephrolithiasis

pain. She is sexually active only with her

Lungs: WNL

■

PID

husband. She has no flank pain, fever, or

CV: WNL

■

Pyelonephritis

nausea.

Abd: Mild suprapubic tenderness

■

Urethritis

Pelvic: WNL

■

Vaginitis

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Office W/U

439

F/U ■

Follow up in four weeks

■

UA and urine culture

■

Patient counseling

■

Urethral Gram stain: Many WBCs/hpf

■

Treat partner

without bacteria

■

Counsel patient re safe sex practices

■

Urethral G&C culture (for Neisseria gonorrhoeae and Chlamydia trachomatis)

■

CBC

■

VDRL

Rx ■

Azithromycin (single dose)

■

Ceftriaxone (single dose) Final Dx: Urethritis

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

UA: ↑↑ WBCs, +4 bacteria, ⊕ nitrites,

■

■

Urine culture

Rx

■

CBC

■

■

Chem 8

■

Pregnancy test—urinary

■

F/U

⊕ esterase

Urine culture: ⊕ for E coli sensitive to TMP-SMX TMP-SMX

Rx TMP-SMX × 3 days Final Dx: Acute cystitis

440

CHAPTER 19

HIGH-YIELD CCS CASES

A M EN O R R H E A

CASE 71 HX

PE

DDX

21 yo F complains of irregular menstrual

VS: T 36°C (97°F), P 80, BP 120/80, RR 14

■

Adrenal tumor

periods every 3–5 months since menarche

Gen: Obese

■

Cushing’s syndrome

at age 15. She also complains of facial hair,

Skin: Thick hair on face, chest, and buttocks;

■

Idiopathic hirsutism

■

Late-onset congenital adrenal hyperplasia

Lungs: WNL

■

Ovarian neoplasm

CV: WNL

■

Polycystic ovarian syndrome

weight gain, acne, and darkening of the skin in her axillae.

thickened skin in axillae

Abd: WNL Pelvic: WNL

CASE 72 HX

PE

DDX

50 yo F presents with hot flashes and

VS: T 36°C (97°F), BP 120/60, HR 70, RR 13

■

Hyperthyroidism

dyspareunia. Her last menstrual period was

Gen: NAD

■

Hypothyroidism

six months ago.

HEENT: WNL

■

Menopause

Breast: WNL

■

Pregnancy

Lungs: WNL

■

Prolactinoma

CV: WNL Abd: WNL Pelvic: Atrophy of vaginal mucosa

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Office W/U ■

441

F/U ■

Follow up in six months

DHEAS

■

Testosterone: ↑

■

U/S—pelvis: Ovaries with multiple small cysts

■

Serum 17-hydroxyprogesterone

■

LH/FSH: ↑

■

Prolactin

■

TSH/free T4

■

Insulin/fasting glucose

Rx ■

Weight loss

■

Exercise program

■

OCPs

■

Spironolactone

■

Smoking cessation Final Dx: Polycystic ovarian syndrome (PCOS)

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U ■

Follow up in 12 months

■

Counsel patient re HRT—not

■

Urine pregnancy test

■

Prolactin

recommended unless only short-term

■

TSH

treatment is planned and if the patient has

■

FSH: ↑

no CAD, breast cancer, or thromboembolic

■

Wet mount

risk factors

■

Pap smear

■

Mammogram

■

DEXA scan

Rx ■

Calcium

■

Vitamin D

■

SSRI (venlafaxine) for hot flashes

■

Premarin (vaginal estrogen)

■

Vaginal jelly for lubrication Final Dx: Menopause

442

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 73 HX

PE

DDX

14 yo F is brought into the office by her

VS: Afebrile, BP 110/70, HR 70, RR 12

■

Constitutional growth delay

mother. The mother is concerned because

Gen: Short stature

■

Familial short stature

her daughter is considerably shorter than her

HEENT: Low posterior hairline, high-arched

■

Hypopituitarism

■

Hypothyroidism

■

Turner’s syndrome

classmates and because her daughter has

palate

not yet had her menses. The girl’s parents

Neck: Short and wide

are of normal height, and her sisters had

Lungs: Widely spaced nipples

their menses at age 13.

CV: Tachycardia, irregular

V A GI N A L B L E E DI N G

CASE 74 HX

PE

DDX

21 yo F complains of prolonged and

VS: T 36°C (97°F), P 65, BP 120/60, RR 14

■

Bleeding disorder

excessive menstrual bleeding and menstrual

Gen: NAD

■

Dysfunctional uterine bleeding

frequency for the past six months.

HEENT: WNL

■

Fibroids

Lungs: WNL

■

Hyperthyroidism

CV: WNL

■

Hypothyroidism

Abd: WNL

■

Pregnancy

GU: WNL

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

443

F/U ■

Stop growth hormone when bone age

■

TSH

■

2D echocardiography

■

FSH: ↑

■

U/S—renal

■

Audiogram every 3–5 years

■

LH: ↑

■

U/S—pelvis: Streaked ovaries

■

Check yearly for hypertension

■

Karyotyping: Consistent with Turner’s

■

Skeletal survey: Short fourth metacarpal

■

Monitor aortic root diameter every 3–5

syndrome

■

Chem 13

■

Lipid panel

■

CBC

■

Fasting glucose

■

UA

Rx

■

Lipid profile

■

Growth hormone therapy

■

Hearing test

■

Estrogen + progestin

Rx

■

Psychiatry consult for IQ estimation

■

■

Vitamin D

■

Calcium

> 15 years

years

Continue growth hormone therapy until epiphysis is closed

■

Combination estrogen and progestin

■

Encourage weight-bearing exercises Final Dx: Turner’s syndrome

INITIAL MGMT Office W/U ■

Qualitative urine pregnancy test

■

TSH

■

CBC: Hypochromic microcytic anemia

■

Bleeding time

■

PT/aPTT, INR

■

U/S—pelvis

■

Pap smear

CONTINUING MGMT

F/U ■

Follow up in six months

■

Counsel patient re safe sex practices

Rx Iron sulfate NSAIDs OCPs Final Dx: Dysfunctional uterine bleeding

444

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 75 HX

PE

DDX

27 yo F whose last menstrual period was

VS: T 36°C (97°F), BP 120/60, HR 80, RR 12

seven weeks ago presents with lower

Gen: NAD

abdominal cramping and heavy vaginal

Lungs: WNL

■

bleeding.

CV: WNL

■

Ectopic pregnancy

Abd: Suprapubic tenderness with no

■

Menstrual period with dysmenorrhea

■

Spontaneous abortion

■

Cervical or vaginal pathology (polyp, infection, neoplasia)

rebound or guarding

Cervical polyp

Pelvic: Active bleeding from cervix, cervical os open, seven-week-size uterus, mildly tender, no cervical motion tenderness, no adnexal masses or tenderness

CASE 76 HX

PE

DDX

60 yo F G0 who had her last menstrual

VS: T 36°C (97°F), BP 120/60, HR 80, RR 14

■

Atrophic endometritis

period 10 years ago presents with mild

Gen: NAD

■

Cervical cancer

vaginal bleeding for the last two days. Her

HEENT: WNL

■

Endometrial cancer

medical history is significant for type 2

Lungs: WNL

■

Endometrial polyp

diabetes, hypertension, and infertility.

CV: WNL Abd: WNL Pelvic: WNL

CASE 77 HX

PE

DDX

32 yo F G2P1011 presents with vaginal

VS: WNL

■

Cervical cancer

bleeding after intercourse for the last month.

Gen: NAD

■

Cervical polyp

She has no history of abnormal Pap smears

Abd: WNL

■

Cervicitis

or STDs and has had the same partner for

Pelvic: Visible cervical lesion

■

Ectropion

the last eight years. She uses OCPs.

Rectal exam: 䊞, guaiac 䊞

■

Vaginal cancer

■

Vaginitis

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

Qualitative urine pregnancy test: ⊕

■

■

Quantitative serum β-hCG: 3000

Rx

■

CBC: Hemoglobin 9

■

Methylergonovine

■

Blood type and cross-match

■

Doxycycline

■

Rh factor

■

Counsel patient re birth control

■

U/S—pelvis: Intrauterine pregnancy sac,

■

Grief counseling

fetal pole, no fetal heart tones

■

Pelvic rest for two weeks

■

■

445

F/U ■

Follow up in three weeks

CBC

Gynecology consult

Rx ■

Fluids, IV normal saline

■

D&C Final Dx: Spontaneous abortion

INITIAL MGMT

CONTINUING MGMT

F/U

Ward W/U

Office W/U ■

CBC

■

CXR

■

Chem 14

■

ECG

■

PT/PTT, INR

■

CA-125

■

Bleeding time

Rx

■

Pap smear

■

Exploratory laparotomy

■

Endometrial biopsy: Poorly differentiated

■

TAH-BSO

endometrioid adenocarcinoma

■

Depending on staging, patient may benefit

■

U/S—pelvis: 10-mm endometrial stripe

from adjuvant therapy (radiation vs.

■

Gynecology consult

chemo vs. hormonal therapy) Final Dx: Endometrial cancer

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

F/U ■

Radical hysterectomy vs. radiation therapy

■

UA

■

Colposcopy

■

+/− adjuvant chemoradiotherapy

■

Pap smear: HGSIL

■

Cervical biopsy: Invasive squamous cell

■

Console patient

■

Pelvic: Visible cervical lesion

■

G&C culture or PCR

■

Wet mount

■

Gynecology consult

carcinoma of the cervix

Final Dx: Cervical cancer

446

CHAPTER 19

HIGH-YIELD CCS CASES

MU S C UL O SK E LE T AL PA IN

CASE 78 HX 28 yo F complains of multiple facial and bodily injuries. She claims that she fell on the stairs. She was hospitalized for some physical injuries seven months ago. She denies any abuse.

PE VS: P 90, BP 120/64, RR 22, O2 sat 95% room air Gen: Moderate distress with shallow

DDX ■

Accident proneness

■

Domestic violence

■

Substance abuse

breathing HEENT: 2.5-cm bruise on forehead; 2-cm bruise on left cheek Chest/lungs: Severe tenderness on left fifth and sixth ribs; CTA bilaterally CV: WNL Abd: WNL Ext: WNL Neuro: WNL

CASE 79 HX

PE

28 yo F presents with joint pain and swelling

VS: T 38°C (101°F), BP 140/95, HR 80, RR 18

■

Dermatomyositis

along with a butterfly-like rash over her

Gen: Pallor, fatigue

■

Drug reaction

nasal bridge and cheeks that worsens

HEENT: Oral ulcers, malar rash

■

Photosensitivity

after exposure to the sun. She also reports

Lungs: CTA, pleural friction rub

■

Polymyositis

pleuritic chest pain, shortness of breath,

CV: WNL

■

SLE

myalgia, and fatigue over the past few

Abd: WNL

months. She says that her joint pain tends

Ext: Maculopapular rash over arms and

to move from joint to joint and primarily involves her hands, wrists, knees, and ankles. She also has weight loss, loss of appetite, and night sweats.

chest; effusion in knees, wrists, and ankles

DDX

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

Emergency room W/U ■

XR—ribs: Fracture of left fifth and sixth ribs

■

Urine toxicology

■

CT—head

■

Skeletal survey: Old fracture in forearm

447

F/U ■

Support group referral

■

Social work referral

Rx ■

Ibuprofen

■

Oxycodone PRN

■

Splint

■

Counsel patient re domestic abuse

■

Counsel patient re safety plan

Final Dx: Domestic abuse

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

F/U ■

Follow up in four weeks with UA

■

CBC: ↓ hemoglobin

■

Anti-dsDNA or SLE prep: ⊕

■

Patient counseling

■

BMP

■

Bone densitometry

■

Counsel patient to cease alcohol intake

■

PT/PTT

Rx

■

Smoking cessation

■

ESR: ↑

■

Prednisone

■

Sunblock

■

Serum ANA: ⊕

■

NSAIDs

■

UA: Proteinuria

■

Rheumatology consult

■

CXR

■

Nephrology consult

■

Total complement: ↓ C3 and C4

Rx ■

NSAIDs Final Dx: Systemic lupus erythematosus (SLE)

448

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 80 HX 35 yo M with a history of hypertension presents with pain and swelling in his left

PE VS: T 38°C (100.7°F), P 80, BP 130/60, RR 12

DDX ■

Bacterial arthritis

■

Gout Infective endocarditis

knee for the last three days. He was recently

Gen: In pain

■

started on HCTZ for his hypertension. He is

Skin: WNL

■

Lyme disease

sexually active only with his wife and denies

HEENT: WNL

■

Pseudogout

any history of trauma or IV drug abuse.

Lungs: WNL

■

Psoriatic arthritis

CV: WNL

■

Reiter’s arthritis

Abd: WNL Ext: Left knee is swollen, erythematous, and tender with limited range of motion and effusion

CASE 81 HX

PE

DDX

40 yo M with a history of diabetes

VS: T 38°C (100.5°F), P 70, BP 120/60, RR 12

■

mellitus presents with pain, swelling, and

Gen: NAD

■

Cellulitis

discoloration of his right leg for the last

Lungs: WNL

■

Deep venous thrombosis

week. He denies any trauma.

CV: WNL

■

Lymphedema

Abd: WNL

■

Osteomyelitis

Ext: +2 edema in right lower extremity;

■

Popliteal (Baker’s) cyst

■

Venous insufficiency

warmth, erythematous discoloration of

Calf tear or pull

skin, 20-cm ulcer

CASE 82 HX 50 yo M complains of a single episode of steady, diffuse, aching pain that affected his skeletal muscles and made it difficult for him to climb stairs. He states that he

PE VS: T 37°C (99°F), P 85, BP 127/85, RR 20, O2 sat 94% room air HEENT and neck: No dysarthria, dysphagia, diplopia, or ptosis; exam WNL

has never experienced anything like this

Chest: WNL

before and that no one in his family has

CV: WNL

had a disease similar to his. Because of his

Abd: WNL

↑ LDL cholesterol, ↓ HDL cholesterol, and ↑

Ext: Proximal muscle weakness that is more

triglycerides, he was started on simvastatin

obvious in lower limbs; no evidence of

and gemfibrozil about one year ago.

myotonia

DDX ■

Cocaine abuse

■

Inclusion body myositis

■

Myopathy due to drugs/toxins

■

Myotonic dystrophy

■

Polymyositis

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT

Blood culture: 䊞

CBC: ↑ WBC count

■

■

Chem 14

■

■

ESR: ↑

■

Urethral culture: 䊞 Lyme serology: 䊞

■

PT/PTT, INR

■

CBC: WBC is trending down

■

XR—left knee

Rx

■

Joint aspiration fluid analysis: Gram stain

■

䊞, culture 䊞, 䊞 birefringent and needleshaped crystals, WBC 8000 ■

F/U

Ward W/U

■

449

■

Follow up in two weeks in the clinic

■

Uric acid ↑

■

Low-purine diet

■

Start allopurinol or colchicine (to prevent an attack if serum uric acid > 12 or if the patient has tophaceous gout)

Continue NSAIDs and corticosteroids until patient improves

■

Low-purine diet

Urethral Gram stain: 䊞

Rx ■

NSAIDs or corticosteroids

■

Discontinue HCTZ and start losartan Final Dx: Gout

INITIAL MGMT Emergency room W/U

CONTINUING MGMT

F/U

Ward W/U

■

■

CBC: ↑ WBC count

■

Blood culture: 䊞

■

Chem 14

■

Blood glucose: Controlled on insulin

■

Two weeks later his leg is back to normal Amoxicillin is discontinued after a course of 14 days

regimen

■

PT/PTT

■

U/S—left lower extremity: 䊞 for deep

■

venous thrombosis

Rx

■

ESR

■

■

X-ray

■

■

Blood culture: Pending

CBC: WBC is trending down Elevate the leg Switch to amoxicillin when patient is afebrile and symptoms improve (usually in 3–5 days)

Rx ■

IV ampicillin-sulbactam

■

Surgical consult: Debridement of ulcers

■

Discharge home

Final Dx: Cellulitis

INITIAL MGMT Emergency room W/U

CONTINUING MGMT

F/U

Ward W/U

■

Follow up in four weeks

■

IV normal saline

■

CPK, LDH: ↑

■

Patient counseling

■

CBC

■

UA: ⊕ for myoglobin

■

Rest at home

■

BMP

Rx

■

Counsel patient re medication side effects

■

Serum CPK: ↑

■

■

LDH: ↑

■

EMG: Muscle injury

■

UA: Myoglobinuria

Stop the offending simvastatin and gemfibrozil

Rx ■

Counsel patient re medication side effects

■

NSAIDs Final Dx: Myopathy due to simvastatin and gemfibrozil

450

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 83 HX 21 yo F stripper complains of hot,

PE VS: T 39°C (102°F), P 122, BP 138/82, RR 28,

DDX ■

Chlamydia trachomatis infection

swollen, painful knee joints following an

O2 sat 96% room air

■

Neisseria gonorrhoeae infection

asymptomatic dermatitis that progressed

HEENT and neck: WNL

■

Reactive arthritis

from macules to vesicles and pustules. She

Chest: Four vesicles on thoracic skin

■

S aureus infection

admits using IV drugs, binge drinking, and

CV: WNL

■

Streptococcus infection

having sex with multiple partners. She states

Abd: Three vesicles and one pustule on

that about three weeks ago, during a trip to Mexico, she had dysuria, frequency, and urgency during her menses, followed a few

abdominal skin Ext: Knee joints are hot, swollen, and tender; ↓ ROM due to severe pain

days later by bilateral conjunctivitis.

CASE 84 HX 25-month-old M is brought to the ER because of sudden respiratory distress.

PE VS: T 37°C (99°F), P 129, BP 82/59, RR 40, O2 sat 89% room air

His mother does not remember the boy’s

Gen: Undernourished

immunization, developmental, or nutritional

HEENT: Circumferential cord marks around

history. She calmly states that her son fell

neck

from a sofa a few days ago, and that this

Lungs: Clear; pain with exam

accident explains the boy’s reluctance

CV: Tachycardia; I/VI systolic murmur

to walk. She adds that her son has been

Abd: Bruising over nipples

exposed to sick children lately and that she

Ext: Circumferential burns of both feet and

has used coin rubbing and cupping as folk

ankles with a smooth, clear-cut border;

medicine practices.

light brown bruises; pain on palpation of right lower limb Neuro/psych: Withdrawn, apprehensive

DDX ■

Accidental trauma

■

Child abuse

■

Deliberate criminal violence (home invasion)

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

Follow up in one week

Joint fluid analysis and culture: 60,000

■

Patient counseling

leukocytes/mL, ⊕ for N gonorrhoeae

■

Counsel patient re safe sex practices

Throat culture

■

Treat sexual partner

Anorectal culture

■

Counsel patient to cease illegal drug use

■

Counsel patient to cease alcohol intake

■

CBC: ↑ WBC count

■

GC culture assay: ⊕

■

Blood culture: 䊞

■

■

Arthrocentesis

■

■

Joint fluid analysis

Rx

■

Joint fluid culture: Pending

■

■

■

Azithromycin (for C trachomatis),

■

Smoking cessation

Throat culture: Pending

penicillin (if susceptible), ceftriaxone (if

■

Rest at home

■

Anorectal culture: Pending

not resistant), or fluoroquinolones (if not

■

Urine β-hCG: 䊞

Rx ■

NSAIDs

■

Antibiotics: Azithromycin (for

451

resistant) ■

Joint drainage and irrigation (if indicated)

■

Arthroscopy (if indicated)

C trachomatis), penicillin (if susceptible), ceftriaxone (if not resistant), or fluoroquinolones (if not resistant) Final Dx: Septic arthritis due to N gonorrhoeae infection

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

■

CBC

■

■

PT/aPTT

■

■

Electrolyte panel, BUN, creatinine

■

CXR: Posterior rib fractures

■

Ventilator (if necessary)

■

Skeletal survey: Posterior rib fractures;

■

IV fluids

F/U ■

Child Protective Services

Child abuse report Social work/Child Protective Services evaluation in hospital

obliquely oriented callus formation in right femur ■

CT—head: Short-length skull fractures; small subdural hemorrhages

■

Ophthalmologic exam: Bilateral retinal hemorrhages

Rx ■

Admission to hospital

■

IV fluids

■

Neurosurgery consult

■

Ventilator (if necessary) Final Dx: Nonaccidental trauma (child abuse)

452

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 85 HX 36 yo F complains of malaise, anorexia, unintended weight loss, and morning

PE VS: T 38°C (100°F), P 95, BP 132/86, RR 20, O2 sat 95% room air

DDX ■

Gout

■

Lyme disease Osteoarthritis

stiffness together with swollen and painful

HEENT and neck: Cervical lymphadenopathy

■

wrist, knee, and ankle joints of two years’

Chest: WNL

■

Paraneoplastic syndrome

duration. Initially, she disregarded her

CV: WNL

■

Rheumatoid arthritis

symptoms, as they were insidious. However,

Ext: Symmetric wrist, knee, and ankle

■

Sarcoidosis

over time they persisted and ↑ in severity.

joint swelling with tenderness and

An acute disabling episode prompted her to

warmth; subcutaneous nodules over

visit the office.

both olecranon prominences; no ulnar deviation of fingers, boutonnière deformity, or swan-neck deformity; no evidence of carpal tunnel syndrome; knee valgus is observed

CASE 86 HX 45 yo F bus driver comes to the clinic complaining of pain radiating down the

PE VS: T 37°C (99°F), P 86, BP 128/86, RR 20, O2 sat 93% room air

DDX ■

Cauda equina syndrome

■

Compression fracture Facet joint degenerative disease

leg that followed back pain. The pain is

Trunk: Lumbar spine mobility ↓ due to pain

■

aggravated by coughing, sneezing, straining,

Ext: ⊕ straight leg raising (Lasègue) sign; ⊕

■

Lumbar disk herniation

■

Spinal stenosis

or prolonged sitting.

crossed straight leg sign Neuro: Weak plantar flexion of foot; loss of Achilles tendon reflex

■

Tumor involving the spine causing radiculopathy

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

Office W/U

Office W/U ■

CONTINUING MGMT

F/U ■

Follow up in four weeks

CBC: Hypochromic normocytic anemia,

■

RF: High titer

■

Patient counseling

thrombocytosis

■

Joint fluid analysis: Abnormalities

■

Physical therapy

suggesting inflammation

■

Occupational therapy

■

Rest at home Exercise program

■

ESR: ↑

■

XR—joints: Soft tissue swelling, juxta-

Rx

articular demineralization, joint space

■

Methotrexate (if unresponsive to NSAIDs)

■

narrowing, erosions in juxta-articular

■

Etanercept (if unresponsive to

■

Splint extremity

methotrexate); place PPD

■

Ophthalmologic consult if using

margin ■

RF: High titer

■

453

Hydroxychloroquine for mild disease

hydrochloroquine

Rx ■

Ibuprofen or celecoxib

■

Intra-articular triamcinolone (for acute disabling episodes) Final Dx: Rheumatoid arthritis

INITIAL MGMT Office W/U ■

None initially

CONTINUING MGMT Office W/U ■

Rx

F/U ■

Follow up in two weeks

MRI—lumbar spine: Disk herniation at

■

Patient counseling

L5–S1 level (MRI is not routinely ordered

■

Rest at home

■

Conservative treatment

for a disk herniation; it is ordered if

■

Pain control (NSAIDs)

conservative treatment fails) Rx ■

Conservative treatment

■

Orthopedic surgery consult (if conservative treatment fails) Final Dx: Lumbar disk herniation

454

CHAPTER 19

HIGH-YIELD CCS CASES

C H I LD W I T H FE V E R

CASE 87 HX 40-day-old M is brought to the ER because of irritability and lethargy, vomiting, and ↓

PE VS: T 39°C (102°F), P 160, BP 77/50, RR 40,

DDX ■

O2 sat 92% room air

CNS fungal infection (in immunocompromised patients)

oral intake of three days’ duration. Today his

Gen: Irritable infant

parents noted that he had a fever of 101.5°F,

Lungs: Clear

and he subsequently had a seizure. The

CV: Tachycardia; I/VI systolic murmur

■

Meningitis (viral or bacterial)

baby’s weight at delivery was 2500 grams,

Abd: WNL

■

Osteomyelitis

and he has been well.

Neuro/psych: Bulging fontanelle, ↓

■

Pneumonia

■

Sepsis

■

UTI

■

HIV infection (in immunocompromised patients)

responsiveness

CASE 88 HX 4-month-old M is brought to the ER because of apneic episodes following a runny nose,

PE VS: T 39°C (102°F), P 160, BP 77/50, RR 40, O2 sat 88% room air

DDX ■

Asthma

■

CHF

cough, labored breathing, wheezing, and

Gen: Irritable infant

■

Cystic fibrosis

fever of two days’ duration. His asthmatic

Lungs: Tachypnea, intercostal retractions,

■

Pneumonia

■

RSV bronchiolitis

mother was diagnosed with rubella infection

nasal flaring, expiratory wheezing, bilateral

during her pregnancy. The baby was

crackles

delivered prematurely at 28 weeks. The boy

CV: Tachycardia; continuous II/VI murmur

has a history of respiratory difficulty and

Abd: WNL

tachycardia, and he has missed several of his

Neuro/psych: Fontanelle is soft and flat;

health maintenance appointments.

infant is irritable

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

F/U ■

CBC

■

Serum glucose: 75 mg/dL

■

Blood cultures

■

Urine culture: 䊞

■

Electrolyte panel, BUN, creatinine, glucose

■

Blood culture: ⊕ for S pneumoniae

■

CXR

■

Ventilator (if necessary)

■

UA and urine culture

Rx

■

LP: Cell count, differential, bacterial

■

IV fluids, (D5½NS)

culture, viral PCR pending

■

IV antibiotics × 10–14 days.

■

ABG: Metabolic acidosis, hyponatremia

■

455

Follow up in 48 hours of discharge from hospital

■

Family counseling

Rx ■

Empiric IV antibiotics (ampicillin and cefotaxime)

■

Admission to the hospital

■

IV fluid bolus

■

IV fluids with dextrose Final Dx: Meningitis

INITIAL MGMT Emergency room W/U

CONTINUING MGMT ICU W/U

■

CBC: WBC 14,000

■

Serum glucose: 70 mg/dL

■

Blood culture

■

Urine culture: 䊞

■

Electrolyte panel, BUN, creatinine, glucose

■

CXR: No change

■

CXR: Hyperinflation, bilateral patchy

■

Blood culture: 䊞

interstitial infiltrates, ↑ pulmonary blood

■

RSV PCR ⊕

■

flow, prominent left atrium and ventricle

■

Ventilator (if necessary)

UA and urine culture

■

Echocardiogram: Patent ductus arteriosus

■

ABG: Hypoxemia

Rx

■

RSV PCR: Pending

■

IV fluids (D5½NS)

■

Supplemental O2 Nebulized albuterol (if effective) Cardiology consult

■

Empiric IV antibiotics

■

■

Admission to the ICU

■

■

IV fluid bolus

■

Supplemental O2

■

Nebulized albuterol trial

Follow up in 48 hours of discharge from hospital

■

■

Rx

F/U

Family counseling

Final Dx: Bronchiolitis with patent ductus arteriosus (PDA)

456

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 89 HX

PE

DDX

8-month-old F is brought to the urgent

VS: T 37°C (100°F); other vital signs WNL

■

Fifth disease

care clinic because of abrupt onset of

HEENT and neck: Bilateral cervical

■

Measles

fever that lasted a couple of days with one

lymphadenopathy, ears WNL,

■

Meningitis

seizure episode (the girl and her parents

ophthalmologic exam WNL

■

Roseola infantum

■

Rubella

were camping in a remote area). The fever

Trunk: Macular rash

resolved after a rash appeared on the

Neuro: Alert and active; no abnormalities

girl’s chest and abdomen. Her parents did not notice any lethargy, poor feeding, or vomiting. She has no history of seizures.

CASE 90 HX 3-day-old M presents to the ER with ↑ temperature, lethargy, respiratory distress, and poor feeding for the past 24 hours. His Apgar scores at birth were 6 and 8.

PE VS: T 39°C (102°F), P 170, BP 74/51, RR 70, O2 sat 90% room air Lungs: Grunting respiration, chest indrawing

DDX ■

Bordetella lung infection

■

Chlamydia lung infection

■

with breathing, ↓ air entry

Complicated congenital lung abnormalities (eg, sequestration)

His mother had a prolonged rupture of

CV: No murmurs or rubs

■

Foreign body causing obstruction

membranes (30 hours).

Abd: Distended; 䊞 BS

■

Group B streptococcus bacterial

Neuro: Lethargy

pneumonia

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

457

F/U

Office W/U

■

Follow up in seven days or as needed

CBC: WNL

■

Family counseling

■

Rx ■

Hydrate

■

Acetaminophen

Final Dx: Roseola infantum (exanthem subitum)

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U

CBC: ↑ WBC count

■

Random serum glucose: 65 mg/dL

Random serum glucose: 60 mg/dL

■

Blood cultures: Group B streptococcus

■

CXR: Patchy infiltrates, pleural effusion,

■

ABG: Po2 60 mm Hg, Pco2 50 mm Hg

gastric dilation

Rx

■

Blood cultures: Pending

■

■

Viral culture

■

■ ■

ABG: Po2 50 mm Hg, Pco2 55 mm Hg Rx ■

O2

■

Fluids, D5¼NS

■

Empiric IV antibiotics

■

Respiratory and hemodynamic support

F/U ■

Follow up in 48 hours

■

Family counseling

Antibiotics Ventilatory and hemodynamic support (if necessary)

■

Antiviral drugs (if appropriate)

■

Bronchoscopy (if indicated)

(if necessary) Final Dx: Pneumonia

458

CHAPTER 19

HIGH-YIELD CCS CASES

FE V E R

CASE 91 HX 49 yo F presents to the ER with fever of three days’ duration. Since she turned 49

PE VS: T 39°C (102°F), P 132, BP 108/77, RR 29, O2 sat 88% room air

DDX ■

Deep abscess (unknown location)

■

Pneumonia Pyelonephritis

(about seven months ago), she has had

Lungs: No evidence of consolidation

■

recurrent infections that have been treated

CV: WNL

■

Sepsis

with antibiotics. She has also been treated

Abd: WNL

■

Severe infection (unknown location)

with anthracyclines and alkylating agents

Ext: WNL

for another disease for the past 18 months.

Neuro: WNL

However, she has not seen a doctor lately. She works in a manufacturing plant that produces cosmetics.

CASE 92 HX 43 yo F presents to the ER with fever, fatigue, malaise, and diffuse musculoskeletal

PE VS: T 40°C (104°F), P 134, BP 113/83, RR 31, O2 sat 93% room air

DDX ■

Complicated pyelonephritis

■

Infective endocarditis

■

Infective process (undetermined location)

conjunctival hemorrhage

■

Intracranial infection

has a history of diabetes mellitus and mitral

Funduscopy: Abnormal spots

■

Sepsis

valve prolapse with regurgitation.

Lungs: WNL

pain of two days’ duration. She complains of difficulty moving her right eye. The patient

Ophthalmology: Visual field defects,

CV: Regurgitant murmur Abd: WNL Ext: Petechiae on feet Neuro: CN III palsy

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room W/U ■

CT—abdomen: WNL

■

CBC: Neutropenia

■

CXR: Bilateral infiltrates in both lungs

■

Sputum cultures: ⊕ for several bacterial

CONTINUING MGMT Ward W/U ■

■

F/U ■

Follow up in four weeks

Bone marrow biopsy, needle: Low

■

Patient counseling

myelogenous progenitor cell lines

■

Counsel patient to cease alcohol intake

CT—chest, spiral: Widespread bilateral

■

Smoking cessation

infiltrates in both lungs

■

Chest physical therapy

species, including Klebsiella

Rx

■

Blood cultures: ⊕ for Klebsiella

■

■

UA: WNL

■

Urine cultures: 䊞

IV antibiotics (appropriate for Klebsiella); tailor antibiotics to sensitivities

Rx ■

459

■

IV normal saline

■

G-CSF (for neutropenia)

IV antibiotics (empiric cefepime or quinolone)

■

Acetaminophen

■

IV normal saline Final Dx: Multilobar pneumonia in a neutropenic patient

INITIAL MGMT Emergency room W/U

CONTINUING MGMT Ward W/U Blood cultures: ⊕ for S viridans

■

ESR: 59 mm/hr

■

■

CBC : ↑ WBC

Rx

■

CXR: Some areas of patchy consolidation

■

■

Blood cultures: Pending

■

Acetaminophen

■

Echocardiography: Mobile mass attached

■

IV normal saline

IV antibiotics

F/U ■

Follow up in four weeks

■

Patient counseling

■

Counsel patient to cease alcohol intake

■

Smoking cessation

to a valve ■

ECG: RBBB

■

UA: Microscopic hematuria

Rx ■

IV normal saline

■

O2

■

Empiric IV antibiotics (oxacillin and gentamicin)

■

Acetaminophen Final Dx: Infective endocarditis

460

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 93 HX 60 yo M presents with fever and altered mental status eight hours after undergoing a diverticular abscess drainage.

PE VS: T 39°C (102°F), P 110, BP 60/35, RR 22, O2 sat 92% on 2-L NC Gen: Acute distress

DDX ■

Cardiogenic shock

■

Hypovolemic shock

■

Septic shock

HEENT: WNL Lungs: WNL CV: Tachycardia Abd: Lower abdominal tenderness Neuro: WNL

CASE 94 HX

PE

DDX

17 yo F G0 whose last menstrual period was

VS: T 39°C (102°F), BP 75/30, HR 120

■

Meningococcemia

two days ago presents with fever, vomiting,

Gen: NAD

■

Rocky Mountain spotted fever

myalgia, and a generalized skin rash.

Skin: Diffuse macular erythema; hyperemic

■

Streptococcal toxic shock syndrome

■

Toxic shock syndrome

■

Typhoid fever

mucous membranes Lungs: WNL CV: WNL Pelvic: Menstrual flow; foul-smelling tampon Limited PE

HIGH-YIELD CCS CASES

INITIAL MGMT Emergency room STAT

CONTINUING MGMT

O2

■

Urine output q 1 h

■

IV normal saline/central line

■

2D echocardiography

■

Blood culture: Pending

■

■

Wound culture

■

UA and urine culture

Blood culture: ⊕ for E coli sensitive to

■

Wound culture: ⊕ for E coli sensitive to gentamicin and ceftriaxone

CBC: ↑ WBC count

Rx

■

Chem 14

■

Tailor antibiotics to sensitivities

■

ABG: Metabolic acidosis

■

Surgery consult

ECG

■

Serum amylase, lipase

■

Serum lactate: 6

■

Cardiac enzymes

■

CXR

■

CT—abdomen: Persistent diverticular

F/U

gentamicin and ceftriaxone

Emergency room W/U

■

461

ICU W/U

■

■

CHAPTER 19

abscess Rx ■

Ampicillin-gentamicin-metronidazole or piperacillin-tazobactam or ticarcillinclavulanate Final Dx: Septic shock

INITIAL MGMT Emergency room STAT

CONTINUING MGMT ICU W/U

■

O2 inhalation

■

Blood culture: 䊞

■

IV normal saline

■

Urine culture: 䊞

■

Tampon removal

Rx

Emergency room W/U ■

CBC with differential

■

Chem 14

■

UA

■

Blood culture: Pending

■

Urine culture: Pending

F/U

■

Continue IV clindamycin and vancomycin

■

Wound care

Rx ■

IV clindamycin + vancomycin

■

Methylprednisolone Final Dx: Toxic shock syndrome

462

CHAPTER 19

HIGH-YIELD CCS CASES

OU T P AT I EN T P O TP O U RR I

CASE 95 HX

PE

DDX

50 yo F presents with a painless lump in her

VS: Afebrile, P 70, BP 110/50, RR 12

■

Breast cancer

right breast. She first noted this mass one

Gen: NAD

■

Fibroadenoma

month ago. There is no nipple discharge.

Skin: WNL

■

Fibrocystic disease

HEENT: WNL

■

Mastitis

Lymph nodes: 䊞

■

Papillomas

Breast: 3-cm, hard, immobile, nontender mass with irregular borders; no nipple discharge Lungs: WNL CV: WNL Abd: WNL

CASE 96 HX

PE

DDX

62 yo F complains of vaginal itching, painful

VS: WNL

■

Atrophic vaginitis

intercourse, and a clear discharge.

Gen: NAD

■

Bacterial vaginosis

Lungs: WNL

■

Candidal vaginitis

CV: WNL

■

Cervicitis (chlamydia, gonorrhea)

Pelvic: Vulvar erythema, thin and pale

■

Trichomonal vaginitis

mucosa with areas of erythema, clear discharge, mucosa bleeds easily during exam

CASE 97 HX 33 yo Rh-negative F who currently lives in a battered-women’s shelter calls the on-

PE VS: T 37°C (99°F), P 96, BP 141/91, RR 26, O2 sat 93% room air

call physician because she noticed ↓ fetal

Gen: No jaundice

movements. She is a G1P0 pregnant F at

Eyes: Normal vision

36 weeks’ gestational age. She states that

Lungs: No rales

fetal growth has been normal and that her

CV: No gallops or murmurs

obstetric ultrasound at 18 weeks showed

Pelvic: Fundal height in centimeters is

a single normal fetus. The patient has no

appropriate for gestational age; cephalic

known preexisting diseases and does not

presentation; speculum exam reveals

smoke, drink alcohol, or take medications or

unripe cervix, no ferning, Nitrazine 䊞

illicit drugs. She received a dose of anti-D at 28 weeks.

Ext: Slight pedal edema

DDX ■

Preeclampsia

■

Pregnancy-induced hypertension

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT

CONTINUING MGMT

463

F/U

Office W/U ■

Mammography: Suspicious of tumor

■

FNA biopsy: Malignancy

Rx ■

Surgery consult

Final Dx: Breast cancer

INITIAL MGMT

CONTINUING MGMT

Office W/U

F/U ■

■

Vaginal pH: 6

■

Chlamydia PCR

■

Gonorrhea PCR

■

Wet mount

■

Pap smear

Follow up as needed

Rx ■

Vaginal jelly for lubrication

■

Counsel patient re local HRT

■

Premarin (vaginal estrogen) Final Dx: Atrophic vaginitis

INITIAL MGMT Office W/U

CONTINUING MGMT Ward W/U

■

BUN, creatinine, ALT, AST

■

CBC

■

Chem 8

■

■

UA: ⊕ protein

Rx

■

Random serum glucose

■

Complete bed rest

■

Serum uric acid

■

Monitor, continue BP cuff

■

Fetal monitoring

Rx ■

Complete bed rest

■

Monitor, continue BP cuff

■

Fetal monitoring

■

UA: Protein 0.3 g/L/24 hrs; normal

F/U ■

Patient counseling

■

Admit to labor and delivery for induction

sediment

of labor

LFTs: WNL

■

Obstetric consult

Final Dx: Antenatal disorder: Pregnancy-induced hypertension

464

CHAPTER 19

HIGH-YIELD CCS CASES

CASE 98 HX 30 yo F presents for her regular checkup. She denies any complaints but is concerned

PE VS: P 75, BP 160/90 (no difference in BP between both arms), RR 12

DDX ■

Cushing’s disease

■

Essential hypertension Hyperaldosteronism

about her BP, as it has been high on both of

Gen: WNL

■

her previous visits over the past two months.

HEENT: WNL

■

Hyperthyroidism

Breast: WNL

■

Pheochromocytoma

Lungs: WNL

■

Renal artery stenosis

CV: WNL

■

White coat hypertension/anxiety

Abd: WNL Pelvic: WNL Ext: WNL Neuro: WNL

CASE 99 HX

PE

DDX

6 yo M is brought by his mother with

VS: Afebrile, P 80, BP 80/50, RR 14

■

DIC

continuous oozing of blood from the site

Gen: NAD

■

Hemophilia

of a tooth extraction he underwent two

Skin: WNL

■

ITP

days ago. The bleeding initially stopped but

HEENT: Blood oozing from site of extracted

■

Liver disease

restarted spontaneously a few hours later.

tooth

■

TTP

His mother denies any history of epistaxis,

Lungs: WNL

■

Vitamin K deficiency

easy bruising, petechiae, or bleeding per

CV: WNL

■

von Willebrand’s disease

rectum. The patient’s mother has a brother

Abd: WNL

with hemophilia.

Ext: WNL

CASE 100 HX

PE

DDX

27 yo F complains of pain during

VS: WNL

■

Endometriosis

intercourse. She has a long history of painful

Gen: NAD

■

PID

periods.

Lungs: WNL

■

Vaginismus

CV: WNL

■

Vaginitis

Pelvic: Normal vaginal walls, normal cervix, mild cervical motion tenderness; uterus tender, retroverted, and fixed; right adnexa slightly enlarged and tender

CHAPTER 19

HIGH-YIELD CCS CASES

INITIAL MGMT Office W/U

CONTINUING MGMT Office W/U

■

Lipid profile

■

Chem 14

given the patient’s young age (MRI/MRA

■

CBC

renal arteries, urine catecholamines, urine

■

UA: +1 protein

cortisol)

■

ECG: LVH

■

Echocardiography: LVH

■

TSH

■

465

F/U ■

Follow up in one month

Consider workup for 2° hypertension

Rx ■

Lisinopril

■

Exercise program

■

Low-sodium diet Final Dx: Essential hypertension

INITIAL MGMT

CONTINUING MGMT

Office W/U

F/U ■

Console and reassure patient

CBC

■

Patient counseling

Peripheral smear

■

Family counseling

■ ■ ■

Bleeding time

■

PTT: Prolonged

■

PT, INR

■

Plasma factor VIII: 3%

■

Plasma factor IX

Rx ■

Factor VIII therapy

■

Genetics consult

■

Counsel parents Final Dx: Hemophilia

INITIAL MGMT Office W/U

CONTINUING MGMT

F/U ■

If initial treatment with OCPs and

■

Wet mount

NSAIDs does not relieve pain, refer to a

■

Chlamydia DNA probe

gynecologist for a trial of GnRH analogs,

■

Gonorrhea DNA probe

progestins, or danazol.

■

U/S—pelvis: Retroverted uterus of normal

■

Follow up as needed

size; 2- × 3-cm cyst on the right adnexa that may represent a hemorrhagic corpus luteum or endometrioma Rx ■

NSAIDs

■

OCPs Final Dx: Endometriosis

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APPENDIX

ACRONYMS AND ABBREVIATIONS Abbreviation

Meaning

Abbreviation

Meaning

A-a AAA ABC ABG AC ACA ACEI ACh ACL ACLS ACTH ADA ADH ADHD AED AF AFB AFI AFP AHI AICD AIDS ALL ALS ALT AMA AML ANA ANCA AP APC aPTT ARB ARDS ARF ARR 5-ASA ASA ASCA ASD ASMA ASO AST ATN

alveolar-arterial (oxygen gradient) abdominal aortic aneurysm airway, breathing, circulation arterial blood gas alternating current anterior cerebral artery angiotensin-converting enzyme inhibitor acetylcholine anterior cruciate ligament advanced cardiac life support (protocol) adrenocorticotropic hormone American Diabetes Association antidiuretic hormone attention-deficit hyperactivity disorder antiepileptic drug atrial fibrillation acid-fast bacillus amniotic fluid index α-fetoprotein apnea-hypopnea index automatic implantable cardiac defibrillator acquired immunodeficiency syndrome acute lymphocytic leukemia amyotrophic lateral sclerosis alanine aminotransferase antimitochondrial antibody acute myelogenous leukemia antinuclear antibody antineutrophil cytoplasmic antibody anteroposterior activated protein C activated partial thromboplastin time angiotensin receptor blocker acute respiratory distress syndrome acute renal failure absolute risk reduction 5-aminosalicylic acid acetylsalicylic acid anti–Saccharomyces cerevisiae antibody atrial septal defect anti–smooth muscle antibody antistreptolysin O aspartate aminotransferase acute tubular necrosis

AV AVM AVN AVNRT AXR AZT BAL BCG BID BMI BMP BMT BP BPH BPP BPPV BS BSA BSO BUN CABG CAD CAH CALLA

arteriovenous, atrioventricular arteriovenous malformation avascular necrosis atrioventricular nodal reentrant tachycardia abdominal x-ray zidovudine British anti-Lewisite bacille Calmette-Guérin twice daily body mass index basic metabolic panel bone marrow transplantation blood pressure benign prostatic hyperplasia biophysical profile benign paroxysmal positional vertigo bowel sounds body surface area bilateral salpingo-oophorectomy blood urea nitrogen coronary artery bypass graft coronary artery disease congenital adrenal hyperplasia common acute lymphocytic leukemia antigen community-acquired pneumonia complete blood count cognitive-behavioral therapy calcium channel blocker cyclic citrullinated peptide cluster of differentiation carcinoembryonic antigen cystic fibrosis total hemolytic complement congestive heart failure confidence interval cervical intraepithelial neoplasia creatine kinase chronic kidney disease creatine kinase, MB fraction chronic lymphocytic leukemia chronic myelogenous leukemia cytomegalovirus cranial nerve

CAP CBC CBT CCB CCP CD CEA CF CH50 CHF CI CIN CK CKD CK-MB CLL CML CMV CN

467

468

APPENDIX

ACRONYMS AND ABBREVIATIONS

Abbreviation

Meaning

Abbreviation

Meaning

CNS COMT COPD CPAP CPR CrCl CRP CSA CSF CST CT CTA CVA CVID CVS CXR D&C DBP DC DCIS DDAVP ddI DES DEXA DHEA DI DIC DIP DKA DLCO DM DMARD DNA DNR DPoA DPP DRE dsDNA DSM

central nervous system catechol-O-methyltransferase chronic obstructive pulmonary disease continuous positive airway pressure cardiopulmonary resuscitation creatinine clearance C-reactive protein central sleep apnea cerebrospinal fluid contraction stress test computed tomography clear to auscultation costovertebral angle common variable immunodeficiency chorionic villus sampling chest x-ray dilation and curettage diastolic blood pressure direct current ductal carcinoma in situ desmopressin acetate didanosine diethylstilbestrol dual-energy x-ray absorptiometry dehydroepiandrosterone diabetes insipidus disseminated intravascular coagulation distal interphalangeal (joint) diabetic ketoacidosis diffusing capacity of carbon monoxide diabetes mellitus disease-modifying rheumatic drug deoxyribonucleic acid do not resuscitate durable power of attorney dipeptidyl peptidase digital rectal examination double-stranded DNA Diagnostic and Statistical Manual of Mental Disorders deep tendon reflexes delirium tremens dysfunctional uterine bleeding deep venous thrombosis diffusion-weighted imaging Epstein-Barr virus electrocardiography extracorporeal membrane oxygenation electroconvulsive therapy erectile dysfunction ethylenediamine tetra-acetic acid electroencephalography ejection fraction esophagogastroduodenoscopy enzyme-linked immunosorbent assay

EM ENT EPS ER ERCP

erythema multiforme ear, nose, and throat extrapyramidal symptoms emergency room, estrogen receptor endoscopic retrograde cholangiopancreatography erythrocyte sedimentation rate extracorporeal shock-wave lithotripsy ethanol endoscopic ultrasound familial adenomatous polyposis focused abdominal sonography for trauma fractional excretion of sodium forced expiratory volume in one second fresh frozen plasma fluorescence in situ hybridization fine-needle aspiration fecal occult blood test follicle-stimulating hormone free thyroxine fluorescent treponemal antibody absorption (test) emtricitabine failure to thrive 5-fluorouracil forced vital capacity fever without a source gonorrhea and chlamydia (culture) gluciose-6-phosphate dehydrogenase gestational age generalized anxiety disorder global assessment of functioning glomerular basement membrane group B streptococcus, Guillain-Barré syndrome Glasgow Coma Scale granulocyte colony-stimulating factor gonadotropin-dependent precocious puberty gastroesophageal reflux disease glomerular filtration rate gamma-glutamyl transferase gastrointestinal gonadotropin-independent precocious puberty glucagon-like peptide granulocyte-macrophage colonystimulating factor gonadotropin-releasing hormone generalized tonic-clonic seizure gestational trophoblastic disease genitourinary history and physical highly active antiretroviral therapy hepatitis A virus

DTRs DTs DUB DVT DWI EBV ECG ECMO ECT ED EDTA EEG EF EGD ELISA

ESR ESWL EtOH EUS FAP FAST FeNa FEV1 FFP FISH FNA FOBT FSH FT4 FTA-ABS FTC FTT 5-FU FVC FWS G&C G6PD GA GAD GAF GBM GBS GCS G-CSF GDPP GERD GFR GGT GI GIPP GLP GM-CSF GnRH GTCS GTD GU H&P HAART HAV

ACRONYMS AND ABBREVIATIONS

APPENDIX

469

Abbreviation

Meaning

Abbreviation

Meaning

Hb HbA1c HBcAb HBeAg HBIG HBsAb HBsAg HBV HCC hCG HCTZ HCV HDCV HDL HDV HEENT HEV HGSIL HHNK

hemoglobin hemoglobin A1c hepatitis B core antibody hepatitis B early antigen hepatitis B immune globulin hepatitis B surface antibody hepatitis B surface antigen hepatitis B virus hepatocellular cancer human chorionic gonadotropin hydrochlorothiazide hepatitis C virus human diploid cell vaccine high-density lipoprotein hepatitis D virus head, eyes, ears, nose, and throat hepatitis E virus high-grade squamous intraepithelial lesion hyperglycemic hyperosmolar nonketotic state 5-hydroxyindoleacetic acid hepato-iminodiacetic acid (scan) Health Insurance Portability and Accountability Act heparin-induced thrombocytopenia human immunodeficiency virus human leukocyte antigen hydroxymethylglutaryl coenzyme A hereditary nonpolyposis colorectal cancer high-power field human papillomavirus heart rate human rabies immune globulin hormone replacement therapy Henoch-Schönlein purpura herpes simplex virus 5-hydroxytryptamine human T-cell lymphotropic virus hemolytic-uremic syndrome homovanillic acid inflammatory bowel disease irritable bowel syndrome intracerebral hemorrhage intracranial pressure intensive care unit immunoglobulin intramuscular isoniazid International Normalized Ratio idiopathic thrombocytopenic purpura intrauterine device intrauterine growth restriction intravenous inferior vena cava intravenous immunoglobulin

IVP JIA JVD JVP KOH KUB LAP LBBB LBP LCIS LCL LDH LDL LEEP LES LFT LGSIL LH LKMA LLQ LMN LP LTBI LUQ LVEF LVH MAOI MAT MCA MCHC

intravenous pyelography juvenile idiopathic arthritis jugular venous distention jugular venous pressure potassium hydroxide kidney, ureter, bladder (study) leukocyte alkaline phosphatase left bundle branch block low back pain lobular carcinoma in situ lateral collateral ligament lactate dehydrogenase low-density lipoprotein loop electrosurgical excision procedure lower esophageal sphincter liver function test low-grade squamous intraepithelial lesion luteinizing hormone liver/kidney microsomal antibody left lower quadrant lower motor neuron lumbar puncture latent tuberculosis infection left upper quadrant left ventricular ejection fraction left ventricular hypertrophy monoamine oxidase inhibitor multifocal atrial tachycardia middle cerebral artery mean corpuscular hemoglobin concentration medial collateral ligament metacarpophalangeal (joint) mean corpuscular volume major depressive disorder metered-dose inhaler Modification of Diet in Renal Disease (equation) multiple endocrine neoplasia myasthenia gravis monoclonal gammopathy of undetermined significance microhemagglutination assay for Treponema pallidum myocardial infarction 131I-metaiodobenzylguanidine (scan) medial longitudinal fasciculus 6-mercaptopurine magnetic resonance angiography magnetic resonance imaging methicillin-resistant S aureus multiple sclerosis maternal serum α-fetoprotein metatarsophalangeal (joint) muscle-specific kinase

5-HIAA HIDA HIPAA HIT HIV HLA HMG-CoA HNPCC hpf HPV HR HRIG HRT HSP HSV 5-HT HTLV HUS HVA IBD IBS ICH ICP ICU Ig IM INH INR ITP IUD IUGR IV IVC IVIG

MCL MCP MCV MDD MDI MDRD MEN MG MGUS MHA-TP MI MIBG MLF 6-MP MRA MRI MRSA MS MSAFP MTP MuSK

470

APPENDIX

ACRONYMS AND ABBREVIATIONS

Abbreviation

Meaning

Abbreviation

Meaning

NAD NC NCS NE NEC NG NHL NICU NK NNRTI

no acute distress nasal cannula nerve conduction study norepinephrine necrotizing enterocolitis nasogastric non-Hodgkin’s lymphoma neonatal intensive care unit natural killer (cells) non-nucleoside reverse transcriptase inhibitor number needed to treat nil per os (nothing by mouth) negative predictive value nucleoside reverse transcriptase inhibitor normal saline nonsteroidal anti-inflammatory drug non–small cell lung cancer nonstress test neural tube defect ova and parasites osteoarthritis obsessive-compulsive disorder oral contraceptive pill 17-hydroxyprogesterone odds ratio, operating room obstructive sleep apnea pulse posteroanterior premature atrial contraction perinuclear antineutrophil cytoplasmic antibody partial pressure of oxygen in arterial blood posterior cruciate ligament partial pressure of carbon dioxide polycystic ovarian syndrome phencyclidine hydrochloride, Pneumocystic carinii (now jiroveci) pneumonia polymerase chain reaction polycythemia vera pulmonary capillary wedge pressure Parkinson’s disease patent ductus arteriosus phosphodiesterase type 5a physical exam, pulmonary embolism pulseless electrical activity positive end-expiratory pressure polyethylene glycol positron emission tomography (scan) platelet factor pulmonary function test prostaglandin F2-α protease inhibitor pelvic inflammatory disease

PIP PIV PMI PMN PNH PNS PO POC Posm PPD PPH PPI PPROM PPV PR PRN PROM PSA PSGN PT PTH PTHrP PTSD PTT PTU PUD PUVA PVC PVS PWI RA RAST RBBB RBC RCT RDS RDW REM RF RIBA RLQ ROM RPR RR RRR

proximal interphalangeal (joint) parainfluenza virus point of maximal impulse polymorphonuclear (leukocyte) paroxysmal nocturnal hemoglobinuria peripheral nervous system per os (by mouth) product of conception plasma osmolarity purified protein derivative (of tuberculin) postpartum hemorrhage proton pump inhibitor preterm premature rupture of membranes positive predictive value progesterone receptor pro re nata (as needed) premature rupture of membranes prostate-specific antigen poststreptococcal glomerulonephritis prothrombin time parathyroid hormone parathyroid hormone–related peptide post-traumatic stress disorder partial thromboplastin time propylthiouracil peptic ulcer disease psoralen and ultraviolet A premature ventricular contraction persistent vegetative state perfusion-weighted imaging rheumatoid arthritis radioallergosorbent testing right bundle branch block red blood cell randomized controlled trial respiratory distress syndrome red cell distribution width rapid eye movement rheumatoid factor recombinant immunoblot assay right lower quadrant rupture of membranes rapid plasma reagin relative risk, respiratory rate regular rate and rhythm, relative risk reduction Reed-Sternberg (cells) respiratory syncytial virus renal tubular acidosis right upper quadrant residual volume right ventricular hypertrophy serum-ascites albumin gradient spontaneous abortion seasonal affective disorder

NNT NPO NPV NRTI NS NSAID NSCLC NST NTD O&P OA OCD OCP 17-OHP OR OSA P PA PAC p-ANCA PaO2 PCL PCO2 PCOS PCP

PCR PCV PCWP PD PDA PDE-5a PE PEA PEEP PEG PET PF PFT PGF2α PI PID

RS RSV RTA RUQ RV RVH SAAG SAB SAD

ACRONYMS AND ABBREVIATIONS

APPENDIX

471

Abbreviation

Meaning

Abbreviation

Meaning

SAH SBFT SBI SBP SCLC SERM SES SIADH

subarachnoid hemorrhage small bowel follow-through serious bacterial infection systolic blood pressure small cell lung cancer selective estrogen receptor modulator socioeconomic status syndrome of inappropriate secretion of antidiuretic hormone sudden infant death syndrome systemic inflammatory response syndrome systemic lupus erythematosus superior mesenteric artery sulfamethoxazole serotonin-norepinephrine reuptake inhibitor serum protein electrophoresis solitary pulmonary nodule subcutaneous selective serotonin reuptake inhibitor sexually transmitted disease supraventricular tachycardia triiodothyronine thyroxine total abdominal hysterectomy tuberculosis lamivudine technetium tricyclic antidepressant tetanus and diphtheria toxoid traveler’s diarrhea terminal deoxynucleotidyl transferase transesophageal echocardiography transposition of the great arteries transient ischemic attack total iron-binding capacity three times daily tetanus immune globulin

TIPS

transjugular intrahepatic portosystemic shunt total lung capacity tumor lysis syndrome trimethoprim trimethoprim-sulfamethoxazole tumor necrosis factor tenofovir tissue plasminogen activator total parenteral nutrition thyroid-stimulating hormone thrombotic thrombocytopenic purpura transurethral resection of the prostate urinalysis upper motor neuron urine osmolarity urine protein electrophoresis uvulopalatopharyngoplasty upper respiratory infection United States Preventive Services Task Force urinary tract infection ultraviolet voiding cystourethrography Venereal Disease Research Laboratory ventricular fibrillation vasoactive intestinal peptide vanillylmandelic acid ventilation-perfusion (ratio) vancomycin-resistant enterococcus vital signs ventricular septal defect venous thromboembolism von Willebrand’s disease von Willebrand’s factor varicella-zoster virus white blood cell well developed, well nourished within normal limits

SIDS SIRS SLE SMA SMX SNRI SPEP SPN SQ SSRI STD SVT T3 T4 TAH TB 3TC Tc TCA Td TD TdT TEE TGA TIA TIBC TID TIG

TLC TLS TMP TMP-SMX TNF TNV tPA TPN TSH TTP TURP UA UMN Uosm UPEP UPPP URI USPSTF UTI UV VCUG VDRL VF VIP VMA V/Q VRE VS VSD VTE vWD vWF VZV WBC WD/WN WNL

472

APPENDIX

ACRONYMS AND ABBREVIATIONS

NO T E S

INDEX

473

Index A Abacavir, 185 Abdominal aortic aneurysm (AAA), screening for, 29 Abdominal pain, 412–425 Abdominal trauma, 52 Abciximab, 32 Abortion recurrent, 274 spontaneous (SAB), 273–274, 444–445 types of, 273 Absence seizures, 326 Absolute risk, 97 Absolute risk reduction (ARR) or attributable risk, 98 ABVD cocktail, 147 Acarbose, 77 Accutane (isotretinoin), 24 Acetaminophen toxicity, 60, 124 estimation of severity, 124 Acetylcholinesterase inhibitors, 254 N-Acetylcysteine, 60, 124 Acid-base disorders, 229–230 Acinetobacter, 176 Achalasia, 104 Achilles tendon rupture, 206 Acne, neonatal, 302, 303 Acne vulgaris (common acne), 24 Actinobacillus actinomycetemcomitans, 46 Acute chest syndrome, 135 Acute coronary syndrome (unstable angina), 32 Acute lymphocytic leukemia (ALL), 144 Acute myelogenous leukemia (AML), 145 Acute renal failure (ARF), 222–223 causes of, 223 Acute respiratory distress syndrome (ARDS), 368–369 Acute tubular necrosis (ATN), 224 Adenosine, 39, 40, 57 Adenovirus, enteric, 187 Addisonian crisis, 86 Addison’s disease, 86–87 Adrenal crisis, 87 Adrenal insufficiency, 86–87 primary vs. secondary, 87 Advance directives, 94 Advanced cardiac life support (ACLS), 56–58

pulseless arrest, 57 tachycardia, 57 unstable bradycardia, 56 Agoraphobia, 334 Akathisia, 354 Albuterol, 363, 372 Alcohol intoxication, 345 withdrawal, 61, 345, 386–387 Alcoholism, 346 All-trans-retinoic acid, 145 Allergic rhinitis, 18–19 “Allergy shots,” 19 Allopurinol, 144, 148 α-blockers, 26, 27 α1-antitrypsin deficiency, 154 disorder, 125 α-fetoprotein (AFP), 164 maternal serum (MSAFP), 259 Alprazolam, 335 Alzheimer’s disease, 384–385 Altered mental status/loss of consciousness, 384–390 Amenorrhea, 277–278, 440–443 secondary, workup for patients with, 278 Aminocaproic acid, 60 Amiodarone, 57 Amitriptyline, 352 Amniocentesis, 259 Amoxicillin, 63, 69, 192, 363 Amphetamines intoxication, 345 withdrawal, 61, 345 Ampicillin, 192 Amyl nitrite, 60 Amyotrophic lateral sclerosis (ALS), 253 Anal wink, 244 Anaphylactic shock, 53 Anaplasma, 188 Anemia, 128–136 iron-deficiency, 129 macrocytic, 130–131 microcytic, 128–130 causes of, 128, 129 thalassemia, 130 normocytic normochromic, 131– 136 microangiopathic hemolytic, 133–134 sickle cell anemia, 134–136

Angina, 32, 404–405 stable, 32 unstable (acute coronary syndrome), 32, 404–405 Angiotensin receptor blockers (ARBs), 32, 41 Angiotensin-converting enzyme inhibitors (ACEIs), 32, 33, 41 Animal and insect bites, 62–63 Ankle-brachial index, 44 Ankylosing spondylitis, 205 Ann Arbor system, 147 Anorexia nervosa, 347 Anticholinergic toxidrome, 59 Anti-digitalis Fab, 60 Anticholinergics, 26 intranasal, 19 toxicity, 60 Antidepressants, 351–353 atypical, 352 monoamine oxidase inhibitors (MAOIs), 353 selective serotonin reuptake inhibitors (SSRIs), 352 tricyclic (TCAs), 352–353 Antidiabetic medications, oral, 77 Antihistamines, 19, 351 Antihypertensive medications, 41 Antimicrobial selection, 192–193 Antipsychotics, 353–354 extrapyramidal symptoms and treatment, 354 first-generation (“typical”), 353 second-generation (“atypical”), 353–354 Antiretroviral drugs, categories of, 185 Antisocial personality disorder, 333 Anxiety disorders, 332–336 generalized anxiety disorder (GAD), 332–333 obsessive-compulsive disorder (OCD), 334 panic disorder, 334–335 phobias, 335 posttraumatic stress disorder (PTSD), 336 Anxiolytics and sedative-hypnotics, 351 antihistamines, 351 benzodiazepines, 351 buspirone, 351 zolpidem, 351

474

INDEX

Aortic dissection, 41–43, 51, 408–409 ascending vs. descending, 43 Aortic injury, 52 Aortic regurgitation, 33 Aortic stenosis, 33 Aplastic crisis, 134 ARDS. See Acute respiratory distress syndrome Aripiprazole, 353 Arthritis juvenile idiopathic (JIA), 310–311 pauciarticular, 310 polyarticular, 310–311 systemic, 310 psoriatic, 21 reactive, 311 rheumatoid (RA), 198–199, 452– 453 radiographic findings in, 199 septic, 168–169, 450–451 Ascites. See Cirrhosis and ascites Asperger’s disorder, 348 Aspergillus, 189 Asthma, 359–361 chronic, medications for treatment of, 361 Ataxia-telangiectasia, 307 Atazanavir, 185 Atrial fibrillation (A-fib), 55, 410–411 Atrial flutter, 55 Atrial septal defect (ASD), 313–314 Atrioventricular (AV) block primary, 54 secondary, 54 tertiary, 54 Atrioventricular nodal reentrant tachycardia (AVNRT), 55 Atropine, 56, 60 Attention-deficit hyperactivity disorder (ADHD), 349 Attributable risk, 98 Auer rods, 145 Autism spectrum disorders, 348 Autonomy, 92–93 informed consent, 92 rights of minors, 92–93 Avoidant personality disorder, 333 AVPU system, 50 Azathioprine, 23 Azithromycin, 193, 324, 363 Aztreonam, 193 B Babesia, 188 Babesiosis, 188–189 Bacillus cereus, 112

Back pain, low (LBP), 204–205 causes of, 205 Bacteremia, 53 Bacteroides fragilis, 63 Banana bag, 61 Barbiturate intoxication, 345 withdrawal, 61, 345 Barium enema, 71 Barium swallow, 71 Barrett’s esophagus, 105, 156 Basal cell carcinoma, 161, 162 Bat bites, 63 Battle’s sign, 51, 244 Beck’s triad, 52 Behavioral therapy, 334 Bell’s palsy, 237 Benificence, 92 Benign paroxysmal positional vertigo (BPPV), 249 Benign partial epilepsy, 326 Benign prostatic hyperplasia (BPH), 26–27, 436–437 Benzodiazepines, 64, 333, 335, 337, 346, 351 intoxication, 345 toxicity, 60 withdrawal, 61, 345 Benztropine, 60 Bereavement, 339 Bernard-Soulier syndrome, 138 β-blockers, 26, 32, 35, 36, 41, 78, 335, 336 toxicity, 60 Bigeminy, 54 Biguanides, 77 Bile acid–binding resins, 45 Biliary cirrhosis, primary, 125 Biliary colic, 118 Biostatistics, 96–98 absolute risk, 97 absolute risk reduction (ARR) or attributable risk, 98 confidence interval (CI), 98 incidence, 97 number needed to treat (NNT), 98 odds ratio (OR), 98 predictive values, 96 prevalence, 97 relative risk (RR), 97–98 relative risk reduction (RRR), 98 sensitivity and specificity, 96 statistical significance/p-value, 98 Bipolar disorder, 339–340 Bisoprolol, 35 Bisphosphonates, 84, 149, 221 Bizarre delusion, 341

Bladder cancer, 157–158 Blast crisis, 146 Bleeding disorders, 136–140 coagulopathies, 138–140 von Willebrand’s disease (vWD), 140 platelet disorders, 137–138 Blepharoconjunctivitis, 69 Body dysmorphic disorder, 343 Bone marrow biopsy, 144 Bone marrow transplantation, 145, 146 Bone scan, 71 Borderline personality disorder, 333 Bordetella parapertussis, 324 Bordetella pertussis, 324 Borrelia burgdorferi, 187 Bouchard’s nodes, 203 Boxer’s fracture, 206 Bradyarrhythmias, common, 54 Bradycardia, 58 unstable, 56 Brain death, 242–243 Breast cancer, 150–151, 462–463 inflammatory, 151 Paget’s disease, 151 screening guidelines for, 28 Breast disorders, benign, 287 Bretylium, 65 Brief psychotic disorder, 341 British anti-Lewisite (BAL), 60 Broca’s aphasia, 239 Bromocriptine, 88 Bronchiolitis, 324–325, 371–372, 454–455 with patent ductus arteriosus (PDA), 454–455 Bronchitis, 177 chronic, 361 Bruton’s agammaglobulinemia, 307 Bulimia nervosa, 347–348 Bullae, definition of, 20 Bullous pemphigoid, 23–24 Buprenorphine, 61 Burkitt’s lymphoma, 147 Bupropion, 352 Burns, 66–67 classification of, 66 Buspirone, 333, 351 C C1 esterase deficiency, 309 CA 15-3, 164 CA 125, 164 CA 19-9, 164 Cabergoline, 88

INDEX

Caffeine, intoxication and withdrawal, 345 CAGE questions, 346 Calcitonin, 164 Calcium channel blockers (CCBs), 36, 41 Calcium gluconate, 60 Campylobacter, 187, 311 Campylobacter jejuni, 112, 247 Candida, 19, 46, 104, 189, 280 Candida albicans, 280 Carbamazepine, 355 Carbidopa, 253 Carbon monoxide toxicity, 60, 66 Carcinoembryonic antigen (CEA), 164 Carcinoid tumors, gastrointestinal, 157 Cardiac arrest, 56 Cardiac evaluation, advanced, 39–40 evaluating modalities in, 39 stressing modalities in, 39 Cardiac tamponade, 38, 51, 53 Cardiobacterium hominis, 46 Cardiology, pediatric, 313–316 atrial septal defect (ASD), 313–314 coarctation of the aorta, 316 patent ductus arteriosus (PDA), 314 tetralogy of Fallot, 315 transposition of the great arteries (TGA), 315 ventricular septal defect (VSD), 313 Carvedilol, 35 Case-control study, 100 Cat bites, 63 Cataplexy, 344 Cataracts, 69 Catatonia, 340 Cauda equina syndrome, 204, 205 Cefaclor, 193 Cefazolin, 193 Cefepime, 193 Cefotaxime, 193 Cefotetan, 193 Ceftazidime, 193 Ceftriaxone, 193, 297 Cefuroxime, 193 Celiac sprue, 112–113, 428–429 Cellulitis, 166, 448–449 Central nervous system (CNS) tumors, 163–164 glial tumors, 164 meningioma, 163–164 Cephalexin, 193 Cervical cancer, 160–161, 444–445 screening guidelines for, 28 Cervical intraepithelal neoplasia (CIN), 161

Cervical spine fracture, 51 Cervicitis/urethritis, 183 Cesarean section, indications for, 272 Charcot’s triad, 118 Chédiak-Higashi syndrome, 308 Chest pain, 404–411 Child abuse, 293–294, 450–451 Childhood disintegrative disorder, 348 Chlamydia, 174, 193 Chlamydia pneumoniae, 311 Chlamydia trachomatis, 68, 311 Chlorpropamide, 77 Cholangitis, 118–119 primary sclerosing, 126 Cholecystitis, 118–119, 422–423 acute, 422–423 Cholelithiasis, 118 Cholesterol absorption inhibitors, 45 Cholinergic toxidrome, 59 CHOP therapy, 148 Chorionic villus sampling, 259 Chromogranin A, 164 Chronic granulomatous disease (CGD), 308 Chronic lymphocytic leukemia (CLL), 145–146 Chronic myelogenous leukemia (CML), 146 Chronic obstructive pulmonary disease (COPD), 361 exacerbation, 398–399 Chvostek’s syndrome, 153 Ciprofloxacin, 193 Circadian rhythm sleep disorder, 344 Cirrhosis and ascites, 122–124 Citalopram, 352 Clarithromycin, 193, 363 Clavicular fracture, 207 Clavulanate, 63, 71 Cleft lip/palate, 298 Clindamycin, 193 Clomiphene, 284 Clomipramine, 352 Clonazepam, 335 Clonidine, 26, 61, 336 Clopidogrel, 32 Clostridium, 63 Clostridium difficile, 111–112, 193, 311, 428–429 Clostridium tetani, 63 Clotrimazole, 25 Clozapine, 353 Cluster headache, 247 Coagulopathy, 136–137 Coarctation of the aorta, 316 Cocaine intoxication, 345

475

withdrawal, 61, 345 Coccidioidomycosis, 192 Cognitive disorders, 337–338 delirium, 337–338 vs. dementia, 337 dementia, 338 delirium vs. 337 depression and anxiety due to a general medical condition, 338 Cognitive-behavioral therapy (CBT), 335, 348 Cohort study, 99 Colchicine, 37 Cold agglutinin disease, 132 Colic, 294 Colitis ischemic, 432–433 pseudomembranous, 428–429 ulcerative, 109, 432–433 Colles’ fracture, 206 Colon cancer, 156 screening guidelines for, 28 Colorectal cancer, 155–156, 426–427 risk factors for, 156 Common variable immunodeficiency (CVID), 307 Competency, 93 vs. capacity, 93 detention and use of restraints, 93 durable power of attorney (DPoA) for health care, 93 surrogate/proxy, 93 Computed tomography with contrast, 71 without contrast, 71 Computer-Based Clinical Simulations (CCS), guide to, 9–13 Conduct disorder, 348 Confabulation, 255 Confidence interval (CI), 98 Confidentiality, 93–94 follow-up questions, 94 importance of, 93 reportable conditions, 94 when to violate, 94 Congenital adrenal hyperplasia (CAH), 303–304 Congenital anomalies and malformations, 297, 298–299 Congenital diaphragmatic hernia, 295 Congestive heart failure (CHF), 34– 36, 400–401 arrhythmia causing, 36 cardiomyopathies, 35–36 dilated, 35 hypertrophic, 36 restrictive, 35

476

INDEX

Congestive heart failure (CHF), (Continued) diastolic, 35 exacerbation, 400–401 systolic, 34–35 valvular causes of, 36–37 Conjunctivitis, 68–69 allergic, 68 bacterial, 68–69 chemical, 68 neonatal, timeline of, 69 viral (“pink eye”), 69 Conotruncal anomaly face syndrome, 329 Constipation/diarrhea, 426–430 Continuous positive airway pressure (CPAP), 344, 371 Contraception, 283–284 emergency, 284 intrauterine devices (IUDs), 283 oral contraceptives (OCPs), 283 other hormonal contraceptives, 283 Conversion disorder, 342 Cor pulmonale, 362 Corneal abrasion, 68 Corticosteroids, intranasal, 19 Cough/shortness of breath, 394–403 Coxiella burnetii, 46 Craniopharyngioma, 163–164 CREST syndrome, 104, 212 Crohn’s disease, 107–108, 426–427 Croup (laryngotracheobronchitis), 321–323, 396–397 characteristics of, 322 Cryptococcosis, 191 Cryptococcus neoformans, 191 Cryptosporidium, 112, 187 CT. See Computed tomography Cullen’s sign, 115 Cushing’s disease, 85–86 Cushing’s syndrome (hypercortisolism), 85–86 endogenous, laboratory characteristics of, 85 Cushing’s triad, 51 Cyanide toxicity, 60 Cyclospora, 187 Cyclothymic disorder, 340 Cystic fibrosis (CF), 372–373, 400–401 Cystitis, 181, 438–439 acute, 438–439 Cystoscopy, 71 Cytomegalovirus (CMV), 298 D Dacryostenosis, 69 Dalfopristin, 193

Dantrolene, 65 Dawson’s fingers, 251 Deferoxamine, 60 Delirium, 337–338 vs. dementia, 337 Delusion, bizarre, 341 Delusional disorder, 341 Dementia, 253–254, 338 delirium vs. 337 Dental emergencies, 70–71 dental avulsion, 70 mandibular fracture, 70–71 Dependent personality disorder, 333 Depo-Provera, 283 Depression and anxiety due to a general medical condition, 338 major, 394–395 Dermatitis, 20–21 atopic (eczema), 20 contact, 21 Dermatitis herpetiformis, 112 Dermatology, 20–25, 301–303 acne vulgaris (common acne), 24 bullous pemphigoid, 23–24 dermatitis, 20–21 atopic (eczema), 20 contact, 21 dermatophytoses, 25 erythema multiforme (EM), 22–23 erythema nodosum, 21–22 herpes zoster, 24–25 pediatric, 301–303 eczema, 301–302 neonatal rashes, 301, 302 pemphigus vulgaris, 23 psoriasis, 21 rosacea, 22 terms, 20 Dermatomyositis, 210–211 Gottron’s papules in, 211 Dermatophytoses, 25 Desipramine, 352 Desmopressin, 140 Detention and use of restraints, 93 DEXA scan, 84 Diabetes mellitus (DM), 74–79, 261 complications of, 78–79 diabetic ketoacidosis (DKA), 78 hyperglycemic hyperosmolar nonketotic state (HHNK), 78–79 pregestational vs. gestational, 261 in pregnancy, 261 screening for, 29 target glucose levels in, 7 type 1, 74–75 type 2, 75–76

Diabetic ketoacidosis (DKA), 78, 424–425 Diabetic retinopathy, 16–17 Diagnostic and Statistical Manual of Mental Disorders (DSM), 332 Dialysis, 60 Diarrhea, 111–112 traveler’s (TD), 186–187, 428–429 common pathogens causing, 187 Diazepam, 65, 351 Dicloxacillin, 192 Didanosine (ddI), 185 DiGeorge syndrome (thymic aplasia), 307, 329 Digoxin, 35 toxicity, 60 Diltiazem, 57 Dimercaprol, 60 Dipeptidyl peptidase (DPP-4) inhibitors, 77 Diphenhydramine, 19, 53, 60 Dipyramidamole, 39, 40 Disease-modifying antirheumatic drugs (DMARDs), 311 Disopyramide, 36 Disruptive behavioral disorders, 348 Disseminated intravascular coagulation (DIC), 133 Dissociative fugue, 342 Dissociative identity disorder, 342 Distributive justice, 92 Diuretics loop, 35 thiazide, 41 Divalproex, 336 Diverticulitis, 169, 422–423 Diverticulosis, 114, 434–435 Do not resuscitate (DNR) orders/code status, 95 Dobutamine, 39 Dog bites, 62–63 Domestic abuse, 446–447 Dopamine, 56 “Double effect,” principle of, 95 Doxepin, 352 Doxycycline, 363 Dressler’s syndrome, 36 Drug withdrawal syndromes and treatment, 61 Duchenne’s muscular dystrophy, 252 Duplex ultrasound, 71 Durable power of attorney (DPoA) for health care, 93 Dyskinesia, 354 Dysmenorrhea, 278 Dysrhythmias, common, 54–56 Dysthymia, 339 Dystonia, acute, 354

INDEX

E Ear, nose, and throat (ENT), 17–19 allergic rhinitis, 18–19 epistaxis, 19 hearing loss, 18 influenza, 17–18 leukoplakia, 19 Eating disorders, 347–348 anorexia nervosa, 347 bulimia nervosa, 347–348 Echocardiography, 39 Eclampsia, 262, 263 Ectopic pregnancy, 281–282, 420– 421 Eczema (atopic dermatitis), 20 pediatric, 301–302 Edrophonium chloride (Tensilon), 248 EDTA, 60 Efavirenz, 185 Ehrlichia, 188 Ehrlichiosis, 188 Eikenella corrodens, 46, 62 Eisenmenger’s syndrome, 313, 314 Electrical injuries, 67 Electrocardiography, 39 Electroconvulsive therapy (ECT), 39 Electrolytes, 216–221 calcium, 219–221 hypercalcemia, 220–221 hypocalcemia, 219–220 potassium, 218–219 hyperkalemia, 218–219 hypokalemia, 218 sodium, 216–217 hypernatremia, 216–217 hyponatremia, 216 ELISA screen, 184, 372 Emphysema, 361 Emtricitabine (FTC), 185 Encephalitis, 170 herpes simplex virus (HSV), 170 West Nile, 170 Encephalopathy, lead intoxication with, 418–419 End-of-life care, 94–96 advance directives, 94 do not resuscitate (DNR) orders/ code status, 95 “double effect,” principle of, 95 euthanasia, 95 pain in terminally ill patients, 95 palliation and hospice, 95 persistent vegetative state (PVS), 95 quality of life, 95 withdrawal of treatment, 96

Endocarditis, infective, 46–48, 458– 459 causes of, 46 Endocrinology, pediatric, 303–305 congenital adrenal hyperplasia (CAH), 303–304 precocious puberty, 304–305 Endometrial cancer, 444–445 Endometriosis, 278–279, 284, 464– 465 Endometritis, 265 Endoscopy, upper or lower, 71 Enfuvitide (T20), 185 Entamoeba histolytica, 112, 187 Enterobacteriaceae, 193 Enterococcus, 46, 192, 193 vancomycin-resistant (VRE), 193 Enuresis, 349 Environmental emergencies, 64–65 cold emergencies, 64–65 frostbite, 64 hypothermia, 58, 64–65 heat emergencies, 65 heat exhaustion, 65 heat stroke, 65 Epidural hematoma, 243 Epiglottitis, 323–324 characteristics of, 322 Epilepsy syndromes, pediatric, 325– 326 Epinephrine, 53, 56, 57, 114 Epistaxis, 19 Epstein-Barr virus (EBV), 147 Eptifibatide, 32 Ertepenem, 193 Erythema multiforme (EM), 22–23 Erythema nodosum, 21–22 Erythema toxicum neonatorum, 302, 303 Erythromycin, 193, 324 Erythropoietin (Epogen), 130, 149 Escherichia coli, 112, 171, 181, 192, 193, 296, 428–429 enterotoxic (ETEC), 187 O157:H7, 133 Escitalopram, 352 Esophageal carcinoma, 104, 156 Esophageal pathology, 104–105 Esophageal spasm, 104 Esophagitis, 104 Ethambutol, 180 Ethanol, 60 Ethics and statistics, 91–101 autonomy, 92–93 informed consent, 92 rights of minors, 92–93 basic principles, 92

477

biostatistics, 96–98 absolute risk, 97 absolute risk reduction (ARR) or attributable risk, 98 confidence interval (CI), 98 incidence, 97 number needed to treat (NNT), 98 odds ratio (OR), 98 predictive values, 96 prevalence, 97 relative risk (RR), 97–98 relative risk reduction (RRR), 98 sensitivity and specificity, 96 statistical significance/p-value, 98 competency, 93 vs. capacity, 93 detention and use of restraints, 93 durable power of attorney (DPoA) for health care, 93 surrogate/proxy, 93 confidentiality, 93–94 follow-up questions, 94 importance of, 93 reportable conditions, 94 when to violate, 94 end-of-life care, 94–96 advance directives, 94 do not resuscitate (DNR) orders/ code status, 95 “double effect,” principle of, 95 euthanasia, 95 pain in terminally ill patients, 95 palliation and hospice, 95 persistent vegetative state (PVS), 95 quality of life, 95 withdrawal of treatment, 96 study design, 99–101 case-control study, 100 cohort study, 99 prospective and retrospective studies, 99 randomized controlled trial (RCT), 101 surveys, 99 Ethylene glycol toxicity, 60 Euthanasia, 95 Exanthem subitum (roseola infantum), 456–457 Exenatide, 77 Extracorporeal shock-wave lithotripsy (ESWL), 233 Extrapyramidal toxidrome, 59 Ezetimibe, 45

478

INDEX

F Factitious disorder, 343 Factor V Leiden deficiency, 140 Failure to thrive (FTT), 290–291 Fatigue/weakness, 390–394 Febrile seizures, 325 Fern test, 271 Ferritin, serum, 129 Fetal alcohol syndrome, 349 Fetal malpresentation, 271–272 Fetal well-being, tests of, 260–261 biophysical profile (BPP), 260 contraction stress test (CST), 260 fetal heart rate patterns, 260–261 nonstress test (NST), 260 Fever, 305, 454–461, 458–461 in child, 454–461 without a source (FWS), 305 Fexofenadine, 19 Fibrates, 45 Fibromyalgia, 209–210, 343 trigger points in, 210 Finasteride, 27 Fludrocortisone, 87 Flumazenil, 60 Fluorescein staining, 68 Fluoxetine, 352 Fluvoxamine, 352 Focused abdominal sonography for trauma (FAST), 51, 52 Folate deficiency, 131 Fomepizole, 60 Foreign-body aspiration, 394–395 Fragile X syndrome, 330 Framingham risk calculator, 29 Fresh frozen plasma (FFP), 60 Frostbite, 64 Fungal infections, 191–192 coccidioidomycosis, 192 cryptococcosis, 191 histoplasmosis, 191–192 Furosemide, 35, 124 Fusion inhibitors, 185 G Gabapentin, 355 Gastric MALToma, 147, 148 Gastric ulcer, bleeding, 430–431 Gastritis, 418–419 Gastrointestinal bleeding, 430–434 Gastrointestinal (GI) tumors, 153–157 carcinoid tumors, 157 colorectal cancer, 155–156 risk factors for, 156 esophageal cancer, 156 gastric tumors, 156–157

hepatocellular cancer (hepatoma), 154–155 islet cell tumors, 157 pancreatic cancer, 153–154 Gastroschisis, 298 Gatifloxacin, 193 Gallstone disease, 118–119 Gallstones, 115–116 Gardnerella vaginalis, 280 Gastroenterology, pediatric, 316–321 intussusception, 317–318 malrotation/volvulus, 318–319 Meckel’s diverticulum, 320 necrotizing enterocolitis (NEC), 320–321 pyloric stenosis, 316–317 Gastroesophageal reflux disease (GERD), 105 Gastrointestinal (GI) bleeding, 113– 114 lower, 114 upper, 113–114 Gemfibrozil, 45 myopathy due to, 448–449 Generalized anxiety disorder (GAD), 332–333 Genetic abnormalities, detection of, 259 Genetics, 329–330 disorders, common, 329–330 22q11 syndrome, 329 trisomy 13, 329 trisomy 18, 329 trisomy 21, 329 Genital herpes, 183 Genitourinary disorders, 25–27 benign prostatic hyperplasia (BPH), 26–27 erectile dysfunction (ED), 25–26 Genitourinary tract infections, 181 cystitis, 181 prostatitis, 181 pyelonephritis, 181 Genitourinary tumors, 157–161 bladder cancer, 157–158 cervical cancer, 160–161 ovarian cancer, 160 prostate cancer, 158 renal cell carcinoma, 159–160 testicular cancer, 158–159 Gentamicin, 193 Gestational trophoblastic disease, 263–264 Giant cell arteritis (temporal arteritis), 208–209, 380–381 Giardia, 112, 187 Giardiasis, 430–431

Glanzmann’s thrombasthenia, 148 Glasgow Coma Scale (GCS), 50 scoring of, 50 Glaucoma, 16, 69 closed-angle, 16 open-angle, 16, 17 Gleason score, 158 Gleevec (imatinib mesylate), 146 Glial tumors, 164 Glioblastoma multiforme, 164 Glipizide, 77 Glomerular filtration rate (GFR) and surrogates, 214 Glomerulonephritis, acute, 223–224, 436–437 Glomerulosclerosis, focal segmental, 228 Glucagon, 60 Glucagon-like peptide-1 (GLP-1) agonists, 77 Glucagonoma, 157 Glucose-6-phosphate dehydrogenase (G6PD) deficiency, 132, 414–415 α-Glucosidase inhibitors, 77 Glucosuria, 214 Glyburide, 77 Gottron’s papules, 211 Gout, 200–202, 448–449 and pseudogout, differential diagnosis of, 201 Gowers’ sign, 252 Graves’ disease, 80 Greenstick fracture, 207 Grey Turner’s sign, 115 Griseofulvin, 25 Growth and development, 290–292 developmental milestones, 292 failure to thrive (FTT), 290–291 Guillain-Barré syndrome, 247, 392– 393 H HACEK organisms, 46 Haemophilus aphrophilus, 46 Haemophilus influenzae, 171, 172, 174, 175, 192, 193, 307, 363 type b, 172, 308 Haemophilus parainfluenzae, 46 Hallucinogenic toxidrome, 59 Haloperidol, 61, 338 Headache, 246–247, 380–383 cluster, 247 migraine, 246–247, 380–381 tension, 246, 380–381 Health care maintenance, 27–30 cancer screening, 27–28

INDEX

immunizations, 30 routine screening, 28–29 Health Insurance Portability and Accountability Act (HIPAA), 93 Hearing loss, 18 Heart block, complete, 388–389 Heart disease ischemic, 32 pericardial, 36–38 pericardial effusion and cardiac tamponade, 38 pericarditis, 36–37 valvular, 33 Heart failure (congestive heart failure), 34–36 arrhythmia causing, 36 cardiomyopathies, 35–36 dilated, 35 hypertrophic, 36 restrictive, 35 diastolic, 35 systolic, 34–35 valvular causes of, 36–37 Heberden’s nodes, 202, 203 Helicobacter pylori, 106, 147, 148, 418–419 HELLP syndrome, 262 Hematologic malignancies, 144–149 leukemia, 144–146 acute lymphocytic (ALL), 144 acute myelogenous (AML), 145 chronic lymphocytic (CLL), 145–146 chronic myelogenous (CML), 146 lymphoma, 147–148 Hodgkin’s, 147 non-Hodgkin’s, 147–148 multiple myeloma, 148–149 Hematuria, 214, 225–226, 327, 434–437 Hemochromatosis, hereditary, 124 Hemolytic-uremic syndrome, 133 Hemophilia, 464–465 Henoch-Schönlein purpura (HSP), 311–312 Heparin low-molecular-weight (LMWH), 140, 368 toxicity, 60 Hepatic encephalopathy, 124 Hepatitis, 119–121 autoimmune, 125 viral etiologies, diagnosis, and treatment of, 121 and serologic tests, 120

Hepatitis A immunization, 30 Hepatitis B immunization, 30 Hepatocellular cancer (hepatoma), 154–155 Herpes, genital, 183 Herpes simplex virus (HSV), 298 encephalitis, 170 Herpes zoster, 24–25, 249 HIDA scan, 71, 118 High-density lipoprotein (HDL), 45 Highly active antiretroviral therapy (HAART), 185 Hip dislocation, 206 Hip fracture, 51, 206 Hirschsprung’s disease, 299 Histoplasmosis, 191–192 Histrionic personality disorder, 333 HIV infection, 184–186 antiretroviral drugs, categories of, 185 prophylaxis in, 186 HMG-CoA reductase inhibitors, 32, 45 Hodgkin’s lymphoma, 147 Hordeolum, 69 Horner’s syndrome, 151, 247 Hospice, 95 Howell-Jolly bodies, 134 Human bites, 63 Human chorionic gonadotropin (hCG), 164 Human diploid cell vaccine (HDCV), 63 Human rabies immune globulin (HRIG), 63 Humerus fracture, 206 Hyaline membrane disease, 295 Hydralazine, 33 Hydrocephalus, normal pressure, 384–385 Hydrocortisone, 87 Hydroxocobalamin, 60 Hydroxyurea, 134 Hypercalcemia, 83, 149, 153 Hypercholesterolemia, 44–45 Hypercalcemia, 220–221 causes of, 220 Hypercoagulable state (thrombophilia), 140–141 Hypercortisolism (Cushing’s syndrome), 85–86 endogenous, laboratory characteristics of, 85 Hyperemesis gravidarum, 262 Hypergammaglobulinemia, 125 Hyperglycemic hyperosmolar nonketotic state (HHNK), 78–79

479

Hyperkalemia, 148, 218–219 effects of, as seen on ECG, 219 treatment of, 219 Hyperlipidemia, 28–29 screening for, 28–29 treatment of, 29 Hypernatremia, 216–217 causes of, secondary to renal losses, 217 Hyperphosphatemia, 148 Hypertension, 35, 40–41, 58, 327 antihypertensive medications, 41 essential, 464–465 pregnancy-induced, 462–463 screening for, 28 Hypertensive emergency, 382–383 Hyperthermia, 58 Hyperthyroidism, 80–82, 406–407 Hyperuricemia, 148, 202 causes of, 202 Hyphema, 69 Hypnagogic hallucinations, 344 Hypnopompic hallucinations, 344 Hypocalcemia, 148, 219–220 causes of, 220 Hypochondriasis, 342–343 Hypokalemia, 218 Hypomania, 340 Hyponatremia, 153, 216, 227, 262 evaluation of, 217 Hypotension, 58 Hypothermia, 58, 64–65 Hypothyroidism, 80–82, 392–393 Hypoxia and hypoxemia, 359 Hypsarrhythmia, 325 I Idiopathic thrombocytopenic purpura (ITP), 138 IgA deficiency, 307 Imatinib mesylate (Gleevec), 146 Imipenem, 193 Imipramine, 352 Immunizations adult, 30 pediatric, 293 Immunology, pediatric, 306–309 immunodeficiency syndromes, 306–309 Kawasaki disease (mucocutaneous lymph node syndrome), 309 Incidence, 97 Incontinence, urinary, 285–286 types of, 286 Indinavir, 185 Infantile spasms (West syndrome), 326

480

INDEX

Infectious disease, pediatric, 305–306 fever without a source (FWS), 305 Infertility, 284 Inflammatory bowel disease (IBD), 107–109 Crohn’s disease, 107–108 ulcerative colitis, 109 Influenza, 17–18 immunization, 30 Informed consent, 92 Insomnia, primary, 343 Insulin, types of, 75 Insulinoma, 157 Intestinal atresias, 299 Intracerebral hemorrhage (ICH), 237, 238 Intrauterine devices (IUDs), 283 Intrauterine growth restriction (IUGR), 268 Intussusception, 317–318, 416–417 Ipratropium, 19 Iron, serum, 129 Iron toxicity, 60 Irritable bowel syndrome (IBS), 110, 426–427 Ischemic colitis, 432–433 Islet cell tumors, gastrointestinal, 157 Isoniazid (INH), 180 toxicity, 60 Isospora belli, 187 Isotretinoin (Accutane), 24 Itraconazole, 25 J J waves, 65 Janeway lesions, 46 Jaundice, neonatal, 297, 299–301, 418–419 breast milk, 300, 418–419 pathologic, 300–301 physiologic, 297, 299–300 Joint aspiration, inerpretation of, 196 Juvenile idiopathic arthritis (JIA), 310–311 pauciarticular, 310 polyarticular, 310–311 systemic, 310 Juvenile myoclonic epilepsy, 326 K Kawasaki disease (mucocutaneous lymph node syndrome), 309 Kayser-Fleischer rings, 125 Keratitis, 69 Ketoconazole, 25 Ketonuria, 214

Kimmelstiel-Wilson lesions, 228 Kidney disease chronic (CKD), 224–225 polycystic, 434–435 Kingella kingae, 46 Klebsiella, 175, 193 Knee injuries, 207 Korsakoff amnesia, 255 Korsakoff’s syndrome, 346 L Labor and delivery, abnormal, 270– 272 cesarean section, indications for, 272 fetal malpresentation, 271–272 preterm labor, 271 preterm premature rupture of membranes (PPROM), 270–271 shoulder dystocia, 272 Labyrinthitis, 249 Lactic dehydrogenase (LDH), 164 Ladd’s bands, 318 Lambert-Eaton syndrome, 153 Lamivudine (3TC), 185 Lamotrigine, 355 Landau-Kleffner syndrome, 326 Laryngotracheobronchitis (croup), 321–323 “Lazy eye” (strabismus), 69 Lead toxicity, 60, 416–417 with encephalopathy, 416–417 Learning disabilities, 349 Legionella, 174, 175, 176, 193 Lennox-Gastaut syndrome, 326 Leptospira, 63 Leukemia, 144–146 acute lymphocytic (ALL), 144 acute myelogenous (AML), 145 chronic lymphocytic (CLL), 145–146 chronic myelogenous (CML), 146 Leukoplakia, 19 Levamisole, 23 Levodopa, 253, 350 Levofloxacin, 193 Levothyroxine, 82 Lhermitte’s sign, 250 Libman-Sacks endocarditis, 46, 47 Lidocaine, 57, 60 Linezolid, 193 Listeria monocytogenes, 171, 172, 296 Lithium, 354, 355 Liver function tests, approach to, 117 Localization, neurologic, 236–237 Loop diuretics, 35

Lorazepam, 351 Low back pain (LBP), 204–205 causes of, 205 Low-density lipoprotein (LDL), 45 Lower esophageal ring, 104 Lower GI bleed, 114 Lower motor neuron (LMN) lesions, 236 LSD, intoxication and withdrawal, 345 Lumbar disk herniation, 452–453 Lung cancer, 151–153, 396–397 classification of, 152 non–small cell (NSCLC), 152 small cell (SCLC), 152 Lupus nephritis, 228 Lyme disease, 187–188 Lymphoma, 147–148 Hodgkin’s, 147 non-Hodgkin’s, 147–148 M Macule, definition of, 20 Magnesium, 60 Major depressive disorder (MDD), 338–339 Malaria prophylaxis, 186 Malingering, 343 Mallory-Weiss syndrome, 113–114 Malrotation/volvulus, 318–319, 416–417 Mandibular fracture, 70–71 Marcus Gunn pupil, 250 Marfan’s syndrome, 41, 330 Marijuana (THC), intoxication and withdrawal, 345 Mastitis, 265 McCune-Albright syndrome, 304 Meckel’s diverticulum, 320 Meconium aspiration syndrome, 295 Mefloquine, 186 Meglitinides, 77 Meigs’ syndrome, 160 Melanoma, 161–162 Melena, 113 Ménière’s disease, 249 Meningioma, 163–164 Meningitis, 454–455 bacterial, 170–172, 382–383, 454–455 antibiotic regimens for, 172 common causes of, 171 common CSF findings in, 171 Meningococcal immunization, 30 Menopause, 284–285, 440–441 Menorrhagia, 276 Mental retardation, 349

INDEX

Mentzer index, 129 Meperidine, 58 Meropenem, 193 Metabolic acidosis, 229–230 Metabolic alkalosis, 229–230, 262 Metformin, 77 Methanol toxicity, 60 Methemoglobinemia, 359 Methimazole, 81 Methylene blue, 60 Methylphenidate, 344 Metoclopramide, 354 Metoprolol, 35, 57 Metronidazole, 64, 193 Metromenorrhagia, 276 Metrorrhagia, 276 Microsporidia, 187 Microsporum canis, 25 Midazolam, 57 Migraine headache, 246–247, 380– 381 Milia, 302 Miliaria, 302 Minimal change disease, 228 Miosis, 58 Mirena, 283 Mirtazapine, 352 Mitral regurgitation, 33 Mitral stenosis, 33 Mitral valve prolapse, 33 MLF syndrome (internuclear ophthalmoplegia), 250 Mobitz I (Wenckebach), 54 Mobitz II, 54 Monkey bites, 63 Monoamine oxidase inhibitors (MAOIs), 336, 350, 353 side effects of, 353 Mononucleosis, infectious, 392–393 Mood (affective) disorders, 338–340 bipolar disorder, 339–340 major depressive disorder (MDD), 338–339 Mood stabilizers, 354–355 anticonvulsants, other, 355 carbamazepine, 355 lithium, 354 valproic acid, 355 Moraxella, 174, 363 Moraxella catarrhalis, 172 Moxifloxacin, 193 MRI with contrast, 71 Mucocutaneous lymph node syndrome (Kawasaki disease), 309 Mucor, 172 Multifocal atrial tachycardia (MAT), 55

Multiple endocrine neoplasia (MEN), 89 pheochromocytoma, 89 Multiple myeloma, 148–149 Multiple sclerosis (MS), 250–251 Munchausen’s syndrome, 343 Muscular dystrophy, 252 Musculoskeletal disorders, initial diagnosis of, 196 Musculoskeletal pain, 446–453 Myasthenia gravis (MG), 248–249 Mycobacterium avium-intracellulare (MAI), 186 Mycobacterium tuberculosis, 177, 180 Mycoplasma, 22, 174, 193 Mycoplasma genitalium, 183 Mydriasis, 58 Myelofibrosis, 132 Myeloproliferative disorders, laboratory features of, 133 Myofascial strain, 205 Myopathy due to simvastatin and gemfibrozil, 448–449 Myxedema coma, 82 N Nafcillin, 192 Naloxone, 60 Naltrexone, 61 Narcissistic personality disorder, 333 Narcolepsy, 343–344 Narcotic overdose, 388–389 Necrotizing enterocolitis (NEC), 320–321 Necrotizing fasciitis, 166–167 Negative predictive value (PPV), 96 Neisseria, 193, 309 Neisseria gonorrhoeae, 68 septic arthritis due to, 450–451 Neisseria meningitidis, 171, 172, 308 Nelfinavir, 185 Neonatology, 294–301 congenital anomalies, 297, 298 congenital ToRCHeS infections, 297, 298 jaundice, 297, 299–301 breast milk, 300 pathologic, 300–301 physiologic, 297, 299–300 neonatal sepsis, 296–297 respiratory distress, 295–296 Nephritis, lupus, 228 Nephrolithiasis, 231–233, 412–413 types of, 232 Nephropathy, 79 contrast, 224

481

diabetic, 228 membranoproliferative, 228 membranous, 228 Nephrotic syndrome, 226, 227–229 causes of, 228 Neural tube defects, 299 Neuroblastoma, 327 Neurogenic shock, 53 Neuroleptic malignant syndrome, 65, 350 Neurology, pediatric, 325–326 epilepsy syndromes, 325–326 febrile seizures, 325 Neuronitis, 249 Neuropathy, 79 Neurosyphilis, 183 Neutropenic fever, 189 Nevirapine, 185 Nicotine, intoxication and withdrawal, 345 Nicotinic acid (niacin), 45 Nikolsky’s sign, 23 Nitrazine paper test, 271 Nitrite toxicity, 60 Nodule, definition of, 20 Non-Hodgkin’s lymphoma, 147–148 Non-nucleoside reverse transcriptase inhibitors (NRTIs), 185 Nonmaleficence, 92 Nonsteroidal anti-inflammatory drugs (NSAIDs), 36, 37 Normal pressure hydrocephalus, 384–385 Nortriptyline, 352 Norwalk virus, 112 Nucleoside reverse transcriptase inhibitors (NRTIs), 185 Number needed to treat (NNT), 98 Nursemaid’s elbow, 207 NuvaRing, 283 O Obsessive-compulsive disorder (OCD), 334 Obsessive-compulsive personality disorder, 333 Obstructive sleep apnea (OSA), 371 Ocular trauma, 68 corneal abrasion, 68 ruptured globe, 68 Odds ratio (OR), 98 Odynophagia, 104 Olanzapine, 336, 338, 353 Oligohydramnios and polyhydramnios, 268, 269 Omphalocele, 298

482

INDEX

Oncology, pediatric, 326–328 neuroblastoma, 327 retinoblastoma, 328 tumor lysis syndrome (TLS), 328 Wilms’ tumor, 326–327 Onychomycosis, 25 Ophthalmology, 16–17, 68–69 conjunctivitis, 68–69 allergic, 68 bacterial, 68–69 chemical, 68 neonatal, timeline of, 69 viral (“pink eye”), 69 diabetic retinopathy, 16–17 glaucoma, 16, 69 closed-angle, 16 open-angle, 16, 17 ocular trauma, 68 corneal abrasion, 68 ruptured globe, 68 other conditions of the eye, 69 Ophthalmoplegia, internuclear (MLF syndrome), 250 Opioid toxidrome, 59, 60 Opioids intoxication, 345 withdrawal, 61, 345 Oppositional defiant disorder, 348 Optic neuritis, 250 Oral contraceptives (OCPs), 283 Ortho Evra, 283 Orthopedic injuries, common, 206– 208 adult, 206–207 pediatric, 207–208 Osborne/J waves, 65 Osgood-Schlatter disease, 207 Osler’s nodes, 46 Osteoarthritis (OA), 202–203 radiographic changes in knee, 203 Osteomyelitis, acute, 167–168 Osteopenia, 84 Osteoporosis, 84 screening for, 29 Otitis externa, 173 Otitis media, 173 Otosclerosis, 18 Oxacillin, 192 Oxcarbazepine, 355 Ovarian cancer, 160, 420–421 P p-value, 98 Paget’s disease, 151 Pain disorder, 343 Pain in terminally ill patients, 95

Palliation and hospice, 95 Pancoast’s syndrome, 151 Pancreatic cancer, 153–154, 420–421 Pancreaticoduodenectomy (Whipple procedure), 154 Pancreatitis, 115–116, 414–415 acute, 414–415 Pancytopenia, 128 Panic attack, 334–335, 410–411 Panic disorder, 334–335 Papule, definition of, 20 Paranoid personality disorder, 333 Parathyroid hormone (PTH), 220 Parkinson’s disease (PD), 252–253 Parkland formula, 66 Paroxetine, 352 Paroxysmal nocturnal hemoglobinuria (PNH), 132 Pasteurella multocida, 63 Patch, definition of, 20 Patent ductus arteriosus (PDA), 314, 454–455 bronchiolitis with, 454–455 Paternalism, 92 PDE-5a inhibitor, 26 Pelvic fractures, 52 Pelvic inflammatory disease (PID), 184, 284, 424–425 Pemphigus vulgaris, 23 Penicillamine, 60 Penicillin G, 192 Penicillin V, 192 Peptic stricture, 104 Peptic ulcer disease (PUD), 106–107 Pericardial disease, 36–39 pericarditis, 36–37, 406–407 Pericardial tamponade, 408–409 Pericardiocentesis, 51, 52, 53 Pericarditis, 36–37, 406–407 Periorbital/orbital infections, 167 Periorbital/preseptal cellulitis, 69, 167 Peripartum complications, 264–265 intrapartum and postpartum fevers, 265 mastitis, 265 postpartum hemorrhage, 264 causes of, 264 Sheehan’s syndrome (postpartum hypopituitarism), 264 Peripheral vascular disease, 43–44 Peritonitis, spontaneous bacterial (SBP), 123 Persistent vegetative state (PVS), 95 Personality disorders, 332, 333 signs and symptoms of, 333 Pertussis, 324 PET scan, 71

Pharyngitis, 173–174 Phencyclidine hydrochloride (PCP), intoxication and withdrawal, 345 Phenelzine, 353 Phenothiazine toxicity, 60 Pheochromocytoma, 89 Philadelphia chromosome, 146 Phobias, 335 Physostigmine, 60 “Pink eye” (viral conjunctivitis), 69 Pioglitazone, 77 Piperacillin, 192 Pituitary adenoma, 88 Placental separation, 269 Plain film, 71 Plaque, definition of, 20 Plasmodium falciparum, 186 Pleural effusion, 363–365 assays for exudative fluid and their differential diagnosis, 364 thoracentesis findings in transudative vs. exudative, 364 Plummer-Vinson syndrome, 104 Pneumatosis intestinalis, 320 Pneumococcal immunization, 30 Pneumocystis jiroveci, 176, 186, 402–403 Pneumonia, 174–176, 398–399, 402– 403, 456–457, 458–459 community-acquired (CAP), 174–175 empiric antibiotic treatment strategies for, 175 multilobar, 458–459 Pneumocystis jiroveci, 176, 186, 402–403 ventilator-associated, 176 Pneumothorax, 51, 365–366 tension, 53, 366, 404–405 Polycystic kidney disease, 434–435 Polycystic ovarian syndrome (PCOS), 279–280, 440–441 Polycythemia vera (PCV), 136 Polyhydramnios, 268, 269 Polymyalgia rheumatica, 209 Polymyositis, 210–211 Polysomnography, overnight, 371 Portal hypertension, 123 Positive predictive value (PPV), 96 Postpartum fever, 265 Postpartum hemorrhage, 264 causes of, 264 Postpartum hypopituitarism (Sheehan’s syndrome), 264 Posttraumatic stress disorder (PTSD), 336

INDEX

Pralidoxime, 60 Precocious puberty, 304–305 Predictive values, 96 Preeclampsia/eclampsia, 262, 263 Pregnancy ectopic, 281–282, 420–421 medical complications of, 261–264 diabetes mellitus (DM), 261 gestational trophoblastic disease, 263–264 hyperemesis gravidarum, 262 preeclampsia/eclampsia, 262 obstetric complications of, 268–270 intrauterine growth restriction (IUGR), 268 oligohydramnios and polyhydramnios, 268, 269 third-trimester bleeding, 269–270 teratogens in, 266–267 Premature atrial contraction (PAC), 54, 55 Premature ventricular contraction (PVC), 54, 56 Prenatal care and nutrition, 258 Prenatal diagnostic testing, 259 amniocentesis, 259 chorionic villus sampling, 259 triple-marker screen/quadruple test (quad screen), 259 Presbycusis, 18 Presbyopia, 69 Preterm labor, 271 Preterm premature rupture of membranes (PPROM), 270–271 Prevalence, 97 Prolactinoma, 88 Propionibacterium acnes, 24 Proportionality, 92 Propranolol, 81, 336 Propylthiouracil, 81 Prospective and retrospective studies, 99 Prostaglandin E, 315 Prostate cancer, 158, 434–435 screening guidelines for, 28 Prostate-specific antigen (PSA), 164 Prostatic nodules and abnormal PSA, workup of, 27, 28 Prostatitis, 181, 436–437 Protamine sulfate, 60 Protease inhibitors (PIs), 185 Proteinuria, 214, 226–227 location of renal disease in, 227 Proteus, 63, 192, 193 Pseudodementia, 339 Pseudoephedrine, 19 Pseudomembranous colitis, 428–429

Pseudomonas, 168, 172, 173, 175, 176, 189, 192, 193 Pseudomonas aeruginosa, 63, 373 Psoriasis, 21 Psoriatic arthritis, 21 Psychiatric disorders, childhood, 348–349 attention-deficit hyperactivity disorder (ADHD), 349 autism spectrum disorders, 348 disruptive behavioral disorders, 348 enuresis, 349 learning impairment, other causes of, 349 Psychiatric emergencies, 349–350 neuroleptic malignant syndrome, 350 serotonin syndrome, 350 suicide risk assessment, 349–350 Psychotic disorders, 340–342 dissociative fugue, 342 dissociative identity disorder, 342 schizophrenia, 340–341 Pulmonary embolism (PE), 53, 366– 368, 394–395 diagnostic approach to, 367 Pulmonary function tests (PFTs), 358 Pulmonary nodule, solitary (SPN), 369–370 Pulmonology, pediatric, 321–325 bronchiolitis, 324–325 croup (laryngotracheobronchitis), 321–323 characteristics of, 322 epiglottitis, 323–324 characteristics of, 322 pertussis, 324 Pulseless arrest, 57 Pustules, definition of, 20 Pyelonephritis, 181, 412–413 Pyloric stenosis, 316–317 Pyoderma gangrenosum, 107 Pyrazinamide, 180 Pyridoxine (vitamin B6), 60 Q Quetiapine, 336, 338, 353 Quinupristin, 193 R R-CHOP therapy, 148 “Raccoon eyes,” 51, 244 Radiation exposure from common radiologic procedures, 266 Radiology, 71

483

Radionuclide tracer (thallium or technetium), 39 Ramsay Hunt syndrome, 249 Randomized controlled trial (RCT), 101 Recurrent abortion, 274 Reed-Sternberg cells, 147 Relative risk (RR), 97–98 Relative risk reduction (RRR), 98 Renal amyloidosis, 228 Renal artery stenosis, 43, 44 Renal basics, 214–215 fractional excretion of sodium (FeNa), 215 glomerular filtration rate (GFR) and surrogates, 214 urinalysis (UA), intrepretation of, 214–215 Renal cell carcinoma, 159–160, 412–413 Renal failure, 149 acute (ARF), 222–223 causes of, 223 Renal tubular acidosis (RTA), 230– 231 types of, 231 Repaglinide, 77 Respiratory acidosis, 229–230 Respiratory alkalosis, 229–230 Respiratory depression, 58 Respiratory disorders, neonatal, 295 Respiratory distress syndrome, 295 Restraints, use of, 93 Retinal detachment, 69 Retinoblastoma, 328 Retinopathy, 79 Retrograde amnesia, 339 Rett’s disorder, 348 Reynolds’ pentad, 118 Rhinitis, allergic, 18–19 Rhinophyma, 22 Rheumatoid arthritis (RA), 198–199, 452–453 radiographic findings in, 199 Rheumatology, pediatric, 310–312 Henoch-Schönlein purpura (HSP), 311–312 juvenile idiopathic arthritis (JIA), 310–311 pauciarticular, 310 polyarticular, 310–311 systemic, 310 reactive arthritis, 311 Ribavirin, 372 Richter’s transformation, 146 Rickettsia, 193 Rifampin, 180

484

INDEX

Rights of minors, 92–93 Rinne test, 18 Risperidone, 336, 338, 353 Ritonavir, 185 Rodent bites, 63 Rome III criteria, 110 Rosacea, 22 Roseola infantum (exanthem subitum), 456–457 Rosiglitazone, 77 Rotavirus, 112, 187 Roth’s spots, 46 Rubella, 298 Ruptured globe, 68 S Salicylate toxicity, 60 Salmonella, 112, 168, 187, 311 Salter-Harris fractures, 207–208 Saquinavir, 185 Sarcoidosis, 370 Schizoaffective disorder, 341 Schizoid personality disorder, 333 Schizophrenia, 340–341 Schizophreniform disorder, 341 Schizotypal personality disorder, 333 Schwannoma, 249 Scleroderma, 104, 211–212 limited vs. diffuse, 212 Scorpion stings, 62 Seasonal affective disorder (SAD), 339 Seborrheic dermatitis, neonatal, 302, 303 Sedative-hypnotic toxidrome, 59 Seizures, 241–242 grand mal (complex tonic-clonic), 386–387 prevention of, first-line drugs for, 242 Selective serotonin reuptake inhibitors (SSRIs), 26, 333, 335, 336, 347, 350, 352 Selegiline, 353 Selenium sulfide, 25 Seminoma, 159 Sensitivity and specificity, 96 Sepsis, 189–191 severity of, 190 Septic arthritis, 168–169, 450–451 Septic shock, 53, 460–461 Serotonin syndrome, 350, 353 Sertraline, 352 Serum protein electrophoresis (SPEP), 148 Severe combined immunodeficiency (SCID), 308

Sexual assault, 62 Sexually transmitted diseases (STDs), 182–184 cervicitis/urethritis, 183 genital herpes, 183 pelvic inflammatory disease (PID), 184 syphilis, 182–183 Sheehan’s syndrome (postpartum hypopituitarism), 264 Shigella, 112, 187, 311 Shock, 53 hemodynamic characteristics of, 53 symptoms of, 53 types of, 53 Shoulder dislocation, 206 Shoulder dystocia, 272 Shprintzen syndrome, 329 Sickle cell anemia, 134–136 complications of, 135 Sildenafil (Viagra), 26 Simvastatin, myopathy due to, 448– 449 Sinus bradycardia, 54, 65 Sinus tachycardia, 55 Sinusitis, 172 acute, 172 chronic, 172 Sipple’s syndrome, 89 Sitagliptin, 77 Sjögren’s syndrome, 198 Skin tumors, 161–163 basal cell carcinoma, 161, 162 melanoma, 161–162 squamous cell carcinoma, 162–163 Skull fracture, basilar, 51 Sleep apnea, 344 obstructive (OSA), 371 Sleep disorders, 343–344 circadian rhythm sleep disorder, 344 insomnia, primary, 343 narcolepsy, 343–344 sleep apnea, 344 Smallpox immunization, 30 Smudge cells, 146 Snake bites, 63 Social phobia, 335 Sodium, fractional excretion of, 215 Sodium bicarbonate, 60 Sodium nitrite, 60 Sodium thiosulfate, 60 Soft tissue infections, 166–167 cellulitis, 166 necrotizing fasciitis, 166–167 Somatoform disorders, 342–343 body dysmorphic disorder, 343

conversion disorder, 342 hypochondriasis, 342–343 pain disorder, 343 somatization disorder, 342 Spherocytosis, hereditary, 132, 133 Spider bites, 63 Spinal cord compression, 244–246 Spinal nerve damage, 205 Spinal stenosis, 44, 205 Spironolactone, 35, 124 Spontaneous abortion (SAB), 273– 274, 444–445 types of, 273 Spontaneous bacterial peritonitis (SBP), 123 Squamous cell carcinoma, 162–163 Staphylococcus, 68, 112, 193, 307, 373 Staphylococcus aureus, 46, 47, 63, 69, 168, 173, 174, 265, 308 methicillin-resistant (MRSA), 175, 176, 192, 193 methicillin-sensitive, 176, 192 Staphylococcus epidermidis, 46 Statins, 45 Statistical significance/p-value, 98 Status epilepticus, 241 “Steakhouse syndrome,” 104 Steeple sign, 321 Stevens-Johnson syndrome, 355 Strabismus (“lazy eye”), 69 Streptococci, α-hemolytic, 63 group A, 173 group B, 171, 296 viridans, 46, 63 Streptobacillus moniliformis, 63 Streptococcus, 68, 192, 193, 363 Streptococcus agalactiae, 172 Streptococcus bovis, 47 Streptococcus pneumoniae, 171, 172, 174, 175, 308 Streptokinase toxicity, 60 Stroke, 237–240 hemorrhagic, 237–238 ischemic, 237–238 Study design, 99–101 case-control study, 100 cohort study, 99 prospective and retrospective studies, 99 randomized controlled trial (RCT), 101 surveys, 99 Subarachnoid hemorrhage (SAH), 237, 239 Subdural hematoma, 244

INDEX

Substance-related disorders, 344–346 alcoholism, 346 substance abuse/dependence, 344–346 intoxication and withdrawal, signs and symptoms of, 345 Succimer, 60 Suicide risk assessment, 349–350 Sulfonylureas, 77 Superior vena cava syndrome, 152 Surrogate/proxy, 93 Surveys, 99 Syndrome of inappropriate secretion of antidiuretic hormone (SIADH), 153, 221 causes of, 221 Syphilis, 182–183, 298 Systemic inflammatory response syndrome (SIRS) criteria, 190 Systemic lupus erythematosus (SLE), 196–197, 446–447 T 22q11 syndrome, 329 Tachyarrhythmias, common, 55–56 supraventricular, 55 ventricular, 56 Tachycardia, 58 Tachypnea, 58 Tadalafil, 26 Takayasu’s arteritis, 41 Tardive dyskinesia, 354 Tazobactam, 192 Technetium, 39 Teeth, numbering system and types of, 70 Temporal arteritis (giant cell arteritis), 208–209, 380–381 Tenofovir (TNV), 185 Tensilon (edrophonium chloride), 248 Tension headache, 246, 380–381 Tension pneumothorax, 53, 366, 404–405 Teratogens in pregnancy, 266–267 Terazosin, 27 Terbinafine, 25 Terminal complement deficiency, 309 Testicular cancer, 158–159 Tetanus, 63–64 immunization, 30 prophylaxis schedule, 64 Tetracyclines, 193 Tetralogy of Fallot, 315 Thallium, 39 Thiazide diuretics, 41 Thiazolinediones (“glitazones”), 77

Third-trimester bleeding, 269–270 Thrombocytopenia, 136, 137–138 acquired, 138 autoimmune, 138 drug-induced, 137 heparin-induced, 138 inherited, 138 Thrombophilia, 140–141 Thrombotic thrombocytopenic purpura (TTP), 133–134 Thumbprint sign, 323 Thymic aplasia (DiGeorge syndrome), 307 Thyroid disorders, 80–82 functional, 80–82 clinical presentation of, 80 differential and treatment of, 81 workup of, 81 thyroid nodules, 82 Thyroid storm, 82 Thyroidectomy, 81 Ticarcillin, 192 Tick-borne diseases, 187–189 babesiosis, 188–189 ehrlichiosis, 188 Lyme disease, 187–188 Tinea capitis, 25 Tinea corporis, 25 Tinea pedis, 25 Tinea versicolor, 25 Tirofiban, 32 Tissue plasminogen activator (tPA) toxicity, 60 Tobramycin, 193 Todd’s paralysis, 241 Topiramate, 336, 355 ToRCHeS infections, congenital, 297, 298 Torsades de pointes, 56, 57 Tourette’s syndrome, 349 Toxic shock syndrome, 460–461 Toxicology, 58–61 drug withdrawal syndromes and treatment, 61 specific antidotes and treatments, 60 toxidromes, classic, 59 Toxoplasma gondii, 186 Toxoplasmosis, 298 Tracheitis, characteristics of, 322 Tracheoesophageal fistula, 298 Transcutaneous pacing, 56 Transfusion complications, 142 Transient ischemic attack (TIA), 237, 390–391 Transient neonatal pustular melanosis, 302

485

Transient tachypnea of the newborn, 295 Transposition of the great arteries (TGA), 315 Transurethral resection of the prostate (TURP), 27 Tranylcypromine, 353 Trauma, 50–52, 450–451 ABCs and the primary survey, 50 nonaccidental, 450–451 secondary survey, 51–52 Travel medicine, 186–187 malaria prophylaxis, 186 traveler’s diarrhea (TD), 186–187, 428–429 common pathogens causing, 187 Trazodone, 352 Treadmill (stress test), 39 Treatment, withdrawal of, 96 Treponema pallidum, 182, 192 Trichomonas vaginalis, 280 Tricophyton mentagrophytes, 25 Tricophyton rubrum, 25 Tricophyton tonsurans, 25 Tricyclic antidepressants (TCAs), 26, 333, 335, 336, 352–353 intoxication, 390–391 toxicity, 60, 352 Trigeminy, 54 Triglycerides, 45 Trimethoprim-sulfamethoxazole (TMP-SMX), 193, 363 Trisomy 13, 329 Trisomy 18, 329 Trisomy 21, 329 Trousseau’s sign, 220 Trousseau’s syndrome, 153 Truth telling, 92 Tuberculosis, 177–180, 398–399 drugs, common side effects of, 180 extrapulmonary, 177 latent, 177 pulmonary, 178, 179 evolution of, 178 purified protein derivative (PPD) interpretation, 179 reactivation, 177 Tubo-ovarian abscess, 184 Tumor lysis syndrome, 148, 328 Tumor markers, 164 Tumors, definition of, 20 Turner’s syndrome, 316, 330, 442–443 U Ulcerative colitis, 109, 432–433 Ultrasound, 71

486

INDEX

Upper GI bleed, 113–114 Upper motor neuron (UMN) lesions, 236 Upper respiratory tract infections, 172–174 otitis externa, 173 otitis media, 173 pharyngitis, 173–174 sinusitis, 172 acute, 172 chronic, 172 Urethritis, 183, 438–439 Urinalysis (UA), intrepretation of, 214–215 Urinary incontinence, 285–286 types of, 286 Urine protein electrophoresis (UPEP), 148 Urinary tract infection, pediatric, 305–306 USMLE Step 3, guide to, 1–7 computer-based testing basics, 2–6 examination results, recent, 5 incomplete test, 6 questions, types of, 3–4 registering, 4–6 rescheduling, 6 scoring, 4, 6 structure, 2 test format, 2–3 time, 6 testing agencies, 7 USMLE/NBME resources, 7 Uterine bleeding, abnormal, 276–277, 442–443 types of, 276 Uveitis, 69

Vancomycin, 193 Vardenafil, 26 Vaso-occlusive crisis, 135 Vasopressin, 114 Velocardiofacial syndrome, 329 Venlafaxine, 334, 350, 352 Venom snake, 63 spider, 63 Ventricular fibrillation (VF), 56 Ventricular septal defect (VSD), 313 Ventricular tachycardia (V-tach), 56 Vertigo, 249–250 central, 249–250 peripheral, 249 Vesicles, definition of, 20 Vesicoureteral reflux, 305, 306 Viagra (sildenafil), 26 Vibrio, 187 Vibrio parahaemolyticus, 112 Vildagliptin, 77 VIPoma, 157 Virchow’s triad, 140, 366 Viridans streptococci, 46, 63 Vitamin B6 (pyridoxine), 60 Vitamin B12 deficiency, 131 Vitamin K, 60 deficiency, 138 Volitional/intentional disorders, 343 factitious disorder, 343 malingering, 343 Volvulus, 318–319, 416–417 von Willebrand’s disease (vWD), 140 V/Q scan, 71 Vulvovaginitis, 280–281 common causes of, 281 W

V Vaginal bleeding, 442–445 Vaginitis, atrophic, 462–463 Valproic acid, 355

Waldenström’s macroglobulinemia, 148 Warfarin, 141 toxicity, 60

Weber test, 18 Well-child care/routine health screening, 290 anticipatory guidance, 294 growth and development, 290–292 developmental milestones, 292 failure to thrive (FTT), 290–291 prevention of illness, 293 immunizations, 293 safety, 293–294 child abuse, 293–294 general principles, 293 Wermer’s syndrome, 89 Wernicke-Korsakoff syndrome, 255 Wernicke’s aphasia, 239 Wernicke’s encephalopathy, 255, 346 West Nile encephalitis, 170 West syndrome (infantile spasms), 326 Western blot, 184, 188 Whipple procedure (pancreaticoduodenectomy), 154 Wilms’ tumor, 326–327 Wilson’s disease, 125 Wiskott-Aldrich syndrome, 308 Wolff-Parkinson-White syndrome, 55, 57 X Xanthomas, 44 Xerophthalmia, 69 Y Yersinia, 112, 187, 311 Z Zavanelli maneuver, 272 Zenker’s diverticulum, 104 Zidovudine (AZT), 185 Ziprasidone, 353 Zolpidem, 351 Zoster immunization, 30

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ABOUT THE AUTHORS 497

About the Authors Tao Le, MD, MHS Tao has pursued his passion for medical education for the past 18 years. As senior editor, he has led the expansion of First Aid into a global educational series. In addition, he is the founder of the USMLERx online learning system as well as a cofounder of the Underground Clinical Vignettes series. As a medical student, he was editor-in-chief of the University of California, San Francisco Synapse, a university newspaper with a weekly circulation of 9000. Tao earned his medical degree from the University of California, San Francisco in 1996 and completed his residency training in internal medicine at Yale University and allergy and immunology fellowship training at Johns Hopkins University. At Yale, he was a regular guest lecturer on the USMLE review courses and an adviser to the Yale University School of Medicine curriculum committee. Tao subsequently went on to cofound Medsn, a medical e-learning company, and served as its chief medical officer. He is currently section chief of adult allergy and immunology at the University of Louisville. He enjoys travel, movies, good food, and spending time with his family.

Vikas Bhushan, MD Vikas is an author, editor, entrepreneur, and teleradiologist. In 1990 he conceived and authored the original First Aid for the USMLE Step 1. His entrepreneurial adventures include a successful software company, a medical publishing enterprise (S2S), an e-learning company (Medsn), and an ER teleradiology service (24/7 Radiology). His eclectic interests include medical informatics, independent film, humanism, Urdu poetry, world music, South Asian diasporic culture, and avoiding a day job. A dilettante at heart, he coproduced a music documentary on qawwali music and coproduced and edited Shabash 2.0: The Hip Guide to All Things South Asian in North America. Vikas completed a bachelor’s degree in biochemistry from the University of California, Berkeley; an MD with thesis from the University of California, San Francisco; and a radiology residency from the University of California, Los Angeles.

Herman Singh Bagga, MD Herman is a urology resident at the University of California, San Francisco. He has been involved in multiple First Aid projects since his time in medical school at the Johns Hopkins University School of Medicine. He was raised in New York City (which explains his rough and tough exterior) until moving to Erie, Pennsylvania (a small, quiet city responsible for cultivating his soft side), for the rest of his youth. As an undergraduate at Case Western Reserve University, he studied economics and biology before committing to medicine as his career path. His academic interests include outcomes research and medical education.