Saturday, September 23, 2006

ER docs

I know there are good ER docs. There must be. Unfortunately, it has not been my good fortune to run into many. What got me thinking about this most recently was an encounter from my last night on call.

So my team is down in the ER, seeing a patient. We want the guy to come in, because he has had chest pain which is a bit concerning, but the enzyme levels we look at to detect a heart attack are not demonstrating any damage. So we lay out the story exactly like it is, telling him he needs a stress test, but he'll have to wait until Monday to get it. So he'll be camped out in the hospital over the weekend.

Mr. Brooks (the patient) decides he'd rather spend the weekend at home. Not smart, but it is his right, and we told him about the risk for death, etc., if he checked out.

Enter Dr. Oaks.

He's the ER doc who had been seeing Mr. Brooks, and upon hearing that the patient was going to leave, he swung into the room and said "oh, that's a bad idea sir, one of your cardiac enzymes is elevated, which means there is muscle damage to your heart, you know, that you're probably having a heart attack, so we'd like to watch you here."

This is both true and false, and the result means that Dr. Oaks is a)a liar or b)an idiot.

Let me explain. The enzyme we are talking about is called CK-MB, and it is part of the CK group of enzymes. We worry about it, because one of the places it is released from is the heart, and so if it is elevated, it can mean that a person is having a heart attack. However, we measure two more things as part of this test. One, we compare the total elevation of CK enzymes to the CK-MB elevation, and get a ratio. If the total level of enzymes is high, then the CK-MB part will be high only if you measure the number, but the percentage doesn't change. Put more vividly, if you have a set of marbles, with 10 red and 1 blue, and you combine it with another set of 10 red and 1 blue, now you have two blue marbles, but the ratio of blue to red is still 1/10. Mr. Brooks' CK ratio was normal, and the elevation in total CK (total marbles) is probably just a normal variation.

The other enzyme we measure is called troponin, and it is much more specific to the heart. It's almost 100% specific (but nothing in medicine is 100%) so if the troponin goes up, you can tell someone's probably having a heart attack. If it isn't up, they probably aren't. (Though that has more to do with sensitivity. Nevermind. If you wanted a lecture on EBM, you wouldn't be reading my blog)

So the options: Dr. Oaks didn't know enough about cardiac enzyme tests to be able to tell Mr. Brooks was not, in fact, positive, or he intentionally violated his medical ethics and lied to patient. It doesn't matter that he intended it for good.

My resident was, shall we say, vexed. She called out Dr. Oaks right there, and when he didn't respond favorably, she wrote up a report on the incident and filed it with the hospital.

We'll see if that helps his practice (or his ethics), but it probably won't improve relations between the medicine and ER teams.

C'est la vie.

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