IN-VITRO EVALUATION OF THE EFFECT OF PROFOUND HEMODILUTION WITH HYDROXYETHYL STARCH 6-PERCENT, MODIFIED FLUID GELATIN 4-PERCENT AND DEXTRAN-40 10-PERCENT ON COAGULATION PROFILE MEASURED BY THROMBOELASTOGRAPHY

Synthetic colloids have been implicated as a cause of coagulopathy whe n administered in large quantities. The effect of profound haemodiluti on (50%) on coagulation profile was measured in vitro by thromboelasto graphy. Blood samples were taken from 11 ASA grade 1 patients prior to induction of anaesthesia for elective surgery. Each sample was simult aneously tested in four different preparations: undiluted blood (contr ol sample); blood diluted with hydroxyethyl starch 6%; blood diluted w ith modified fluid gelatin 4%; blood diluted with dextran 40 10%. Ther e was a significant decrease in reaction time in the preparations trea ted with hydroxyethyl starch 6% and modified fluid gelatin 4%, reflect ing activation of initial fibrin formation. A significant increase in clot formation time was noted in the hydroxyethyl starch 6%-treated pr eparations. There was also a significant decrease in clot formation ra te and maximum amplitude in the hydroxyethyl starch 6% group. Clot for mation time, clot formation rate and maximum amplitude did not change in the modified fluid gelatin 4% group. Profound haemodilution with de xtran 40 10% exerted extreme effects on the measured variables, very o ften resulting in a straight line on the thromboelastography profile.