Mayo Clinic Internal Medicine Concise Textbook 1stEdition

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Mayo Clinic

Internal Medicine

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Editors-in-Chief

Thomas M. Habermann, MD

Amit K. Ghosh, MD

Mayo Clinic

Internal Medicine

Concise Textbook

MAYO CLINIC SCIENTIFIC PRESS

INFORMA HEALTHCARE

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The triple-shield Mayo logo and the words MAYO, MAYO CLINIC, and MAYO CLINIC SCIENTIFIC PRESS are marks of Mayo Foundation for Medical Education and Research.

All rights reserved. This book is protected by copyright. No part of it may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means—electronic, mechanical, photocopying, recording, or oth-erwise—without the prior written consent of the copyright holder, except for brief quotations embodied in critical articles and reviews. Inquiries should be addressed to Scientific Publications, Plummer 10, Mayo Clinic, 200 First Street SW, Rochester, MN 55905.

For order inquiries, contact Informa Healthcare, Kentucky Distribution Center, 7625 Empire Drive, Florence, KY 41041. E-mail: orders@taylorandfrancis.com.

www.informahealthcare.com

Library of Congress Cataloging-in-Publication Data

Mayo Clinic internal medicine concise textbook / edited by Thomas M. Habermann, Amit K. Ghosh. p. ; cm.

Includes bibliographical references and index. ISBN-13: 978-1-4200-6749-1 (hb : alk. paper)

ISBN-10: 1-4200-6749-4 (hb : alk. paper) 1. Internal medicine--Handbooks, manuals, etc. I.

Habermann, Thomas M. II. Ghosh, Amit. III. Mayo Clinic. IV. Title: Internal medicine concise textbook. [DNLM: 1. Internal Medicine--Handbooks. 2. Communicable Diseases--therapy--Handbooks. WB 39 M4727 2007]

RC55.M34 2007 616--dc22

2007027847 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices. However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, express or implied, with respect to the contents of the publication. This book should not be relied on apart from the advice of a qualified health care provider.

The authors, editors, and publisher have exerted efforts to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relat-ing to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new or infrequently employed drug. Readers are instructed to use caution while writing drug prescriptions and to verify the information, if necessary, with a local pharmacy to check on drug-drug interactions and to review the risk profile assessment of patients before writing prescriptions.

Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings. It is the responsibility of the health care providers to ascertain the FDA status of each drug or device planned for use in their clinical practice.

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Haitham S. Abu-Lebdeh, MD

Consultant, Division of General Internal Medicine, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Timothy R. Aksamit, MD

Consultant, Division of Pulmonary and Critical Care Medicine, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Robert C. Albright, Jr., DO

Consultant, Division of Nephrology and Hypertension, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Thomas J. Beckman, MD

Consultant, Division of General Internal Medicine, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Thomas Behrenbeck, MD

Consultant, Division of Cardiovascular Diseases, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Eduardo E. Benarroch, MD

Consultant, Department of Neurology, Mayo Clinic; Professor of Neurology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Peter A. Brady, MD

Consultant, Division of Cardiovascular Diseases, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Robert D. Brown, Jr., MD

Chair, Department of Neurology, Mayo Clinic; Professor of Neurology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Darryl S. Chutka, MD

Consultant, Division of Preventive and Occupational Medicine, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Brian A. Crum, MD

Consultant, Department of Neurology, Mayo Clinic; Assistant Professor of Neurology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Lisa A. Drage, MD

Consultant, Department of Dermatology, Mayo Clinic; Assistant Professor of Dermatology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Stephen B. Erickson, MD

Lynn L. Estes, PharmD

Infectious Disease Pharmacist Specialist, Mayo Clinic; Assistant Professor of Pharmacy, College of Medicine, Mayo Clinic; Rochester, Minnesota

Fernando C. Fervenza, MD, PhD

Consultant, Division of Nephrology and Hypertension, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Amit K. Ghosh, MD

Consultant, Division of General Internal Medicine, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

William W. Ginsburg, MD

Consultant, Division of Rheumatology, Mayo Clinic, Jacksonville, Florida; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Thomas M. Habermann, MD

Consultant, Division of Hematology, Mayo Clinic; Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

C. Christopher Hook, MD

Consultant, Division of Hematology, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

CONTRIBUTORS

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My father, who dedicated his life to medicine and represents the so many who have provided opportunities and examples for each of us in our careers.

Thomas M. Habermann, MD

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FOREWORD

ayo Clinic Internal Medicine: Concise Textbook reflects the continued commitment by the faculty of the Department of Internal Medicine to its mission of scholarship. One of the key traditions in medicine is the passing of knowledge from physician to physi-cian. In 1928, William J. Mayo, MD, wrote, “The glory of medicine is that it is constantly moving forward, that there is always more to learn. The ills of today do not cloud the horizon of tomorrow, but act as a spur to greater effort.”*_{This book is a response} to these themes. My hope is that it will aid in the care of patients.

Nicholas F. LaRusso, MD

Chair, Department of Internal Medicine Mayo Clinic, Rochester, Minnesota

*Mayo WJ. The aims and ideals of the American Medical Association. Proceedings of the 66th Annual Meeting of the National Education Association of the United States, 1928. p. 158-63.

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cientific observations and clinical advances are moving at a remarkable pace. These changes require physicians to remain abreast of the latest developments not only in their areas of expertise but also in areas beyond their sphere of expertise. To assist physicians in this endeavor, the Department of Medicine at Mayo Clinic remains committed to providing information to physicians in a timely manner. Mayo Clinic Internal Medicine: Concise Textbook is designed to meet the needs of medical students, nurse practi-tioners, physician assistants, physicians-in-training, and practicing clinicians by updating their knowledge of internal medicine and providing a concise review of internal medicine.

The overall approach to learning medicine can be summed up in two questions: What is it? What do you do for it? The goal is to have a concise review that is readable and easy to follow with algorithms, diagrams, radiographs, and pathologic find-ings. This book is divided into subspecialty topics, each chapter written by an author(s) with clinical expertise in the designated topic. Images and tables are provided. Each chapter has bulleted items that highlight key points. These may be summary points from previous paragraphs or new points. Bulleted items also address typical clinical scenarios. These scenarios emphasize classic clinical presentations. Pharmacy tables are included with many of the chapters. The scenarios and pharmacy tables highlight two key points. First, general internists, subspecialists, nurse practitioners, physician assistants, and family physicians diagnose dis-eases in internal medicine. Second, the predominant type of patient management is pharmacologic. Knowledge of the indications, toxic effects, and drug interactions is of paramount importance.

We thank everyone who contributed to the development of this book. We are indebted to all authors for their contribu-tions. We thank the staffs of the Section of Scientific Publications, Department of Medicine, and Division of Media Support Services at Mayo Clinic for their contributions to this book. The support and cooperation of the publisher, Informa Healthcare, are gratefully acknowledged.

We trust that this book will serve as an update and advance the reader’s knowledge of internal medicine. We hope that you enjoy this review as much as we have.

Thomas M. Habermann, MD Amit K. Ghosh, MD

Editors-in-Chief

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Consultant, Division of Tertiary Psychiatry and Psychology, Mayo Clinic; Assistant Professor of Psychiatry, College of Medicine, Mayo Clinic; Rochester, Minnesota

Barry L. Karon, MD

Kyle W. Klarich, MD

Lois E. Krahn, MD

Chair, Department of Psychiatry and Psychology, Mayo Clinic, Scottsdale, Arizona; Professor of Psychiatry, College of Medicine, Mayo Clinic; Rochester, Minnesota

Scott C. Litin, MD

Consultant, Division of General Internal Medicine, Mayo Clinic; Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

William F. Marshall, MD

Consultant, Division of Infectious Diseases, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Marian T. McEvoy, MD

Consultant, Department of Dermatology, Mayo Clinic; Professor of Dermatology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Bryan McIver, MBChB

Consultant, Division of Endocrinology, Diabetes, Metabolism, and Nutrition, Mayo Clinic, Rochester, Minnesota

Virginia V. Michels, MD

Consultant, Department of Medical Genetics, Mayo Clinic; Professor of Medical Genetics, College of Medicine, Mayo Clinic; Rochester, Minnesota

Clement J. Michet, Jr., MD

Consultant, Division of Rheumatology, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Timothy J. Moynihan, MD

Consultant, Division of Medical Oncology, Mayo Clinic; Assistant Professor of Oncology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Paul S. Mueller, MD

Consultant, Division of General Internal Medicine, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Steve R. Ommen, MD

Robert Orenstein, DO

John G. Park, MD

Steve G. Peters, MD

Consultant, Division of Pulmonary and Critical Care Medicine, Mayo Clinic; Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

John J. Poterucha, MD

Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Abhiram Prasad, MD

Deborah J. Rhodes, MD

Consultant, Division of Preventive and Occupational Medicine, Director, Women’s Health Fellowship, and Director, Women’s Executive Health Program, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

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Frank A. Rubino, MD

Emeritus Member (deceased), Department of Neurology, Mayo Clinic, Jacksonville, Florida; Emeritus Professor of Neurology, College of Medicine, Mayo Clinic; Rochester, Minnesota

Thomas R. Schwab, MD

Gary L. Schwartz, MD

Robert E. Sedlack, MD

Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic; Assistant Professor of Medical Education and of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Lynne T. Shuster, MD

Consultant, Division of General Internal Medicine and Director, Women’s Health Clinic, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Peter C. Spittell, MD

Karen L. Swanson, DO

Zelalem Temesgen, MD

Consultant, Division of Infectious Diseases, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Charles F. Thomas, Jr., MD

Consultant, Division of Pulmonary and Critical Care Medicine, Mayo Clinic; Associate Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Sally J. Trippel, MD, MPH

Consultant, Division of Preventive and Occupational Medicine, Mayo Clinic; Instructor in Preventive Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Thomas R. Viggiano, MD

Consultant, Division of Gastroenterology and Hepatology, Mayo Clinic; Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Abinash Virk, MD

Gerald W. Volcheck, MD

Consultant, Division of Allergic Diseases, Mayo Clinic; Assistant Professor of Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

Amy W. Williams, MD

John W. Wilson, MD

Christopher M. Wittich, PharmD, MD

Chief Medical Resident in Internal Medicine, Mayo School of Graduate Medical Education; Instructor in Medicine, College of Medicine, Mayo Clinic; Rochester, Minnesota

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Alma N. Adrover, PharmD, MS Jeffrey J. Armon, PharmD Sansana D. Bontaveekul, PharmD

Lisa K. Buss, PharmD Julie L. Cunningham, PharmD, BCPP

Lynn L. Estes, PharmD Jamie M. Gardner, PharmD

Darryl C. Grendahl, RPh Anna C. Gunderson, PharmD Heidi D. Gunderson, PharmD Thomas M. Habermann, MD Robert W. Hoel, RPh, PharmD

Todd M. Johnson, PharmD Philip J. Kuper, PharmD Jennifer D. Lynch, PharmD

Eric T. Matey, PharmD Kari L. B. Matzek, PharmD

Susan V. McCluskey, RPh Kevin W. Odell, PharmD John G. O’Meara, PharmD

Narith N. Ou, PharmD Lance J. Oyen, PharmD Michael A. Schwarz, PharmD

Virginia H. Thompson, RPh Christopher M. Wittich, PharmD, MD

Kelly K. Wix, PharmD Robert C. Wolf, PharmD

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1. Preparing for the U. S. Medical Licensing Examination Step 2

. . . .

1

Amit K. Ghosh, MD, Christopher M. Wittich, PharmD, MD

2. Allergy

. . . .

11

Gerald W. Volcheck, MD

3. Cardiology

. . . .

35

Kyle W. Klarich, MD, Thomas Behrenbeck, MD, Peter A. Brady, MD, Abhiram Prasad, MD, Steve R. Ommen, MD, Barry L. Karon, MD

4. Critical Care Medicine

. . . .

129

Steve G. Peters, MD

5. Dermatology

. . . .

147

Lisa A. Drage, MD, Marian T. McEvoy, MD

6. Endocrinology

. . . .

171

Bryan McIver, MBChB

7. Gastroenterology and Hepatology

. . . .

217

Robert E. Sedlack, MD, Thomas R. Viggiano, MD, John J. Poterucha, MD

8. General Internal Medicine

. . . .

279

Scott C. Litin, MD

9. Genetics

. . . .

305

Virginia V. Michels, MD

10. Geriatrics

. . . .

323

Darryl S. Chutka, MD

11. Hematology

. . . .

347

Thomas M. Habermann, MD

12. HIV Infection

. . . .

405

Zelalem Temesgen, MD

13. Hypertension

. . . .

429

Gary L. Schwartz, MD xiii

15. Medical Ethics

. . . .

549

C. Christopher Hook, MD, Paul S. Mueller, MD

16. Men’s Health

. . . .

559

Thomas J. Beckman, MD, Haitham S. Abu-Lebdeh, MD

17. Nephrology

. . . .

569

Fernando C. Fervenza, MD, PhD, Thomas R. Schwab, MD, Amy W. Williams, MD, Robert C. Albright, Jr., DO, Stephen B. Erickson, MD

18. Neurology

. . . .

613

Brian A. Crum, MD, Eduardo E. Benarroch, MD, Robert D. Brown, Jr., MD; Frank A. Rubino, MD

19. Oncology

. . . .

661

Timothy J. Moynihan, MD

20. Preventive Medicine

. . . .

693

Sally J. Trippel, MD, MPH

21. Psychiatry

. . . .

707

Lois E. Krahn, MD, Sheila G. Jowsey, MD

22. Pulmonary Diseases

. . . .

725

John G. Park, MD, Timothy R. Aksamit, MD, Karen L. Swanson, DO, Charles F. Thomas, Jr., MD

23. Rheumatology

. . . .

803

Clement J. Michet, Jr., MD, Kevin G. Moder, MD, William W. Ginsburg, MD

24. Vascular Diseases

. . . .

861

Peter C. Spittell, MD

25. Women’s Health

. . . .

879

Lynne T. Shuster, MD, Deborah J. Rhodes, MD

Index

. . . .

893

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1

Preparing for the

U.S. Medical Licensing Examination

Step 2

Amit K. Ghosh, MD

Christopher M. Wittich, PharmD, MD

The National Board of Medical Examiners (NBME) is responsible for administering the U.S. Medical Licensing Examination (USMLE). In its current form, the examination has four parts: step 1, step 2 CK (clinical knowledge), step 2 CS (clinical skills), and step 3. The step 1, step 2 CK, and step 3 examinations all include multiple-choice questions of different degrees of complexity.

The USMLE step 1 includes questions that measure the ability of candidates to apply basic science to clinical problems and is set at the level expected of a U.S. student finishing the second year of med-ical school. The USMLE step 2 CK focuses on principles of clinmed-ical science that are important for the student to apply while practicing medicine under supervision during postgraduate training. The USMLE step 2 CS is typically taken during the third or fourth year of medical school. Many students choose to take and pass the exam-ination before applying for a residency position. A student or grad-uate of a school accredited by the Liaison Committee on Medical Education or the American Osteopathic Association can take the examinations in any order. Graduates of a foreign medical school

can take the USMLE step 2 CK before step 1, although they have to pass the USMLE step 1 before registering for the USMLE step 2 CS. The USMLE step 3 assesses the ability of a physician to care for patients in an unsupervised setting and has a greater emphasis toward management of disorders. Candidates have to pass both steps1 and2 before registering for step 3. The step 3 examination is usually taken at the end of the first year of residency, although a few states do per-mit graduates to take this examination before joining a residency.

Part I of this chapter is aimed at candidates preparing for the USMLE step 2 CK. However, candidates preparing for any exam-inations that have multiple-choice questions also may benefit from the information, which covers various aspects of preparation for an examination, strategies to answer the questions effectively, and avoid-ance of pitfalls. Part II of this chapter is aimed at candidates prepar-ing for the USMLE step 2 CS. However, candidates preparprepar-ing for any examination dealing with standardized patients (such as Objective Structured Clinical Examinations, administered by many medical schools) also may benefit from the information.

1

Aim of the USMLE Step 2 CK Examination

The NBME has stated that the USMLE step 2 CK tests the breadth and depth of a candidate’s knowledge in clinical sciences to ensure that the candidate has attained the necessary proficiency required for the practice of medicine under supervision during postgrad-uate training.

Examination Format

Details regarding the examination, training requirements, eligibility requirements, application forms, and other related information can be obtained from the USMLE Web site: http://www.usmle.org. This site also includes information on test material and software tutorials. Candidates can save time on the day of the examination

Part I

Clinical Knowledge Examination

Amit K. Ghosh, MD

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by familiarizing themselves with the tutorial session well beforehand, and they can then use the 15 minutes assigned for this activity on examination day as additional break time.

The USMLE step 2 CK examination is a computerized exam-ination of 9 hours in duration. It includes eight 60-minute exami-nation blocks, an optional 15-minute tutorial session, and 45 minutes of self-scheduled free time. The average number of questions in each examination block varies from 46 to 50. Within the 60-minute examination blocks, candidates can review and change their responses (although this tendency needs to be kept to a minimum). After 60 minutes or if a candidate has declared that a block is finished, there is no returning to that portion of the examination. The candidate then decides whether to take a brief break or start working on the next 60-minute examination block.

Almost all of the questions are clinical and based on correct diagnosis and management. Because there is no penalty for guessing the answers, candidates should answer every question. Most questions are based on the presentations of patients. The ability to answer these questions requires integration of information provided from sever-al sources (such as history, physicsever-al examination, laboratory test results, and consultations), prioritization of alternatives, or use of clinical judgment. The overall ability to manage a patient in a cost-effective, evidence-based approach is stressed. Questions that require simple recall of medical facts are usually kept to a minimum. The examination is reviewed by committee members from academic set-tings, community practices, and licensing communities across the United States and Canada to ensure the questions are relevant to a general practice.

• Candidates should answer every question; there is no penalty for guessing.

• Most questions are based on presentations of patients.

• Questions that require simple recall of medical facts are in the minority.

A list of normal laboratory values and illustrative materials (such as electrocardiograms, blood smears, Gram stains, urine sediments, chest radiographs, and photomicrographs) necessary to answer ques-tions are provided. Candidates should interpret the abnormal values on the basis of the normal values provided and not on the basis of the normal values to which they are accustomed in their practice or train-ing. Although much of the information contained in this chapter is obtained from the previous information booklets, candidates for USMLE step 2 CK examination should read the material from the USMLE Web site because the NBME may change various components of the format of the examination.

• A list of normal laboratory values and illustrative materials nec-essary to answer questions are provided.

• The materials in the USMLE Web site should be read by candidates.

Scoring

The final score is dependent on the total number of correct answers. There is no negative marking for incorrect answers; hence, candidates

are advised to answer all questions.

Each candidate receives a 3-digit score that is calculated from a formula that includes the percentage score and percentile com-pared with those of other examinees. The minimum passing score is 182. This corresponds to answering 60% to 70% of the questions correctly.

The Examination Content

The content of USMLE step 2 CK examinations is developed from material along two dimensions (dimensions 1 and 2).

Dimension 1 includes topics on normal growth and development, basic concepts, and general principles. Questions address normal growth and development during infancy and childhood, adolescence and senescence, medical ethics, jurisprudence, applied biostatistics, and clinical epidemiology.

Dimension 2 includes questions on individual disorders, sub-divided according to physician task. The first set of tasks addresses promoting preventive medicine and health maintenance and includes assessment of risk factors, understanding epidemiologic data, and application of primary and secondary preventive measures. The sec-ond set of tasks addresses understanding mechanisms of disease, including etiology, pathophysiology, and effects of treatments. The third set of tasks addresses establishing a diagnosis, determining the next best step from the history and results of physical examination, or interpreting laboratory and radiologic test results. The fourth set of tasks addresses applying principles of management, including questions on best-care practices for ambulatory and inpatient settings. The full content of topics for both dimensions of the USMLE step 2 CK examination is available on the USMLE Web site (http://www.usmle.org), which all candidates should review criti-cally and with which they should be completely familiar.

Question Format

Each examination block contains 46 to 50 questions, 75% to 80% of which are multiple-choice, single-best–answer questions. The question may include a case history, a brief statement, a radiograph, a graph, or a picture (such as a blood smear or Gram stain). Each question has five possible answers (lettered A to E), and the candi-dates should identify the single-best answer. More than one answer may seem to be correct or partially correct for a question. Also, the traditionally correct answer may not be listed as an option. In that situation, the one answer that is better than the others should be selected. If unsure of an answer, candidates should make a calculated guess. Remember, unanswered questions are counted as wrong answers. The remaining questions are of the matching-set variety, and they are usually at the end of the examination. They are related to a common topic. There could be as many as 26 lettered options, fol-lowed by two or more relatively brief vignettes. Candidates are asked to choose the best single option that answers a question. One should start by reading and becoming familiar with the option list. The question should be read carefully. Within a set, a given option might be used once or more than once or never used. When faced with answering matching-set questions with several options, one should

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Chapter 1 U.S. Medical Licensing Examination Step 2 3

try to answer the question before looking at the list of choices in the option list as a means of being efficient with time. As noted above, most questions are based on the presentations of patients. The exam-ples in this chapter and the examexam-ples included in the USMLE step 2 CK information booklet (138 questions) should help candidates become familiar with the question format. Several books and com-puter programs are available that can be used to practice answering these types of questions.

• Questions are mostly of the single-best–answer type (75%), and the remaining are of the matching-set type (25%).

• Various study guides should be used to become familiar with the question format.

Examples of Questions

Single-Best Answer

Select the single best answer for each of the following questions. 1. A 56-year-old woman is referred to you for evaluation of

dys-pnea and chest pain of 6 weeks in duration. The chest pain is nonpleuritic, nonexertional, and located along the lower right lateral chest cage. She has no fever, cough, or chills. During the past few weeks, she has been experiencing constant low back pain. The patient underwent right mastectomy 4 years ago because of carcinoma of the breast with metastatic involvement of the right axillary lymph nodes. She received radiotherapy fol-lowed by chemotherapy for 24 months. Examination now shows diminished breath sounds in the right lower lung field. Results of the remainder of the examination are unremarkable. A chest radiograph suggests a moderate right pleural effusion. Which one of the following tests is most likely to be helpful in confirming the suspected diagnosis?

A. Bone scanning with technetium Tc 99m diphosphonate B. Bone marrow aspirate and biopsy

C. Scalene fat pad biopsy D. Thoracentesis E. Mammography

2. A 20-year-old male military recruit returns home from several weeks of summer training in boot camp. He appears in your office the following day with a 12-day history of fever (38°C), coryza, pharyngitis, and cough. Physical examination discloses a bullous lesion over the right tympanic membrane and scat-tered crackles in both lung fields. Blood cell count shows mild thrombocytopenia. A chest radiograph shows patchy alveolar-interstitial infiltrates in both lungs. Which one of the following is the best treatment for this patient?

A. Erythromycin B. Penicillin C. Trimethoprim D. Clindamycin E. Ceftazidime

3. A 49-year-old male executive comes to your office with a 6-month history of cough, shortness of breath, and chest tight-ness soon after substantial exertion. He notices these symptoms soon after he finishes a game of racquetball. He is a nonsmoker and has no risk factors for coronary artery disease. Results of physical examination in your office are normal. His weight is normal for his height. The chest radiograph is normal. A tread-mill test for ischemic heart disease is negative. Which one of the following diagnostic tests is indicated?

A. CT of the chest

B. Arterial blood gas studies at rest and after exercise C. Spirometry before and after exercise

D. Ventilation-perfusion lung scanning E. Cardiopulmonary exercise testing

4. A 43-year-old asymptomatic man has chronic hepatitis C. Therapy for 12 months with a combination of interferon and ribavirin failed to clear the virus. Laboratory results are notable for an alanine aminotransferase value of 65 U/L and normal values for bilirubin, albumin, and prothrombin time. A liver biopsy shows a mild lymphocytic portal infiltrate but no fibrosis. Which one of the following statements about this patient is true? A. He should be given lamivudine.

B. He should have screening for hepatocellular carcinoma and undergo ultrasonography and α-fetoprotein testing every 6 months.

C. He should have endoscopy to look for esophageal varices. D. He should be referred for liver transplantation.

E. He should receive the hepatitis A and B vaccines if he is not already immune.

5. A patient who is positive for human immunodeficiency virus (HIV) and has low CD4 counts is receiving multidrug treat-ment. He complains of colicky flank pain, and many crystals are subsequently noted on urinalysis. Which one of the fol-lowing drugs is most likely causative?

A. Ribavirin

B. Trimethoprim-sulfamethoxazole C. Indinavir

D. Acyclovir E. Ganciclovir

6. A 34-year-old woman comes to your office with a 4-week history of hemoptysis, intermittent wheeze, and generalized weakness. On examination her blood pressure is 186/112 mm Hg. She appears cushingoid and has noted these changes taking place during the past 12 weeks. Auscultation discloses localized wheezing in the left mid-lung area. The chest radi-ograph indicates partial atelectasis of the left upper lobe. She is referred to you for further evaluations. Which one of the following is least likely to provide useful information for diagnosis and treatment?

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A. Serum adrenocorticotropic hormone level

B. 24-Hour urine test for 5-hydroxyindoleacetic acid level C. Bronchoscopy

D. CT of the chest E. Serum potassium level

7. A 62-year-old woman presents with the onset of eye discomfort and diplopia. She has not noted any other new neurologic symp-toms. Neurologic examination shows a normal mental status and neurovascular findings. Reflexes are slightly decreased in the lower extremities. Gait and coordination are normal. Cranial nerves show an inability to adduct, elevate, and depress the eye. Pupillary reaction is normal. Motor strength testing is negative. Sensation is normal, except there is decreased vibratory and joint position sensation in the feet. What abnormality would be expected? A. Saccular aneurysm of the cavernous sinus on CT B. Brain stem neoplasm on MRI

C. Left temporal sharp waves on electroencephalography D. Increased fasting blood sugar

E. Increased erythrocyte sedimentation rate

8. A 42-year-old man who is an office worker presents to the emer-gency department with acute dyspnea. He has smoked 1 1/2 packs per day for 25 years and had been relatively asympto-matic except for a smoker’s cough and mild dyspnea on exertion. Physical examination findings are not remarkable except for slightly diminished intensity of breath sounds over the right lung and some prolonged expiratory slowing, consistent with obstructive lung disease. The chest radiograph shows extensive infiltrates in the upper two-thirds of the lung fields. Which one of the following conditions is most likely responsible for this patient’s symptoms?

A. Pulmonary alveolar proteinosis B. Silicosis

C. Pulmonary eosinophilic granuloma (histiocytosis X) D. Idiopathic pulmonary fibrosis

E. Sarcoidosis

9. In a 34-year-old man with acute myelomonocytic leukemia, fever and progressive respiratory distress develop, and the chest radiograph shows diffuse alveolar infiltrates. The patient com-pleted intensive chemotherapy 6 weeks earlier. The total leuko-cyte count has remained less than 0.5 × 109_{/L for more than 3} weeks. He is currently (for at least 10 days) receiving a cephalosporin (ceftazidime). Which one of the following is the most appropriate therapy for this patient?

A. Clindamycin

B. Blood transfusion to increase the number of circulating leukocytes

C. Antituberculous (triple-drug) therapy D. Amphotericin intravenously

E. Pentamidine aerosol

The answers to the questions are as follows: 1, D (metastatic pleural effusion); 2, A (Mycoplasma infection); 3, C (exercise-induced asthma); 4, E; 5, C (side effect of HIV medications); 6, B (bronchial carcinoid); 7, D (complications of diabetes mellitus, paralysis of cra-nial nerve III); 8, C (histiocytosis X, or pulmonary eosinophilic gran-uloma, with spontaneous pneumothorax); 9, D (disseminated aspergillosis in a leukopenic patient).

Questions 1 through 3 are examples of questions that are aimed at evaluating knowledge and judgment about problems that are encountered frequently in practice and for which physician inter-vention makes a considerable difference. These questions judge the candidate’s minimal level of clinical competence. These questions include descriptions of typical clinical features of metastatic breast carcinoma, Mycoplasma pneumonia, and exercise-induced asthma, respectively. Therefore, the decision making is relatively easy and straightforward. Questions 4 through 9 are more difficult to answer because they are structured to reflect excellence in clinical compe-tence rather than just minimal compecompe-tence. In other words, they require more extensive knowledge (i.e., knowledge beyond that required for minimal competence) in internal medicine and its sub-specialties. Although most of the questions on the examination are based on the presentations of patients, some require recall of well-known medical facts.

Matching-Set Questions Questions 10-14

Match the characteristics of each of the genitourinary disorders described below with its associated organism.

A. Trichomonas vaginalis B. Gardnerella vaginalis C. Human papillomavirus D. Candida albicans E. Neisseria gonorrhoeae

10. Greenish, frothy, vaginal discharge, motile flagellate seen micro-scopically on wet mount preparation

11. Cheesy-white vaginal discharge 12. Associated with carcinoma of the cervix

13. Right iliac fossa pain, Gram stain of cervical smear might show gram-negative diplococci

14. Vaginal discharge with fishy odor, “clue” cells on microscopy The answers to the questions are as follows: 10, A; 11, D; 12, C; 13, E; 14, D.

Preparation for the Test

Training during medical school forms the foundation on which advanced clinical knowledge is accumulated. Most candidates will require a minimum of 6 to 8 months of intense preparation for the examination. Cramming just before the examination is

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counter-productive and is unlikely to be successful. It must be remembered that this is a 9-hour grueling computerized examination for which adequate preparation is mandatory. Candidates should start by becoming familiar with the scope of and kinds of questions in the examination. All orientation materials are available on a CD or by download from the Web site. The tutorial on how to take the test should be reviewed several times in order to become completely familiar with the steps required to move from screen to screen, mark questions for later review, look up the table of normal laboratory values, and open figures in the questions. One should get into the habit of spending around 60 seconds with each question.

Preparation for the USMLE Step 2 CK examination should start at the beginning of the third year of medical school. Some of the methods of preparation for the USMLE examination are described below. Additionally, each candidate may develop her or his own system.

Each candidate should study a standard textbook of internal medicine to obtain a thorough knowledge base in all areas of internal medicine. Ideally, the candidate should use one textbook and not jump from one to another, except for reading certain chap-ters that are outstanding in a particular textbook. The most effec-tive way to use the textbook is with patient-centered reading; this should occur throughout medical school and the residency program. This book and similar board review syllabi are excellent tools for brushing up on important board-relevant information several weeks to months before the examination. This book is designed as a study guide rather than a comprehensive textbook of medicine. Therefore, it should not be used as the sole source of medical information for the examination.

• Candidates should thoroughly study a standard textbook of internal medicine.

• This book is designed as a study guide and should not be used as the sole source of information for preparation for the examination. The Review for USMLE Step 2 CK, part of the National Medical Series for Independent Study, is extremely valuable for obtaining practice in answering multiple-choice questions. The questions and answers are useful for learning the type of questions asked and the depth of knowledge expected for various subjects.

Some candidates find it helpful to prepare for the examination in study groups. Formation of two to five candidates per group per-mits study of different textbooks and review articles in journals. The group should meet regularly as each candidate is assigned reading materials. Selected review articles on common and important topics in internal medicine should be included in the study materials. Indiscriminate reading of articles from many journals should be avoided. In any case, most candidates who begin preparation 6 to 8 months before the examination will not find time for extensive study of journal materials. Information in recent (within 6-9 months of the examination) medical journals is unlikely to be included in the examination. Notes and other materials the candidates have gath-ered during medical school are also good sources of information. These clinical “pearls” gathered from mentors will be of help in remembering certain important points.

• Study groups may help cover large amounts of information.

• Indiscriminate reading of articles from many journals should be avoided.

• Information in recent (within 6-9 months of the examination) medical journals is unlikely to be included in the examination.

Candidates should try to remember some of the uncommon manifestations of the most common diseases (such as polycythemia in common obstructive pulmonary disease) and common manifes-tations of uncommon diseases (such as pneumothorax in eosinophilic granuloma). The majority of the questions on the examination involve conditions most commonly encountered in clinical prac-tice. Several formulas and points should be memorized (such as the anion gap, calculated serum osmolality, and osmolar gap equations). The clinical training obtained and the regular study habits formed during medical school are the most important aspects of preparation for the examination.

In general, the examination rarely has questions about specific drug dosages or specific chemotherapy regimens used in oncology. Rather, questions are geared toward concepts regarding the treat-ment of patients. Questions regarding adverse effects of medica-tions are common on the examination, especially when the adverse effect occurs frequently or is potentially serious. The candidate is also expected to recognize when a clinical condition is a drug-related event.

• Study as much as possible about board-eligible topics.

• Learn about the uncommon manifestations of common diseases and the common manifestations of uncommon diseases.

Day of the Examination

Adequate time is allowed to read and answer all the questions; there-fore, there is no need to rush or become anxious. The time is given in the right lower corner of the computer screen, and this should be checked to ensure that you are at least halfway through the exami-nation when half the time has elapsed. Start by answering the first question and continue sequentially. Almost all of the questions fol-low a case presentation format. Do not be alarmed by lengthy ques-tions; look for the question’s salient points. When faced with a confusing question, do not become distracted by that question. Mark it so you can find it later, then go to the next question and come back to the unanswered ones at the end. However, as mentioned before, this tendency to leave questions unanswered should be limited because experience has shown that the initial intuitive response to questions is often accurate and efforts to change the answer at a later time could prove counterproductive. Extremely lengthy stem state-ments or case presentations are apparently intended to test the can-didate’s ability to separate the essential from the unnecessary or unimportant information. You may want to highlight important information presented in the question in order to review this infor-mation after reading the entire question and the answer options. This habit, too, should be kept to a minimum. Remember that each additional activity that you do (e.g., highlight sections of the question and hesitation) uses precious time.

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• Look for the salient points in each question.

• If a question is confusing, mark it to find it later and come back to the unanswered questions at the end.

Some candidates may fail the examination despite the possession of an immense amount of knowledge and the clinical competence nec-essary to pass the examination. Their failure to pass the examination may be caused by the lack of ability to understand or interpret the questions properly. The ability to understand the nuances of the question format is sometimes referred to as “boardsmanship.” Intelligent interpretation of the questions is very important for can-didates who are not well versed in the format of multiple-choice questions. Tips on “boardsmanship” include the following:

• All questions whose answers are known should be answered first.

• Spend adequate time on questions for which you are certain of the answers to ensure that they are answered correctly. It is easy to become overconfident with such questions, and thus you may fail to read the questions or the answer options carefully. Make sure you never make mistakes on easy questions.

• Read the final sentence (that appears just before the multiple answers) several times to understand how an answer should be selected. Recheck the question format before selecting the cor-rect answer. Read each answer option thoroughly through to the end. Occasionally a response may be only partially correct. At times, the traditionally correct answer is not listed. In these situ-ations, select the best alternative listed. Watch for qualifiers such as “next,” “immediately,” or “initially.”

• Avoid answers that contain absolute or very restrictive words such as “always,” “never,” or “must.” Answer options that contain absolutes are likely incorrect.

• Try to think of the correct answer to the question before looking at the list of potential answers. Assume you have been given all the necessary information to answer the question. If the answer you had formulated is not among the list of answers provided, you may have interpreted the question incorrectly. When a patient’s case is presented, think of the diagnosis before looking at the list of answers. It will be reassuring to realize (particularly if your diagnosis is supported by the answers) that you are on the “right track.”

• Abnormalities on, for example, the photographs, radiographs, and electrocardiograms will be obvious. Remember that pictures and figures are expensive. Hence, truly normal figures, radiographs, and electrocardiograms are not used on the examination.

• If you do not know the answer to a question, very often you are

able to rule out one or several answer options and improve your odds at guessing.

• Occasionally, you can use information presented in one question to help you answer other difficult questions.

Candidates are well advised to use the basic fund of knowledge accumulated from clinical experience and reading to solve the ques-tions. Approaching the questions as “real-life” encounters with patients is far better than trying to second-guess the examiners or trying to ana-lyze whether the question is “tricky.” As indicated above, the questions are never “tricky,” and there is no reason for the NBME to trick the candidates into choosing wrong answers.

It is better not to discuss the questions or answers (after the examination) with other candidates. Such discussions usually cause more consternation, although some candidates may derive a false sense of having performed well on the examination. In any case, the candidates are bound by their oath to the NBME not to discuss or disseminate the questions. Do not study between examination ses-sions; also, cramming the night before the examination might pro-duce anxiety or fatigue and might be counterproductive.

• Approach questions as “real-life” encounters with a patient.

• There are no “trick” questions.

Connections

Associations, causes, complications, and other relationships between a phenomenon or disease and clinical features are important to remember and recognize. For example, Table 1-1 lists some of the “connections” between infectious and occupational factors and pul-monary diseases. Each subspecialty has many similar connections, and candidates for the USMLE and other examinations may want to prepare lists like this for different areas.

Computer-Based Testing

Candidates can take the computer-based test for the certification test examination. Computer-based testing provides a more flexible, quieter, and professional environment for examination.

Candidates are encouraged to access the online tutorial at http://www.usmle.org. This tutorial allows the candidate to become familiar with answering questions, changing answers, making notes electronically, accessing the table of normal laboratory values, and marking questions for review.

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Chapter 1 U.S. Medical Licensing Examination Step 2 7

Table 1-1 Examples of Connections Between Etiologic Factors and Diseases

Etiologic factor Agent, disease

Cattle, swine, horses, wool, hide Anthrax

Abattoir worker, veterinarian Crucellosis

Travel to Southeast Asia, South America Melioidosis

Squirrels, chipmunks, rabbits, rats Plague

Rabbits, squirrels, infected flies, or ticks Tularemia

Birds Psittacosis, histoplasmosis

Rats, dogs, cats, cattle, swine Leptospirosis

Goats, cattle, swine Q fever

Soil, water-cooling tower Legionellosis

Military camps Mycoplasmosis

Chicken coops, starling roosts, caves Histoplasmosis

Soil Blastomycosis

Travel in southwestern United States Coccidioidomycosis Ohio and Mississippi river valleys Histoplasmosis

Decaying wood Histoplasmosis

Gardeners, florists, straw, plants Sporotrichosis

Progressive, massive fibrosis Silicosis, coal, hematite, kaolin, graphite, asbestosis

Autoimmune mechanism Silicosis, asbestosis, berylliosis

Monday morning sickess Byssinosis, bagassosis, metal fume fever

Metals and fumes producing asthma Baker’s asthma, meat wrapper’s asthma, printer’s asthma, nickel, platinum, toluene diisocyanate (TDI), cigarette cutter’s asthma

Increased incidence of tyberculosis Silicosis, hematite lung

Increased incidence of carcinoma Asbestos, hematite, arsenic, nickel, uranium, chromate

Welding Siderosis, pulmonary edema, bronchitis, emphysema

Centrilobar emphysema Coal, hematite

Generalized emphysema Cadmium, bauxite

Silo filler’s lung Nitrogen dioxide

Farmer’s lung Thermoactinomyces, Micopolyspora

Asbestos exposure Mesothelioma, bronchogenic carcinoma, gastrointestinal cancer

Eggshell calcification Silicosis, sarcoid

Sarcoid-like disease Berylliosis

Diaphragmatic calcification Asbestosis (also ankylosing spondylitis) Nonfibrogenic neumoconioses Tin, emery, antimony, titanium, barium Minimal pathology in lungs Siderosis, baritosis, stannosis

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The USMLE step 2 CS examination is unique because, instead of the ubiquitous multiple-choice format, it uses standardized patients to test the examinee. Unlike the other steps of the USMLE, which are computer-based and offered at many testing locations around the United States, it is offered only in Atlanta, Chicago, Houston, Los Angeles, and Philadelphia.

Aim of the USMLE Step 2 CS Examination

The NBME has stated that the USMLE step 2 CS assesses the breadth and depth of a candidate’s knowledge in clinical science to ensure that the candidate has attained the necessary proficiency required for the practice of medicine under supervision during postgraduate training. There is special focus on determining whether the candidate has the foundation for the safe and effective practice of medicine. According to the NMBE, the USMLE step 2 CS tests the ability to gather information from patients, perform a physical examination, and communicate the results verbally and in a written format.

The patient encounters are designed to test the applicant’s ability to practice medicine in a safe manner while under supervision. The cases included are aimed to include diseases commonly seen in practice in the United States.

Examination Format

The USMLE step 2 CS examination is 8 hours in duration. During this time, 12 patient encounters occur. There are two breaks during the examination; the first is 30 minutes long, and the second is 15 minutes long. Candidates are given 15 minutes for each patient encounter and then 10 minutes to write the note. The proctors notify you when 5 minutes remain and when time is up. Do not write or continue to work after time has been called. If you finish the patient encounter in less than 15 minutes, you may leave the examination room and begin writing your note. However, you will not be allowed to reenter the examination room.

A stethoscope and white laboratory coat should be taken to the examination. If you forget to bring these items, they will be supplied by the testing center. However, you could benefit from using your own stethoscope because it would allow you to become familiar with its use before the examination. Professional but comfortable attire should be worn on the test day. No other equipment, including telephones, digital watches, or personal digital assistants, should be taken to the examination. The examination rooms are equipped with the tools needed for the physical examination: an examination table, sink with paper towels, examination gloves, blood pressure cuffs, otoscopes, and ophthalmoscopes. A clipboard, paper, and a pen also are provided. The testing center is a series of examination rooms. Testing

coordinators direct the candidates through the test. You will be directed to a patient room. At the door will be an instruction sheet. It is vital to read this sheet at the start of the patient encounter. The instruction sheet contains pertinent information needed for the patient encounter, including the patient’s name, age, reason for the visit, and vital signs.

After reading the instruction sheet, you will be told to enter the examination room. Typically, you will encounter a standardized patient. Treat this person as you would any patient you would see as a medical student. It is important to be polite, empathetic, and professional. Greet the patient, and then proceed with the patient encounter. The goal of the patient encounter is to obtain a focused history and examination, based on the information given on the instruction sheet, that are sufficient to develop an initial differential diagnosis and plan. If the patient asks a question, it should be answered to the best of your ability. Patients can have either acute or chronic problems. Your patient encounter should focus only on the reason the patient is visiting the physician. You should not do a complete physical examination. The USMLE does not allow rectal, pelvic, genitourinary, female breast, or corneal reflex examinations to be performed. If you believe that these would provide useful informa-tion, they can be included in the diagnostic plan. It is important to remember that the patients are trained to simulate physical findings. If you encounter a positive physical finding, assume it really is pos-itive and document it in the patient note. You also will be evaluat-ed on hygiene (washing your hands before and after the physical examination) and patient modesty (proper draping of the patient during the physical examination).

• Before entering the examination room, read the instruction sheet to obtain vital information about the patient and the setting.

• On the basis of the instruction sheet, complete a focused history and physical on the standardized patient.

After the patient encounter is finished, you will be required to document the findings in a patient note. You could be expected to either handwrite your note or type it on a computer. If you are asked to handwrite your note, it is imperative that your handwriting be legible. A standard form will be supplied on which to write the note. The sections of the note include History, Physical Examination, Differential Diagnosis (possibilities listed as #1 to #5), and Diagnostic Work-up (possibilities listed as #1 to #5).

The NBME allows two styles of notes to be submitted for scoring. The first style is a narrative note. In this type of note, complete or nearly complete sentences are used to relay the details of the perti-nent positive and negative findings from the history or present illness, past medical history, review of systems, social history, and family

Part II

Clinical Skills Examination

Christopher M. Wittich, PharmD, MD

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history. The second style is a bulleted note. In this type of note, short statements using key words and phrases are listed with bullets or dashes. In both types of notes, common medical abbreviations are allowed. The USMLE gives a list of common and allowed abbrevi-ations on its Web site (http://www.usmle.org).

• After the patient encounter, you will be required to document the history, physical, differential diagnosis, and diagnostic work-up. In the differential diagnosis section of the note, five possibilities can be listed. List them in descending order of likelihood (the most likely diagnosis as #1 and the least likely as #5). In the work-up sec-tion of the note, five possible evaluasec-tions can be listed. Remember that if a prohibited physical examination finding would be useful, list it in the work-up section. In both the differential diagnosis and work-up sections of the patient note, although five possibilities can be listed, a fewer number might be correcct. List only those that are most appropriate. Do not list consultations or treatment plans in the work-up section. This section should only include evaluations that would aid in diagnosis. If no diagnostic studies are warranted, do not leave the sec-tion blank. Instead, write “No studies warranted.”

In addition to a simulated patient encounter, other types of encounters are possible. Instead of a chief complaint, laboratory val-ues could be supplied. If this is the case, the focus should be on coun-seling and educating the patient. If no physical examination is warranted, write “no examination warranted” in the physical exam-ination section of the patient note. Also, in certain cases, mannequins or simulators could be used for the physical examination (these will be for genital or rectal examinations).

Another case format is a telephone call. In this type of case, the patient information sheet will tell you specific information about the patient. After entering the room, you will speak by telephone with the simulated patient. Once the telephone is hung up, you are not allowed to make a second call to the simulated patient.

Further details regarding the examination, training require-ments, eligibility requirerequire-ments, application forms, and other perti-nent information can be obtained from the USMLE Web site (http://www.usmle.org). This site also includes copies of the patient note template, examples of patient notes, and software to practice typing the note. It is recommended that these materials be reviewed before the examination to become familiar with their use.

Scoring

The USMLE step 2 CS is a pass or fail examination. There are three domains that all must be passed on a single test administration for a passing score to be awarded for the entire test: Integrated Clinical Encounter, Communication and Interpersonal Skills, and Spoken English Proficiency. Communication, interpersonal skills, and spo-ken English proficiency are evaluated by the trained standardized patients using rating scales. The ability to document the findings from the patient encounter, the differential diagnosis, and the diag-nostic assessment plan are scored by physician raters. According to the NBME, these ratings are monitored to ensure consistency and fairness in rating.

The Integrated Clinical Encounter domain assesses data gath-ering and documentation. Data gathgath-ering is assessed from check-lists of history and physical examination findings pertinent to the case. Documentation is assessed from the patient note generated by the candidate; physician raters score these notes.

The Communication and Interpersonal Skills domain assesses questioning skills, information-sharing skills, and professional man-ner and rapport. These are scored by the trained standardized patients using rating scales.

Spoken English Proficiency is assessed by the trained standard-ized patient using rating scales. This section is designed to test the clarity of spoken English during the patient encounter. Word pro-nunciation, word choice, and the effort required to understand the candidate are rated.

Preparation for the Test

Training during medical school forms the foundation on which advanced clinical knowledge is accumulated. Preparation for the USMLE step 2 CS examination should start at the beginning of the third year of medical school. Most candidates require 6 to 8 months of preparation for the examination. Cramming just prior to the examination is unlikely to be successful. Remember that the test is 8 hours of patient interaction and documentation of the findings. One should start by becoming familiar with the scope of the test and the patient simulation format before the testing day. The candidate should review the note template, acceptable abbreviations, and the styles of acceptable notes on the USMLE Web site (http://www.usmle.org). It is also important to review the time allot-ted for the patient interaction and for documentation of the findings. Some methods of preparation for the USMLE step 2 CS exam-ination are described below. Additionally, each candidate can develop his or her own system.

• Preparation for the USMLE step 2 CS examination should start at the beginning of the third year of medical school.

Each candidate should use a standard textbook of physical diagnosis. The elements of a history and physical examination should become second nature to the candidate. The most effec-tive use of the textbook is patient-centered reading. As the candi-date encounters patients during the third year of medical school, the salient features of disease presentation and physical findings should be explored.

An important step in preparation for the USMLE step 2 CS is demonstrating your physical diagnosis abilities to an expert and requesting feedback to improve. While on rotations during the third year of medical school, ask attending physicians or senior residents to watch you do a physical examination and give you suggestions on how to improve. Develop a system when doing a physical exam-ination. Know the important components of the examination of all the organ systems. Become systematic, on the basis of recommen-dations of physical diagnosis textbooks, when approaching each organ system. Additionally, the more physical findings you deter-mine, the more likely you are to recognize an abnormality when you

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come across it again in the future. One technique to obtain increased exposure to auscultatory findings is to review tapes of, for exam-ple, heart sounds and lung sounds (available in most medical school libraries).

To prepare for the differential diagnosis section of the exami-nation, it is helpful to review handbooks for symptom-driven dif-ferential diagnosis. These handbooks provide common difdif-ferential diagnoses based on symptoms in the patient history. For example, the differential diagnosis of leg edema could include cellulitis, edema, venous thrombosis, or lymphedema.

Candidates for whom English is a second language should be sure that their spoken English is easily understood by a patient. Practice avoiding medical jargon. Practice correct pronunciation of medical terms. Ask attending physicians or classmates to give you feedback as to whether your spoken English is easy to understand. If it is not, extra time should be devoted to improvement.

Writing a succinct note after a patient encounter is a skill that takes refinement. Practice writing patient notes after every patient encounter during the third year of medical school. Ask your attending physicians to give you feedback about the content and style of your notes. When writing notes, practice getting to the point without leaving out important details. Develop a system to document physical

examination findings in a logical order and use the system for every patient encounter.

• Candidates should thoroughly study a standard textbook of phys-ical diagnosis.

• Handbooks on symptom-specific differential diagnosis are helpful to review.

• Practice written documentation of patient encounters.

• Ask for feedback from attending physicians on whether your spoken English is easily understood.

Day of the Examination

Confirm the date and directions to the testing center before your examination day, and arrive at the testing center early. It is imperative to bring a government-issued identification that includes a picture of yourself, the scheduling permit supplied by USMLE, and your stethoscope and white laboratory coat. Follow the directions of testing officials as you move from one patient encounter to the next. Once time is called, stop working immediately. Remember to relax and treat the standardized patient as you would any patient you would see as a medical student.

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Allergy Testing

Standard allergy testing relies on identifying the IgE antibody specific for the allergen in question. Two classic methods of doing this are the immediate wheal-and-flare skin test (a small amount of antigen is introduced into the skin and evaluated at 15 minutes for the presence of an immediate wheal-and-flare reaction) and in vitro testing.

Allergy testing that does not have a clear scientific basis includes cytotoxic testing, provocation-neutralization testing or treatment, and “yeast allergy” testing.

Patch Tests and Prick (Cutaneous) Tests

Many seem confused about the concept of patch testing of skin as opposed to immediate wheal-and-flare skin testing. Patch testing is used only to investigate contact dermatitis, a type IV hypersensitivity reaction. Patch tests require about 96 hours for complete evalua-tion (similar to tuberculin skin reactivity that requires 72 hours). Most substances that cause contact dermatitis are small organic molecules that can penetrate various barriers inherent in the skin surface. The mechanisms of hypersensitivity postulated to explain these reactions usually involve the formation of haptens of endoge-nous dermal proteins.

Inhalant allergens, in comparison, generally are sizable intact proteins in which each molecule can be multivalent with respect to IgE binding. These molecules penetrate the skin poorly and are seldom involved in cutaneous type IV hypersensitivity reac-tions. They cause respiratory symptoms and are identified by prick skin testing.

• Patch testing is used to investigate contact dermatitis.

• Prick (immediate) skin testing is used to investigate respiratory allergy to pollens and molds.

Prick, scratch, and intradermal testing involve introducing allergen to the skin layers below the external keratin layer. Each of these techniques becomes increasingly sensitive (but less specific) because with the deeper, intradermal tests, allergen is introduced more closely to responding cells and at higher doses. Allergen skin tests

performed by the prick technique adequately identify patients who have important clinical sensitivities without identifying a large number of those who have minimal levels of IgE antibody and no clinical sensitivity. Intradermal testing is used in selected cases, including evaluating allergy to stinging insect venoms and to penicillin. Drugs with antihistamine properties, such as H1receptor antagonists, and many anticholinergic and tricyclic antidepressant drugs can suppress immediate allergy skin test responses. The H2receptor antagonists have a small suppressive effect. Corticosteroids can suppress the delayed-type hypersensitivity response but not the immediate response.

• Intradermal skin tests are more sensitive but less specific than prick skin tests.

• Intradermal skin testing is used to investigate allergy to insect venoms and penicillin.

In Vitro Allergy Testing

In vitro allergy testing initially involves chemically coupling allergen protein molecules to a solid-phase substance. The test is then con-ducted by incubating serum (from the patient) that may contain IgE antibody specific for the allergen that has been immobilized to the membrane for a standard time. The solid phase is then washed free of nonbinding materials from the serum and incubated in a second solution containing a reagent (e.g., radiolabeled anti-IgE antibody). The various wells are counted, and the radioactivity is correlated directly with the preparation of a standard curve in which known amounts of allergen-specific IgE antibody were incubated with a set of standard preparations of a solid phase. In vitro allergy testing uses the principles of radioimmunoassay or chromogen activation. It is important to understand that this test only identifies the presence of allergen-specific IgE antibody in the same way that the allergen skin test does. Generally, in vitro allergy testing is not as sensitive as any form of skin testing and has some limitations because of the potential for chemical modification of the allergen protein while it is being coupled to the solid phase by means of covalent reaction. Generally, it is more expensive than allergen skin tests and has no advantage in routine clinical work. In vitro allergy testing may be useful clinically for patients who have been taking antihistamines

11

Mayo Clinic Internal Medicine Concise Textbook 1stEdition

Mayo Clinic

Internal Medicine

Editors-in-Chief

Thomas M. Habermann, MD

Amit K. Ghosh, MD

Mayo Clinic

Internal Medicine

Concise Textbook

MAYO CLINIC SCIENTIFIC PRESS

INFORMA HEALTHCARE

CONTRIBUTORS

FOREWORD

M

1. Preparing for the U. S. Medical Licensing Examination Step 2

1

2. Allergy

11

3. Cardiology

35

4. Critical Care Medicine

129

5. Dermatology

147

6. Endocrinology

171

7. Gastroenterology and Hepatology

217

8. General Internal Medicine

279

9. Genetics

305

10. Geriatrics

323

11. Hematology

347

12. HIV Infection

405

13. Hypertension

429

TABLE OF CONTENTS

15. Medical Ethics

549

16. Men’s Health

559

17. Nephrology

569

18. Neurology

613

19. Oncology

661

20. Preventive Medicine

693

21. Psychiatry

707

22. Pulmonary Diseases

725

23. Rheumatology

803

24. Vascular Diseases

861

25. Women’s Health

879

Index

893

1

Preparing for the

U.S. Medical Licensing Examination

Step 2

Amit K. Ghosh, MD

Christopher M. Wittich, PharmD, MD

Aim of the USMLE Step 2 CK Examination

Examination Format

Part I

Clinical Knowledge Examination

Amit K. Ghosh, MD

Scoring

The Examination Content

Question Format

Examples of Questions