In injured patients at risk for hemorrhagic shock, the prehospital administration of thawed plasma was safe and resulted in lower 30-day mortality and a lower median prothrombin-time ratio than standard-care resuscitation. (Funded by the U.S. Army Medical Research and Materiel Command; PAMPer ClinicalTrials.gov number, NCT01818427 .).

IMPORTANCE Both military and civilian clinical practice guidelines include early plasma transfusion to achieve a plasma to red cell ratio approaching 1:1 to 1:2. However, it was not known how early plasma should be given for optimal benefit. Two recent randomized clinical trials were published, with apparently contradictory results. The Prehospital Air Medical Plasma (PAMPer) clinical trial showed a nearly 30% reduction in mortality with plasma transfusion in the prehospital environment, while the Control of Major Bleeding After Trauma (COMBAT) clinical trial showed no survival improvement.OBJECTIVE To facilitate a post hoc combined analysis of the COMBAT and PAMPer trials to examine questions that could not be answered by either clinical trial alone. We hypothesized that prehospital transport time influenced the effects of prehospital plasma on 28-day mortality.DESIGN, SETTING, AND PARTICIPANTS A total of 626 patients in the 2 clinical trials were included. Patients with trauma and hemorrhagic shock were randomly assigned to receive either standard care or 2 U of thawed plasma followed by standard care in the prehospital environment. Data analysis was performed between September 2018 and January 2019.INTERVENTIONS Prehospital transfusion of 2 U of plasma compared with crystalloid-based resuscitation. MAIN OUTCOMES AND MEASURESThe main outcome was 28-day mortality. RESULTSIn this post hoc analysis of 626 patients (467 men [74.6%] and 159 women [25.4%]; median [interquartile range] age, 42 [27-57] years) who had trauma with hemorrhagic shock, a Cox regression analysis showed a significant overall survival benefit for plasma (hazard ratio [HR], 0.65; 95% CI, 0.47-0.90; P = .01) after adjustment for injury severity, age, and clinical trial cohort (COMBAT or PAMPer). A significant association with prehospital transport time was detected (from arrival on scene to arrival at the trauma center). Increased mortality was observed in patients in the standard care group when prehospital transport was longer than 20 minutes (HR, 2.12; 95% CI, 1.05-4.30; P = .04), while increased mortality was not observed in patients in the prehospital plasma group (HR, 0.78; 95% CI, 0.40-1.51; P = .46). No serious adverse events were associated with prehospital plasma transfusion.CONCLUSIONS AND RELEVANCE These data suggest that prehospital plasma is associated with a survival benefit when transport times are longer than 20 minutes and that the benefit-risk ratio is favorable for use of prehospital plasma.

In-hospital administration of tranexamic acid after injury improves outcomes in patients at risk for hemorrhage. Data demonstrating the benefit and safety of the pragmatic use of tranexamic acid in the prehospital phase of care are lacking for these patients.OBJECTIVE To assess the effectiveness and safety of tranexamic acid administered before hospitalization compared with placebo in injured patients at risk for hemorrhage.DESIGN, SETTING, AND PARTICIPANTS This pragmatic, phase 3, multicenter, double-blind, placebo-controlled, superiority randomized clinical trial included injured patients with prehospital hypotension (systolic blood pressure Յ90 mm Hg) or tachycardia (heart rate Ն110/min) before arrival at 1 of 4 US level 1 trauma centers, within an estimated 2 hours of injury, from May 1, 2015, through October 31, 2019.INTERVENTIONS Patients received 1 g of tranexamic acid before hospitalization (447 patients) or placebo (456 patients) infused for 10 minutes in 100 mL of saline. The randomization scheme used prehospital and in-hospital phase assignments, and patients administered tranexamic acid were allocated to abbreviated, standard, and repeat bolus dosing regimens on trauma center arrival. MAIN OUTCOMES AND MEASURESThe primary outcome was 30-day all-cause mortality.RESULTS In all, 927 patients (mean [SD] age, 42 [18] years; 686 [74.0%] male) were eligible for prehospital enrollment (460 randomized to tranexamic acid intervention; 467 to placebo intervention). After exclusions, the intention-to-treat study cohort comprised 903 patients: 447 in the tranexamic acid arm and 456 in the placebo arm. Mortality at 30 days was 8.1% in patients receiving tranexamic acid compared with 9.9% in patients receiving placebo (difference, -1.8%; 95% CI, -5.6% to 1.9%; P = .17). Results of Cox proportional hazards regression analysis, accounting for site, verified that randomization to tranexamic acid was not associated with a significant reduction in 30-day mortality (hazard ratio, 0.81; 95% CI, 0.59-1.11, P = .18). Prespecified dosing regimens and post-hoc subgroup analyses found that prehospital tranexamic acid were associated with significantly lower 30-day mortality. When comparing tranexamic acid effect stratified by time to treatment and qualifying shock severity in a post hoc comparison, 30-day mortality was lower when tranexamic acid was administered within 1 hour of injury (4.6% vs 7.6%; difference, −3.0%; 95% CI, −5.7% to −0.3%; P < .002). Patients with severe shock (systolic blood pressure Յ70 mm Hg) who received tranexamic acid demonstrated lower 30-day mortality compared with placebo (18.5% vs 35.5%; difference, −17%; 95% CI, −25.8% to −8.1%; P < .003). CONCLUSIONS AND RELEVANCEIn injured patients at risk for hemorrhage, tranexamic acid administered before hospitalization did not result in significantly lower 30-day mortality. The prehospital administration of tranexamic acid after injury did not result in a higher incidence of thrombotic complications or adverse events. Tranexamic acid given to injured patient...

Objective: The aim of this study was to determine whether prehospital blood products reduce 30-day mortality in patients at risk for hemorrhagic shock compared with crystalloid only resuscitation. Summary of Background Data: Hemorrhage is the primary cause of preventable death after injury. Large volume crystalloid resuscitation can be deleterious. The benefits of prehospital packed red blood cells (PRBCs), plasma, or transfusion of both products among trauma patients is unknown compared with crystalloid. Methods: Secondary analysis of the multicenter PAMPer trial was performed on hypotensive injured patients from the scene. The trial randomized 27 helicopter bases to prehospital plasma or standard resuscitation. Standard resuscitation at the sites was equally divided between crystalloid and crystalloid + PRBC. This led to 4 prehospital resuscitation groups: crystalloid only; PRBC; plasma; and PRBC+plasma. Cox regression determined the association between resuscitation groups and risk-adjusted 30-day mortality. The dose effect of resuscitation fluids was also explored. Results: Four hundred seven patients were included. PRBC+plasma had the greatest benefit [hazard ratio (HR) 0.38; 95% confidence interval (95% CI) 0.26–0.55, P < 0.001], followed by plasma (HR 0.57; 95% CI 0.36–0.91, P = 0.017) and PRBC (HR 0.68; 95% CI 0.49–0.95, P = 0.025) versus crystalloid only. Mortality was lower per-unit of PRBC (HR 0.69; 95% CI 0.52–0.92, p = 0.009) and plasma (HR 0.68; 95% CI 0.54–0.88, P = 0.003). Crystalloid volume was associated with increased mortality among patients receiving blood products (HR 1.65; 95% CI 1.17–2.32, P = 0.004). Conclusion: Patients receiving prehospital PRBC+plasma had the greatest mortality benefit. Crystalloid only had the worst survival. Patients with hemorrhagic shock should receive prehospital blood products when available, preferably PRBC+plasma. Prehospital whole blood may be ideal in this population.

BACKGROUND Tranexamic acid (TXA) is used as a hemostatic adjunct for hemorrhage control in the injured patient and reduces early preventable death. However, the risk of venous thromboembolism (VTE) has been incompletely explored. Previous studies investigating the effect of TXA on VTE vary in their findings. We performed a propensity matched analysis to investigate the association between TXA and VTE following trauma, hypothesizing that TXA is an independent risk factor for VTE. METHODS This retrospective study queried trauma patients presenting to a single Level I trauma center from 2012 to 2016. Our primary outcome was composite pulmonary embolism or deep vein thrombosis. Mortality, transfusion, intensive care unit and hospital lengths of stay were secondary outcomes. Propensity matched mixed effects multivariate logistic regression was used to determine adjusted odds ratio (aOR) and 95% confidence intervals (95% CI) of TXA on outcomes of interest, adjusting for prespecified confounders. Competing risks regression assessed subdistribution hazard ratio of VTE after accounting for mortality. RESULTS Of 21,931 patients, 189 pairs were well matched across propensity score variables (standardized differences <0.2). Median Injury Severity Score was 19 (interquartile range, 12–27) and 14 (interquartile range, 8–22) in TXA and non-TXA groups, respectively (p = 0.19). Tranexamic acid was associated with more than threefold increase in the odds of VTE (aOR, 3.3; 95% CI, 1.3–9.1; p = 0.02). Tranexamic acid was not significantly associated with survival (aOR, 0.86; 95% CI, 0.23–3.25; p = 0.83). Risk of VTE remained elevated in the TXA cohort despite accounting for mortality (subdistribution hazard ratio, 2.42; 95% CI, 1.11–5.29; p = 0.03). CONCLUSION Tranexamic acid may be an independent risk factor for VTE. Future investigation is needed to identify which patients benefit most from TXA, especially given the risks of this intervention to allow a more individualized treatment approach that maximizes benefits and mitigates potential harms. LEVEL OF EVIDENCE Therapeutic, level III.