Effects of Hydroxyethylstarch (HespanR), a Plasma Expander, on the Functional Activity of the Reticuloendothelial System. Comparison with Human Serum Albumin and Pyran Copolymer

The purpose of the present investigation was to determine if RES activity was altered after the infusion (bolus i.v. injection over approximately 3-5 min) of hydroxyethylstarch (HES). RES function was determined by vascular clearance of 51Chromium-labeled sheep erythrocytes and the subsequent uptake into the liver, spleen, lungs, and thymus at 1 hr, 3 hr, 6 hr, 1 day, 3 days, and 7 days post infusion. Infusion with the low doses of HES (20 and 40 ml/kg) produced changes in vascular clearance which were comparable to physiological saline. Infusion with 80 ml/kg HES produced a biphasic response with a modest suppression of vascular clearance (i.e., 151% increase in half life) and hepatic phagocytosis (50%) during the first 6 hours after injection, followed by recovery at 24 hours and a stimulation in hepatic uptake (42%) after 3 days. These effects by HES were compared to those produced by infusion with 80 ml/kg HSA, a comparable colloid and with 80 ml/kg pyran copolymer, a positive control.