Do you prefer transtubular potassium gradient (TTKG) or urine potassium to urine creatinine ratio when evaluating patients with abnormal potassium levels?

Metrics for assessing dyskalemias have become controversial over the last few years. There is very little data, but a fair amount of theorizing, addressing this issue. Importantly, no metric for diagnosing the cause of a dyskalemia should be used without careful assessment of the overall clinical and pathophysiologic context of the individual patient.

In terms of actual data, one recent study found fractional excretion of potassium (FEK) to perform best overall, however, TTKG was best at identify...