Increased intra-operative and postoperative blood loss might be caused by acquired platelet function disorders. In particular because conventional coagulation analyses and platelet count fail to detect impaired platelet function, implementation of bedside-tests for platelet function in the peri-operative period is desirable according to the results of retrospective studies. Following adequate adjustment of basic conditions of haemostasis (e.g. temperature, pH, Ca2+-concentration, haematocrit) a pharmacological approach with desmopressin (1-desamino-8-d-arginine vasopressin; DDAVP) or tranexamic acid potentially represents a low cost alternative to platelet transfusions with minor side effects.