A Computerized Cumulative Integral Method for the Precise Measurement of the Glomerular Filtration Rate 1

Summary A new computerized method for the accurate determination of the glomerular nitration rate (GFR) is presented. It is based on an integral formulation which expands the collection period and minimizes the errors of transit time, bladder storage and A-V concentration differences. A single injection of tracer, followed by serial sampling of blood and a single urine sample taken over 120 min will give an accuracy of within 5% in individuals whose GFR is 50% of normal or more. An additional blood and urine sample at 180 min is occasionally required when the GFR is below this level. The use of a labeled tracer makes this test a practical simple method for evaluation of the GFR in clinical practice.