Measurement of Renal Function without Urine Collection

Abstract

The assessment of renal function in infants and children is made difficult by problems in obtaining complete urine collections. The traditional and the constant-infusion methods of determining inulin and paraaminohippurate clearance were compared in 61 patients, 32 of whom had a variety of renal diseases. Glomerular filtration rates ranged from 1.6 to 133 ml per minute. Values for inulin clearance by the two methods correlated closely (r equal to 0.993) at all levels of renal function and in the presence or absence of edema. Inulin clearance by the constant-infusion technic averaged 103.2 per cent of true clearance.