Transfusion of older red blood cells increases the risk of acute kidney injury after orthotopic liver transplantation: A propensity score analysis

BACKGROUND: Acute kidney injury (AKI) is a common and serious complication of orthotopic liver transplantation (OLT). Transfusion of older red blood cells (RBCs) has been implicated in poor outcomes in trauma, cardiac surgery, and critically ill patients. However, whether transfusion of older RBCs plays any role in post-OLT AKI remained unknown. The aim of this study was to investigate the effect of the age of transfused RBCs on post-OLT AKI. METHODS: The clinical data of consecutive adult patients who received donation after cardiac death and underwent OLT from December 2011 to December 2015 were analyzed. These patients were divided into 2 groups: the newer blood group, who received exclusively RBCs that had been stored for <14 days; and the older blood group, who received RBCs that had been stored for 14 days or more. The incidence of post-OLT AKI, severe AKI, lengths of intensive care unit and hospital stay, and in-hospital mortality after OLT were analyzed. RESULTS: Postoperative AKI occurred in 65.1% of patients in the older blood group and 40.5% of patients in the newer blood group (P < .01). The incidence of severe AKI after OLT was significantly higher, and the duration of intensive care unit stay was significantly longer, in the older blood group. After adjustment by the multivariable regression logistic analysis, transfusion of older blood was independently associated with post-OLT AKI (odds ratio [OR] = 2.47 [95% confidence interval {CI}, 1.13-5.41]; P = .024) and severe AKI (OR = 5.88 [95% CI, 2.06-16.80]; P = .001). After adjustment by the inverse probability of treatment weighting analysis, patients in the older blood group still had significantly higher incidences of postoperative AKI (OR = 2.13 [95% CI, 1.07-4.22]; P = .030) and severe AKI (OR = 3.34 [95% CI, 1.47-7.60]; P = .003) than those in the newer blood group. CONCLUSIONS: Transfusion of older RBCs significantly increased the risk of postoperative AKI in liver transplant recipients.