The Functions Of Thromboelastography During Orthotopic Liver Transplantation Without Veno-venous Bypass

Objective: the purpose of this study is to use the thromboelastography to monitor the coagulation during orthotopic liver transplantation without veno-venous bypass, to investigate the changes of coagulopathy and to evaluate the effects of treatment during OLT. It also analyzes the important reasons of the postreperfusion coagulopathy through thromboelastography, and finds out the best therapies. Methods: in this study, data was collected from 48 patients aged 30-55 years with terminal liver disease, ASAⅡ～Ⅲ, Child's classification B or C undergoing OLT. Depending On the dose of protamine given postreperfusion, patients were divided into three groups: P30(30mg protamine postreperfusion), P50(50mg protamine postreperfusion), P80(80mg protamine postreperfusion). All the patients wereperformed general anesthesia. The catheter was inserted through the right jugular vein for blood collecting. The native TEG and the haparinase modified TEG were measured beforethe operation began(T1), 5 min before reperfusion(T2), 5 min after reperfusion(T3), 10 min after protamine were given(T4). The measured variables included the R(reaction) time, K(coagulation) time, Angles(reflecting fibrin-platelet interaction), MA(maximal amplitude). In addition, the other measured variables included the patient's blood lose, body temperature and the graft liver weight, the graft conservation time.Results: The patients' age and weight have no significant differences(P＞0.05). At T1 time, NTEG shows that K prolonged and MA decreased in three groups. There is no significant difference between HTEG and NTEG. At T2 time, K shorten to normal and compared with T1, there is significant difference(p＜0.01). The trace of NTEG and HTEG are almost the same. Within 60 minutes after graft liver reperfusion(T3), None of the TEG samples of all the groups formed effective thromboelastography, 46 of which presented a straight line. Compared with HTEG at T1 and T2, K remarkably prolonged, and meanwhile, Angle and MA significantly decreased(P＜0.01). After the intravenous injection of different doses of protamine, NTEG effective thromboelastography signature at T4 resumed. Compared with those in NTEG-P50, R,K,Angle and MA in NTEG-P30 all comparatively prolonged at T1 and T2(P＜0.01, P＜0.05). R,K,Angle and MA in NTEG-P80 were quite close to the level before reperfusion(P＞0.05). R in NTEG-P80 and NTEG-PS0 differed greatly from the one in NTEG-P30. As for HTEG, R,K,Angle and MA were all closethe level before reperfusion. R in HTEG-P30 differed greatly from that in NTEG-P30.Conclusion: The postreperfusion coagulapathy caused by several reasons. In different period of OLT, the major reason is various. The thrombelastography has been shown as a useful monitor of coagulation during liver transplantation, and provides a rational approach for use of blood component therapy or pharmacological intervention. Exogenous heparin or heparin-like substances were released during reperfusion, due to its administration to the donor before harvesting the graft and may contribute to critical coagulapathy. Protamine was used to eliminate heparin during postreperfusion. The use of haparinase modified TEG to monitor coagulation during OLT provides useful information in all groups of patients.