Monday, December 21, 2009

Creatinine Clearance

Creatinine clearance rate (CCr) is the volume of blood plasma that is cleared of creatinine per unit time and is a useful measure for approximating the glomerular filtration rate (GFR). The creatinine clearance test compares the level of creatinine in urine with the creatinine level in the blood. Both GFR and CCr may be accurately calculated by comparative measurements of substances in the blood and urine, or estimated by formulas using just a blood test result (eGFR and eCCr).

The results of the creatinine clearance rate tests are important in assessing the excretory function of the kidneys. For example, grading of chronic renal insufficiency and dosage of drugs that are primarily excreted via urine are based on GFR (or creatinine clearance).

Normal Creatinine Clearance

Average: 120 ml/min/1.73 m2 (+/-25) or 175 Liters/dayRange: 97-137 ml/min/1.73 m2 (0.93-1.32 ml/sec/m2 IU)

Average: 95 ml/min/1.73 m2 (+/-20) or 135 Liters/day Range: 88-128 ml/min/1.73 m2 (0.85-1.23 ml/sec/m2 IU)