02/03/2008 - 22:00

Stethoscopes belong in museums

Laura H. Kahn

Laura H. Kahn

A general internist who began her career in health care as a registered nurse, Kahn works on the research staff of Princeton University's ...

More

A common criticism of today's high cost of medicine is that physicians rely too often on advanced technologies such as CT scans and MRI machines to make diagnoses. Much of the overuse is blamed on perverse insurance-industry incentives that pay for these costly services. (See the New York Times editorial, "The High Cost of Health Care.") While it's true that the insurance industry prefers to pay for costly tests and procedures rather than for cognitive services, in many cases, the real problem is that these technologies aren't cheaper and more readily available.

For the average primary-care physician, the stethoscope, a nineteenth-century technology, is the most readily available diagnostic technology. Flung around physicians' necks or coiled in their white-coat pockets, the stethoscope is arguably less useful to medicine than the slide rule was to engineering.

French physician Rene-Theophile-Hyacinthe Laennec invented the stethoscope in 1816, first using a rolled-up piece of paper before switching to a hollow wooden tube. At the time, physicians routinely placed their ears on patients' chests to hear them breath and listen to their heart. However, it was a useless practice for obese patients and socially awkward for female patients. Five years later, the New England Journal of Medicine reported on Lannec's invention, which helped it achieve acceptance in the medical community. For the time, it was a major technological advance.

Yet, most humans rely on vision more than hearing for precision work. Therefore, it's counterproductive to force physician trainees to improve their hearing to the degree of accuracy that auscultation (listening to sounds arising within organs) requires. This unrealistic expectation is evident in internal medicine and family medicine residents' low-competency levels of hearing heart sounds during auscultation exercises. Even expert physicians can make diagnostic auscultation errors that imaging studies such as a CT scan or MRI can detect. (See "Children with Heart Murmurs: Can Ventricular Septal Defect Be Diagnosed Reliably Without An Echocardiogram?")

Errors in auscultation are especially a concern because hearing loss increases as people age, and evidence exists that hearing loss begins as early as childhood. To compensate, electronic stethoscopes have been developed to help transmit sounds. But an electronic stethoscope is akin to an electronic slide rule; the technology is still outdated.

With imaging technologies now allowing physicians to see inside the body, some believe that these technologies should eventually replace the stethoscope--particularly since abnormal heart sounds are generally sent for scanning anyway. What physicians need are pocket-sized imaging devices that they can carry with them--a la the stethoscope. This advanced technology isn't far off. The FDA has approved a portable MRI machine, which is now being used at the University of California, Irvine. Smaller CT scans are helping individuals with traumatic brain injuries get scanned faster since they don't require patients to be transported from emergency rooms or intensive care units to radiology. Handheld ultrasound scanners are also now becoming available and might be the technology that replaces the stethoscope.

There are risks with the widespread use of portable imaging devices. With improved diagnostic capabilities, physicians would likely pick up many incidental tumors of unknown significance. Called "incidentalomas," these tumors could be benign, presenting a dilemma as to how to approach them. Physicians and their patients would need to decide whether these incidentally discovered tumors warranted invasive and expensive workups, leading to needless anguish and suffering for the patients. On the other hand, if the tumors were malignant, earlier detection could potentially save lives.

Despite the challenges posed by "incidentalomas," physicians would perform better diagnostics if they used portable imaging scanners. To accomplish widespread adoption, the technology would need to be of high quality and affordable. Also, medical residency would need to include extensive training in radiology. Indeed, it might make sense to combine primary care and radiology residencies so that practicing physicians would have the diagnostic skills and capabilities to do their own imaging. If primary-care physicians were able to do their own imaging tests, health care could be simpler and more accessible, with patients enduring one less appointment and office visit.

As slide rules have come and gone, so must stethoscopes. Once pocket-sized imaging devices become as common and cheap as stethoscopes, the cost of care should decrease. Hopefully, in the twenty-first century, advanced imaging technologies will become the standard of care.