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In defense of the stethoscope and the bedside

2000; Elsevier BV; Volume: 108; Issue: 8 Linguagem: Inglês

10.1016/s0002-9343(00)00385-5

1555-7162

Howard H. Weitz, Salvatore Mangione,

Clinical Reasoning and Diagnostic Skills

Chest sounds have been utilized since antiquity to assess cardiovascular structure and function. Hippocrates taught physicians how to apply their ear to the patient’s chest to detect sounds of medical importance, a technique known as direct auscultation. Auscultation was subsequently mentioned by Caelius Aurelianus, Leonardo Da Vinci, Ambroise Paré, Giovan Battista Morgagni, Gerhard Van Swieten, William Hunter, and many others. In 1628, William Harvey described heart sounds in his De Motu Cordis. Four decades later Robert Hooke wrote: “Who knows? It may even be possible to discover the motions of internal parts … by the sounds they make.” Still, it took another century and a half before technology came to the rescue. In 1816, a shy, diminutive, introverted, very asthmatic, and very tuberculotic French physician named Théophile René Hyacinthe Laënnec was examining a young and obese woman with symptoms of heart disease. Limited in percussion by her obesity, he first considered direct auscultation. But given the patient’s young age and sex, he quickly discarded the idea as “inadmissible” (1Laennec RTH. A Treatise on the Diseases of the Chest. Translated by John Forbes. London: T and G Underwood; 1821.Google Scholar). Remembering that a few days before he had seen children scraping a stick of wood and listening to the other end, Laënnec fashioned a cylinder from a tightly rolled piece of paper, applied it to the patient’s chest, and to his amazement, could “hear the beating of the heart much more clearly than if I had applied my ear directly” (1Laennec RTH. A Treatise on the Diseases of the Chest. Translated by John Forbes. London: T and G Underwood; 1821.Google Scholar). Not to mention that he did not even have to touch her! And thus he invented the stethoscope. Being handy—he used to make musical instruments—he immediately fashioned a flutelike contraption that he dubbed the “cylinder,” creating the symbol of physician-patient interaction and one of the earliest applications of technology to patient care. After 3 years of intense clinical-pathologic correlation, Laënnec published a two-volume book of observations bundled to a wooden cylinder that he had personally fabricated. It was a commercial failure. But the second edition sold well, and soon auscultation became the centerpiece of patient assessment. More importantly, Laënnec had also laid the foundation for physical examination as the royal road to diagnosis. Rather than reliance on subjective symptoms extracted with difficulty from confused patients, physicians could now say: “That was very interesting. Now please take your clothes off and let me listen to your chest.” This golden age lasted less than a century. In 1908 technology again came to the rescue with the invention of phonocardiography. The clinician could now visualize cardiovascular sounds, follow the course of specific diseases, and teach others the intricacies of auscultation. But the discoveries of radiography and electrocardiography supplied new and more powerful diagnostic tools. The subsequent development of echocardiography (which, intriguingly, also relies on sound to infer the structure and function of the heart, albeit reflected rather than directly auscultated) further weakened the need for sophisticated physical examination. The simultaneous discontinuation of reimbursement for phonocardiography and the decision of the American Board of Internal Medicine to stop testing physicians’ auscultatory skills as part of the final certifying examination additionally weakened the importance of the stethoscope. Recent surveys indicate that only one of four primary care residencies in the United States offers any structured teaching of cardiac auscultation (2Mangione S. The teaching of cardiac auscultation during internal medicine and family medicine training a nationwide comparison.Acad Med. 1998; 73: S10-S12Crossref PubMed Scopus (27) Google Scholar). Not surprisingly, trainees’ and practitioners’ skills are poor (3Mangione S. Nieman L.Z. Cardiac auscultatory skills of internal medicine and family practice trainees.JAMA. 1997; 278: 717-722Crossref PubMed Google Scholar, 4Paauw D.S. Wenrich M.D. Curtis J.R. et al.Ability of primary care physicians to recognize physical findings associated with HIV infection.JAMA. 1995; 274: 1380-1382Crossref PubMed Google Scholar). Is this deplorable or does it just represent an inevitable transition toward more sophisticated, objective, and accurate technology-based diagnosis? Is there a role in the future for a tool that was invented only a year after the battle of Waterloo? Would the FDA approve the stethoscope if Laënnec were to invent it today? If we think of tomorrow, there is not much ground for optimism. After all, Dr. McCoy (of Star Trek fame) was never seen with a stethoscope. His diagnoses come directly from the tricorder. But times of transition like ours should rely more on evolution than revolution. Our challenge as educators should be to retain the value of our past while acquiring the power and sophistication of the future. Stethoscopy (and the bedside) still play an important role in 21st-century medicine. To preserve what is valuable in these time-honored skills, however, we must jettison what has become misleading and outdated. For this, we need scientific evidence to guide our judgment. This is why we welcome the work by Jost et al in this issue of the Journal(5Attenhofer Jost C.H. Turina J. Mayer K. et al.Echocardiography in the evaluation of systolic murmurs of unknown cause.Am J Med. 2000; 108: 614-620Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar). The authors compared the diagnostic accuracies of cardiologist-performed physical examination with transthoracic echocardiography in the evaluation of patients with systolic murmurs. In their hands, physical examination had a 70% to 97% accuracy. Sensitivity was highest for ventricular septal defects and lowest for combined aortic and mitral disease, aortic insufficiency, and intraventricular gradients. Three of 4 patients with moderate-to-severe aortic stenosis were missed on examination because left ventricular dysfunction had decreased the turbulence necessary for the ejection murmur. This study did have several limitations. Participating cardiologists were blinded to patients’ histories as well as to laboratory studies. Thus, we do not know which of the patients, if any, had effort-related syncope or aortic valve calcification seen on a chest radiograph. Such findings would have been very valuable in interpreting a systolic murmur as, for example, due to aortic stenosis. We also do not know whether participating physicians sought other helpful physical findings for the recognition of aortic stenosis, such as radiation of the murmur to the right carotid artery or right clavicle and greatest loudness over the aortic area (6Etchells E.E. Bell C. Robb K.V. Does this patient have an abnormal systolic murmur?.JAMA. 1997; 277: 564-571Crossref PubMed Google Scholar, 7Etchells E.E. Glenns V. Shadowitz S. et al.A bedside clinical predic-tion rule for detecting moderate or severe aortic stenosis.J Gen Intern Med. 1998; 13: 699-704Crossref PubMed Scopus (29) Google Scholar). Although the accuracy of physical examination for hypertrophic obstructive cardiomyopathy was also poor, we do not know whether squatting and passive leg raising were utilized in these patients. These maneuvers have high sensitivity for the diagnosis of hypertrophic obstructive cardiomyopathy (95% for squatting and 85% for leg raising) (8Lembo N. Dell’Italia L. Crawford M. O’Rourke R. Bedside diagnosis of systolic murmurs.NEJM. 1988; 318: 1572-1578Crossref PubMed Scopus (99) Google Scholar), much higher than that of the Valsalva maneuver, which was used in this study. The examiners comprised staff cardiologists as well as “young cardiology associates,” but we do no know whether the physical examination skills of these physicians were similar. Finally, physical examination without knowledge of a patient’s history is hampered substantially. Thus, we are unsure whether the conclusions of this study are generalizable, as the authors acknowledge. Nevertheless, we agree with the conclusion that echocardiography is an important tool for assessing systolic murmurs of unknown cause whenever there is clinical suspicion of significant heart disease. This is also the recommendation of the consensus committee of the American College of Cardiology and the American Heart Association. In that panel’s recommendations, two-dimensional Doppler echocardiography should be used only after obtaining a careful history, physical examination, and appropriate basic tests (electrocardiogram and chest radiograph). Echocardiography should “not be used to replace the cardiovascular examination. …” Moreover, when evaluating a murmur, echocardiography should be used “in patient(s) with cardiorespiratory symptoms as well as in asymptomatic patient(s) if clinical features indicate at least a moderate probability that a murmur reflects structural heart disease” (9ACC/AHAGuidelines for the clinical application of echocardiography.Circulation. 1997; 95: 1686-1744Crossref PubMed Scopus (600) Google Scholar). Thus, technology will not render physical examination obsolete, at least not yet. Overreliance on technology, however, may erode interest and enthusiasm for teaching and using those physical examination skills that are still clinically valuable. This would be regrettable, as it would deprive clinicians of an essential filter (and guidance) for the proper use and interpretation of the laboratory. Because unnecessary tests beget more tests, the loss of such a filter might raise costs of care, and possibly harm patients. Hence, we need to rekindle interest and competence in essential bedside skills like auscultation. This renewal will require time and effort. Some clinicians may not utilize (or teach) physical diagnosis because they are unsure of their own skills. As Sir James Kingston Fowler of the Brompton Hospital used to quip: “Those who advise that all stethoscopes should be ‘scrapped’ may be influenced by the fact that they do not know how to use their own… .” Thus, we need time for medical school faculty not only to teach physical diagnosis, but also to relearn it when necessary. With increasing emphasis on objective measurement of physicians’ bedside skills at the time of internal medicine recertification, this task might even become a timely area for future faculty development. In the early part of the last century, the cardiac pioneer James Herrick overturned the commonly held belief that myocardial infarction was always fatal. This revolution in our understanding of coronary artery disease was rooted in clinical observation and the use of technology (the electrocardiogram), and it set the stage for subsequent developments in cardiac care. Yet Dr. Herrick never lost his respect for the bedside examination. In a 1930 address before the American College of Physicians, he gave a passionate “plea for the sane use of every means that may help in diagnosis, including the stethoscope and all that it stands for in the way of physical diagnosis. Physical examination should not yet be regarded as displaced by other methods. It still has a legitimate function. Undergraduates and practitioners should still be taught its theory and its practice so that it may not become a lost art” (10Herrick J.B. In defense of the stethoscope.Ann Intern Med. 1930; 4: 113-116Crossref Google Scholar). These words are as valid today as they were 70 years ago.