The predictive value of hippuran uptake in acute renal failure

In this study the hippuran uptake capacity (HUC) in 32 patients with an acute deterioration of renal function was measured. The HUC2 is the ratio between the activity accumulated in the kidneys in the first two minutes, divided by the injected dose, which was measured by the gammacamera, during standardised renography. Thirteen patients had an acute glomerular disease (AGD) and 19 patients had acute tubular necrosis (ATN). During the acute deterioration of renal function, the HUC2 values ranged between 0 and 3.0 in the AGD group and between 1.9 and 8.7 in the ATN group. In only one patient of this latter group was the HUC2 value below three. Measurement of HUC2 is useful in the differential diagnosis of acute renal failure. It can be performed in the absence of urine production and indicates renal blood perfusion despite complete absence of filtration. When the HUC2 value is higher than three, ATN is the most probable aetiology of the acute renal failure and recovery of renal function can be expected. Values below this limit most probably indicate AGD.