Review of the effects of hydroxyethyl starch on the blood coagulation system.

The literature related to the effects of hydroxyethyl starch on blood coagulation was reviewed to determine whether or not recipients are placed at risk of hemorrhage or thrombosis. Effects on coagulation observed when blood and HES were mixed in vitro were trivial and seemed related simply to dilution. HES affected coagulation in vivo in a dose-related fashion. When infused in moderate amounts (as employed in leukapheresis), HES rarely, if ever, caused overt bleeding, and only minor changes of laboratory coagulation tests were detected. Following massive infusions, however, a wide variety of laboratory abnormalities were observed, and hemorrhage was documented in some reports. It must be emphasized that information is limited. Not all investigators employed a complete battery of modern techniques; data regarding massive infusions are derived almost exclusively from animal studies; and data are insufficient to determine the effects of HES on thrombosis. Additional studies are required to completely define the relationship between HES and coagulation in man.