No coagulation disorders under high-dose volume therapy with low-molecular-weight hydroxyethyl starch

Hydroxyethyl starch (HES) is often used for volume therapy. Since bleeding complications have been reported repeatedly, a strict dose limitation of a maximum of 1,500 ml 6% solution per day is recommended. However, many indications require higher dosages. Bleeding complications are known to be caused by an acquired von Willebrand syndrome. It has been shown that the accumulation of large molecules and their impairment in the coagulation system can be avoided by using HES preparations with a low in vivo molecular weight. However, the effects of a high-dose therapy have not been studied yet. We have investigated, how a 4-day high-dose therapy, using 3,000 ml 6% HES 70/0.5 on the 1st day and 1,500 ml on days 2-4, affects the coagulation system and hemorheological parameters of acute stroke patients. Thromboplastin time, activated partial thromboplastin time and thrombin time showed no significant changes, except for a slight, clinically irrelevant change due to dilution. The subunits of von Willebrand factor VIII showed no significant change. Hematocrit decreased from 42.3 +/- 4.6 to 37.4 +/- 3.9% (p < 0.05) after day 1, reaching 35.3 +/- 4.2% (p < 0.01) at the end of the therapy, demonstrating a substantial volume effect. Plasma viscosity and erythrocyte aggregation decreased slightly, however not significantly. Our study shows that even a high-dose therapy with 6% HES 70/0.5 has no influence on the coagulation system.