Recent studies have produced conflicting results on the influence of hemodilution on the coagulation system. Furthermore, only a few clinical studies have been conducted regarding actual blood loss and associated hemodilution. The purpose of this study was to investigate changes in thromboelastograph (TEG) findings after moderate bleeding-induced hemodilution in patients undergoing radical hysterectomy.

23 patients scheduled for radical hysterectomy were included. No patient had a preoperative coagulation abnormality or was receiving anticoagulant or antiplatelet medication. TEG findings 15 min after induction of anesthesia and after an estimated blood loss equaling 15% of the estimated blood volume were compared. Only crystalloid solution was administered until the second blood sampling for TEG analysis in order to produce a hemodilution state.

After hemodilution R time, K time and coagulation time (r + k) showed significant reductions, and alpha angle and TEG index showed significant increases (P < 0.01), and increased coagulability. MA increased after hemodilution, but this was not statistically significant. A60 and CL60 also increased, showing decreased fibrinolysis (P < 0.05).

Moderate bleeding-induced hemodilution increased coagulability according to TEG compared to pre-hemodilution findings. We recommend that the decision to replace coagulation factors and/or platelets should not be based on empirically derived, arbitrary standards.