High Blood Product Ratio May Increase Survival in Pediatric Trauma
Purpose: Acute hemorrhage is the most common cause of death within the first hours following traumatic injury; optimizing transfusion strategies is an opportunity to improve mortality by reducing death from hemorrhage in injured children. Adult studies show that high ratio transfusion of fresh frozen plasma (FFP) to packed red blood cells (PRBC) can improve survival by reducing death from hemorrhage in massively transfused patients. The objective of this study was to demonstrate the association of high ratio transfusion (>/=1:2 units of FFP:PRBC) with the outcome of injured children who receive massive transfusion.
Methods: We conducted a retrospective chart review of children < 18 years-old presenting to an urban pediatric level-1 trauma center from 2007-2011 and received PRBCs within 24 hours of injury. We excluded children who died within 1 hour of arrival, presented 24 hours after injury, and had injuries unrelated to blunt or penetrating trauma. We collected data for age, gender, race, payer, mechanism, injury, transferring hospital care, pre-hospital care, injury severity score (ISS), volume/timing of blood products transfused, intensive care unit and hospital length of stay, operations, 24-hour mortality, overall mortality, and cause of death. We used FFP:PRBC unit ratios calculated 24 hours from injury to identify children who received a high ratio (>/=1:2) verses low ratio (<1:2). We used non-parametric methods to describe the cohort and analytical groups. We plotted Kaplan-Meier survival curves comparing high and low ratio groups among children who received massive transfusion (>/=40ml/kg PRBCs or >/=80ml/kg total blood products in 24 hours).
Results: We identified 6724 children over 5 years, of which 144(2.1%) met study criteria; 31/144(21.5%) received massive transfusion. The high (n=18, median ratio 1:1.2) and low ratio (n=13, median 1:3.5) groups did not differ statistically in ISS and all other variables measured except racial make-up; time from injury to trauma center admission (0.7 vs. 2.3hrs, p=0.02) and pre-hospital IVF administration (10.7 vs. 33.3ml/kg, p=0.05), respectively. Survival curve analysis indicates a trend toward significance (p=0.06) with an approximate 25% survival benefit for the high verses low FFP:PRBC unit ratio group (fig 1). However, there was no significant difference in overall mortality, 8/18(44%) vs. 9/13(69.2%) (p=0.27). Causes of death were not statistically significantly different between groups. In the high verses low ratio group, 7/8(87.5%) vs. 5/9(55.6%) deaths were from brain injury, 0/8(0%) vs. 1/9(11.1%) from organ failure, and 1/8(12.5%) vs. 0/9(0%) unknown. While not statistically significant, all hemorrhagic deaths (3/9, 33%) occurred in the low ratio group.
Conclusion: This study suggests that high FFP:PRBC ratio transfusion at 24 hours from injury may improve survival of injured children with less death from hemorrhage, which to our knowledge, has not yet been reported in the pediatric population.
Fig 1. Survival between groups with high vs. low FFP:PRBC ratio at 24 hours