They were invented when doctors still used leeches.
There are few technologies more symbolic of western medicine than the stethoscope. Medical schools often gift them to new med students along with a white coat when they start their studies. As far as medical tools go, it's a fairly versatile and cost-effective one, allowing doctors to detect early signs of trouble in the body with a device that costs just a few hundred dollars.
It's also 200 years old.
Medical technology has advanced tremendously in the past few decades, yet doctors cling to a tool that was invented at a time when medical practitioners still regularly used leeches as a form of treatment. In 1816, there were few other ways of "seeing" what was happening inside of a body, but these days we have incredible imaging technology. Why are docs still slinging 19th century rubber tubes to get a sense of what's going on inside of us?
"The problem is only that people are attached to stethoscopes. This is our identification card," said Dr. Jagat Narula, a cardiologist at Mount Sinai Hospital who is a proponent of phasing out the stethoscope. "People are very sensitive about it."
The stethoscope was invented in 1816 by Rene Theophile Hyacinthe Laënnec, a French doctor who was looking for a solution to listening to the heart of a "plump" woman. He recalled seeing some children sending messages by pressing their ear to one end of a length of wood and scratching the other end (kind of like the 19th century version of a tin can phone). He created a device that would, with one end pressed against the body and the other pressed to the doctor's ear, amplify the sounds inside the chest cavity.
But listening to the sounds of the body as a diagnostic tool—a process called auscultation—dates back to ancient times. Doctors in the past would simply press their ears to patients' backs, chests, and abdomens to listen for signs of trouble, like gurgling, wheezing, and palpitations. The stethoscope was a tool to facilitate this practice.
"There was no way of looking into the chest at that time," Narula explained. "By listening to it, they were able to look into it indirectly."
In fact, Narula points out, stethoscope literally translates as "to see into the chest." And for a long time, particularly as stethoscope designs became more refined, the tool remained the best first point of entry for diagnostics. Gradually, technologies emerged allowing us to actually see into the body: the x-ray in 1895, the electrocardiogram in 1902, the ultrasound in the 50s, and magnetic resonance imaging (MRI) in 1977.
But while these technologies advanced doctors' abilities to diagnose, they were too costly and intrusive to use as a first step. When someone comes into your office saying they're short of breath, you're not going to just send them to an MRI without at least doing a physical exam first.
"You can put a patient into an MRI scanner and get much more detailed images of the heart than you could ever imagine. There's not much the MRI would miss," said Dr. Zachary Goldberger, a cardiologist and assistant professor at the University of Washington who focuses on electrocardiography and the cardiac physical examination. "But at the same time, if someone comes into your office complaining of chest pain, laying a stethoscope on his chest is very valuable."
But new technologies are starting to give the stethoscope a run for its money. In particular, handheld ultrasounds are becoming more compact, powerful, and easy-to-use, giving trained doctors the ability to actually see into the chest from the comfort of their office, rather than simply listening. In cardiology, a doctor might use a stethoscope and, if he hears a potential problem, send the patient for an echocardiogram to investigate further. Narula says the handheld ultrasounds could streamline this process.
"There are very few issues that you would not be able to detect with an ultrasound," Narula told me. "With handheld ultrasounds, you'll be able to pick up all of the cases that you would have otherwise missed and you will not send cases for an echocardiogram when it's not needed."
There are a number of reasons why ultrasounds have yet to replace the stethoscope, and it's not just to do with a resistance to change. First of all, Narula said these devices cost between $5,000 and $10,000 (compared to $200 or less for a stethoscope). They also are not quite refined enough to catch everything a stethoscope might, according to Dr. Valentin Fuster, a cardiologist, physician-in-chief at Mount Sinai, and the editor of the Journal of the American College of Cardiology. In an editorial published this month, Fuster gives a list of six examples from 48 hours at his clinic where a stethoscope caught something an ultrasound missed.
"Claims that the 'stethoscope is dead' are entirely false. In fact, with its new digital capabilities, the stethoscope is healthier than ever," Fuster writes.
He points out that the training required to do a proper diagnosis using handheld devices is extensive and that doctors need to know how to work when they don't have access to this technology—he uses the example of working abroad, though my mind called up a post-apocalyptic scenario. In either case, a doctor needs to have the skills to assess a patient without digital assistance.
And Goldberger brought up another point: the physical closeness between doctor and patient that stethoscopes require is a rare commodity in a time when doctors are often overworked and rushed.
"Using a stethoscope—the laying on of hands—is how we can connect with patients. That's what medicine is," Goldberger said. "It's important that we continue to stress the importance of the physical exam when we interact with trainees. Medical students are often given a stethoscope on their first day of medical school. It offers a lot more than a way of simply listening to heart sounds."
We may not need the stethoscope to peek inside the body anymore, but there are a lot of reasons by doctors still want it. After 200 years, it's still the most cost-effective and practical first step in most diagnostic analyses. And at the end of the day, there's something to be said about consistency. It would be kind of off-putting to go to the doctor and not get a few good thumps from a cold stethoscope.