Early lactate clearance as a reliable predictor of initial poor graft function after orthotopic liver transplantation

Abstract

Initial poor graft function (IPGF) following orthotopic liver transplantation is a major determinant of postoperative survival and morbidity. Lactate clearance is a good marker of liver function. In this study, we investigated the clinical utility of early lactate clearance as an early and accurate predictor for IPGF following liver transplantation. This was a prospective observational study of 222 patients referred to the surgical intensive care unit (SICU) after orthotopic liver transplantation. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) >1500 IU/L within 72 hours after orthotopic liver transplantation. Early lactate clearance was defined as lactate at SICU presentation (hour 0) minus lactate at hour 6, divided by lactate at SICU presentation. The model for end-stage liver disease (MELD) score, Child-Pugh score and laboratory data including AST, ALT, total bilirubin (TB) and prothrombin time (PT) were recorded at SICU presentation and compared between the non-IPGF and IPGF groups. Receiver operating characteristic (ROC) curves were plotted to measure the performance of early lactate clearance, MELD score, Child-Pugh score, TB and PT. IPGF occurred in 45 of the 222 patients (20.3%). The early lactate clearance in the non-IPGF group was markedly higher than that in the IPGF group (43.2+/-13.8% vs 13.4+/-13.7% P<0.001). The optimum cut-off value for early lactate clearance predicting IPGF was 24.8% (sensitivity 95.5%, specificity 88.9%). The area under the curve of the ROC was 0.961, which was significantly superior to MELD score, Child-Pugh score, TB and PT. Patients with early lactate clearance ≤24.8% had a higher IPGF rate (OR=169) and a higher risk of in-hospital mortality (OR=3.625). Early lactate clearance can serve as a prompt and accurate bedside predictor of IPGF. Patients with early lactate clearance less than 24.8% are associated with a higher incidence of IPGF.