Thread by @nephrotox

@J_Corky @MNpoisoncenter @Eastmanov1 @jonbcole2 Perfect timing to ask. See below: our PC was called with this case at the same time I was on renal service and our fellow was asked to see them. 50-odd yo woman presents with fatigue and these labs.

@J_Corky @MNpoisoncenter @Eastmanov1 @jonbcole2 This is all uremia here (Ketones neg, sal neg)
I have personally not found a reference which correlates anion gap to degree of uremia - probably because degree of uremia is:
2/

@J_Corky @MNpoisoncenter @Eastmanov1 @jonbcole2 a) Poorly coorelated with azotemia (BUN)
b) Poorly correlated with degree of symptoms and manifestations: you can "get used to" uremia (just like patients with chronic hyperK can have no EKG manifestations, but an acute rise from 4 -> 6 mEq/L might widen QRS) 3/

@J_Corky @MNpoisoncenter @Eastmanov1 @jonbcole2 If we could *actually* measure all the organic acids, weirdo compounds like indole derivatives which are largely in tissue (and not well dialyzed), etc., then we might be able to measure uremia.
Same deal for anion gap and uremia.
But there is one thing we can measure!

@J_Corky @MNpoisoncenter @Eastmanov1 @jonbcole2 ...and by one thing I mean one anion: phosphorus.
Anion gap in my experience correlates pretty well with phos, even though animal studies suggest that phosphorus accounts for a minority of anion gap.
So look for hyperphosphatemia: closest surrogate we have for ⬆️AG in uremia.