Storage age of transfused red blood cells during liver transplantation and its intraoperative and postoperative effects

Background Recent studies suggest that the storage age of red blood cells (RBCs) may be associated with morbidity and mortality in surgical patients. We studied perioperative effects of RBC storage age in patients undergoing orthotopic liver transplant (OLT). Methods Adult patients who received ≤5 U of RBCs during OLT between January 2004 and June 2009 were studied. The subjects were divided into two groups according to the mean storage age of RBCs they received: new or old RBCs (stored ≤14 or>14 days, respectively). Effects of storage age of transfused RBCs during OLT on intraoperative potassium (K ⁺) concentrations, incidence of hyperkalemia (K ⁺ ≥5.5 mmol/L), postoperative morbidity, and patient and graft survival were studied. Results The mean serum K ⁺ concentrations and the incidence of hyperkalemia during OLT were significantly associated with storage age of the RBCs. Logistic analysis showed that storage age of RBCs was an independent risk factor for intraoperative hyperkalemia (odds ratios 1.067-1.085, p<0.001) in addition to baseline K ⁺ concentration and units of RBCs transfused. Patient and graft survival and postoperative morbidity including postoperative ventilation, reoperation, acute renal dysfunction defined by the RIFLE criteria was not associated with old RBCs. Conclusions Transfusion of RBCs stored for a longer time was associated with intraoperative hyperkalemia but not with postoperative adverse outcomes in adult OLT. Prevention and treatment of potentially harmful hyperkalemia should be considered when old RBCs are administered.