Military use of tranexamic acid in combat trauma: Does it matter?

Effectiveness and safety of prehospital tranexamic acid in patients with trauma: an updated systematic review and meta-analysis with trial sequential analysis

BACKGROUND

The use of prehospital tranexamic acid (TXA) in patients with trauma has attracted considerable attention. This systematic review and meta-analysis aimed to provide the best evidence for clinicians.

METHODS

All related literature in PubMed, Embase, and the Cochrane Central Register of Controlled Trials (Central) databases were searched systematically from their establishment to July 1, 2023. The outcome measures included 24-hour and 28-30-day mortality and adverse events (multiple organ dysfunction syndrome, acute respiratory distress syndrome, thrombotic events, and infection events). The Revised Cochrane Risk of Bias Tool for Randomized Trials was used to evaluate the quality of the randomized controlled trials (RCTs). The Methodological Index for Nonrandomized Studies (MINORS) was used to evaluate the risk of bias in non-RCTs. The required information size was estimated using trial sequential analysis. The Grading of Recommendations, Assessment, Development, and Evaluation approach was used to evaluate the evidence quality.

RESULTS

Eleven studies (comprising 11,259 patients) were included; two of these were RCTs. The overall risks of bias were low in the RCTs. ROBINS-I risk of bias was Moderate in 3 studies, serious in 5 studies, and critical in 1 study. A significant reduction in 24-hour mortality was observed (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.71-0.94). A subgroup analysis that included only RCTs revealed that prehospital TXA was associated with reduced 28-30-day mortality (OR, 0.80; 95% CI, 0.66-0.97) and increased risks of thromboembolism (OR, 1.22; 95% CI, 1.03-1.44) and infection (OR, 1.13; 95% CI, 1.00-1.28) events. The blood products for transfusion decreased by 2.3 units on average (weighted mean difference [WMD], - 2.30; 95%CI, - 3.59 to - 1.01).

CONCLUSIONS

This updated systematic review showed that prehospital TXA reduced the 24-hour and 28-38-day mortality and blood transfusion but increased the risks of infection and thromboembolism in patients with trauma. Future RCTs with larger and more homogeneous samples will help verify our results.

A Systematic Review of Tranexamic Acid-Associated Venous Thromboembolic Events in Combat Casualties and Considerations for Prolonged Field Care

INTRODUCTION

Tranexamic acid (TXA) is a standard component of Tactical Combat Casualty Care. Recent retrospective studies have shown that TXA use is associated with a higher rate of venous thromboembolic (VTE) events in combat-injured patients. We aim to determine if selective administration should be considered in the prolonged field care environment.

MATERIALS AND METHODS

We performed a systematic review using the 2020 Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. Clinical trials and observational studies of combat casualties published between January 1, 1960, and June 20, 2022, were included. We analyzed survival and VTE outcomes in TXA recipients and non-recipients. We discussed the findings of each paper in the context of current and future combat environments.

RESULTS

Six articles met criteria for inclusion. Only one study was powered to report mortality data, and it demonstrated a 7-fold increase in survival in severely injured TXA recipients. All studies reported an increased risk of VTE in TXA recipients, which exceeded rates in civilian literature. However, five of the six studies used overlapping data from the same registry and were limited by a high rate of missingness in pertinent variables. No VTE-related deaths were identified.

CONCLUSIONS

There may be an increased risk of VTE in combat casualties that receive TXA; however, this risk must be considered in the context of improved survival and an absence of VTE-associated deaths. To optimize combat casualty care during prolonged field care, it will be essential to ensure the timely administration of VTE chemoprophylaxis as soon as the risk of significant hemorrhage permits.

Adherence to a Balanced Approach to Massive Transfusion in Combat Casualties

BACKGROUND

Hemorrhage is the most common cause of potentially preventable death on the battlefield. Balanced resuscitation with plasma, platelets, and packed red blood cells (PRBCs) in a 1:1:1 ratio, if whole blood (WB) is not available, is associated with optimal outcomes among patients with hemorrhage. We describe the use of balanced resuscitation among combat casualties undergoing massive transfusion.

MATERIALS AND METHODS

We conducted a secondary analysis of data from the Department of Defense Trauma Registry (DODTR) spanning encounters from January 1, 2007, to March 17, 2020. We included all casualties who received at least 10 units of either PRBCs or WB. We categorized casualties as recipients of plasma-balanced resuscitation if the ratio of plasma to PRBC units was 0.8 or greater; similarly, we defined platelet-balanced resuscitation as a ratio of platelets to PRBC units of 0.8 or greater. We portrayed these populations using descriptive statistics and compared characteristics between non-balanced and balanced resuscitation recipients for both plasma and platelets.

RESULTS

We identified 28,950 encounters in the DODTR with documentation of prehospital activity. Massive transfusions occurred for 2,414 (8.3%) casualties, among whom 1,593 (66.0%) received a plasma-balanced resuscitation and 1,248 (51.7%) received a platelet-balanced resuscitation. During the study period, 962 (39.8%) of these patients received a fully balanced resuscitation with regard to both the plasma:PRBC and platelet:PRBC ratios. The remaining casualties did not undergo a balanced resuscitation.

CONCLUSIONS

While a majority of massive transfusion recipients received a plasma-balanced and/or platelet-balanced resuscitation, fewer patients received a platelet-balanced resuscitation. These findings suggest that more emphasis in training and supply may be necessary to optimize blood product resuscitation ratios.

Empiric tranexamic acid use provides no benefit in urgent orthopedic surgery following injury

Background

Orthopedic literature has demonstrated a significant decrease in postoperative transfusion requirements when tranexamic acid (TXA) was given during elective joint arthroplasty. The purpose of this study was to evaluate the empiric use of TXA in semi-urgent orthopedic procedures following injury. We hypothesized that TXA would be associated with increased rates of venous thromboembolic events (VTE) and have no effect on transfusion requirements.

Methods

Patients who empirically received TXA during a semi-urgent orthopedic surgery following injury (TXA+) were matched using propensity scoring to historical controls (CONTROL) who did not receive TXA. Outcomes included VTE within 6 months of injury and packed red blood cell utilization. Multivariable logistic regression and generalized linear modeling were used to determine odds of VTE and transfusion.

Results

200 patients were included in each group. There was no difference in mortality between groups. TXA+ patients did not have an increase in VTE events (OR 0.680, 95% CI 0.206 to 2.248). TXA+ patients had a significantly higher odds of being transfused during their hospital stay (OR 2.175, 95% CI 1.246 to 3.797) and during the index surgery (increased 0.95 units (SD 0.16), p<0.0001). Overall transfusion was also significantly higher in the TXA+ group (p=0.0021).

Conclusion

Empiric use of TXA in semi-urgent orthopedic surgeries did not increase the odds of VTE. Despite the elective literature, TXA administration did not associate with less transfusion requirements. A properly powered, prospective, randomized trial should be designed to elucidate the risks and benefits associated with TXA use in this setting.

Level of evidence

Level IV.

Association of Tranexamic Acid Administration With Mortality and Thromboembolic Events in Patients With Traumatic Injury: A Systematic Review and Meta-analysis

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.

Clinical use of tranexamic acid: evidences and controversies

Tranexamic acid (TXA) significantly reduces blood loss in a wide range of surgical procedures and improves survival rates in obstetric and trauma patients with severe bleeding. Although it mainly acts as a fibrinolysis inhibitor, it also has an anti-inflammatory effect, and may help attenuate the systemic inflammatory response syndrome found in some cardiac surgery patients. However, the administration of high doses of TXA has been associated with seizures and other adverse effects that increase the cost of care, and the administration of TXA to reduce perioperative bleeding needs to be standardized. Tranexamic acid is generally well tolerated, and most adverse reactions are considered mild or moderate. Severe events are rare in clinical trials, and literature reviews have shown tranexamic acid to be safe in several different surgical procedures. However, after many years of experience with TXA in various fields, such as orthopedic surgery, clinicians are now querying whether the dosage, route and interval of administration currently used and the methods used to control and analyze the antifibrinolytic mechanism of TXA are really optimal. These issues need to be evaluated and reviewed using the latest evidence to improve the safety and effectiveness of TXA in treating intracranial hemorrhage and bleeding in procedures such as liver transplantation, and cardiac, trauma and obstetric surgery.

Prehospital evaluation and detection of induced coagulopathy in trauma: The PREDICT study

BACKGROUND

Hemorrhage with trauma-induced coagulopathy (TIC) and hyperfibrinolysis (HF) increases the mortality risk after severe trauma. While TIC at hospital admission is well studied, little is known about coagulopathy at the incident site. The aim of the study was to investigate coagulation disorders already present on scene.

METHODS

In a prospective single-center observational study, blood samples of trauma patients obtained before and at hospital admission were analyzed. Data on rotational thromboelastometry, blood gas analysis, prehospital treatment, injury severity, in-hospital blood transfusions, and mortality were investigated according to the presence of coagulation disorders at the incident site. The patients were divided into three groups according to the presence of coagulation disorders (no coagulopathy, TIC, TIC with HF). In a subgroup analysis, patients with a Trauma-Induced Coagulopathy Clinical Score (TICCS) of ≥10 were investigated.

RESULTS

Between August 2015 and February 2018, 148 patients were enrolled in the study. The mean Injury Severity Score was 22.1, and overall mortality was 7.4%. Trauma-induced coagulopathy and HF were already detectable at the incident site in 18.2% and 6.1%, respectively. Patients with HF had significantly altered circulation parameters with significant changes in pH, hemoglobin, lactate, and base excess at the incident site. In patients with TICCS of ≥10 (14.2%), TIC was detected in 47.6% of the cases and HF in 28.6%. Furthermore, in these patients, blood gas parameters significantly changed and the need for blood transfusion and mortality.

CONCLUSION

Trauma-induced coagulopathy and HF can be detected in severely injured patients even before medical treatment is started. Furthermore, in patients with HF and TICCS of ≥10, blood gas parameters were significantly changed at the incident site.

LEVEL OF EVIDENCE

Prognostic study, level III.

Pathologic Fibrinolysis is More Common in a Rural Trauma Setting

INTRODUCTION

Fibrinolysis (lysis) has been extensively studied in trauma patients. Many studies on the distribution of lysis phenotype have been conducted in setting with short prehospital time. This study aimed to evaluate the distribution of lysis phenotypes in a population with prolonged prehospital times in a rural environment.

METHODS

A retrospective study was performed at an American College of Surgeons-verified level 1 trauma center, serving a large rural population. Full trauma team activations from January 1, 2017 to August 31, 2018 were evaluated, and all patients with an ISS>15 analyzed. Thromboelastography was routinely performed on all participants on arrival. Lysis phenotypes were classified based on LY30 results: shutdown (≤.8%), physiologic (.9-2.9%), and hyper (>2.9%).

RESULTS

259 patients were evaluated, 134 (52%) presented direct from the scene. For scene patients, lysis distribution was 24% physiologic, 49% shutdown, and 27% hyper. Transferred patients demonstrated a reduction in physiologic lysis to 14% (P = .03), shutdown present in 66%, and hyper in 20%. Empiric prehospital tranexamic acid was given to 18 patients, physiologic lysis was present in 6%, shutdown 72%, and hyper 22%; this increase was not statistically significant (P = .5).

CONCLUSION

Fibrinolysis phenotypes are not consistent across all trauma populations. This study showed rural trauma patients had a significantly increased rate of pathologic lysis. This was consistent for scene and transfer patients who received care at another facility prior to arrival for definitive care. Future studies to evaluate the factors influencing these differences are warranted.

Chinese expert consensus on diagnosis and treatment of trauma-induced hypercoagulopathy

Trauma-induced coagulopathy (TIC) is caused by post-traumatic tissue injury and manifests as hypercoagulability that leads to thromboembolism or hypocoagulability that leads to uncontrollable massive hemorrhage. Previous studies on TIC have mainly focused on hemorrhagic coagulopathy caused by the hypocoagulable phenotype of TIC, while recent studies have found that trauma-induced hypercoagulopathy can occur in as many as 22.2-85.1% of trauma patients, in whom it can increase the risk of thrombotic events and mortality by 2- to 4-fold. Therefore, the Chinese People's Liberation Army Professional Committee of Critical Care Medicine and the Chinese Society of Thrombosis, Hemostasis and Critical Care, Chinese Medicine Education Association jointly formulated this Chinese Expert Consensus comprising 15 recommendations for the definition, pathophysiological mechanism, assessment, prevention, and treatment of trauma-induced hypercoagulopathy.

Efficacy and Safety of Tranexamic Acid in Emergency Trauma: A Systematic Review and Meta-Analysis

In trauma patients, bleeding can lead to coagulopathy, hemorrhagic shock, and multiorgan failure, and therefore is of fundamental significance in regard to early morbidity. We conducted a meta-analysis to evaluate the efficacy and safety of tranexamic acid (TXA) in civil and military settings and its impact on in-hospital mortality (survival to hospital discharge or 30-day survival), intensive care unit and hospital length of stay, incidence of adverse events (myocardial infarct and neurological complications), and volume of blood product transfusion. The systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic review of the literature using PubMed, Scopus, EMBASE, Web of Science, and the Cochrane Central Register and Controlled Trials (CENTRAL) database was conducted from inception to 10 January 2021. In-hospital mortality was reported in 14 studies and was 15.5% for the TXA group as compared with 16.4% for the non-TXA group (OR = 0.81, 95% CI 0.62-1.06, I2 = 83%, p = 0.12). In a civilian TXA application, in-hospital mortality in the TXA and non-TXA groups amounted to 15.0% and 17.1%, respectively (OR = 0.69, 95% CI 0.51-0.93, p = 0.02, I2 = 78%). A subgroup analysis of the randomized control trial (RCT) studies showed a statistically significant reduction in in-hospital mortality in the TXA group (14.3%) as compared with the non-TXA group (15.7%, OR = 0.89, 95% CI 0.83-0.96, p = 0.003, I2 = 0%). To summarize, TXA used in civilian application reduces in-hospital mortality. Application of TXA is beneficial for severely injured patients who undergoing shock and require massive blood transfusions. Patients who undergo treatment with TXA should be monitored for clinical signs of thromboembolism, since TXA is a standalone risk factor of a thromboembolic event and the D-dimers in traumatic patients are almost always elevated.

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.

The impact of blood product ratio and procoagulant therapy on the development of thromboembolic events in severely injured hemorrhaging trauma patients

INTRODUCTION

Transfusion therapy in hemorrhaging trauma patients is associated with the development of thromboembolic events. It is unknown whether current resuscitation strategies, including large volumes of plasma and early administration of procoagulant therapy, increases this risk.

METHODS

A systematic search was conducted in MEDLINE, PubMed, and Embase. Studies were screened by two independent reviewers and included if they reported on thromboembolic events in patients with severe trauma (injury severity score ≥16) who received transfusion of at least 1 unit of red blood cells. The ratio by which blood products were transfused, as well as use of procoagulant or antifibrinolytic medication, was recorded.

RESULTS

A total of 40 studies with 11.074 bleeding trauma patients were included, in which 1.145 thromboembolic events were reported, yielding an incidence of 10% thromboembolic events. In studies performing routine screening for thromboembolic complications, the incidence ranged from 12% to 23%. The risk of thromboembolic events was increased after administration of tranexamic acid (TXA; odds ratio [OR], 2.6; 95% confidence interval [CI], 1.7-4.1; p < 0.001) and fibrinogen concentrate (OR, 2.1; 95% CI, 1.0-4.2; p = 0.04). Blood product ratio, the use of prothrombin complex concentrate or recombinant factor VIIa were not associated with thromboembolic events.

CONCLUSION

This systematic review identified an incidence of thromboembolic events of 10% in severely injured bleeding trauma patients. The use of TXA and fibrinogen concentrate was associated with the development of thromboembolic complications.

Outcomes of tranexamic acid administration in military trauma patients with intracranial hemorrhage: a cohort study

Background

Tranexamic acid (TXA) may be a useful adjunct for military patients with severe traumatic brain injury (TBI). These patients are often treated in austere settings without immediate access to neurosurgical intervention. The purpose of this study was to evaluate any association between TXA use and progression of intracranial hemorrhage (ICH), neurologic outcomes, and venous thromboembolism (VTE) in TBI.

Methods

This was a retrospective cohort study of military casualties from October 2010 to December 2015 who were transferred to a military treatment facility (MTF) in the United States. Data collected included: demographics, types of injuries, initial and interval head computerized tomography (CT) scans, Glasgow Coma Scores (GCS), and six-month Glasgow Outcome Scores (GOS). Results were stratified based on TXA administration, progression of ICH, and VTE.

Results

Of the 687 active duty service members reviewed, 71 patients had ICH (10.3%). Most casualties were injured in a blast (80.3%), with 36 patients (50.7%) sustaining a penetrating TBI. Mean ISS was 28.2 ± 12.3. Nine patients (12.7%) received a massive transfusion within 24 h of injury, and TXA was administered to 14 (19.7%) casualties. Patients that received TXA had lower initial reported GCS (9.2 ± 4.4 vs. 12.5 ± 3.4, p = 0.003), similar discharge GCS (13.3 ± 4.0 vs. 13.8 ± 3.2, p = 0.58), and a larger improvement between initial and discharge GCS (3.7 ± 3.9 vs. 1.3 ± 3.1, p = 0.02). However, there was no difference in mortality (7.1% vs. 7.0%, p = 1.00), progression of ICH (45.5% vs. 14.7%, p = 0.09), frequency of cranial decompression (50.0% vs. 42.1%, p = 0.76), or mean GOS (3.5 ± 0.9 vs. 3.8 ± 1.0, p = 0.13). Patients administered TXA had a higher rate of VTE (35.7% vs. 7.0%, p = 0.01). On multivariate analysis, however, TXA was not independently associated with VTE.

Conclusions

Patients that received TXA were associated with an improvement in GCS but not in progression of ICH or GOS. TXA was not independently associated with VTE, although this may be related to a paucity of patients receiving TXA. Decisions about TXA administration in military casualties with ICH should be considered in the context of the availability of neurosurgical intervention as well as severity of extracranial injuries and need for massive transfusion.

The Role of Tranexamic Acid in the Management of an Acutely Hemorrhaging Patient

Background: Acute hemorrhage, both traumatic and nontraumatic, leads to significant morbidity and mortality, both in the United States and globally. Traditional treatment of acute hemorrhage is focused on hemostasis and blood product replacement. Tranexamic acid is an antifibrinolytic agent that may reduce acute hemorrhage through inhibition of plasminogen. Newer research suggests that coagulopathy, specifically fibrinolysis, may contribute significantly to the pathology of acute hemorrhage. Methods: We searched the PubMed database for relevant articles from 2000 to 2018 for the terms "tranexamic acid," "TXA," "antifibrinolytic," "hyperfibrinolysis," and "coagulopathy." Our search was limited to studies published in the English language. Results: A total of 53 studies were included in this review. These articles suggest a potential role for tranexamic acid in the management of acute intracranial hemorrhage, epistaxis, hematuria, postpartum hemorrhage, gastrointestinal hemorrhage, and trauma-related hemorrhage. A theoretical risk of thrombotic events following tranexamic acid use exists, though large clinical trials suggest this risk remains exceedingly small. Conclusions: Recent studies suggest a mortality benefit with tranexamic acid following acute hemorrhage. First responders such as emergency medical technicians and emergency department clinicians should consider tranexamic acid as an adjunct therapy in the management of acute, severe traumatic and nontraumatic hemorrhage.

TXA (Tranexamic Acid) Risk Evaluation in Combat Casualties (TRECC)

Background

The use of tranexamic acid (TXA) has become increasingly prevalent for hemorrhage prevention in military trauma patients due to its known survival benefits. There is concern of increased venous thromboembolism (VTE) subsequent to receiving TXA. The purpose of this retrospective study was to determine the rate of VTE in severely injured military personnel during Operation Enduring Freedom (2009-2014).

Methods

An analysis of 859 military trauma patients from the 2009-2014 Department of Defense Trauma Registry included subjects with an injury severity score (ISS) >10 and a massive transfusion (MT) (>10 units of blood products in the first 24 hours). Outcomes included a documented VTE (eg, deep vein thrombosis (DVT) or pulmonary embolism (PE)) during the patient's hospital course. Comparison between those who did/did not receive TXA was analyzed using three separate multiple regression analyses using listwise deletion, systematic replacement and multiple imputation.

Results

Subjects (n=620) met inclusion criteria with 27% (n=169) having a documented VTE. A total of 30% that received TXA had a documented VTE, 26% that did not receive TXA had a documented VTE and 43% (n=264, n=620) of the sample did not have TXA documented as either given or not given. Multiple regression analyses using listwise deletion and systematic replacement of the TXA variable demonstrated no difference in odds of VTE, whereas the multiple imputation analysis demonstrated a 3% increased odds of VTE, a9.4% increased odds of PE and 8.1% decreased odds of DVT with TXA administration.

Discussion

TXA use with an ISS >10 and MT resuscitation had a 3% increased odds of VTE and an increased odds of PE, whereas the odds of DVT were found to be decreased after multiple imputation analysis. Further research on the long-term risks and benefits of TXA usage in the military population is recommended.

Level of evidence

IV-therapeutic.

Trauma Embolic Scoring System in military trauma: a sensitive predictor of venous thromboembolism

Introduction

Clinical decision support tools capable of predicting which patients are at highest risk for venous thromboembolism (VTE) can assist in guiding surveillance and prophylaxis decisions. The Trauma Embolic Scoring System (TESS) has been shown to model VTE risk in civilian trauma patients. No such support tools have yet been described in combat casualties, who have a high incidence of VTE. The purpose of this study was to evaluate the utility of TESS in predicting VTE in military trauma patients.

Methods

A retrospective cohort study of 549 combat casualties from October 2010 to November 2012 admitted to a military treatment facility in the USA was performed. TESS scores were calculated through data obtained from the Department of Defense Trauma Registry and chart reviews. Univariate analysis and multivariate logistic regression were performed to evaluate risk factors for VTE. Receiver operating characteristic (ROC) curve analysis of TESS in military trauma patients was also performed.

Results

The incidence of VTE was 21.7% (119/549). The median TESS for patients without VTE was 8 (IQR 4–9), and the median TESS for those with VTE was 10 (IQR 9–11). On multivariate analysis, Injury Severity Score (ISS) (OR 1.03, p=0.007), ventilator days (OR 1.05, p=0.02), and administration of tranexamic acid (TXA) (OR 1.89, p=0.03) were found to be independent risk factors for development of VTE. On ROC analysis, an optimal high-risk cut-off value for TESS was ≥7 with a sensitivity of 0.92 and a specificity of 0.53 (area under the curve 0.76, 95% CI 0.72 to 0.80, p<0.0001).

Conclusions

When used to predict VTE in military trauma, TESS shows moderate discrimination and is well calibrated. An optimal high-risk cut-off value of ≥7 demonstrates high sensitivity in predicting VTE. In addition to ISS and ventilator days, TXA administration is an independent risk factor for VTE development.

Level of evidence

Level III.

Tranexamic Acid for Acute Hemorrhage: A Narrative Review of Landmark Studies and a Critical Reappraisal of Its Use Over the Last Decade

The publication of the Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage-2 (CRASH-2) study and its intense dissemination prompted a renaissance for the use of the antifibrinolytic agent tranexamic acid (TXA) in acute trauma hemorrhage. Subsequent studies led to its widespread use as a therapeutic as well as prophylactic agent across different clinical scenarios involving bleeding, such as trauma, postpartum, and orthopedic surgery. However, results from the existing studies are confounded by methodological and statistical ambiguities and are open to varied interpretations. Substantial knowledge gaps remain on dosing, pharmacokinetics, mechanism of action, and clinical applications for TXA. The risk for potential thromboembolic complications with the use of TXA must be balanced against its clinical benefits. The present article aims to provide a critical reappraisal of TXA use over the last decade and a "thought exercise" in the potential downsides of TXA. A more selective and individualized use of TXA, guided by extended and functional coagulation assays, is advocated in the context of the evolving concept of precision medicine.

An Analysis of Adherence to Tactical Combat Casualty Care Guidelines for the Administration of Tranexamic Acid

BACKGROUND

Hemorrhage is the leading cause of potentially survivable deaths in combat. Previous research demonstrated that tranexamic acid (TXA) administration decreased mortality among casualties. For casualties expected to receive a transfusion, the Committee on Tactical Combat Casualty Care (TCCC) recommends TXA. Despite this, the use and adherence of TXA in the military prehospital combat setting, in accordance with TCCC guidelines, is low.

OBJECTIVES

We sought to analyze TXA administration and use among combat casualties reasonably expected to require blood transfusion, casualties with tourniquet placement, amputations, and gunshot wounds.

METHODS

Based on TCCC guidelines, we measured proportions of patients receiving prehospital TXA: casualties undergoing tourniquet placement, casualties sustaining amputation proximal to the phalanges, patients sustaining gunshot wounds, and patients receiving ≥10 units of blood products within 24 h of injury. Univariable and multivariable analyses were also completed.

RESULTS

Within our dataset, 255 subjects received TXA. Four thousand seventy-one subjects had a tourniquet placed, of whom 135 (3.3%) received prehospital TXA; 1899 subjects had an amputation proximal to the digit with 106 (5.6%) receiving prehospital TXA; and 6660 subjects had a gunshot wound with 88 (1.3%) receiving prehospital TXA. Of 4246 subjects who received ≥10 units of blood products within the first 24 h, 177 (4.2%) received prehospital TXA.

CONCLUSIONS

We identified low TXA administration despite TCCC recommendations. Future studies should seek to both identify reasons for limited TXA administration and methods to increase future utilization.

Fibrinolysis Shutdown in Trauma: Historical Review and Clinical Implications

Despite over a half-century of recognizing fibrinolytic abnormalities after trauma, we remain in our infancy in understanding the underlying mechanisms causing these changes, resulting in ineffective treatment strategies. With the increased utilization of viscoelastic hemostatic assays (VHAs) to measure fibrinolysis in trauma, more questions than answers are emerging. Although it seems certain that low fibrinolytic activity measured by VHA is common after injury and associated with increased mortality, we now recognize subphenotypes within this population and that specific cohorts arise depending on the specific time from injury when samples are collected. Future studies should focus on these subtleties and distinctions, as hypofibrinolysis, acute shutdown, and persistent shutdown appear to represent distinct, unique clinical phenotypes, with different pathophysiology, and warranting different treatment strategies.

Severely injured trauma patients with admission hyperfibrinolysis: Is there a role of tranexamic acid? Findings from the PROPPR trial

INTRODUCTION

Administration of tranexamic acid (TXA) in coagulopathy of trauma gained popularity after the CRASH-2 trial. The aim of our analysis was to analyze the role of TXA in severely injured trauma patients with admission hyperfibrinolysis.

METHODS

We reviewed the prospectively collected Pragmatic, Randomized Optimal Platelet and Plasma Ratios database. We included patients with admission hyperfibrinolysis (Ly30 >3%) on thromboelastography. Patients were stratified into two groups (TXA and No-TXA) and were matched in 1:2 ratio using propensity score matching for demographics, admission vitals, and injury severity. Primary outcome measures were 6-, 12-, and 24-hour and 30-day mortality; 24-hour transfusion requirements; time to achieve hemostasis; and rebleeding after hemostasis requiring intervention. Secondary outcome measures were thrombotic complications.

RESULTS

We analyzed 680 patients. Of those, 118 had admission hyperfibrinolysis, and 93 patients (TXA: 31 patients; No-TXA: 62 patients) were matched. Matched groups were similar in age (p = 0.33), gender (p = 0.84), race (p = 0.81), emergency department (ED) Glasgow Coma Scale (p = 0.34), ED systolic blood pressure (p = 0.28), ED heart rate (p = 0.43), mechanism of injury (p = 0.45), head Abbreviated Injury Scale score (p = 0.68), injury severity score (p = 0.56), and blood products ratio (p = 0.44). Patients who received TXA had a lower 6-hour mortality rate (34% vs. 13%, p = 0.04) and higher 24-hour transfusion of plasma (15 vs. 10 units, p = 0.03) compared with the No-TXA group. However, there was no difference in 12-hour (p = 0.24), 24-hour (p = 0.25), and 30-day mortality (p = 0.82). Similarly, there was no difference in 24-hour transfusion of RBC (p = 0.11) or platelets (p = 0.13), time to achieve hemostasis (p = 0.65), rebleeding requiring intervention (p = 0.13), and thrombotic complications (p = 0.98).

CONCLUSION

Tranexamic acid was associated with increased 6-hour survival but does not improve long-term outcomes in severely injured trauma patients with hemorrhage who develop hyperfibrinolysis. Moreover, TXA administration was not associated with thrombotic complications. Further randomized clinical trials will identify the subset of trauma patients who may benefit from TXA.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Mortality and Thrombosis in Injured Adults Receiving Tranexamic Acid in the Post-CRASH-2 Era

Introduction

The CRASH-2 trial demonstrated that tranexamic acid (TXA) reduced mortality with no increase in adverse events in severely injured adults. TXA has since been widely used in injured adults worldwide. Our objective was to estimate mortality and adverse events in adults with trauma receiving TXA in studies published after the CRASH-2 trial.

Methods

We systematically searched PubMed, Embase, MicroMedex, and ClinicalTrials.gov for studies that included injured adults who received TXA and reported mortality and/or adverse events. Two reviewers independently assessed study eligibility, abstracted data, and assessed the risk of bias. We conducted meta-analyses using random effects models to estimate the incidence of mortality at 28 or 30 days and in-hospital thrombotic events.

Results

We included 19 studies and 13 studies in the systematic review and meta-analyses, respectively. The pooled incidence of mortality at 28 or 30 days (five studies, 1538 patients) was 10.1% (95% confidence interval [CI], 7.8–12.4%) (vs 14.5% [95% CI, 13.9–15.2%] in the CRASH-2 trial), and the pooled incidence of in-hospital thrombotic events (nine studies, 1656 patients) was 5.9% (95% CI, 3.3–8.5%) (vs 2.0% [95% CI, 1.8–2.3%] in the CRASH-2 trial).

Conclusion

Compared to the CRASH-2 trial, adult trauma patients receiving TXA identified in our systematic review had a lower incidence of mortality at 28 or 30 days, but a higher incidence of in-hospital thrombotic events. Our findings neither support nor refute the findings of the CRASH-2 trial but suggest that incidence rates in adults with trauma in settings outside of the CRASH-2 trial may be different than those observed in the CRASH-2 trial.

Tranexamic acid in severe trauma patients managed in a mature trauma care system

BACKGROUND

Tranexamic acid (TXA) use in severe trauma remains controversial notably because of concerns of the applicability of the CRASH-2 study findings in mature trauma systems. The aim of our study was to evaluate the outcomes of TXA administration in severely injured trauma patients managed in a mature trauma care system.

METHODS

We performed a retrospective study of data prospectively collected in the TraumaBase registry (a regional registry collecting the prehospital and hospital data of trauma patients admitted in six Level I trauma centers in Paris Area, France). In hospital mortality was compared between patients having received TXA or not in the early phase of resuscitation among those presenting an unstable hemodynamic state. Propensity score for TXA administration was calculated and results were adjusted for this score. Hemodynamic instability was defined by the need of packed red blood cells (pRBC) transfusion and/or vasopressor administration in the emergency room (ER).

RESULTS

Among patients meeting inclusion criteria (n = 1,476), the propensity score could be calculated in 797, and survival analysis could be achieved in 684 of 797. Four hundred seventy (59%) received TXA, and 327 (41%) did not. The overall hospital mortality rate was 25.7%. There was no effect of TXA use in the whole population but mortality was lowered by the use of TXA in patients requiring pRBC transfusion in the ER (hazard ratio, 0.3; 95% confidence interval, 0.3-0.6).

CONCLUSION

The use of TXA in the management of severely injured trauma patients, in a mature trauma care system, was not associated with reduction in the hospital mortality. An independent association with a better survival was found in a selected population of patients requiring pRBC transfusion in the ER.

LEVEL OF EVIDENCE

Therapeutic study, level III.

Blood transfusion management in the severely bleeding military patient

PURPOSE OF REVIEW

Hemorrhage remains the primary cause of preventable death on the battlefield and in civilian trauma. Hemorrhage control is multifactorial and starts with point-of-injury care. Surgical hemorrhage control and time from injury to surgery is paramount; however, interventions in the prehospital environment and perioperative period affect outcomes. The purpose of this review is to understand concepts and strategies for successful management of the bleeding military patient. Understanding the life-threatening nature of coagulopathy of trauma and implementing strategies aimed at full spectrum hemorrhage management from point of injury to postoperative care will result in improved outcomes in patients with life-threatening bleeding.

RECENT FINDINGS

Timely and appropriate therapies impact survival. Blood product resuscitation for life-threatening hemorrhage should either be with whole blood or a component therapy strategy that recapitulates the functionality of whole blood. The US military has transfused over 10 000 units of whole blood since the beginning of the wars in Iraq and Afghanistan. The well recognized therapeutic benefits of whole blood have pushed this therapy far forward into prehospital care in both US and international military forces. Multiple hemostatic adjuncts are available that are likely beneficial to the bleeding military patient; and other products and techniques are under active investigation.

SUMMARY

Lessons learned in the treatment of combat casualties will likely continue to have positive impact and influence and the management of hemorrhage in the civilian trauma setting.

Prehospital Tranexamic Acid Administration During Aeromedical Transport After Injury

BACKGROUND

Tranexamic acid (TXA) has been shown to reduce mortality in the treatment of traumatic hemorrhage. This effect seems most profound when given early after injury. We hypothesized that extending a protocol for TXA administration into the prehospital aeromedical setting would improve outcomes while maintaining a similar safety profile to TXA dosed in the emergency department (ED).

MATERIALS AND METHODS

We identified all trauma patients who received TXA during prehospital aeromedical transport or in the ED at our urban level I trauma center over an 18-mo period. These patients had been selected prospectively for TXA administration using a protocol that selected adult trauma patients with high-risk mechanism and concern for severe hemorrhage to receive TXA. Patient demographics, vital signs, lab values including thromboelastography, blood administration, mortality, and complications were reviewed retrospectively and analyzed.

RESULTS

One hundred sixteen patients were identified (62 prehospital versus 54 ED). Prehospital TXA patients were more likely to have sustained blunt injury (76% prehospital versus 46% ED, P = 0.002). There were no differences between groups in injury severity score or initial vital signs. There were no differences in complication rates or mortality. Patients receiving TXA had higher rates of venous thromboembolic events (8.1% in prehospital and 18.5% in ED) than the overall trauma population (2.1%, P < 0.001).

CONCLUSIONS

Prehospital administration of TXA during aeromedical transport did not improve survival compared with ED administration. Treatment with TXA was associated with increased risk of venous thromboembolic events. Prehospital TXA protocols should be refined to identify patients with severe hemorrhagic shock or traumatic brain injury.

Chinese expert consensus on echelons treatment of pelvic fractures in modern war

The characteristics and treatment of pelvic fractures vary between general conditions and modern war. An expert consensus has been reached based on pelvic injury epidemiology and the concepts of battlefield treatment combined with the existing levels of military medical care in modern warfare. According to this consensus, first aid, emergency treatment and early treatment of pelvic fractures are introduced in three separate levels. In Level I facilities, simple triage and rapid treatment following the principles of advanced trauma life support are recommended to evaluate combat casualties during the first-aid stage. Re-evaluation, further immobilization and fixation, and hemostasis are recommended at Level II facilities. At Level III facilities, the main components of damage control surgery are recommended, including comprehensive hemostasis, a proper resuscitation strategy, the treatment of concurrent visceral and blood vessel damage, and battlefield intensive care. The grading standard for evidence evaluation and recommendation was used to reach this expert consensus.