[Thromboelastograph in cardiac surgery: state of the art.].

BACKGROUND AND OBJECTIVES Management of hemostasis of cardiopulmonary bypass (CPB) patients is still a major challenge. New monitoring methods, new hemostatic drugs and new platelet function inhibitors are being added to the pre, intra and postoperative periods. The multifactorial nature of CBP-induced hemostasis disorders requires the understanding of their pathophysiology and the accurate hemostasis evaluation for effective coagulation during CPB, in addition to the maintenance of adequate postoperative hemostasis. Activated clotting time (ACT) and coagulogram are not enough for this management. A broader evaluation is needed with monitors able to measure platelet function and hemostatic process dynamics as a whole. CONTENTS Hemostasis is the result of the balance of coagulation, anticoagulation and fibrinolysis systems components. This balance is disrupted during CPB making patients susceptible to microvascular bleeding. CPB induces multifactorial changes in platelet force growth and clot elastic properties. Blood products are often used and there is the need for protocols to guide transfusion decisions. It is important to determine platelet function with monitors measuring clot visco-elastic properties, such as thromboleastograph (TEG) and Sonoclot. CONCLUSIONS Thromboelastograph is an important hemostasis monitor for patients submitted to CPB. It has been incorporated to hemostatic disorders evaluation protocols and transfusion therapy, with good results.