Effect of antifibrinolytic drugs on transfusion requirement and blood loss during orthotopic liver transplantation: Results from a single center

Abstract

Background: During orthotopic liver transplantation (OLT), activation of the fibrinolytic system can contribute significantly to perioperative bleeding. Prophylactic administration of antifibrinolytic agents has been shown to reduce blood loss and the need for allogenic transfusion.

Objective: To study the effect of antifibrinolytics on requirement of blood components, blood loss and operative time during OLT in patients with end stage liver disease, reporting to a single centre.

Materials and methods: Consecutive patients who underwent OLT at this centre during the period February 2003-October 2007 were the subjects of this study. Based on the individual anesthesiologist's preference, patients were assigned to receive either two million units of aprotinin (AP) as a bolus followed by 5,00,000 units/hour or 10 mg/kg tranexamic acid (TA) as a bolus followed by 10 mg/kg every six to eight hours, administered from the induction till the end of the surgery. Transfusion policy was standardized in all patients. Intraoperative red cell salvage was done wherever possible. The effect of these two antifibrinolytic drugs on transfusion requirement was evaluated as a whole and in a sub group of patients from each treatment group and compared with a concurrent control group that did not receive antifibrinolytic drugs.

Results: Fifty patients (40 M / 10 F, 44 adults, 6 pediatric patients) underwent OLT in the study period. Fourteen patients were given AP, 25 patients were given TA and 11 patients did not receive any of the agents(control group). The median volume of total blood components transfused in antifibrinolytic group (n = 39) was 4540 ml(0-19,200ml), blood loss 5 l(0.7-35l) and operative time 9h (4.5-17h) and that of control group(n = 11) was 5700 ml(0-15,500ml), 10 l(0.6-25 l) and 9h (6.4-15.8h) respectively. The median volume of blood transfusions, blood loss and operative time was lesser in AP group(n = 14) than that of TA group(n = 25).

Conclusion: There is definite decrease in transfusion requirement, blood loss and operative time in the patients who received antifibrinolytic drugs than that of patients who did not receive. Because of the small sample size, comparisons carried between different groups did not show statistical significance. Prophylactic use of antifibrinolytics during OLT, possibly helps in blood conservation.

Keywords: Antifibrinolytics; blood transfusion; fibrinolysis; liver transplantation.

Figure 1

Schematic presentation of the influence of aprotonin on fibrinolysis and the kallikrein-kinin pathway. Aprotonin is known as an inhibitor for plasmin (at concentrations of >50 KIU/mL) and kallikrein (at concentrations of > 200 KIU/mL). Plasmin inhibition leads to a reduction of fibrinolysis. Inhibition of the kallikreinkinin pathway leads to a reduction of bradykinin formation, which may explain the improved hemodynamic stability after graft reperfusion, but it also decreases the formation of t-PA.