Effect of storage duration on outcome of patients receiving red blood cell in emergency department

The effect of the duration of red blood cell (RBC) storage on the outcomes of transfused patients remains controversial, and studies on patients in the emergency department (ED) are limited. This study aimed to determine the association between RBC storage duration and outcomes of patients receiving transfusions in the ED. For RBCs issued to patients in the ED between 2017 and 2022, the storage period of the RBC and data on the transfused patient were obtained. Patients were divided into fresh (≤ 7 days) and old (> 7 days) RBC groups, and the associations between storage duration, outcomes, and laboratory changes were evaluated. There was no significant difference in outcomes between the two groups in the 28-day mortality (adjusted odds ratio [OR] 0.91, 95% confidence interval [CI] 0.75–1.10, P = 0.320) and the length of stay (fresh 13.5 ± 18.1 vs. old 13.3 ± 19.8, P = 0.814). Regarding changes in laboratory test results, the increase in hemoglobin and hematocrit levels was not affected by the storage durations. The study revealed that transfusion of older RBCs is not associated with inferior outcomes or adverse clinical consequences when compared to that of fresh RBCs in patients in the ED.