Glomerular filtration rate measurement; a new cumulative integral method

A reliable method of assessing glomerular filtration rate (GFR) is useful in measuring the degree of impairment of kidney function resulting from renal disease. The standard technique is the constant infusion method utilizing inulin as described by Shannon and Smith (33) in 1935. The GFR is calculated using the derivative formulation based on the equation of Van Slyke (32) modified for use with inulin, GFR = urine inulin concentration x urine volume / plasma inulin concentration x time, for each short urine collection period of 20-30 minutes. The physiological basis and inherent weaknesses of this test are described