The effect of 6% hydroxyethyl starch and desmopressin infusion on von Willebrand factor: ristocetin cofactor activity.

Hydroxyethyl starch is commonly used as a plasma volume expander in the surgical patient. Although it is generally considered a safe plasma substitution, some reports of an acquired von Willebrand's disease-like syndrome have been documented. To examine this further, von Willebrand factor: ristocetin cofactor activity (RCoF) was measured in two groups of patients perioperatively, following hydroxyethyl starch infusion and at 30, 60, and 240 minutes following either deamino-8-D-arginine vasopressin (DDAVP) (group I, n = 12) or saline (group II, n = 11). Following hydroxyethyl starch infusion, ristocetin cofactor activity decreased to 58 percent (group I) and 55 percent (group II) of their respective baseline values. After infusion of DDAVP, mean ristocetin cofactor activity in group I increased significantly to 95 percent at 30 minutes and 100 percent of baseline at 60 minutes. Mean ristocetin cofactor activity levels in group II, however, remained decreased, 69 percent and 57 percent of baseline at the same time points. There was no statistical difference between groups before or immediately after hydroxyethyl starch administration or at 240 minutes post-DDAVP or saline infusion. It is our conclusion that DDAVP is a safe therapy for the mild coagulapathy infrequently associated with hydroxyethyl starch administration.