Prehospital low titer group O whole blood is feasible and safe: Results of a prospective randomized pilot trial.

INTRODUCTION: Low titer group O whole blood (LTOWB) resuscitation is increasingly common in both military and civilian settings. Data regarding the safety and efficacy of prehospital LTOWB remain limited. METHODS: We performed a single-center, prospective, cluster randomized, prehospital through in-hospital whole blood pilot trial for injured air medical patients. We compared standard prehospital air medical care including red cell transfusion and crystalloids followed by in-hospital component transfusion to prehospital and in-hospital LTOWB resuscitation. Prehospital vital signs were used as inclusion criteria (systolic blood pressure ≤90 mm Hg and heart rate ≥108 beats per minute or systolic blood pressure ≤70 mm Hg for patients at risk of hemorrhage). Primary outcome was feasibility. Secondary outcomes included 28-day and 24-hour mortality, multiple organ failure, nosocomial infection, 24-hour transfusion requirements, and arrival coagulation parameters. RESULTS: Between November 2018 and October 2020, 86 injured patients were cluster randomized by helicopter base. The trial has halted early at 77% enrollment. Overall, 28-day mortality for the cohort was 26%. Injured patients randomized to prehospital LTOWB (n = 40) relative to standard care (n = 46) were similar in demographics and injury characteristics. Intent-to-treat Kaplan-Meier survival analysis demonstrated no statistical mortality benefit at 28 days (25.0% vs. 26.1%, p = 0.85). Patients randomized to prehospital LTOWB relative to standard care had lower red cell transfusion requirements at 24 hours (p < 0.01) and a lower incidence of abnormal thromboelastographic measurements. No transfusion reactions during the prehospital or in-hospital phase of care were documented. CONCLUSION: Prehospital through in-hospital LTOWB resuscitation is safe and may be associated with hemostatic benefits. A large-scale clinical trial is feasible with protocol adjustment and would allow the effects of prehospital LTOWB on survival and other pertinent clinical outcomes to be appropriately characterized. LEVEL OF EVIDENCE: Therapeutic/Care Management, Level II.

Patient and surrogate attitudes via an interviewer-administered survey on exception from informed consent enrollment in the Prehospital Air Medical Plasma (PAMPer) trial.

OBJECTIVES: With increased focus on early resuscitation methods following injury to improve patient outcomes, studies are employing exception from informed consent (EFIC) enrollment. Few studies have assessed patients' opinions following participation in an EFIC study, and none have been conducted within the realm of traumatic hemorrhage. We surveyed those patients and surrogates previously enrolled in the Prehospital Air Medical Plasma (PAMPer) Trial to clarify their opinions related to consent and emergency research. METHODS: Telephone calls were made between January-June 2019 to all patients who were enrolled under EFIC in the PAMPer study at the Pittsburgh site (169 of the 501 total patients enrolled, May 2014-Oct 2017) and their surrogates. Questions gauging approval of EFIC enrollment were asked before discussion of PAMPer trial outcomes, after disclosure of positive outcomes, and after a hypothetical negative trial outcome was proposed. RESULTS: Of the total 647 telephone calls made, ninety-three interviews, reflecting 70 of 169 patient enrollments, were conducted. This included 13 in which only the patient was interviewed, 23 in which the patient and a surrogate were interviewed, and 34 in which only a surrogate was interviewed. Nearly half (48.4%) of respondents did not recall their personal or family member enrollment in the study. No patients or surrogates recalled hearing about the study through community consultation or being aware of opt out procedures. Patients and surrogates were glad they were enrolled (90.3%), agreed with EFIC use for their personal enrollment (88.17%), and agreed with the general use of EFIC for the PAMPer study (81.7%). Disclosure of the true positive PAMPer study outcome resulted in a significant increase in opinions regarding personal enrollment, EFIC for personal enrollment, and EFIC for general enrollment (all p < 0.001). Disclosure of a hypothetical neutral or negative study outcome resulted in significant decreases in opinions regarding EFIC for personal enrollment (p = 0.003) and EFIC for general enrollment (p < 0.001). CONCLUSIONS: Clinical trial participants with traumatic hemorrhagic shock enrolled with EFIC, and surrogates of such participants, are generally accepting of EFIC. The results of the trial in which EFIC was utilized significantly affected patient and surrogate agreement with personal and general EFIC enrollment.

Tranexamic Acid During Prehospital Transport in Patients at Risk for Hemorrhage After Injury: A Double-blind, Placebo-Controlled, Randomized Clinical Trial.

IMPORTANCE: 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 ≤90 mm Hg) or tachycardia (heart rate ≥110/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 MEASURES: The 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 ≤70 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 RELEVANCE: In 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 patients at risk for hemorrhage in the prehospital setting is safe and associated with survival benefit in specific subgroups of patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02086500.

Implementation of a prehospital air medical thawed plasma program: Is it even feasible?

BACKGROUND: The Prehospital Air Medical Plasma (PAMPer) trial demonstrated a 30-day survival benefit among hypotensive trauma patients treated with prehospital plasma during air medical transport. We characterized resources, costs and feasibility of air medical prehospital plasma program implementation. METHODS: We performed a secondary analysis using data derived from the recent PAMPer trial. Intervention patients received thawed plasma (5-day shelf life). Unused plasma units were recycled back to blood bank affiliates, when possible. Distribution method and capability of recycling varied across sites. We determined the status of plasma units deployed, utilized, wasted, and returned. We inventoried thawed plasma use and annualized costs for distribution and recovery. RESULTS: The PAMPer trial screened 7,275 patients and 5,103 plasma units were deployed across 22 air medical bases during a 42-month period. Only 368 (7.2%) units of this total thawed plasma pool were provided to plasma randomized PAMPer patients. Of the total plasma pool, 3,716 (72.8%) units of plasma were returned to the blood bank with the potential for transfusion prior to expiration and 1,019 (20.0%) thawed plasma units were deemed wasted for this analysis. The estimated average annual cost of implementation of a thawed plasma program per air medical base at an average courier distance would be between US $24,343 and US $30,077, depending on the ability to recycle plasma and distance of courier delivery required. CONCLUSION: A prehospital plasma program utilizing thawed plasma is resource intensive. Plasma waste can be minimized depending on trauma center and blood bank specific logistics. Implementation of a thawed plasma program can occur with financial cost. Products with a longer shelf life, such as liquid plasma or freeze-dried plasma, may provide a more cost-effective prehospital product relative to thawed plasma. LEVEL OF EVIDENCE: Therapeutic, level III.

Prehospital Plasma during Air Medical Transport in Trauma Patients at Risk for Hemorrhagic Shock.

BACKGROUND: After a person has been injured, prehospital administration of plasma in addition to the initiation of standard resuscitation procedures in the prehospital environment may reduce the risk of downstream complications from hemorrhage and shock. Data from large clinical trials are lacking to show either the efficacy or the risks associated with plasma transfusion in the prehospital setting. METHODS: To determine the efficacy and safety of prehospital administration of thawed plasma in injured patients who are at risk for hemorrhagic shock, we conducted a pragmatic, multicenter, cluster-randomized, phase 3 superiority trial that compared the administration of thawed plasma with standard-care resuscitation during air medical transport. The primary outcome was mortality at 30 days. RESULTS: A total of 501 patients were evaluated: 230 patients received plasma (plasma group) and 271 received standard-care resuscitation (standard-care group). Mortality at 30 days was significantly lower in the plasma group than in the standard-care group (23.2% vs. 33.0%; difference, -9.8 percentage points; 95% confidence interval, -18.6 to -1.0%; P=0.03). A similar treatment effect was observed across nine prespecified subgroups (heterogeneity chi-square test, 12.21; P=0.79). Kaplan-Meier curves showed an early separation of the two treatment groups that began 3 hours after randomization and persisted until 30 days after randomization (log-rank chi-square test, 5.70; P=0.02). The median prothrombin-time ratio was lower in the plasma group than in the standard-care group (1.2 [interquartile range, 1.1 to 1.4] vs. 1.3 [interquartile range, 1.1 to 1.6], P<0.001) after the patients' arrival at the trauma center. No significant differences between the two groups were noted with respect to multiorgan failure, acute lung injury-acute respiratory distress syndrome, nosocomial infections, or allergic or transfusion-related reactions. CONCLUSIONS: 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 .).

Taking the Blood Bank to the Field: The Design and Rationale of the Prehospital Air Medical Plasma (PAMPer) Trial.

Hemorrhage and trauma induced coagulopathy remain major drivers of early preventable mortality in military and civilian trauma. Interest in the use of prehospital plasma in hemorrhaging patients as a primary resuscitation agent has grown recently. Trauma center-based damage control resuscitation using early and aggressive plasma transfusion has consistently demonstrated improved outcomes in hemorrhaging patients. Additionally, plasma has been shown to have several favorable immunomodulatory effects. Preliminary evidence with prehospital plasma transfusion has demonstrated feasibility and improved short-term outcomes. Applying state-of-the-art resuscitation strategies to the civilian prehospital arena is compelling. We describe here the rationale, design, and challenges of the Prehospital Air Medical Plasma (PAMPer) trial. The primary objective is to determine the effect of prehospital plasma transfusion during air medical transport on 30-day mortality in patients at risk for traumatic hemorrhage. This study is a multicenter cluster randomized clinical trial. The trial will enroll trauma patients with profound hypotension (SBP ≤ 70 mmHg) or hypotension (SBP 71-90 mmHg) and tachycardia (HR ≥ 108 bpm) from six level I trauma center air medical transport programs. The trial will also explore the effects of prehospital plasma transfusion on the coagulation and inflammatory response following injury. The trial will be conducted under exception for informed consent for emergency research with an investigational new drug approval from the U.S. Food and Drug Administration utilizing a multipronged community consultation process. It is one of three ongoing Department of Defense-funded trials aimed at expanding our understanding of the optimal therapeutic approaches to coagulopathy in the hemorrhaging trauma patient.