Calculating Renal Clearance Rates
CLEARANCE is how much plasma is cleaned of a particular compound in one minute.
The clearance rate most often calculated is CREATININE CLEARANCE. This is because creatinine is filtered into the urine at the glomerulus, and then is neither reabsorbed or secreted by the tubular cells. So the amount of plasma that has had the creatinine cleared out of it equals the amount of plasma that was filtered by the kidneys -- the GLOMERULAR FILTRATION RATE. This is a major index of kidney function.
Its normal value is around 125 mL plasma/min.
Calculating clearance rates is simple -- it's a basic conversion factor problem.
