Introduction: Massive blood transfusion is a frequent condition amongst liver transplant recipients. Recipient-related risk factors, including cirrhosis, multiple surgeries, and suboptimal donors, can be decreased but not eliminated. The first index designed to predict massive blood transfusion was the McCluskey index, and several more complex mathematical models have followed, without a significant increase in sensitivity. Furthermore, all of these models have failed to include donor characteristics.

Methods: One thousand four hundred and sixty-nine liver transplants were performed at our institution between May 1998 and December 2019, and data was available regarding transfusion for 1469 of them. We divided the patients into two groups, with regards to transfusion of 6 or more units of packed red blood cells in the first 24 hours post transplant, and we analyzed the differences between the groups. We created dichotomic variables in relation to the group median for massive transfusion. Later on, we performed binary logistic regression, we analyzed the risk factors for massive transfusion and created a new index taking into account the results from our multivariable study, assigning one or two points to the most significant variables, using an OR of 1.9 as a cut-off.

Results: Out of the 1198 patients, 607 (50.7%) met criteria for massive transfusion. Both groups were statistically different with regards to hepatocellular carcinoma, autoimmune cause, liver/kidney transplant, uDCD, retransplantation, albumin serum levels, creatinine, sodium, bilirubin, haemoglobin, platelets, INR, MELD, McCluskey and Child scores. Logistical regression analysis of our variables yielded the following results for a new model, including Creatinine (OR 1.97), sodium (OR 1.73), Hemoglobin (OR 1.99), platelets (OR 1.37), INR (OR 1.4), uDCD (OR 2.13) and split liver donation. Upon comparing the different available models, our model presented an AUC of 0.758, which is superior to either MELD, McCluskey or Child scores.

Conclusion: We have created a new prognostic index starting on the most frequently studied variables associated with massive transfusion, and incorporated donor variables for the first time. This new index provides an easy and straight-forward way to assess the preoperative risk of massive blood transfusion for liver transplant.