The simplest things are way more complex than we understand

Recent poll I posted to Twitter

This was inspired by a recent patient encounter. Patient was doing great. No complaints. Here for routine follow up. I ordered renal function panel, as I do with essentially everyone I see, every visit.

Their creatinine was up and as I scanned their vitals, the blood pressure was lower than normal. Not really low, but just as their creatinine was higher than normal, their blood pressure was marginally lower than normal.

So now what to do. I felt that since I check the labs and found a loss of kidney function I was obligated to react. Otherwise what am I doing checking the labs, if I’m not going to act on the results.

I put the blood pressure together with the drop in kidney function together and trimmed the patient’s blood pressure medications. I have no idea if I did the patient a favor.

If they come back next visit and the creatinine is down, was that due to the intervention or just reversion to the mean? If it was due to the intervention, was the rise in blood pressure worth the improvement in renal function? Even if there is no change in blood pressure, did the loss of the RAASi and/or beta-blockade expose the patient to other long term deleterious effects?

None of this would have happened had I not happened to check the patient’s creatinine on a routine visit. Is there evidence for us checking kidney function? Is there evidence for routine CKD visits?

Every time I see a bump in creatinine I worry that I am at the beginning of the yellow arrow, but probably we are just riding the wavey red line.