Association between early red blood cell transfusion after return of spontaneous circulation and clinical outcomes in cardiac arrest patients

Red blood cell (RBC) transfusion is frequently administered to patients after cardiac arrest; however, its association with patient outcomes has not been well established. This study investigated the association between early RBC transfusion after the return of spontaneous circulation (ROSC) and patient outcomes in adults with cardiac arrest. We analyzed data from 586 adult patients who achieved ROSC at two university-affiliated hospitals in Korea between August 2014 and December 2023. Early transfusion was defined as RBC transfusion administered within 24 h after ROSC. Overlap propensity score weighting was used to adjust for confounding, and weighted analysis was performed to assess associations between early transfusion and patient outcomes. Within 24 h after ROSC, 79 patients (13.5%) received RBC transfusions. Early RBC transfusion was not significantly associated with 30-day mortality (adjusted hazard ratio aHR 0.97, 95% confidence interval CI 0.65–1.47), 90-day mortality (aHR 0.95, 95% CI 0.64–1.42), in-hospital mortality (adjusted odds ratio aOR 0.99, 95% CI 0.91–1.07), or neurologic outcome (aOR 0.97, 95% CI 0.92–1.03). Consistent findings were observed when early transfusion was defined as occurring within 48 or 72 h after ROSC. The number of RBC units transfused was also not associated with patient outcomes. Early RBC transfusion after ROSC was not associated with survival or neurologic outcomes in patients with cardiac arrest.