Problems Associated with Coagulation Monitoring during Cardiovascular Surgery
Despite the success of cardiac surgery and the improvement of cardiopulmonary bypass (CPB) instruments, life-threatening bleeding after CPB remains a serious problem that necessitates transfusion of blood components in a high percentage of patients and sometimes requires re-exploration. The incidence of hemorrhage is 5% to 18% in patients who have undergone open-heart procedures (1-4). Many different disorders can occur in patients undergoing CPB; this complicates the identification of specific causes and often delays effective treatment. The modification of routine coagulation tests and the application of new methods of detecting and treating coagulation abnormalities are focused on the reduction of morbidity and mortality in CPB patients. Thromboelastography (TEG) has been utilized for guiding the therapy of postoperative hemorrhage in cardiac patients (5). A system for quantitative determination of heparin concentration is now commercially available, which may obviate the disadvantages of the routine activated clotting time (ACT) measurement. It has recently been reported that, because of the anticoagulation effects of aprotinin, the need for heparin can be reduced in patients given aprotinin (6).
KeywordsCardiopulmonary Bypass Activate Clotting Time Excessive Hemorrhage Heparin Concentration Coagulation Monitoring
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