Medicine is, and always has been, an evolving discipline

Medicine's Progress, One Setback at a Time
"Medicine's Progress, One Setback at a Time
By Lisa Sanders, M.D., The New York Times, March 16, 2003

A decade ago, I stood alongside my 99 fellow freshmen as we were welcomed into the ranks of medicine in a ''white coat ceremony.'' Here, on our first day of med school, we were presented with the short white coats that proclaimed us part of the mystery and the discipline of medicine. During that ceremony, the dean said something that was repeated throughout my education: half of what we teach you here is wrong -- unfortunately, we don't know which half.

At the time it was hard to believe. Within those walls, in the anatomy lab, in the lecture hall, you feel that you are being shown the secrets of how the body is put together, how it lives, how it works, how it dies. It has the feel of authority and certainty. Like math, it has a feeling of inevitability.

But now, as a practicing doctor and teacher of residents, I relive that dean's aphorism daily. Medicine is, and always has been, an evolving discipline. And this necessarily means that what we know about medicine is constantly changing; that medicine is forever putting forth, and simultaneously upending, assumptions (as can be seen in the accompanying chart). This is particularly true at this moment. Virtually all of our medical therapeutic options are being questioned, evaluated and re-evaluated by researchers across the globe. Certainly in this century there will be new genes discovered and inventions developed, but medical progress right now centers on the rapid displacement of old ideas to make room for new knowledge. Medicine, always a fluid and dynamic science, is in the midst of a major growth spurt.

This wave of research changes what we as doctors do almost daily. When I started on the wards as a third-year medical student, for example, we were taught that the use of beta blockers, a class of powerful medicines for the treatment of high blood pressure, could endanger the life of a patient with heart failure. The thinking was that beta blockers, which slow the heart rate, could make an already poorly performing heart perform even worse.

Now, less than eight years later, the opposite is thought to be true: beta blockers reduce the risk of death in patients who suffer heart failure. By slowing the heart, reducing its workload, a poorly performing heart improves. We know this now because researchers tested both theories, side by side, to see which was correct. One group of patients with heart failure was treated with beta blockers, another identical group was not. After several years the answer was clear. Beta blockers are now a widely accepted therapy for heart failure.

These rigorous studies, and their sometimes counterintuitive results, make up the headlines of medical journals -- and sometimes daily papers -- announcing essentially the death of one idea or the birth of another.

This is a relatively new phenomenon. Although the first randomized controlled trial was done more than half a century ago (in that study researchers tested the use of an early antibiotic against TB), it wasn't until the 70's that this sort of scientific examination came into widespread use. Therapies of all kinds had blossomed and so had the expectation that there needed to be a systematic way of evaluating their effectiveness.

By the late 90's, doctors had the appetite for this type of information, and researchers had the technique. Before the computer made its way into virtually every office, doctors often had filing cabinets where they kept articles on topics of interest. It was a reasonable way to keep track of a small amount of data but was easily overwhelmed by the new flood of research. It was technology -- the computer, the Internet -- that finally made it possible for the doctors in the trenches, doctors taking care of patients, to systematically practice what could be considered ''evidence-based medicine.'' We all now have access to the newest and best in medical research right at our own desks. We can find out quickly, for example, that arthroscopic knee surgery for osteoarthritis and postmenopausal hormone replacement for the prevention of heart disease have lost their standing as effective therapies and even that certain techniques discarded long ago can serve a new purpose. (Leeches, for example, are now used on some patients to treat the pain of arthritis.)

Recently, a patient I took care of in the hospital brought that point home to me. She was a youngish woman, in her 40's, with honey-colored hair and bright blue eyes. She had come to this small Connecticut city from her farm in Maine to judge a local dog show, and on the way to the show she had fainted twice. In the E.R., she seemed a little winded, her heart was beating more rapidly than normal and the oxygen meter on her finger showed that despite her efforts she wasn't getting quite as much oxygen as she needed.

She had no fever, chills or cough, and a chest X-ray confirmed that she didn't have pneumonia. A lung scan showed that she had a pulmonary embolus, a clot from somewhere in her veins that had broken loose and traveled to her lungs. She was put on a blood thinner and admitted to the hospital. After a couple of days, she felt better and expressed her eagerness to go home: ''I've got four collies and a husband, and they need me.''

Most patients with a pulmonary embolus are started on blood thinners and sent home within a few days. But since our patient lived an eight-hour car ride away, I was worried. Travel is a risk factor for this disease. When you don't move -- for example, when you're sitting in a car for a long stretch of time -- your blood doesn't move, and whenever blood slows down, there is a chance of clots forming. When you start moving again, the clots can break free and travel to the vital organs.

What if another piece of her clot broke off and went to her lungs again? The clot that brought her to the hospital had been a small one and she had tolerated its effect easily, but large pulmonary emboli are life-threatening. Just the isolation of highway driving might put her at risk. The old teaching was that you kept a person in the hospital for 72 to 96 hours while the clot ''stabilized,'' though like most of the old teachings, that wasn't based so much on research as on reason. What was the real risk of a second clot, perhaps an even larger one, traveling to her lungs even when she was on a blood thinner?

I promised her an answer before lunch, and after completing my rounds, I sat at my computer and called up the related research. A quick review of the literature showed that the average patient had a risk of recurrence of as little as 4 percent over the first six months, and a fraction of that in the first week. I went back to the patient with the good news. Her husband could take her home the next day, given the minimal possibility of a recurrence. Standing at this woman's bedside, explaining her illness and her risk, I felt once again the excitement that feels particular to medicine at this time in history. And yet, even as I rattled off statistics, I had to acknowledge that what feels definitive now may change, as have so many certainties of the past.

From a distance, medicine looks like a complete and beautiful body of knowledge. You get sick, and your doctor examines the sick part and figures out how to make it well. You live happily ever after. And there are aspects of medicine that work that way. But here, up close, where medicine is practiced, it's clear that our body of knowledge is growing rapidly, changing constantly. Every week's journals and patients challenge the old knowledge and sometimes provide the new. It's how progress is made in medicine, one answer at a time.

A patient of mine who came to the office recently was in the hospital a week earlier for an irregular heartbeat. In the hospital, his cardiologist started him on medicine to make his heart beat regularly again, and he was discharged on that medication. When he came to see me, he was still taking it, but his heart had started to beat irregularly once more. He was supposed to see his cardiologist the next week but wanted to know if he would have to keep taking the rhythm medicine. It made him feel tired, and he didn't like it.

Not that long ago, on hearing this story, I would have tried to convince the patient that keeping his heart in a regular rhythm was the best option and that if this drug wasn't working and made him tired, well, there were others we could try. Now I had a different option. A recent study showed that patients who were allowed to remain in an irregular rhythm did just as well as patients who took medicine to control the rhythm, as long as their heart rates -- the number of beats per minute -- were controlled. Now I could tell him that it was probably going to be O.K. for him to stay in that rhythm. He probably wouldn't have to take that medicine anymore.

That study? It was published just three months ago."

Original copy