Comparison of standard coagulation testing with thromboelastometry tests in cardiac surgery

Introduction: According to the several evidences, using thromboelastometry as a point of care test can be effective in reduction in blood loss and transfusion requirements in cardiac surgeries. However, there are limited data regarding to the comparison of thromboelastometry and the standard coagulation tests. In this study, we compared thromboelastometry and standard coagulation tests (PT, PTT and fibrinogen level) in patients under combined coronary-valve surgery. Methods: Forty adult patients who were under on-pump combined coronary-valve surgery were included in this study. Thromboelastometry tests Fibtem, Intem, Extem and Heptem), along with standard coagulation tests (PT, PTT and fibrinogen assay) were simultaneously performed in two time points, before and after the pump (pre-CPB and post-CPB, respectively). Results: A total of 80 blood samples were analyzed. There were no significant correlation between PT test and the CT-Extem parameter as well as PTT and CT-Intem parameter either in pre-CPB and post- CPB (P > 0.05). On the contrary, fibrinogen level had high correlation with A10-Fibtem and A10-Extem in pre-PCB (P < 0.05). 82% of PT and 84% of PTT measurements were outside the reference range, while abnormal CT in Extem and Intem was observed in 17.9%. Conclusion: For management of bleeding, adequate perioperative haemostatic monitoring is indispensable during cardiac surgery. Standard coagulation tests are time consuming and cannot be interchangeably used with thromboelastomety and relying on their results to decide whether blood transfusion is necessary, leads to the inappropriate transfusion.