CREATININE CLEARANCE

CREATININE CLEARANCE

Application: Assessment of glomerular filtration rate, and hence glomerular function.

 
Explanation: Creatinine is is entirely excreted by the kidneys and so is directly proportional to glomerular filtration rate (GFR), or ml of filtrate made by the kidneys per minute. Creatinine clearance is more sensitive than serum creatinine for the detection of early glomerular dysfunction, but significant decreases in creatinine clearance may not occur until up to 30% of glomeruli cease to function. Complete and accurately timed urine collections are essential.

Creatinine clearance (ml/min) =

urine creatinine (mg/dL) x urine volume (ml/min)
                 serum creatinine (mg/dL)


Specimen: 24 hour urine collection for creatinine measurements. The patient should not eat meat at the meal immediately prior to, or during, the procedure.


 Reference Interval:
107-139 ml/min (Male)
87-107 ml/min   (Female)
values decrease 6.5 ml/min per decade of life due to decreased GFR

40-65 ml/min     (Neonate)