VWF and blood coagulation disease: It has been reported that in vivo hemodilution with HES resulted in increased perioperative blood loss2, and that in vitro or in vivo hemodilution caused coagulopathy measured by point-of-care devices such as ROTEM, TEG, and Sonoclot3 as well as reductions in von Willebrand factor (VWF) antigen (Ag) levels and coagulation factor VIII (FVIII) Ag levels4.