Indocyanine Green (ICG) and Evans Blue: Comparative Study of Plasma Volume Measurement.

摘要

Plasma volumes (PV) were measured in two groups of rats by injection of ICG (n = 213) or Evans Blue (n = 100) via indwelling jugular cannulae. Both groups had similar (p > 0.05) body weights, core temperatures, plasma protein concentrations, and corrected venous hematocrits. Serial blood samples were obtained over 10 min (8 samples, ICG) or 60 min (6 samples, Evans Blue). PV's were determined directly by dye dilution, and blood (BV2) and cell volumes (CV were calculated. The coefficients of determination (r squared, X + or - SD) of ICG and Evans Blue plasma dye disappearance curves were 0.995 + or - 0.008 (p 0.05) from corresponding values for Evans Blue. In additional experiments (n = 12), PV was quantitated (21.9 + or - 3.2 ml) by ICG followed by injection of known volumes of 0.9% saline (6.1 + or - 0.5 ml). One h later, the predicted volume (28.0 + or - 3.6 ml) was not significantly different (p > 0.05) from the measured volume (28.2 + or - 4.1 ml), and the correlation (r = 0.858) was significant (p < 0.01). The data indicate that ICG can be used to measure PV in rats and simultaneously assess changes in liver function (i.e. clearance rate). Because of its short t sub 1/2, PV can be reestimated within an h.