Explain the Creatinine Clearance Test

It determines how efficiently the kidneys are clearing creatinine from the blood and serves as an estimate of kidney function. It compares the level of creatinine in urine with the creatinine level in the blood. For this test, urine and serum levels of creatinine are measured, also the volume of urine excreted over a 24-hour period. After that the creatinine clearance rate is calculated and expressed as the volume of blood, in millilitres which can be cleared of creatinine in one minute.

The normal results for the test are 90-1 39 ml/min for adult males less than 40 years old and 80-125 ml/min for adult females less than 40 years old. For people above 40, the values decrease by 6.5 ml/min for each decade of life. A low creatinine clearance value indicates abnormal kidney function. Because creatinine is found in stable plasma concentrations, is without stinting filtered and not reabsorbed, and is minimally secreted through the kidneys, creatinine clearance is utilized to calculate the glomerular filtration rate (GFR). The GFR, in turn, is the standard by which kidney function is assessed.