[Preoperative hemostasis evaluation]

Identify which patients are going to bleed during a surgery or invasive procedure is desirable. The coagulation tests as the prothrombin time (PT), the activated partial thromboplastin time (aPTT), bleeding time (BT) and platelet count are routinely made with this purpose in the preoperative evaluation. But, really these laboratory tests can predict what patients are going to bleed? The answer with the current knowledge is: No. The most efficient method for prediction of bleeding is the clinical history, but still, most surgical bleeding are not by coagulopathy, they are caused by factors related to surgical technique, and therefore are not susceptible to be predicted. This article describes the recommendations for the assessment of bleeding risk prior to surgery or invasive procedures and discusses the value of preoperative coagulation tests.