Group B or not group B? An association between ABO, early mortality, and organ dysfunction in major trauma patients with shock

Background: ABO blood group alters coagulation profiles in the general population and may influence outcomes after trauma. The relationship between trauma-induced coagulopathy, severe injury with hemorrhagic shock, and survival with respect to ABO group is unknown. Objectives: In severe hemorrhagic trauma, we aimed to characterize the association of ABO group with admission coagulation profiles, mortality, and immune-mediated complications. Methods: Clinical and laboratory variables were examined from severely injured adult patients enrolled in a perpetual observational cohort study at a UK Major Trauma Center. Univariate and multivariate analyses were performed to determine differences in clinical outcomes (mortality, organ dysfunction, and critical care support). In a shock subgroup, we performed an exploratory analysis of rotational thromboelastometry parameters and coagulation biomarkers. Results: In 1119 trauma patients, we found no difference in mortality between ABO groups. In patients with shock, 24-hour mortality was significantly lower in group B vs nonB groups (7% vs 16%, adjusted odds ratio [aOR], 0.19; P = .030), but there were increased rates of invasive ventilation (aOR, 3.34; P = .033), renal replacement therapy (aOR, 2.55; P = .037), and a trend for infection (aOR, 1.85; P = .067). Comparing patients with shock, group B vs non-B patients had 40% higher fibrinogen, 65% higher factor (F) VIII, 36% higher FIX, 20% higher FXIII, and 19% higher von Willebrand factor. Conclusion: In this observational study limited by single time-point sampling and subgroup analysis of trauma hemorrhage with shock, group B patients have enhanced hemostatic capability associated with early survival but with increased risk of immunemediated complications.