Assessment of coagulation with 6% hydroxyethyl starch 130/0.4 in cesarean section

BACKGROUND: Third-generation hydroxyethyl starch (HES) solutions have been developed to minimize negative effects on hemostasis. In normal pregnancy, the coagulation activity increases, reaching a maximum around term. This study examined the effects of hemodilution with HES 130/0.4 (6%) on blood coagulation in parturients in vivo and in vitro. METHODS: Forty parturients scheduled for cesarean sections were assigned randomly to receive either 500 or 1,000 ml of HES 130/0.4 (6%). Rotation thromboelastometry (ROTEM®) measurements were performed before and after administering HES 130/0.4 (6%). In addition, blood samples obtained from 20 randomly selected parturients were diluted 10% to 40% using HES 130/0.4 (6%), and ROTEM® measurements were performed before and after dilution. The changes from baseline and the effects of dilution were analyzed by ROTEM® parameters. RESULTS: Infusions of 500 or 1,000 ml of HES 130/0.4 (6%) in the parturients altered the clot formation time, α angle, and maximal clot firmness, although all remained within normal ranges. HES 130/0.4 (6%) affected in vitro blood coagulation in parturients' blood containing 10, 20, 30, and 40% HES. The clotting time was prolonged at each dilution percentage, but remained within the normal range. Other parameters showed an impairment of the coagulation system. CONCLUSIONS: Blood coagulation in parturients may be compromised at high dilution ratios of HES 130/0.4 (6%) to blood. Nevertheless, the infusion of 1,000 ml of HES 130/0.4 (6%) in normal parturients did not significantly affect blood coagulation.