Does the storage age of transfused blood affect outcome in burn patients?

Blood banks now store blood up to 42 days. With increasing duration of storage, units of red blood cells (RBCs) develop a storage lesion characterized by alterations in oxygen transport capability and heightened proinflammatory properties. However, there is considerable controversy as to whether the storage lesion affects outcomes in transfused patients and burn patients, which has not been studied. The purpose was to identify whether any relationship exists between the storage age of transfused blood and outcome in severely burned adults. This is a retrospective review of adults, with burns 20% or more TBSA, treated at an adult regional ABA-verified burn center, who received at least one RBC transfusion. Subjects were stratified a priori based on the mean age of all RBC units transfused during the first 30 days postburn, to either a Fresh Group (mean storage age ≤28 days), or an Old Group (mean storage age >28 days). The Fresh Group (N = 89) did not differ significantly from the Old Group (N = 38) in baseline characteristics. The median (range) mean blood storage age was 22.2 (10.3-28) days in the Fresh Group and 31.5 (28.3-41) days in the Old Group, (P < .001). The Fresh Group had a significantly higher median daily transfusion rate when alive and in hospital, during the first 30 days postburn, than the Old Group (0.5 [range 0.03-5.5] units/day vs 0.35 [0.03-2.7] units/day; P = .04). There were no significant differences between the groups in mean daily sequential organ failure assessment (SOFA) score, peak SOFA score, delta SOFA score (peak-admission SOFA), time to wound healing, length of stay, and 30-day mortality or in-hospital mortality. Linear regression revealed no significant effect of the mean age of transfused blood on mean daily SOFA score/first 30 days postburn. The Fresh Group had a significantly longer median duration of mechanical ventilation (29 [range 1-195] vs 17 [range 1-80] days, P = .03) and had significantly more sepsis episodes. Transfusion of RBCs with a mean storage age of more than 28 days was not associated with any worsened outcome compared with transfusion of blood with a mean storage age of less than 28 days, among this cohort of adult burn patients. These findings do not suggest the need to preferentially transfuse fresher blood to burn patients, but randomized prospective studies of this question are needed.