Effect of plasma and red blood cell transfusions on survival in patients with combat related traumatic injuries

Background: The amount and age of stored red blood cells (RBCs) are independent predictors of multiorgan failure and death in transfused critically ill patients. The independent effect of plasma transfusion on survival has not been evaluated. Our objective was to determine the independent effects of plasma and RBC transfusion on survival for patients with combat-related traumatic injuries receiving any blood products. Methods: We performed a retrospective review of 708 patients transfused at least one unit of a blood product at one combat support hospital between November 2003 and December 2004. Admission vital signs, laboratory values, amount of blood products transfused in a 24-hour period, and Injury Severity Score (ISS) were analyzed by multivariate logistic regression to determine independent associations with in-hospital mortality. Results: Seven hundred and eight of 3,287 (22%) patients admitted for traumatic injuries were transfused a blood product. Median ISS was 14 (range, 9-25). In-hospital mortality was 12%. Survival was associated with admission Glasgow Coma Scale score, SBP, temperature, hematocrit, base deficit, INR, amount of RBCs transfused, and massive transfusion. Each transfused FFP unit was independently associated with increased survival (OR: 1.17; 95% CI: [1.06-1.29]; p = 0.002); each transfused RBC unit was independently associated with decreased survival (OR: 0.86; [0.8-0.92]; p = 0.001). A subset analysis of patients (n = 567) without massive transfusion (1-9 RBC/FWB units) also revealed an independent association between each FFP unit and improved survival (OR: 1.22; 95% CI: [1.0-1.48]; p = 0.05) and between each RBC unit and decreased survival (OR: 0.77; [0.64-0.92]; p = 0.004). Conclusion: For trauma patients transfused at least one unit of a blood product, FFP and RBC amounts were independently associated with increased survival and decreased survival, respectively. Prospective studies are needed to determine whether the early and increased use of plasma and decreased use of RBCs affect mortality for patients with traumatic injuries requiring transfusion.