Compared with COMP therapy, WB did not reduce transfusion volumes in severely injured patients predicted to receive massive transfusion. However, in the sensitivity analysis (patients without severe brain injuries), use of mWB significantly reduced transfusion volumes, achieving the prespecified endpoint of this initial pilot study.

Objective. Earlier use of plasma and red blood cells (RBCs) has been associated with improved survival in trauma patients with substantial hemorrhage. We hypothesized that prehospital transfusion (PHT) of thawed plasma and/or RBCs would result in improved patient coagulation status on admission and survival. Methods. Adult trauma patient records were reviewed for patient demographics, shock, coagulopathy, outcomes, and blood product utilization from September 2011 to April 2013. Patients arrived by either ground or two different helicopter companies. All patients transfused with blood products (either pre- or in-hospital) were included in the study. One helicopter system (LifeFlight, LF) had thawed plasma and RBCs while the other air (OA) and ground transport systems used only crystalloid resuscitation. Patients receiving PHT were compared with all other patients meeting entry criteria to the study cohort. All comparisons were adjusted in multilevel regression models. Results. A total of 8,536 adult trauma patients were admitted during the 20-month study period, of which 1,677 met inclusion criteria. They represented the most severely injured patients (ISS = 24 and mortality = 26%). There were 792 patients transported by ground, 716 by LF, and 169 on OA. Of the LF patients, 137 (19%) received prehospital transfusion. There were 942 units (244 RBCs and 698 plasma) placed on LF helicopters, with 1.9% wastage. PHT was associated with improved acid-base status on hospital admission, decreased use of blood products over 24 hours, a reduction in the risk of death in the sickest patients over the first 6 hours after admission, and negligible blood products wastage. In this small single-center pilot study, there were no differences in 24-hour (odds ratio 0.57, p = 0.117) or 30-day mortality (odds ratio 0.71, p = 0.441) between LF and OA. Conclusions. Prehospital plasma and RBC transfusion was associated with improved early outcomes, negligible blood products wastage, but not an overall survival advantage. Similar to the data published from the ongoing war, improved early outcomes are associated with placing blood products prehospital, allowing earlier infusion of life-saving products to critically injured patients.

Prognostic study, level III.

No abstract

Background Because randomized clinical trials (RCTs) in trauma outcomes research are expensive and complex, they have rarely been the basis for the clinical care of trauma patients. Most published findings are derived from retrospective and occasionally prospective observational studies that may be particularly susceptible to bias. The sources of bias include some common to other clinical domains, such as heterogeneous patient populations with competing and interdependent short- and long-term outcomes. Other sources of bias are unique to trauma, such as rapidly changing multi-system responses to injury that necessitate highly dynamic treatment regimes like blood product transfusion. The standard research design and analysis strategies applied in published observational studies are often inadequate to address these biases. Methods Drawing on recent experience in the design, data collection, monitoring and analysis of the 10-site observational PROMMTT study, seven common and sometimes overlapping biases are described through examples and resolution strategies. Results Sources of bias in trauma research include ignoring 1) variation in patients’ indications for treatment (indication bias), 2) the dependency of intervention delivery on patient survival (survival bias), 3) time-varying treatment, 4) time-dependent confounding, 5) non-uniform intervention effects over time, 6) non-random missing data mechanisms, and 7) imperfectly defined variables. This list is not exhaustive. Conclusion The mitigation strategies to overcome these threats to validity require epidemiologic and statistical vigilance. Minimizing the highlighted types of bias in trauma research will facilitate clinical translation of more accurate and reproducible findings and improve the evidence-base that clinicians apply in their care of injured patients.