[51Cr]EDTA plasma clearance and endogenous creatinine clearance in advanced renal insufficiency

Comparison of [51Cr]EDTA plasma clearance corrected for extrarenal elimination with 24 h endogenous creatinine clearance in patients with advanced renal failure showed that the corrected [51Cr]EDTA clearance was lower than creatinine clearance, and thus might be a better approximation to the glomerular filtration rate in uraemic patients. The corrections cannot be used on [51cr]EDTA clearance values below the mean extrarenal clearance, averaging 3.7 ml/min.