MONITORING OF COAGULATION DURING LIVER-TR ANSPLANTATION - INTEREST OFTHROMBOELASTOGRAPHY

Monitoring of coagulation is mandatory during liver transplantation (L T). Standard coagulation tests may be routinely used. However, they gi ve static information and may be inadequate in case of severe coagulat ion defect. Interest has been recently focused on thromboelastography (TEG) which could give more suitable and rapid information in these ca ses. Few studies have evaluated the clinical interest of TEG compared to conventionnal tests. This comparison was the aim of the present stu dy, performed in 89 patients scheduled for LT. The anaesthetic managem ent as well as procedure of transfusion were similar in all patients. Before unclamping, 5000 KUI kg(-1) of aprotinin were injected. Routine tests and TEG were performed at the beginning and end of both preanhe patic and anhepatic phases, and 5, 30, 60, and 120 min after the revas cularisation of the new liver. A phase of hypocoagulability was observ ed after unclamping. Biological signs included an increase in activate d thromboplastin time, a reduction of a angle and maximum amplitude on TEG with a lengthening of its r + k component. A strong correlation e xisted between maximum amplitude and platelets, maximum amplitude and fibrinogen, a and fibrinogen at each time of the surgical procedure. E uglobulin lysis time decreased significantly after clamping, whereas f ibrin degradation products increased at the same time. However, typica l fibrinolysis with a clot lysis index (CLI) below 55 % was only obser ved in 15 patients. Twelve of them had a CLI value reaching 0 %, assoc iated with severe generalized oozing. Aprotinin (200 000 to 600 000 KI U) corrected these abnormalities. These results show that TEG may not be very helpful to determine whether platelets or fibrinogen are invol ved in the phase of hypocoagulability detected after unclamping. Howev er, TEG allows the actual diagnosis of fibrinolysis and guides therapy . Moreover, it may have a predictive value in some limited cases.