The predictive value of 131I-hippurate clearance in the prognosis of acute renal failure

The aim of this investigation was to study the validity of the radionuclide methods in the estimation of kidney function, for prognosis and follow-up of acute renal failure (ARF). In thirty-one ARF patients, the evaluation of glomerular filtration rate (GFR) by 99mTc-DTPA clearance and effective renal plasma flow (ERPF) by 131 I-ortoiodohippurate (131I-OIH) clearance was performed within 7 days and after 6 months from ARF onset. All patients were divided in three groups according to 131I-OIH clearance values obtained within 7 days: group 1, under 150 mL/min; group 2, 150-250 mL/min; and group 3, over 250 mL/min. Seven days clearance values of both radiopharmaceuticals were found to be very low, however, GFR was found more severely impaired than ERPF. Clearance values obtained after 6 months demonstrated no recovery of renal function in the first group, partial recovery in the second and almost complete recovery in the third group. Patients with the lowest 131I-OIH clearance values at the ARF onset had no recovery of renal function, while in the other two groups recovery corresponded to initial 131I-OIH clearance values. In patients with ARF both, 99mTc-DTPA and 131I-OIH clearances were shown suitable for the follow up of renal function, however, only 131I-OIH clearance had a strong predictive prognostic value for renal function recovery in ARF.