[Comparative effects of low and medium molecular hydroxyethyl starch (HES) solutions on hemorrhagic shock in rats].

ABSTRACT

BACKGROUND: Hydroxyethyl starch (HES) solutions are frequently used plasma expanders. We examined the effects of medium-HES (mean molecular weight of 130,000 dalton) and low-HES (mean molecular weight of 70,000 dalton) on the survival rates (Exp. I), colloid osmotic pressure (COP) (Exp. II) and coagulation (Exp. III) with rats in hemorrhagic shock. METHODS: Hemorrhagic shock was induced by removing 55% (Exp. I) and 20% (Exp. II and III) of the circulating blood volume. Saline, low-HES or medium-HES of the same volume with the removed blood was intravenously infused immediately after bleeding. RESULTS: Exp. I In survival rate, effect of medium-HES was significantly superior to that of saline. Exp. II The COP of medium-HES group was significantly higher than that of saline group 3 hrs after hemorrhagic shock. Exp. III There were no changes in von Willerbrand factor and factor VIII 3 hrs after hemorrhagic shock among saline, low-HES and medium-HES. CONCLUSIONS: Medium-HES and low-HES are efficacious plasma volume substitutes; however, the ability of medium-HES to prolong maintenance of COP better than low-HES is a finding that would be significant in a clinical setting involving preoperative blood management and extreme blood loss.