Sex-based utilization and outcomes of cold-stored whole blood for trauma resuscitation: Analysis of a prospective multicenter study

BACKGROUND: Resuscitation with cold-stored whole blood (WB) has outcome benefits, but benefits varied by patient sex is unknown. There are also concerns about alloimmunization risk for premenopausal females given WB, leading to some protocols excluding this cohort. We sought to analyze WB utilization, outcomes, and disparities by patient sex. METHODS: This is a secondary analysis of a prospective multicenter study of WB resuscitation. Patients were stratified by sex and compared by transfusion strategy of WB or component therapy (CT). Generalized estimated equation models using inverse probability of treatment weighting were utilized. RESULTS: There were 1,617 patients (83% male; 17% female) included. Females were less likely to receive WB versus males (55% vs. 76%; p < 0.001), with wide variability between individual centers (0%–33% female vs. 66%–100% male, p < 0.01). Male WB had more blunt trauma (45% vs. 31%) and higher shock index (1.0 vs. 0.8) compared with the male CT cohort (all p < 0.05) but similar Injury Severity Score. The female WB cohort was older (53 vs. 36) and primarily blunt trauma (77% vs. 62%) compared with the female CT cohort (all p < 0.05) but had similar shock index and Injury Severity Score. Male WB had lower early and overall mortality (27% vs. 42%), but a higher rate of acute kidney injury (16% vs. 6%) vs. the male CT cohort (all p < 0.01). Female cohorts had no difference in mortality, but the WB cohort had higher bleeding complications. Whole blood use was independently associated with decreased mortality (OR, 0.6; p < 0.01) for males but not for females (OR, 0.9; p = 0.78). CONCLUSION: Whole blood was independently associated with a decreased mortality for males with no difference identified for females. Whole blood was significantly less utilized in females and showed wide variability between centers. Further study of the impact of patient sex on outcomes with WB and WB utilization is needed.