Abstract

BACKGROUND Time to treatment matters in traumatic haemorrhage but the optimal prehospital use of blood in major trauma remains uncertain. We investigated whether use of packed red blood cells (PRBC) and lyophilised plasma (LyoPlas) was superior to use of 0·9% sodium chloride for improving tissue perfusion and reducing mortality in trauma-related haemorrhagic shock. METHODS Resuscitation with pre-hospital blood products (RePHILL) is a multicentre, allocation concealed, open-label, parallel group, randomised, controlled, phase 3 trial done in four civilian prehospital critical care services in the UK. Adults (age ≥16 years) with trauma-related haemorrhagic shock and hypotension (defined as systolic blood pressure <90 mm Hg or absence of palpable radial pulse) were assessed for eligibility by prehospital critial care teams. Eligible participants were randomly assigned to receive either up to two units each of PRBC and LyoPlas or up to 1 L of 0·9% sodium chloride administered through the intravenous or intraosseous route. Sealed treatment packs which were identical in external appearance, containing PRBC-LyoPlas or 0·9% sodium chloride were prepared by blood banks and issued to participating sites according to a randomisation schedule prepared by the co-ordinating centre (1:1 ratio, stratified by site). The primary outcome was a composite of episode mortality or impaired lactate clearance, or both, measured in the intention-to-treat population. This study is completed and registered with ISRCTN.com, ISRCTN62326938. FINDINGS From Nov 29, 2016 to Jan 2, 2021, prehospital critical care teams randomly assigned 432 participants to PRBC-LyoPlas (n=209) or to 0·9% sodium chloride (n=223). Trial recruitment was stopped before it achieved the intended sample size of 490 participants due to disruption caused by the COVID-19 pandemic. The median follow-up was 9 days (IQR 1 to 34) for participants in the PRBC-LyoPlas group and 7 days (0 to 31) for people in the 0·9% sodium chloride group. Participants were mostly white (62%) and male (82%), had a median age of 38 years (IQR 26 to 58), and were mostly involved in a road traffic collision (62%) with severe injuries (median injury severity score 36, IQR 25 to 50). Before randomisation, participants had received on average 430 mL crystalloid fluids and tranexamic acid (90%). The composite primary outcome occurred in 128 (64%) of 199 participants randomly assigned to PRBC-LyoPlas and 136 (65%) of 210 randomly assigned to 0·9% sodium chloride (adjusted risk difference -0·025% [95% CI -9·0 to 9·0], p=0·996). The rates of transfusion-related complications in the first 24 h after ED arrival were similar across treatment groups (PRBC-LyoPlas 11 [7%] of 148 compared with 0·9% sodium chloride nine [7%] of 137, adjusted relative risk 1·05 [95% CI 0·46-2·42]). Serious adverse events included acute respiratory distress syndrome in nine (6%) of 142 patients in the PRBC-LyoPlas group and three (2%) of 130 in 0·9% sodium chloride group, and two other unexpected serious adverse events, one in the PRBC-LyoPlas (cerebral infarct) and one in the 0·9% sodium chloride group (abnormal liver function test). There were no treatment-related deaths. INTERPRETATION The trial did not show that prehospital PRBC-LyoPlas resuscitation was superior to 0·9% sodium chloride for adult patients with trauma related haemorrhagic shock. Further research is required to identify the characteristics of patients who might benefit from prehospital transfusion and to identify the optimal outcomes for transfusion trials in major trauma. The decision to commit to routine prehospital transfusion will require careful consideration by all stakeholders. FUNDING National Institute for Health Research Efficacy and Mechanism Evaluation.

Abstract

BACKGROUND A 2-gram bolus of tranexamic acid (TXA) has been shown to reduce 28-day mortality in a RCT. This study investigates whether out-of-hospital TXA use is associated with adverse events or unfavorable outcomes in suspected TBI when intracranial hemorrhage (ICH) is absent on initial CT. METHODS This study utilized data from a 2015-2017, multicenter, randomized trial studying the effect of the following TXA doses on moderate to severe TBI: 2-gram bolus, 1-gram bolus plus 1-gram infusion over 8 hours, and a placebo bolus with placebo infusion. Of the 966 participants enrolled, 395 with an initial CT negative for ICH were included in this analysis. Fifteen adverse events (28-day incidence) were studied: MI, DVT, seizure, pulmonary embolism, ARDS, cardiac failure, liver failure, renal failure, CVA, cardiac arrest, cerebral vasospasm, "any thromboembolism", hypernatremia, AKI, and infection. Other unfavorable outcomes analyzed include mortality at 28 days & 6 months, GOSE ≤4 at discharge & 6 months, ICU-free days, ventilator-free days, hospital-free days, and combined unfavorable outcomes. In both study drug groups the incidence of dichotomous outcomes and quantity of ordinal outcomes were compared to placebo. RESULTS No statistically significant increase in adverse events or unfavorable outcomes was found between either TXA dosing regimen and placebo. Demographics and injury scores were not statistically different other than two methods of injury which were overrepresented in the 1-gram TXA bolus +1-gram TXA infusion. CONCLUSIONS Administration of either a 2-gram TXA bolus or a 1-gram TXA bolus plus 1-gram TXA 8-hour infusion in suspected-TBIs without ICH is not associated with increased adverse events or unfavorable outcomes. Because the out-of-hospital 2-gram bolus is associated with a mortality benefit it should be administered in suspected-TBI. LEVELS OF EVIDENCE Level II, Therapeutic.

Abstract

BACKGROUND Complement activation after trauma promotes hemostasis but is associated with increased morbidity and mortality. However, the specific pathways and downstream mediators remain unclear. Recently the anaphylatoxin C4a has been shown to bind to thrombin receptors. While plasma-based resuscitation has been shown to modify the endotheliopathy of trauma, it may provide complement zymogens that fuel ongoing inflammatory cascades. We sought to characterize the activation of complement after injury and the effect of fresh frozen plasma (FFP) on this inflammatory response. We hypothesized that trauma induces C4 activation, which is associated with worse outcomes and influenced by FFP resuscitation. METHODS Blood was collected from injured patients at a single Level I Trauma Center enrolled in the COMBAT randomized clinical trial. Proteomic analyses were performed through targeted liquid chromatography coupled with mass spectrometry. For the present observational study, concentrations of complement proteins were analyzed at multiple time points, compared between treatment groups, and correlated with outcomes. RESULTS C4 activation occurred over the first six hours post-injury with peak activation 6-24 hours. Tissue hypoperfusion, defined as base deficit >10 mEq/L, and requirement for massive transfusion were associated with greater C4 activation. C4 activation was associated with mortality, multiple organ failure, and longer ventilator requirement. Additionally, temporal trends of C1q, factor B, and C3 by outcome groups support the prevailing theory of primary classical pathway activation with alternative pathway amplification. Resuscitation with FFP over the first six hours was associated with increased C4 activation at 12 and 24 hours. CONCLUSIONS C4 activation has an important inflammatory role post-injury, and FFP has the potential to augment this complement activation during resuscitation. EVIDENCE Level III, Prognostic/Epidemiological.

Abstract

BACKGROUND The antifibrinolytic drug tranexamic acid (TXA) improves survival in adults with traumatic hemorrhage; however, the drug has not been evaluated in a trial in injured children. We evaluated the feasibility of a large-scale trial evaluating the effects of TXA in children with severe hemorrhagic injuries. METHODS Severely injured children (0 up to 18(th) birthday) were randomized into a double-blind randomized trial of 1) TXA 15 mg/kg bolus dose, followed by 2 mg/kg/hr infusion over 8 hours, 2) TXA 30 mg/kg bolus dose, followed by 4 mg/kg/hr infusion over 8 hours, or 3) normal saline placebo bolus and infusion. The trial was conducted at 4 pediatric Level I trauma centers in the United States between June 2018 and March 2020. We enrolled patients under federal exception from informed consent (EFIC) procedures when parents were unable to provide informed consent. Feasibility outcomes included the rate of enrollment, adherence to intervention arms, and ability to measure the primary clinical outcome. Clinical outcomes included global functioning (primary), working memory, total amount of blood products transfused, intracranial hemorrhage progression, and adverse events. The target enrollment rate was at least 1.25 patients per site per month. RESULTS A total of 31 patients were randomized with a mean age of 10.7 years (standard deviation [SD] 5.0 years) and 22 (71%) patients were male. The mean time from injury to randomization was 2.4 hours (SD 0.6 hours). Sixteen (52%) patients had isolated brain injuries and 15 (48%) patients had isolated torso injuries. The enrollment rate using EFIC was 1.34 patients per site per month. All eligible enrolled patients received study intervention (9 patients TXA 15 mg/kg bolus dose, 10 patients TXA 30 mg/kg bolus dose, and 12 patients placebo) and had the primary outcome measured. No statistically significant differences in any of the clinical outcomes were identified. CONCLUSION Based on enrollment rate, protocol adherence, and measurement of the primary outcome in this pilot trial, we confirmed the feasibility of conducting a large-scale, randomized trial evaluating the efficacy of TXA in severely injured children with hemorrhagic brain and/or torso injuries using EFIC.

Abstract

IMPORTANCE Tranexamic acid is widely available and used off-label in patients with bleeding traumatic injury, although the literature does not consistently agree on its efficacy and safety. OBJECTIVE To examine the association of tranexamic acid administration with mortality and thromboembolic events compared with no treatment or with placebo in patients with traumatic injury in the literature. DATA SOURCES On March 23, 2021, PubMed, Embase, and the Cochrane Library were searched for eligible studies published between 1986 and 2021. STUDY SELECTION Randomized clinical trials and observational studies investigating tranexamic acid administration compared with no treatment or placebo among patients with traumatic injury and traumatic brain injury who were 15 years or older were included. Included studies were published in English or German. The electronic search yielded 1546 records, of which 71 were considered for full-text screening. The selection process was performed independently by 2 reviewers. DATA EXTRACTION AND SYNTHESIS The study followed the Cochrane Handbook for Systematic Reviews of Interventions and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data were extracted by 2 independent reviewers and pooled using the inverse-variance random-effects model. MAIN OUTCOMES AND MEASURES Outcomes were formulated before data collection and included mortality at 24 hours and 28 and 30 days (1 month) as well as the incidence of thromboembolic events and the amount of blood products administered. Owing to missing data, overall mortality was added and the amount of blood products administered was discarded. RESULTS Thirty-one studies with a total of 43 473 patients were included in the systematic review. The meta-analysis demonstrated that administration of tranexamic acid was associated with a significant decrease in 1-month mortality compared with the control cohort (risk ratio, 0.83 [95% CI, 0.71-0.97]; I2 = 35%). The results of meta-analyses for 24-hour and overall mortality and thromboembolic events were heterogeneous and could not be pooled. Further investigations on clinical heterogeneity showed that populations with trauma and trial conditions differed markedly. CONCLUSIONS AND RELEVANCE These findings suggest that tranexamic acid may be beneficial in various patient populations with trauma. However, reasonable concerns about potential thromboembolic events with tranexamic acid remain.

Abstract

OBJECTIVES Determine associations between biomarkers of endotheliopathy, 24-hour fibrinolysis phenotypes and clinical outcomes after trauma. BACKGROUND The vascular endothelium is a critical regulator of hemostasis and organ function. The relationship between markers of endotheliopathy and fibrinolysis following trauma has not been evaluated. METHODS We performed a secondary analysis of prospectively collected biomarker data in the Pragmatic Randomized Optimal Platelet and Plasma Ratios (PROPPR) randomized controlled trial. We stratified subjects by 24-hour thromboelastography (TEG) percent clot lysis (LY30) and plasma D-dimer (DD) levels and evaluated differences in endotheliopathy biomarkers and clinical outcomes between subjects with one of four 24-hour fibrinolysis phenotypes: LY30 0.9-2.9% (LY30(norm)), LY30 >2.9% (LY30(high)), LY30 <0.9% and low DD (LY30(low)+DD(low)), and LY30 <0.9% and high DD (LY30(low)+DD(high)). RESULTS The analysis included 168 subjects with LY30(norm), 32 with LY30(high), 147 with LY30(low)+DD(low) and 124 with LY30(low)+DD(high). LY30(low)+DD(high) subjects had greater injury severity and a higher incidence of severe head injury, multiorgan failure (MOF), and mortality than the other phenotypes. All endotheliopathy biomarkers were significantly higher in the LY30(low)+DD(high) phenotype. Adjusting for injury severity, mechanism and head trauma, 24-hour angiopoietin-2 and soluble thrombomodulin were independently associated with the LY30(low)+DD(high) phenotype. Both endothelial biomarkers were discriminating for MOF. Subjects with thrombomodulin level >9.5 ng/mL and angiopoietin-2 level >3.6 ng/mL accounted for 64% of subjects who developed MOF. CONCLUSIONS In a multicenter trauma cohort, subjects with a fibrinolysis phenotype characterized by low TEG lysis and elevated DD 24 hours after injury have significantly worse endotheliopathy and clinical outcomes. Our findings support mechanistic evaluations of the role of the endothelium in fibrinolysis dysregulation that may drive late-stage organ injury.

Abstract

BACKGROUND Early hemorrhage control after interpersonal violence is the most urgent requirement to preserve life and is now recognized as a responsibility of law enforcement. Although earlier entry of first responders is advocated, many shooting scenes remain unsafe for humans, necessitating first responses conducted by robots. Thus, robotic hemorrhage control warrants study as a care-under-fire treatment option. METHODS Two bomb disposal robots (Wolverine and Dragon Runner) were retrofitted with hemostatic wound clamps. The robots' ability to apply a wound clamp to a simulated extremity exsanguination while controlled by 4 experienced operators was tested. The operators were randomly assigned to perform 10 trials using 1 robot each. A third surveillance robot (Stair Climber) provided further visualization for the operators. We assessed the success rate of the application of the wound clamp to the simulated wound, the time to application of the wound clamp and the amount of fluid loss. We also assessed the operators' efforts to apply the wound clamp after an initial attempt was unsuccessful or after the wound clamp was dropped. RESULTS Remote robotic application of a wound clamp was demonstrated to be feasible, with complete cessation of simulated bleeding in 60% of applications. This finding was consistent across all operators and both robots. There was no difference in the success rates with the 2 robots (p = 1.00). However, there were differences in fluid loss (p = 0.004) and application time (p < 0.001), with the larger (Wolverine) robot being faster and losing less fluid. CONCLUSION Law enforcement tactical robots were consistently able to provide partial to complete hemorrhage control in a simulated extremity exsanguination. Consideration should be given to using this approach in care-under-fire and care-behind-the-barricade scenarios as well as further developing the technology and doctrine for robotic hemorrhage control.

Abstract

INTRODUCTION Exsanguination is the most preventable cause of death. Paradigms such as STOP THE BLEED recognize increased responsibility among the less experienced with Wound Packing (WP) being a critical skill. As even trained providers may perform poorly, we compared Video-modelling (VM), a form of behavioural modelling involving video demonstration prior to intervention against remote telementoring (RTM) involving remote real-time expert-guidance. METHODS Search and Rescue (SAR-Techs), trained in WP were asked to pack a wound on a standardized simulator randomized to RMT, VM, or control. RESULTS 24 SAR-Techs (median age 37, median 16.5 years experience) participated. Controls were consistently faster than RTM (p = 0.005) and VM (p = 0.000), with no difference between RTM and VM. However, 50% (n = 4) Controls failed to pack properly, compared to 100% success in both VM and RTM, despite all SAR-Techs feeling the task was "easy". DISCUSSION Performance of a life-saving technique was improved through either VM or RTM, suggesting that both techniques are beneficial and complementary to each other. Further work should be extended to law enforcement/lay public to examine logistical challenges.

Abstract

BACKGROUND Maxillofacial trauma accounts for ~10% of trauma presentations to most centres, with massive haemorrhage occurring in 1.2-4.5% of cases. Despite its infrequent presentation, there is significant associated morbidity and mortality. Transcatheter arterial embolization (TAE) is playing an increasingly prominent role in trauma presentations. The aim of this article was to compare outcomes of TAE with more traditional management methods for the treatment of massive facial haemorrhage following maxillofacial trauma. METHODS A database and Google Scholar search was performed, with articles discussing massive facial haemorrhage secondary to maxillofacial trauma and its management included. RESULTS Twenty-seven articles were found that met inclusion criteria, encompassing 384 patients. Statistical testing comparing mortality between TAE and non-TAE groups did not find a significant difference, with a mortality rate of 30.2% in the TAE group and 38.9% in the non-TAE group. Assessment of morbidity directly related to interventions was difficult, as many of the included participants had significant associated injuries which contributed an indeterminate degree to morbidity. There was a 10% rate of adverse events associated with TAE, most commonly puncture site haematomas and soft tissue swelling, with more significant adverse events including cerebrovascular accidents and blindness. CONCLUSION Embolization was correlated with increased rates of haemorrhage control when compared with other interventions. Overall, despite no significant impact on mortality, embolization is recommended in the management of massive haemorrhage following maxillofacial trauma due to improved success rates at haemorrhage control and a low rate of significant adverse events.

Abstract

BACKGROUND Calcium plays an essential role in physiologic processes, including trauma's "Lethal Diamond." Thus, inadequate serum calcium in trauma patients exacerbates the effects of hemorrhagic shock secondary to traumatic injury and subsequently poorer outcomes compared to those with adequate calcium levels. Evidence to date supports the consideration of calcium derangements when assessing the risk of mortality and the need for blood product transfusion in trauma patients. This review aims to further elucidate the predictive strength of this association for future treatment guidelines and clinical trials. METHODS Publications were collected on the relationship between i-Ca and the outcomes of traumatic injuries from PubMed, Web of Science, and CINAHL. Manuscripts were reviewed to select for English language studies. Hypocalcemia was defined as i-Ca <1.2 mmol/L. RESULTS Using PRISMA guidelines, we reviewed 300 studies, 7 of which met our inclusion criteria. Five papers showed an association between hypocalcemia and mortality. CONCLUSIONS In adult trauma patients, there has been an association seen between hypocalcemia, mortality, and the need for increased blood product transfusions. It is possible we are now seeing an association between low calcium levels prior to blood product administration and an increased risk for mortality and need for transfusion. Hypocalcemia may serve as a biomarker to show these needs. Therefore, hypocalcemia could potentially be used as an independent predictor for multiple transfusions such that ionized calcium measurements could be used predictively, allowing faster administration of blood products.