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 followup of acute renal failure (ARF). In thirty-one ARF patients, the evaluation of glomerular filtration rate (GFR) by Tc-99m-DTPA clearance and effective renal plasma flow (ERPF) by I-131-ortoiodohippurate (I-131-OIH) clearance was performed within 7 days and after 6 months from ARF onset. All patients were divided in three groups according to I-131-OIH clearance values obtained within 7 days: group I, under 150mL/min; group 2, 150-250mL/min; and group 3, over 250mL/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 I-131-OIH clearance Values at the ARF onset had no recovery of renal function, while in the other two groups recovery corresponded to initial I-131-OIH clearance values. In patients with ARF both, Tc-99m-DTPA and I-131-OIH clearances were shown suitable for the follow up of renal function, however, only I-131-OIH clearance had a strong predictive prognostic value for renal function recovery in ARF.