M. McCrum2, B. Leroux1, T. Fang1, E. Bulger1, S. Arbabi1, C. E. Wade3, E. Fox3, J. B. Holcomb3, B. Robinson1 1University Of Washington,Surgery / General Surgery,Seattle, WA, USA 2University Of Utah,Surgery / General Surgery,Salt Lake City, UT, USA 3University Of Texas Health Science Center At Houston,Surgery / General Surgery,Houston, TX, USA
Introduction: Previous studies examining sex-based differences in outcomes after traumatic injury have revealed inconsistent findings, potentially due to heterogeneous study populations and variation in management strategies. We sought to evaluate if sex-based differences in outcomes exist for severely injured patients with hemorrhage who underwent protocolized damage control resuscitation. We hypothesized that female sex is protective against mortality in this setting, and that females would achieve hemostasis more rapidly than males.
Methods: We performed a secondary analysis of severely injured patients predicted to receive a massive transfusion who were randomized to 1:1:1 vs 1:1:2 plasma-platelet-red blood cells (RBCs) ratios at 12 level I North American trauma centers in the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) trial. We used Cox regression to evaluate the sex-based differences in time to hemostasis and mortality. Poisson regression with robust standard errors was used to evaluate differences in volume of blood products transfused in each phase of the study. Pre-randomization and randomization periods occurred prior to hemorrhage control, whereas the post-randomization period occurred after anatomic hemostasis was achieved. All analyses were adjusted for clinical site, age, race, height, base deficit, INR, mechanism of injury, AIS scores, and transfusion arm (1:1:1 vs 1:1:2).
Results:We identified 134 females and 546 males in the study population. Female patients were older (age 40.5 [IQR 26-60] vs 33 [24-47], p<0.001), with higher ISS (29 [21-41] vs 26 [16-38], p=0.04), and with a higher proportion of blunt (76 vs 47%, p<0.001) and severe head injury (AIS ≥3, 33 vs 20%, p0.01); BMI did not differ by sex (p=0.50). There were no differences between the sexes in mortality over the first 24-hours (HR for female=1.08, 95% CI 0.66, 1.74; p=0.77), 30-days (HR=1.00, 95% CI 0.69, 1.45; p=0.99), or time to hemostasis (HR=1.02, 95% CI 0.82, 1.26; p=0.88). Differences by sex were not found in the volume of plasma, platelets or RBCs received in the pre-randomization or randomization periods. However, in the post-randomization period, females received 38% less plasma (95% CI 11%, 57%; p=0.01), 48% less platelets (95% CI 22%, 65%; p=0.001) and 48% less RBC (95% CI 20%, 67%; p=0.01) compared to males (Figure 1).
Conclusion:Mortality rates and time to hemostasis of severely injured trauma patients with hemorrhage did not differ by sex. Female sex appears to be protective against the need for “catch up” blood required after initial hemostasis. Further work is needed to elucidate sex-based differences in coagulopathy and hemostasis during and following damage control resuscitation.
