Whole blood to total transfusion volume ratio in injured children: A national database analysis.

BACKGROUND Whole blood (WB) resuscitation is increasingly common in adult trauma centers and some pediatric trauma centers, as studies have noted its safety and potential superiority to component therapy (CT). Previous analyses have evaluated WB as a binary variable (any versus none), and little is known regarding the "dose response" of WB in relation to total transfusion volume (TTV) (WB/TTV ratio). METHODS Injured children younger than 18 years who received any blood transfusion within 4 hours of hospital arrival across 456 US trauma centers were included from the American College of Surgeons Trauma Quality Improvement Program database. The primary outcome was 24-hour mortality, and the secondary outcome was 4-hour mortality. Multivariate analysis was used to evaluate associations between WB administration and mortality and WB/TTV ratio and mortality. RESULTS Of 4,323 pediatric patients included in final analysis, 88% (3,786) received CT only, and 12% (537) received WB with or without CT. Compared with the CT group, WB recipients were more likely to be in shock, according to pediatric age-adjusted shock index (71% vs. 60%) and had higher median (interquartile range) Injury Severity Score (26 [17-35] vs. 25 [16-24], p = 0.007). Any WB transfusion was associated with 42% decreased odds of mortality at 4 hours (adjusted odds ratio [aOR], 0.58 [95% confidence interval, 0.35-0.97]; p = 0.038) and 54% decreased odds of mortality at 24 hours (aOR, 0.46 [0.33-0.66]; p < 0.001). Each 10% increase in WB/TTV ratio was associated with a 9% decrease in 24-hour mortality (aOR, 0.91 [0.85-0.97]; p = 0.006). Subgroup analyses for age younger than 14 years and receipt of massive transfusion (>40 mL/kg) also showed statistically significant survival benefit for 24-hour mortality. CONCLUSION In this retrospective American College of Surgeons Trauma Quality Improvement Program analysis, use of WB was independently associated with reduced 24-hour mortality in children; further, higher proportions of WB used over the total resuscitation (WB/TTV ratio) were associated with a stepwise increase in survival. LEVEL OF EVIDENCE Prognostic and Epidemiological; Level III.