Sunday, October 9, 2011

Doctors are like the pyromaniac fireman

A patient, on Friday, explained that doctors are like the pyromaniac fireman who when he's not putting out fires is secretly setting them so he can fight them.

Ridiculous?

Well, on that same day I saw a patient who previously had uncontrolled blood pressure. I had gotten her blood pressure under control with a combination of torsemide, spironolactone, carvedilol and amlodipine. Her office blood pressure  was 123/72 with a heart rate 86. During the visit she told me that she had fallen three times in the last few weeks. Her standing blood pressure was 96/53 with a heart rate of 96. On her previous visit I had extinguished and set a new fire at the same time. Her previous blood pressure had been in the 150s. Controlling her blood pressure was the right thing to do medically but undoubtably it was the cause of her recent falls and my attempt to trim long term morbidity resulted in her being exposed to increased short term morbidity.

Pyro fireman.

Another patient I saw has advanced diabetic nephropathy, CKD stage 4. He needs an ACE inhibitor or an angiotensin receptor blocker to stave off dialysis, unfortunately he cannot tolerate them because of recurrent of hyperkalemia. A few months ago I added a loop diuretic to control edema and hypertension and a couple of weeks ago he returned for a follow-up. His potassium was 4.6 mmol/L. The loop diuretic had increased kaluresis enough that I felt that I had some room to give another trial of renin-angiotensin blockade. Yesterday I received a call informing me of a critically high potassium in this patient.

Pyro fireman

These cases are not limited to clinical medicine, the ACCORD trial tried to determine if normalizing the Hgb a1c in diabetics reduced cardiovascular mortality. Better diabetic control caused increased total mortality.

In OnTarget the combination of an ACE inhibitor and an angiotensin receptor blocker was tested to see if it could reduce cardiovascular events. The  combination was a favorite among nephrologists as a way to stave off dialysis in patients with persistant proteinruia despite single drug renin-angiotensin blockade. Dual blockade was the fashion mostly in response to the subsequently retracted COOPERATE trial. In OnTarget there was significant increase in renal dysfunction with dual ACEi/ARB and a trend toward increased dialysis:

"...whereas the rate was increased in the combination-therapy group, with 65 patients (0.8%) undergoing dialysis"
Pyro fireman, academic style. 

It's what makes medicine so difficult, the more you try to help your patients the more you expose them to unintended, adverse reactions. I feel that so little of medical education prepares us to balance these competing end-points, how do you judge what is an acceptable risk of hyperkalemia, how do you balance the risk of hypertension versus the risk of orthostatic hypotension?
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