Background: The lack of acceptance of hydroxyethylstarch (HES) for intravascular volume replacement is most likely due to reports of abnormal coagulation. In a blinded in vitro study, we compared the effects on hemostasis of a new HES, prepared in a balanced solution, with a conventional HES preparation and Ringer's lactate solution.
Methods: Blood was taken from 10 healthy young male volunteers. Blood was diluted by 10%, 30%, and 50% using either 6% HES 130/0.42 prepared in a balanced solution, a conventional nonbalanced 6% HES 130/0.4 or Ringer's lactate solution. Rotation thrombelastography, was performed after adding two activators (thromboplastin-phospholipid to monitor the intrinsic system; tissue factor to monitor the extrinsic system). Whole blood aggregometry adding adenosine diphosphate, collagen, and thrombin receptor-activating protein was used to assess changes of platelet function.
Results: Dilution of blood (30% and 50%) resulted in clot formation time that was significantly more prolonged in the nonbalanced than in the balanced HES group. In the 50% diluted sample using the unbalanced HES, maximum clot firmness was significantly more reduced than by 50% dilution using the balanced HES. In the 50% diluent using the nonbalanced HES, adenosine diphosphate-, collagen-, and thrombin receptor activating protein-induced aggregometry was more reduced than in the balanced HES group.
Conclusions: A balanced HES preparation showed fewer negative effects on thrombelastographic data and platelet aggregation than a nonbalanced HES preparation, especially when using higher degrees of dilution. Future clinical studies may show a decreased influence of balanced HES solutions on coagulation.