JK SCIENCE Estimation of Glomerular Filteration Rate (GFR)

In day to day clinical practice an estimation of glomerular filtration rate (GFR) is required for various reasons viz, a) assessment of renal function. b) severity of renal disease c) calculation of proper drug dosage and d) appraisal of renal involvement in systemic diseases. Various methods of estimating GFR are briefly described below: I. Clearance Methods:- The concept of renal clearance was introduced as a way of expressing the relation between the excretion per unit time and the concentration in the plasma which is obviously an index of kidneys ability to clear the blood of any substance (1). Measurements of GFR are traditionally based on the renal clearance of a marker in plasma, expressed as the volume of plasma completely cleared of the marker per unit time