Measurement of Extracellular Volume and Renal Clearance by a Single Injection of Inulin

Abstract

From the plasma concentration curve obtained after intravenous injection of inulin, the mean transit time and the total clearance were calculated. The extracellular volume equals the product of the total clearance and the mean transit time. Urine sampling is unnecessary. The determination was made twice in 8 subjects and the overall random experimental error for the measurement of extracellular volume was 4.9 per cent of the mean, and 7.1 per cent for the clearance measurement.

Key Words:

• Blood volume
• extracellular volume
• mean transit time
• plasma volume
• red cell volume
• renal clearance