Over-estimation of glomerular filtration rate by single injection [⁵¹Cr]EDTA plasma clearance determination in patients with ascites

Abstract

The total plasma (Cl_t) and the renal plasma (Cl_r) clearances of [⁵¹Cr]EDTA were determined simultaneously in nine patients with ascites due to liver cirrhosis. Cl_t (mean 78 ml/min, range 34-115 ml/min) was significantly higher than Cl_r (mean 52 ml/min, range 13-96 ml/min, P<0.005). The aseitic fluid-plasma activity ratio of [⁵¹Cr]EDTA increased throughout the investigation period (5 h). The results suggest that [⁵¹Cr]EDTA equilibrates slowly with the peritoneal space which indicates that Cl_t will over-estimate the glomerular filtration rate by approximately 20 ml/min in patients with ascites. To assess glomerular filtration rate in presence of ascites, the renal plasma clearance of [⁵¹Cr]EDTA should be used instead of the total plasma clearance.

Key Words:

• ascites
• creatinine clearance
• glomerular filtration rate
• renal [⁵¹Cr]EDTA plasma clearance
• total [⁵¹Cr]EDTA plasma clearance