The PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study.

T PRospective Observational Multicenter Major Trauma Transfusion (PROMMTT) study examined the timing of transfusions during the treatment of adult civilian trauma patients. We believe this is the first trauma study to capture data in real time on the timing and sequence of blood product infusions. Multiple previous retrospective studies had described transfusion and outcomes, but it was apparent that to design a high-quality prospective randomized intervention study, prospective observational data were required. Funded by the US Army Medical Research and Materiel Command, PROMMTT prospectively enrolled 1,245 adult trauma patients who received at least 1 U of red blood cells (RBCs) within 6 hours of admission among 10 nationwide Level 1 trauma centers between July 2, 2009, and October 15, 2010. Detailed description of the study design is available in Rahbar et al. The primary results of the study demonstrated that the median time to hemorrhagic death was 2.6 hours, increased plasma: RBC ratios were associated with improved early outcomes, and rapidly bleeding patients usually do not receive plasma and especially platelets for up to 3 hours after admission. The local principal investigators as well as investigators from the PROMMTT Data Coordinating Center (DCC) had extensive experience in designing, implementing, and analyzing studies within trauma and other clinical specialties, but the results revealed many misconceptions regarding transfusions in acutely bleeding trauma patients. Before PROMMTT, we thought that plasma, platelets, and RBCs were transfused early in a uniform ratio throughout resuscitation. PROMMTT data proved this idea false. In fact, transfusion patterns varied both within and between patients, with few patients receiving a balanced infusion of products, in any constant ratio. We also believed that clinical practice would be similar across the 10 Level 1 trauma centers, and we were wrong about that as well. There was variance in the time of blood product administration as well in the ratios between centers. We did expect and show that rapidly bleeding trauma patients could be enrolled quickly, demonstrating that studies in bleeding trauma patients were feasible. Data from PROMMTTwere used to inform the design of the follow-up randomized clinical trial, the Pragmatic, Randomized Optimal Platelet and Plasma Ratios (PROPPR) study, which is expected to provide Level 1 evidence to answer the question of whether transfusing a 1:1:1 (plasma:platelets:RBC) ratio provides a survival benefit compared to a ratio of 1:1:2. PROPPR is the culmination of a research program, which began with small retrospective military studies, continued with a multicenter retrospective study, then the multicenter prospective study PROMMTT. We believe that the systematic gathering and synthesis of data in this manner helps guide clinically relevant research programs by better defining and refining research questions at each point before a final randomized clinical trial. To date, three articles have been published from the PROMMTT data. The PROMMTT DCC also organized a symposium at the American Association for the Surgery of Trauma (AAST) annual meeting on September 11, 2012, in Kauai, Hawaii, where 19 PROMMTT articles were presented. The 15 articles in this supplement represent those that successfully passed through rigorous peer review and address crucial design and analysis issues currently facing trauma research. The articles run the gamut from regulatory issues, prehospital resuscitation, the impact of early versus late plasma use, laboratory-based profiles, the impact of crystalloid versus plasma