Traumatic injury clinical trial evaluating tranexamic acid in children (TIC-TOC): study protocol for a pilot randomized controlled trial

Effect of age on the efficacy of tranexamic acid: An analysis of heterogeneity of treatment effect within the CRASH-2 dataset

BACKGROUND

Trauma is a major cause of morbidity and mortality in older adults and will become more common as the population ages. Tranexamic acid (TXA) is a lysine analogue frequently used in the setting of significant trauma with hemorrhage. The aim of this study is to investigate the heterogeneity of treatment effect of TXA as it relates to patient age during trauma care.

METHODS

We included patients from the CRASH-2 trial who were randomized within 3 h of injury. Patients were stratified into age groups <26 years, 26 to 35 years, 36 to 45 years, 46 to 55 years, and >55 years. Multiple logistic regression models were utilized to evaluate adjusted odds ratios (OR) with 95% confidence intervals (CI) for mortality. Heterogeneity of treatment effect was evaluated using Akaike and Bayesian information criteria to determine the optimum logistic regression model after which a Wald Chi-square test was utilized to evaluate statistical significance.

RESULTS

On univariate analysis, TXA administration decreased mortality within the <26 years cohort (decrease of 2.1%, 95% CI 0.2 to 4.0), 46 to 55 years cohort (decrease 6.7%, 95% CI 2.7 to 10.7), and >55 years cohort (decrease of 5.3%, 95% CI 0.4 to 10.3). On adjusted analysis, when compared to the 36 to 45 years cohort, the <26 year cohort experienced a decreased mortality (OR 0.72, 95% CI 0.62 to 0.85) whereas the >55 year cohort experienced increased mortality (OR 1.8, 95% CI 1.5 to 2.2). Assessment for heterogeneity of treatment effect of TXA administration between groups approached but did not reach statistical significance (p = 0.11).

CONCLUSIONS

Mortality related to trauma increases with age, however, there does not appear to be heterogeneity of treatment effect for TXA administration among different age groups.

Enrollment with and without exception from informed consent in a pilot trial of tranexamic acid in children with hemorrhagic injuries

BACKGROUND

Federal exception from informed consent (EFIC) procedures allow studies to enroll patients with time-sensitive, life-threatening conditions when written consent is not feasible. Our objective was to compare enrollment rates with and without EFIC in a trial of tranexamic acid (TXA) for children with hemorrhagic injuries.

METHODS

We conducted a four-center randomized controlled pilot and feasibility trial evaluating TXA in children with severe hemorrhagic brain and/or torso injuries. We initiated the trial enrolling patients without EFIC. After 3 months of enrollment, we met our a priori futility threshold and paused the trial to incorporate EFIC procedures and obtain regulatory approval. We then restarted the trial allowing EFIC if the guardian was unable to provide timely written consent. We used descriptive statistics to compare characteristics of eligible patients approached with and without EFIC procedures. We also calculated the time delay to restart the trial using EFIC.

RESULTS

We enrolled one of 15 (6.7%) eligible patients (0.17 per site per month) prior to using EFIC procedures. Of the 14 missed eligible patients, seven (50%) were not enrolled because guardians were not present or were injured and unable to provide written consent. After obtaining approval for EFIC, we enrolled 30 of 48 (62.5%) eligible patients (1.34 per site per month). Of these 30 patients, 22 (73.3%) were enrolled with EFIC. Of the 22, no guardians refused written consent after randomization. There were no significant differences in the eligibility rate and patient characteristics enrolled with and without EFIC procedures. Across all sites, the mean delay to restart the trial using EFIC procedures was 12 months.

CONCLUSIONS

In a multicenter trial of severely injured children, the use of EFIC procedures greatly increased the enrollment rate and was well accepted by guardians. Initiating the trial without EFIC procedures led to a significant delay in enrollment.

The design of a Bayesian adaptive clinical trial of tranexamic acid in severely injured children

BACKGROUND

Trauma is the leading cause of death and disability in children in the USA. Tranexamic acid (TXA) reduces the blood transfusion requirements in adults and children during surgery. Several studies have evaluated TXA in adults with hemorrhagic trauma, but no randomized controlled trials have occurred in children with trauma. We propose a Bayesian adaptive clinical trial to investigate TXA in children with brain and/or torso hemorrhagic trauma.

METHODS/DESIGN

We designed a double-blind, Bayesian adaptive clinical trial that will enroll up to 2000 patients. We extend the traditional Emax dose-response model to incorporate a hierarchical structure so multiple doses of TXA can be evaluated in different injury populations (isolated head injury, isolated torso injury, or both head and torso injury). Up to 3 doses of TXA (15 mg/kg, 30 mg/kg, and 45 mg/kg bolus doses) will be compared to placebo. Equal allocation between placebo, 15 mg/kg, and 30 mg/kg will be used for an initial period within each injury group. Depending on the dose-response curve, the 45 mg/kg arm may open in an injury group if there is a trend towards increasing efficacy based on the observed relationship using the data from the lower doses. Response-adaptive randomization allows each injury group to differ in allocation proportions of TXA so an optimal dose can be identified for each injury group. Frequent interim stopping periods are included to evaluate efficacy and futility. The statistical design is evaluated through extensive simulations to determine the operating characteristics in several plausible scenarios. This trial achieves adequate power in each injury group.

DISCUSSION

This trial design evaluating TXA in pediatric hemorrhagic trauma allows for three separate injury populations to be analyzed and compared within a single study framework. Individual conclusions regarding optimal dosing of TXA can be made within each injury group. Identifying the optimal dose of TXA, if any, for various injury types in childhood may reduce death and disability.

Current Practices in Tranexamic Acid Administration for Pediatric Trauma Patients in the United States

BACKGROUND

Although controversial, early administration of tranexamic acid (TXA) has been shown to reduce mortality in adult patients with major trauma. Tranexamic acid has also been successfully used in elective pediatric surgery, with significant reduction in blood loss and transfusion requirements. There are limited data to guide its use in pediatric trauma patients. We sought to determine the current practices for TXA administration in pediatric trauma patients in the United States.

METHODS

A survey was conducted of all the American College of Surgeons-verified Level I and II trauma centers in the United States. The survey data underwent quantitative analysis.

RESULTS

Of the 363 Level I and II qualifying centers, we received responses from 220 for an overall response rate of 61%. Eighty of 99 verified pediatric trauma centers responded for a pediatric trauma center response rate of 81%. Of all responding centers, 148 (67%) reported they care for pediatric trauma patients, with an average of 513 pediatric trauma patients annually. The pediatric trauma centers report caring for an average of 650 pediatric trauma patients annually. Of all centers caring for pediatric trauma, 52 (35%) report using TXA, with the most common initial dosing being 15 mg/kg (68%). A follow-up infusion was utilized by 45 (87%) of the programs, most commonly dosed at 2 mg/kg/hr × 8 hr utilized by 24 centers (54%).

CONCLUSION

Although the clinical evidence for TXA in pediatric trauma patients is limited, we believe that consideration should be given for use in major trauma with hemodynamic instability or significant risk for ongoing hemorrhage. If available, resuscitation should be guided by thromboelastography to identify candidates who would most benefit from antithrombolytic administration. This represents a low-cost/low-risk and high-yield therapy for pediatric trauma patients.

Nebulized Tranexamic Acid for Pediatric Post-tonsillectomy Hemorrhage: A Report of Two Cases

INTRODUCTION

Tranexamic acid (TXA) use in pediatrics to control hemorrhage has gained interest in recent years, but there is limited literature on nebulized TXA especially regarding dosing and adverse effects. Tranexamic acid has anti-fibrinolytic properties via competitive inhibition of plasminogen activation making it a logical approach to promote hemostasis in cases of post-tonsillectomy hemorrhage.

CASE REPORT

We describe two cases of post-tonsillectomy hemorrhage managed with nebulized TXA. In both cases, bleeding was stopped after TXA administration.

CONCLUSION

To our knowledge, this is the first case report to describe the use of nebulized TXA without an adjunct pharmacotherapy. Our two cases add additional reportable data on the safety of nebulized TXA and possible effectiveness on post-tonsillectomy hemorrhage.

Drug Safety in Translational Paediatric Research: Practical Points to Consider for Paediatric Safety Profiling and Protocol Development: A Scoping Review

Translational paediatric drug development includes the exchange between basic, clinical and population-based research to improve the health of children. This includes the assessment of treatment related risks and their management. The objectives of this scoping review were to search and summarise the literature for practical guidance on how to establish a paediatric safety specification and its integration into a paediatric protocol. PubMed, Embase, Web of Science, and websites of regulatory authorities and learned societies were searched (up to 31 December 2020). Retrieved citations were screened and full texts reviewed where applicable. A total of 3480 publications were retrieved. No article was identified providing practical guidance. An introduction to the practical aspects of paediatric safety profiling and protocol development is provided by combining health authority and learned society guidelines with the specifics of paediatric research. The paediatric safety specification informs paediatric protocol development by, for example, highlighting the need for a pharmacokinetic study prior to a paediatric trial. It also informs safety related protocol sections such as exclusion criteria, safety monitoring and risk management. In conclusion, safety related protocol sections require an understanding of the paediatric safety specification. Safety data from carefully planned paediatric research provide valuable information for children, parents and healthcare providers.

Tranexamic acid in pediatric combat trauma requiring massive transfusions and mortality

BACKGROUND

Tranexamic acid (TXA) has been demonstrated to decrease mortality in adult trauma, particularly in those with massive transfusions needs sustained in combat injury. Limited data are available for the efficacy of TXA in pediatric trauma patients outside of a single combat support hospital in Afghanistan.

METHODS

The Department of Defense Trauma Registry was queried for trauma patients younger than 18 years from Iraq and Afghanistan requiring 40 mL/kg or greater of blood product within 24 hours of injury. Burns and fatal head traumas were excluded. Primary outcome was in-hospital mortality. Secondary outcomes were hospital, ventilator, and intensive care unit-free days, as well as total blood product volume.

RESULTS

Among those pediatric patients receiving massive transfusions, those who received TXA were less likely to die in hospital (8.5% vs. 18.3%). Patients who received TXA and those who did not have similar hospital-free days (19 vs. 20), ventilator-free days (27 vs. 27), and intensive care unit-free days (25 vs. 24). Those who received TXA had higher 24-hour blood product administration (100 mL/kg vs. 75 mL/kg). None of our results rose to the level of statistical significance. The TXA administration significantly reduced odds of death on logistic regression (odds ratio, 0.35; 95% confidence interval, 0.123-0.995; p = 0.0488).

CONCLUSION

Use of TXA in pediatric patients with combat trauma requiring massive transfusions trended toward a significant improvement in in-hospital mortality (p = 0.055). This mortality benefit is similar to that seen in adult studies and a less well characterized cohort in another pediatric study suggesting TXA administration confers mortality benefit in massively transfused pediatric combat trauma victims.

LEVEL OF EVIDENCE

Evidence (retrospective cohort), Level IV.

Tranexamic Acid Use in Pediatric Hemorrhagic Shock From Farm-Related Trauma: A Case Report

This case describes the use of tranexamic acid as an adjunctive treatment in the management of a pediatric patient in hemorrhagic shock. The case also highlights other components of current best practices for hemorrhagic shock in children, including bleeding source control and prompt resuscitation with blood products. A 20-month old male suffered an agricultural accident with significant injury to the right upper extremity. This led to subsequent extremity hemorrhage and clinical evidence of hemorrhagic shock. As a result of interventions performed by emergency medical services as well as the helicopter emergency medical services team, including the application of a tourniquet, prehospital blood product administration, and tranexamic acid administration, the patient had hemodynamically stabilized by arrival at the level 1 pediatric trauma center and was neurologically intact when discharged from the hospital.

Cerebrovascular Complications of Pediatric Blunt Trauma

Ischemic and hemorrhagic stroke can occur in the setting of pediatric trauma, particularly those with head or neck injuries. The risk of stroke appears highest within the first two weeks after trauma. Stroke diagnosis may be challenging due to lack of awareness or concurrent injuries limiting detailed neurological assessment. Other injuries may also complicate stroke management, with competing priorities for blood pressure, ventilator management, or antithrombotic timing. Here we review epidemiology, clinical presentation, and diagnostic approach to blunt arterial injuries including dissection, cerebral sinovenous thrombosis, mineralizing angiopathy, stroke from abusive head trauma, and traumatic hemorrhagic stroke. Owing to the complexities and heterogeneity of concomitant injuries in stroke related to trauma, a single pathway for stroke management is impractical. Therefore providers must understand the goals and possible costs or consequences of stroke management decisions to individualize patient care. We discuss the physiological principles of cerebral perfusion and oxygen delivery, considerations for ventilator strategy when stroke and lung injury are present, and current available evidence of the risks and benefits of anticoagulation to provide a framework for multidisciplinary discussions of cerebrovascular injury management in pediatric patients with trauma.

The European guideline on management of major bleeding and coagulopathy following trauma: fifth edition

BACKGROUND

Severe traumatic injury continues to present challenges to healthcare systems around the world, and post-traumatic bleeding remains a leading cause of potentially preventable death among injured patients. Now in its fifth edition, this document aims to provide guidance on the management of major bleeding and coagulopathy following traumatic injury and encourages adaptation of the guiding principles described here to individual institutional circumstances and resources.

METHODS

The pan-European, multidisciplinary Task Force for Advanced Bleeding Care in Trauma was founded in 2004, and the current author group included representatives of six relevant European professional societies. The group applied a structured, evidence-based consensus approach to address scientific queries that served as the basis for each recommendation and supporting rationale. Expert opinion and current clinical practice were also considered, particularly in areas in which randomised clinical trials have not or cannot be performed. Existing recommendations were re-examined and revised based on scientific evidence that has emerged since the previous edition and observed shifts in clinical practice. New recommendations were formulated to reflect current clinical concerns and areas in which new research data have been generated.

RESULTS

Advances in our understanding of the pathophysiology of post-traumatic coagulopathy have supported improved management strategies, including evidence that early, individualised goal-directed treatment improves the outcome of severely injured patients. The overall organisation of the current guideline has been designed to reflect the clinical decision-making process along the patient pathway in an approximate temporal sequence. Recommendations are grouped behind the rationale for key decision points, which are patient- or problem-oriented rather than related to specific treatment modalities. While these recommendations provide guidance for the diagnosis and treatment of major bleeding and coagulopathy, emerging evidence supports the author group's belief that the greatest outcome improvement can be achieved through education and the establishment of and adherence to local clinical management algorithms.

CONCLUSIONS

A multidisciplinary approach and adherence to evidence-based guidance are key to improving patient outcomes. If incorporated into local practice, these clinical practice guidelines have the potential to ensure a uniform standard of care across Europe and beyond and better outcomes for the severely bleeding trauma patient.