PROFESSIONFine-tuning the thought process (book excerpt: How Doctors Think)Massachusetts hematologist-oncologist Jerome Groopman, MD, examines how doctors arrive at clinical decisions.By Jerome Groopman, MD, amednews contributor. Oct. 8, 2007. 
Book Excerpt
A peek inside what's new on the shelves on topics pertinent to physicians. Dr. Groopman's book details why physicians' thinking can lead them astray and shows how to make the correct diagnosis. This excerpt explores the thought process of an emergency physician who missed a heart problem in a patient who appeared healthy. On a spring afternoon several years ago, Evan McKinley was hiking in the woods near Halifax, Nova Scotia, when a pain in his chest stopped him in his tracks. McKinley was a [Canadian] forest ranger in his early 40s, trim and extremely fit, with straw-blond hair and chiseled features. He had had a growing discomfort in his chest for the past few days, but nothing as severe as this. He wasn't sweating or lightheaded, and didn't feel feverish. But each time he took a breath, the pain got worse. McKinley slowly made his way back through the woods to the shed that housed his office. He sat and waited for the pain to pass, but it didn't. As a forest ranger, he was used to muscle aches from scaling a steep rocky trail or jogging with a loaded pack on his back. But this was different, and he decided he should see a doctor immediately. As it happened, Dr. Pat Croskerry was working in the emergency department that day. He took McKinley's measure: a wiry, muscular man wearing the distinctive bright olive bomber jacket and pants, much like an American park ranger's uniform. McKinley's face was ruddy, as would be expected of someone who spends most of his day working outdoors, and his brow was free of perspiration. Croskerry listened intently as McKinley described how his chest pains had increased over the past few days and how they had worsened today. Croskerry questioned him further to get a more precise description of his symptoms. McKinley said the pains stayed in the center of his chest but did not move down his arms, into his neck, or through to his back. The pain got no worse if he changed position, and even taking a really deep breath didn't make him feel faint.
Croskerry went over a checklist of risk factors for heart and lung disease. McKinley had never smoked and had no family history of heart attack, stroke, or diabetes. He laughed, as Croskerry did, when Croskerry used the term "sedentary lifestyle." McKinley added that he felt under no particular stress, his family life was fine and he loved his job, and he had never been overweight. Croskerry then did a physical examination. First he verified that the vital signs recorded by the triage nurse were correct. McKinley's blood pressure was 110/60, his pulse 60 and regular, as would be expected of an athletic man. Croskerry listened with particular care to McKinley's lungs and heart, especially when he took a deep breath, but everything sounded fine. His muscles were well developed, and when Croskerry pressed on the junction between McKinley's ribs and breastbone, McKinley felt no pain. There was no swelling or tenderness in his calves or thighs. Finally, the doctor ordered an electrocardiogram, a chest x-ray, and blood work that would include tests for oxygen level and cardiac enzymes that indicate heart damage. As he expected, all of these were normal. "I'm not at all worried about your chest pain," Croskerry told McKinley. "You probably overexerted yourself in the field and strained some muscle. My suspicion for this coming from your heart is about zero." Deeply reassured, the forest ranger went home. The next morning, Croskerry was off duty, and read part of a novel that he was keen to finish. He is an avid athlete and rowed on Canada's 1976 Olympic crew in Montreal. He stays in shape, and that day he had jogged four miles around the Halifax harbor. When he arrived in the emergency department in the early evening, he bumped into a colleague. "Very interesting case, that man you saw yesterday," the doctor said. "He came in this morning with an acute myocardial infarction." Croskerry was stunned. He reviewed his notes on the emergency room chart. The colleague tried to reassure him. "If I had seen this guy, I wouldn't have gone as far as you did in ordering all those tests." But Croskerry found this cold comfort. It was not because he expected to be infallible. Rather, he recognized that he had made a common cognitive error that could have cost the forest ranger his life. "Clearly, I missed it," Croskerry told me after recounting McKinley's case. "And why did I miss it? I didn't miss it because of any egregious behavior or negligence. I missed it because my thinking was overinfluenced by how healthy this man looked." Croskerry's voice faltered for a moment. "Happily, he didn't die." Chest pain is the second most common reason for a patient to visit an emergency room (abdominal pain is number one). Each year in the United States and Canada there are more than 6 million evaluations in the ER of patients like McKinley. But despite its frequency, chest pain is one of the most challenging symptoms for the clinician to unravel. In retrospect, Croskerry realized that when he saw Evan McKinley, the ranger was in the midst of unstable angina -- a crescendo of chest pain, caused by coronary artery disease, that usually prefigures a heart attack. "The unstable angina didn't show on the EKG, because 50% of such cases don't," Croskerry said in a voice that sounded to me as if he were lecturing himself. "His unstable angina did not show up on the cardiac enzymes because there wasn't yet injury to the heart muscle, and it didn't show up on the chest x-ray because the heart had not yet begun to fail to pump blood, so there was no fluid backup into the lungs." The mistake Croskerry made is called a representativeness error: your thinking is guided by a prototype, so you fail to consider possibilities that contradict the prototype and thus attribute the symptoms to the wrong cause. Croskerry told me how his eyes had fixed on McKinley's trim frame and his elegant olive uniform, and how the ranger's physique and chiseled features reminded him of a young Clint Eastwood -- all strong associations with health and vigor. Yes, there were unusual aspects to McKinley's angina; his pain was not typical of coronary artery disease, nor did the physical examination and tests point to the heart. But, Croskerry emphasized, that was precisely the point: "You have to be prepared in your mind for the atypical and not so quickly reassure yourself, and your patient, that everything is okay." When Croskerry now teaches students and interns about such errors, he uses Evan McKinley as an example. Excerpted from "How Doctors Think" by Jerome Groopman, MD, published by Houghton Mifflin Co. Copyright © 2007 by Jerome Groopman. Reprinted by permission of Houghton Mifflin Co. All rights reserved; $26. Note that the work appearing herein is protected under copyright laws, and reproduction of the text in any form for distribution is strictly prohibited. The right to reproduce or transfer the work via any medium must be secured with the copyright owner. ADDITIONAL INFORMATION:Copyright 2007 American Medical Association. All rights reserved.
|
Feature articlesHealth reform review The Massachusetts experience Litigation stress Being sued is personal as well as professional Comprehensive coverage
Most-viewed
Nov. 9 issueHouse passes health reform bill, debate moves to Senate New database for out-of-network pay set to replace disputed Ingenix system Columns and series
From the vault: 5 years agoGenetic testing issues land in primary care practices Nov. 8, 2004 
|
SHARE
