What is an internist, and why should you care?

A (long) while back, I gave you a brief explanation of what an “internist” is. I later gave you a personal view of primary care medicine and some of the challenges involved in creating an infrastructure of primary care (only 2% of American medical grads are going into primary care). We also had a little chat about medical mistakes and medical training.

No matter what changes we ultimately make in the way we train internists, one of the lessons that residency teaches is to identify who is truly sick. I don’t mean who is faking it, I mean being able to look at someone briefly and decide whether or not they need your immediate attention. It may seem obvious, but it’s not. Objective factors can sometimes be deceiving. For example, an asthmatic may have perfectly normal vital signs, including a normal oxygen level, and yet be moments away from needing a breathing machine. For an asthmatic, a normal respiratory rate may indicate fatigue rather than health, and absence of wheezing my indicate such severe airway obstruction that wheezes aren’t even possible. The ability to recognize severe illness is one of the critical goals of residency.

This is one area in which the so-called alternative medicine folks can really be dangerous.

To give you one amalgam based on far too many stories, we had a middle aged guy come on once who looked like crap. He was too thin, too weak, too pale, and too breathless. To me, it was obvious that he was seriously ill. But at a brief glance, I’m not so sure a layperson would make that same judgment. None of the individual factors was really strong enough: yes, he was pale, but so are a lot of people; yes he was thin, but maybe that’s natural for him. But when my residents and I saw him, we were fairly certain that he had TB or AIDS or cancer and that he was approaching a crisis that might kill him. We immediately admitted him to the hospital.

But that’s not what his previous health care provider did. He saw a doctor (licensed DO or MD, not sure which) who told him something about his glands not working well, and gave him supplements. When the patient got sicker, the doctor changed him to some different supplements. This isn’t only a failure of an individual doctor to recognize an individual sick patient. It is a failure of a doctor to know how to think like a doctor.

One of my professors was fond of saying that the best internist on TV was Colombo, and while that dated him a bit, the point got through. A good internist meets a patient, takes a thorough history, does a complete physical, and develops what is called a “differential diagnosis”, or a list of potential explanations for the patient’s condition. The internist then uses the data she knows to guide her to further studies, and she will cross potential diagnoses off the list as the data come in. For example, the patient above was short of breath. Physical exam did not reveal any abnormal lung or heart sounds, so pneumonia and heart failure seemed unlikely. His oxygen level was good, so lack of oxygen reaching the blood (indicating a problem likely at the level of the alveoli) seemed unlikely. A blood test showed a very low blood count. This seemed likely to be the proximate cause of his breathlessness, but for a real doctor, that’s not good enough.

The type of anemia is very important—is it from blood loss, and if so, is it acute, sub-acute, or chronic? Is it hemolytic, meaning blood cells are being destroyed? Is it due to inhibition of normal blood cell production? A good look at a blood smear can help sort this out, as can a look at additional labs. A real internist will not be satisfied giving someone “Adrenal Max” or “Energy Boost Plus”, or some such nonsense.

The reason an internist wouldn’t just give a magic potion isn’t because she doesn’t believe in magic potions (although she probably doesn’t). It’s because magic potions wouldn’t even cross her mind. It isn’t relevant to human health and disease. What is relevant is the patient, their illness, what science says is and isn’t plausible, and what medicine has found to be effective or ineffective. The doctor who gave the energy pills wasn’t right—he wasn’t even wrong. He was thinking so far outside the box, that he didn’t need to know anything about the patient or about medical science in order to prescribe the treatment. The thinking was a simplistic “energy low, give so-called energy pill”.

A friend of mine who is a lawyer was talking to me about a similar case recently and said, “why isn’t that fraud?” I didn’t have a good answer.