Association between whole blood ratio and risk of mortality in massively transfused trauma patients: retrospective cohort study.

ABSTRACT

BACKGROUND: Although whole blood (WB) transfusion was reported to improve survival in trauma patients with hemorrhagic shock, little is known whether a higher proportion of WB is associated with an improved survival. This study aimed to evaluate the association between whole blood ratio (WBR) and the risk of mortality in trauma patients requiring massive blood transfusion. METHODS: We performed a retrospective cohort study from the ACS-TQIP between 2020 and 2021. Patients were aged ≥ 18 years and received WB within 4 h of hospital arrival as a part of massive blood transfusion. Study patients were categorized into four groups based on the quartiles of WBR. Primary outcome was 24-h mortality and secondary outcome was 30-day mortality. Multivariable logistic regression analysis, fitted with generalized estimating equations, was performed to adjust for confounding factors and accounted for within-hospital clustering. RESULTS: A total of 4087 patients were eligible for analysis. The median age was 37 years (interquartile range [IQR] 27-53 years), and 85.0% of patients were male. The median number of WB transfusions was 2.3 units (IQR 2.0-4.0 units), and the total transfusion volume was 4940 ml (IQR 3350-8504). When compared to the lowest WBR quartile, the highest WBR quartile had lower adjusted 24-h mortality (adjusted odds ratio [AOR] 0.61, 95% confidence interval [CI] 0.46-0.81) and 30-day mortality (AOR 0.58; 95% CI 0.45-0.75). CONCLUSION: The probability of mortality consistently decreased with higher WBR in trauma patients requiring massive blood transfusion.