Measurement of glomerular filtration rate by single-injection, single-sample techniques, using 51Cr-EDTA or iohexol.

Clearance calculations based on single sample determinations from 51Cr-EDTA samples 180 min after giving radioisotope showed a correlation coefficient of 0.992 to clearance calculations after multiple sampling of 51Cr-EDTA. The range of clearance determinations in 108 patients varied from 4 to 141 ml/min, 1.73 m2 BA. Twenty patients had clearance values below 20 ml/min, 1.73 m2 BA. Clearance calculations from single samples of iohexol from 180 min values showed a correlation coefficient of 0.986 to clearance calculations after multiple sampling of 51Cr-EDTA. These calculations were based on samples from 122 patients with clearance values varying from 4 to 139 ml/min, 1.73 m2 BA. No adverse reactions were registered during the study. This study confirms the reliability of single sample methods for clearance calculations at all levels of renal function.