Whole blood transfusion in the treatment of acute hemorrhage, a systematic review and meta-analysis

Abstract Background Whole blood (WB) transfusion received renewed interest after recent armed conflicts. The effectiveness as compared to blood component transfusion (BCT) is however still topic of debate. Therefore, this study investigated the effect of WB ± BCT as compared to BCT transfusion on survival in trauma patients with acute hemorrhage. Methods Studies published up to the 16 th of January 2023, including patients with traumatic hemorrhage comparing WB ± BCT and BCT were included in meta-analysis. Sub analyses were performed on the effectiveness of WB in the treatment of civilian or military trauma patients, patients with massive hemorrhage and on platelet (PLT):Red Blood Cell (RBC), plasma:RBC and WB:RBC ratios. Methodological quality of studies was interpreted using the Cochrane risk of bias tool. The study protocol was registered in PROSPERO under number CRD42022296900. Results Random effect pooled odds ratio (OR) for 24-hours mortality in civilian and military patients treated with WB as compared to BCT was 0.72 (95% CI 0.53-0.97). In sub analysis of studies conducted in civilian setting (n = 20), early (4-hours, 6-hours and Emergency Department) and 24-hours mortality was lower in WB groups compared BCT groups: OR 0.65 (95% CI 0.44 – 0.96) and OR 0.71 (0.52 – 0.98). No difference in late mortality (28-days, 30-days, in-hospital) was found. In military settings (n = 7) there was no difference in early, 24-hours or late mortality between groups. WB groups received significant higher PLT:RBC (p = 0.030) during early treatment and significant higher PLT:RBC and Plasma:RBC ratios during 24-hours of treatment (p = 0.031 and p = 0.007). The overall risk of bias in the majority of studies was judged as serious due to serious risk on confounding and selection bias, and unclear information regarding co-interventions. Conclusion Civilian trauma patients with acute traumatic hemorrhage treated with WB ± BCT as compared to BCT had lower odds on early and 24-hours mortality. Additionally, WB transfusion resulted in higher plt:RBC and plasma:RBC ratios. Level of evidence Level III, systematic review and meta-analysis.