Comparison between Total and Renal Plasma Clearance of [⁵¹Cr]EDTA

Abstract

The total plasma (E_t) and renal plasma (E_r) clearances of [⁵¹Cr]EDTA ere measured simultaneously in 40 patients with a wide range of renal function. The regression equation was E_t = 0.997 E_r+4.1; the slope of the regression line was not significantly different from 1.00, and the intercept differed significantly from zero. The results suggest that [⁵¹Cr]EDTA has a significant extrarenal clearance of approximately 4 ml/min, independent of renal function. The data are used to correct the total [⁵¹Cr]EDTA plasma clearance, measured by a simplified method, to yield a rapid, accurate, and precise measurement of glomerular filtration rate for routine clinical use.

Key Words:

• Glomerular filtration rate
• renal [⁵¹Cr]EDTA plasma clearance
• total [⁵¹Cr]EDTA plasma clearance