Effect of low central venous pressure and phlebotomy on blood product transfusion requirements during liver transplantations

Abstract

Correction of coagulation defects with plasma transfusion did not decrease the need for intraoperative red blood cells (RBC) transfusions during liver transplantations. On the contrary, it led to a hypervolemic state that resulted in an increase of shed blood. As well, plasma transfusion has been associated with a decreased one-year survival rate. The aim of the present prospective survey was to evaluate whether anesthesiologists could reduce intraoperative RBC transfusions during liver transplantations by changing their anesthesia practice, more specifically by maintaining a low central venous pressure (CVP), through restriction of volume replacement, elimination of all plasma transfusion and by using intraoperative phlebotomy during the transplantation. One hundred consecutive liver transplantations were prospectively studied during a two-year period and were compared to a retrospective series (1998-2002). A low CVP was maintained in all patients prior the anhepatic phase. Coagulation disorders were not corrected preoperatively, intraoperatively, or post-operatively unless uncontrollable bleeding. Phlebotomy and Cell Saver (CS) were used following pre-established criteria. Independent variables were analyzed in a univariate and multivariate fashion. The mean number of intraoperative RBC units transfused was 0.4 +/- 0.8. No plasma, platelets, albumin, or cryoprecipitate were transfused. Seventy-nine percent of the patients received no blood products during their liver transplantation. The average final hemoglobin value was 85.9 +/- 17.8 g/L. In 57 patients (58.2%), intraoperative phlebotomy and CS were used either together or separately. The one-year year survival rate was 89.1%. Logistic regression showed that avoidance of plasma transfusion, starting hemoglobin value and phlebotomy were significantly linked to liver transplantation without RBC transfusion. In conclusion, the avoidance of plasma transfusion and maintenance of a low CVP prior to the anhepatic phase were associated with a decrease in RBC transfusions during liver transplantations. Previous reports indicating that it is neither useful nor necessary to correct coagulation defects with plasma transfusion prior to liver transplantation are further corroborated by this prospective survey. We believe that this work also supports the practice of lowering CVP with phlebotomy in order to reduce blood loss, during liver dissection, without any deleterious effect.