In Vitro Coagulation Study of Hemodiluted Blood with Hydroxyethyl Starch by Thromboelastography

Lee, Sang Oh; Lee, Seung Han; Hur, Chul Hoi; Kim, Mun Chul; Cho, Kang Hee

Abstract

BACKGROUND: To avoid the risks associated with transfusion of homologous blood products, artificial colloid solutions represent an alternative for intra-operative blood loss replacement. However, synthetic colloids have been implicated as a cause of coagulopathy when administered in large quantities. We investigated the effect of Hydroxyethyl starch (HES) on blood coagulation in vitro under thromboelastography (TEG).
METHODS
Whole blood was withdrawn from fifteen volunteers undergoing peripheral surgery who had no history of coagulation defect. Whole blood was diluted with HES to 25, 50 and 75 vol% concentrations, and the changes in coagulation status were analysed using TEG and were compared with those of an undiluted control specimen obtained concurrently from the same patients.
RESULTS
Hemodilution with HES solution at 50 vol% concentration decreased the MA and alpha angle values (P < 0.05), but the R and K values remained unchanged. In case of profound hemodilution at a 75 vol% concentration, the values of MA and alpha angle were severely decreased (P < 0.05) and the values of R and K were severely increased (P < 0.05).
CONCLUSIONS
There were many reports that moderate hemodilution with crystalloids increased coagulability, but hemodilutions up to 50 vol% concentration with HES solution did not significantly change blood coagulability. Significant hypocoagulability occurred at a 75 vol% hemodilution with HES.