BACKGROUND: Predicting blood product transfusion requirements during orthotopic liver transplantation (OLT) remains difficult. Our primary aim in this study was to determine which patient variables best predict recipient risk for large blood transfusion requirements during OLT. The secondary aim was to determine whether the amount of blood products transfused during OLT impacted patient survival.
METHODS: Eight hundred four primary adult OLTs performed during a 9-year period were retrospectively analyzed, and predictive models were developed for blood product usage, usage >20 and usage >30 units of red blood cells (RBCs) plus cell salvage (CS). For survival analysis, potential predictors included all blood products administered during OLT.
RESULTS: For analyses of RBC + CS usage, we used several statistical techniques: regression analysis, logistic regression, and classification and regression tree analysis. Several preoperative factors were highly statistically significant predictors of intraoperative blood product usage in each of the analyses, namely lower platelet count and higher Model for End-Stage Liver Disease Score or one or more of its components (creatinine, total bilirubin, international normalized ratio). Despite these highly significant associations, the models were unable to predict reliably that patients might require the largest amount of blood products during OLT. For example, the classification and regression tree analyses were able to predict only 32% and 11% of patients requiring >20 and >30 units of RBC + CS, respectively. Survival analysis demonstrated poorer survival among patients receiving larger amounts of RBC + CS during OLT.
CONCLUSION: Prediction of intraoperative blood product requirements based on preoperatively available variables is unreliable; however, there is a strong measurable association between transfusion and postoperative mortality.