Effects of progressive haemodilution of two kinds of hydroxyethyl starch on blood coagulation in vitro

Objective To investigate the effects of progressive haemodilution of two kinds of hydroxyethyl starch(HES)on blood coagulation in vitro.Methods Venous blood samples obtained from 20 healthy adult volunteers were diluted with HES 130/0.4 and HES 200/0.5 into four different dilution degrees in vitro:undilution(blood∶diluent=10∶0),10%(9∶1),30%(7∶3)and 60%(4∶6).Coagulation was measured with standard hematological tests and thrombelastography(TEG).Haematocrit(Hct),platelet count(Plt),plasma fibrinogen concentration(Fib),prothrombin time(PT),activated partial thromboplastin time(APTT),reaction time(R),coagulation time(K),angle α(α)and maximum amplitude(MA)were analyzed.Results Parameters were not affected by 10% dilution(all P0.05).Hct and Plt were decreased with the increase of hemodilution in both groups.Plt in HES 130/0.4 group was significantly higer than that in HES 200/0.5 group at 30% and 60% dilution.Fib was significantly lower while PT and APTT were significantly prolonged at 30% dilution in both groups compared with the values in undilution group(all P0.05).R and K at 30% dilution were significantly prolonged and angle α and MA were significantly lower in HES 200/0.5 group compared those in HES 130/0.4 group.R was significantly longer in HES 200/0.5 group compared to that in HES 130/0.4 group at 60% dilution(P0.05).Conclusion Blood coagulation is not affected by 10% dilution in both HES groups.The coagulation of HES 200/0.5 is inhibited and the rate of initial fibrin formation of HES 130/0.4 is activated at 30% dilution(medium dilution).The activities of coagulation factors are depressed and the strength of the blood clot is reduced at 60% dilution(profound dilution)in both HES groups.