Cost-effectiveness analysis of tranexamic acid for the treatment of traumatic brain injury, based on the results of the CRASH-3 randomised trial: a decision modelling approach

The management of severe traumatic brain injury in the initial postinjury hours - current evidence and controversies

PURPOSE OF REVIEW

To provide an overview of recent studies discussing novel strategies, controversies, and challenges in the management of severe traumatic brain injury (sTBI) in the initial postinjury hours.

RECENT FINDINGS

Prehospital management of sTBI should adhere to Advanced Trauma Life Support (ATLS) principles. Maintaining oxygen saturation and blood pressure within target ranges on-scene by anesthetist, emergency physician or trained paramedics has resulted in improved outcomes. Emergency department (ED) management prioritizes airway control, stable blood pressure, spinal immobilization, and correction of impaired coagulation. Noninvasive techniques such as optic nerve sheath diameter measurement, pupillometry, and transcranial Doppler may aid in detecting intracranial hypertension. Osmotherapy and hyperventilation are effective as temporary measures to reduce intracranial pressure (ICP). Emergent computed tomography (CT) findings guide surgical interventions such as decompressive craniectomy, or evacuation of mass lesions. There are no neuroprotective drugs with proven clinical benefit, and steroids and hypothermia cannot be recommended due to adverse effects in randomized controlled trials.

SUMMARY

Advancement of the prehospital and ED care that include stabilization of physiological parameters, rapid correction of impaired coagulation, noninvasive techniques to identify raised ICP, emergent surgical evacuation of mass lesions and/or decompressive craniectomy, and temporary measures to counteract increased ICP play pivotal roles in the initial management of sTBI. Individualized approaches considering the underlying pathology are crucial for accurate outcome prediction.

Guidelines for Prehospital Management of Traumatic Brain Injury 3rd Edition: Executive Summary

Prehospital care markedly influences outcome from traumatic brain injury, yet it remains highly variable. The Brain Trauma Foundation's guidelines informing prehospital care, first published in 2002, have sought to identify and disseminate best practices. Many of its recommendations relate to the management of airway, breathing and circulation, and infrastructure for this care. Compliance with the second edition of these guidelines has been associated with significantly improved survival. A working group developed evidence-based recommendations informing assessment, treatment, and transport decision-making relevant to the prehospital care of brain injured patients. A literature search spanning May 2005 to January 2022 supplemented data contained in the 2nd edition. Identified studies were assessed for quality and used to inform evidence-based recommendations. A total of 122 published articles formed the evidentiary base for this guideline update including 5 providing Class I evidence, 35 providing Class II evidence, and 98 providing Class III evidence for the various topics. Forty evidence-based recommendations were generated, 30 of which were strong and 10 of which were weak. In many cases, new evidence allowed guidelines from the 2nd edition to be strengthened. Development of guidelines on some new topics was possible including the prehospital administration of tranexamic acid. A management algorithm is also presented. These guidelines help to identify best practices for prehospital traumatic brain injury care, and they also identify gaps in knowledge which we hope will be addressed before the next edition.

Therapeutic review: The role of tranexamic acid in management of traumatic brain injury, nontraumatic intracranial hemorrhage, and aneurysmal subarachnoid hemorrhage

PURPOSE

To summarize current literature evaluating tranexamic acid in the management of intracranial bleeding associated with traumatic and nontraumatic brain injuries and implications for clinical practice.

SUMMARY

Intracranial hemorrhage, regardless of etiology, is associated with high morbidity and mortality. Tranexamic acid is an antifibrinolytic with anti-inflammatory properties shown to reduce mortality in trauma patients with extracranial injuries. In traumatic brain injury, a large randomized trial found no difference in outcomes when tranexamic acid was compared to placebo; however, subgroup analyses suggested that it may reduce head injury-related mortality in the context of mild-to-moderate injury if treatment occurs within 1 hour of symptom onset. More recent out-of-hospital data have disputed these findings and even suggested harm in severely injured patients. In spontaneous, nontraumatic intracranial hemorrhage, treatment with tranexamic acid did not result in a difference in functional status; however, rates of hematoma expansion, even though modest, were significantly reduced. In aneurysmal subarachnoid hemorrhage, tranexamic acid may prevent rebleeding, but has not led to improved outcomes or reduced mortality, and there is concern for increased incidence of delayed cerebral ischemia. Overall, tranexamic acid has not been shown to result in increased risk of thromboembolic complications across these classes of brain injury.

CONCLUSION

Despite its favorable safety profile overall, tranexamic acid does not seem to improve functional outcomes and cannot be routinely recommended. More data are needed to determine which head injury subpopulations are most likely to benefit from tranexamic acid and which patients are at increased risk for harm.

Tranexamic acid as a novel adjunct in the management of vessel perforation complicating Endovascular Clot Retrieval

AIM

To assess the safety and utility of tranexamic acid (TXA) as an adjunct salvage therapy in iatrogenic vessel perforation complicating endovascular clot retrieval. Iatrogenic vessel perforation and extravasation are known and potentially fatal complications of endovascular clot retrieval (ECR). Various methods of establishing haemostasis post perforation have been reported. TXA is widely utilised intraoperatively to reduce bleeding in various surgical specialities. The use of TXA in endovascular procedures has not been previously described in the literature.

METHODS

Retrospective case control study of all cases that underwent ECR. Cases where arterial rupture occurred were identified. Details of management and functional status at 3 months were recorded. Modified Rankin score (mRS) 0-2 was considered a good functional outcome. Comparison of proportions analysis was performed.

RESULTS

Of 1378 cases of ECR, rupture complicated 36 (2.6%). TXA was administered in addition to standard care in 11 cases (31%). At 3 months, 4 of 11 cases (36%) where TXA was administered had a good functional outcome compared to 3 of 22 (12%) in the standard care group (P=0.09). Mortality at 3 months occurred in 4 of 11 cases (41.7%) where TXA was administered compared to 16 of 25 (64%) where it was not (P=0.13).

CONCLUSION

Tranexamic acid administration in iatrogenic vessel rupture was associated with a lower mortality rate and a larger proportion of patients achieving a good functional outcome at 3 months. This effect trended towards but was not statistically significant. TXA administration was not associated with adverse effects.

Satureja khuzistanica Jamzad essential oil and pure carvacrol attenuate TBI-induced inflammation and apoptosis via NF-κB and caspase-3 regulation in the male rat brain

Traumatic brain injury (TBI) causes progressive dysfunction that induces biochemical and metabolic changes that lead to cell death. Nevertheless, there is no definitive FDA-approved therapy for TBI treatment. Our previous immunohistochemical results indicated that the cost-effective natural Iranian medicine, Satureja khuzistanica Jamzad essential oil (SKEO), which consists of 94.16% carvacrol (CAR), has beneficial effects such as reducing neuronal death and inflammatory markers, as well as activating astrocytes and improving neurological outcomes. However, the molecular mechanisms of these neuroprotective effects have not yet been elucidated. This study investigated the possible mechanisms involved in the anti-inflammatory and anti-apoptotic properties of SKEO and CAR after TBI induction. Eighty-four male Wistar rats were randomly divided into six groups: Sham, TBI, TBI + Vehicle, TBI + CAR (100 and 200 mg/kg), and TBI + SKEO (200 mg/kg) groups. After establishing the "Marmarou" weight drop model, diffuse TBI was induced in the rat brain. Thirty minutes after TBI induction, SKEO & CAR were intraperitoneally injected. One day after TBI, injured rats exhibited significant brain edema, neurobehavioral dysfunctions, and neuronal apoptosis. Western blot results revealed upregulation of the levels of cleaved caspase-3, NFκB p65, and Bax/Bcl-2 ratio, which was attenuated by CAR and SKEO (200 mg/kg). Furthermore, the ELISA results showed that CAR treatment markedly prevents the overproduction of the brain pro-inflammatory cytokines, including IL-1β, TNF-α, and IL-6. Moreover, the neuron-specific enolase (NSE) immunohistochemistry results revealed the protective effect of CAR and SKEO on post-TBI neuronal death. The current study revealed that the possible neuroprotective mechanisms of SKEO and CAR might be related to (at least in part) modulating NF-κB regulated inflammation and caspase-3 protein expression. It also suggested that CAR exerts more potent protective effects than SKEO against TBI. Nevertheless, the administration of SKEO and CAR may express a novel therapeutic approach to ameliorate TBI-related secondary phase neuropathological outcomes.

Monetised estimated quality-adjusted life year (QALY) losses for non-fatal injuries

BACKGROUND

Quality-adjusted life years (QALYs) provide a means to compare injuries using a common measurement which allows quality of life and duration of life from an injury to be considered. A more comprehensive picture of the economic losses associated with injuries can be found when QALY estimates are combined with medical and work loss costs. This study provides estimates of QALY loss.

METHODS

QALY loss estimates were assigned to records in the 2018 National Electronic Injury Surveillance System - All Injury Program. QALY estimates by body region and nature of injury were assigned using a combination of previous research methods. Injuries were rated on six dimensions, which identify a set of discrete qualitative impairments. Additionally, a seventh dimension, work-related disability, was included. QALY loss estimates were produced by intent and mechanism, for all emergency department-treated cases, by two disposition groups.

RESULTS

Lifetime QALY losses ranged from 0.0004 to 0.388 for treated and released injuries, and from 0.031 to 3.905 for hospitalised injuries. The 1-year monetary value of QALY losses ranged from $136 to $437 000 among both treated and released and hospitalised injuries. The lifetime monetary value of QALY losses for hospitalised injuries ranged from $16 000 to $2.1 million.

CONCLUSIONS

These estimates provide information to improve knowledge about the comprehensive economic burden of injuries; direct cost elements that can be measured through financial transactions do not capture the full cost of an injury. Comprehensive assessment of the long-term cost of injuries, including quality of life losses, is critical to accurately estimate the economic burden of injuries.

Effects of tranexamic acid treatment in severely and non-severely injured trauma patients

BACKGROUND

Urgent treatment with tranexamic acid (TXA) reduces bleeding deaths but there is disagreement about which patients should be treated. We examine the effects of TXA treatment in severely and non-severely injured trauma patients.

STUDY DESIGN AND METHODS

We did an individual patient data meta-analysis of randomized trials with over 1000 trauma patients that assessed the effects of TXA on survival. We defined the severity of injury according to characteristics at first assessment: systolic blood pressure of less than 90 mm Hg and a heart rate greater than 120 beats per minute or Glasgow Coma Scale score of less than nine or any GCS with one or more fixed dilated pupils. The primary measure was survival on the day of the injury. We examined the effect of TXA on survival in severely and non-severely injured patients and how these effects vary with the time from injury to treatment.

RESULTS

We obtained data for 32,944 patients from two randomized trials. Tranexamic acid significantly increased survival on the day of the injury (OR = 1.22, 95% CI 1.11-1.34; p < .01). The effect of tranexamic acid on survival in non-severely injured patients (OR = 1.25, 1.03-1.50) was similar to that in severely injured patients (OR = 1.22, 1.09-1.37) with no significant heterogeneity (p = .87). In severely and non-severely injured pateints, treatment within the first hour after injury was the most effective.

DISCUSSION

Early tranexamic acid treatment improves survival in both severely and non-severely injured trauma patients. Its use should not be restricted to the severely injured.

A cost-effectiveness and value of information analysis to inform future research of tranexamic acid for older adults experiencing mild traumatic brain injury

BACKGROUND

Tranexamic acid reduces head injury deaths in patients with CT scan evidence of intracranial bleeding after mild traumatic brain injury (TBI). However, the cost-effectiveness of tranexamic acid for people with mild TBI in the pre-hospital setting, prior to CT scanning, is uncertain. A large randomised controlled trial (CRASH-4) is planned to address this issue, but the economic justification for it has not been established. The aim of the analysis was to estimate the likelihood of tranexamic acid being cost-effective given current evidence, the treatment effects required for cost-effectiveness, and the expected value of performing further research.

METHODS

An early economic decision model compared usual care for mild TBI with and without tranexamic acid, for adults aged 70 and above. The evaluation was performed from a UK healthcare perspective over a lifetime time horizon, with costs reported in 2020 pounds (GBP) and outcomes reported as quality-adjusted life years (QALYs). All analyses used a £20,000 per QALY cost-effectiveness threshold.

RESULTS

In the base case analysis, tranexamic acid was associated with an incremental cost-effectiveness ratio of £4885 per QALY gained, but the likelihood of it being cost-effective was highly dependent on the all-cause mortality treatment effect. The value of perfect information was £22.4 million, and the value of perfect information for parameters that could be collected in a trial was £21.9 million. The all-cause mortality risk ratio for tranexamic acid and the functional outcomes following TBI had the most impact on cost-effectiveness.

CONCLUSIONS

There is a high degree of uncertainty in the cost-effectiveness of tranexamic acid for older adults experiencing mild TBI, meaning there is a high value of performing future research in the UK. The value in a global context is likely to be far higher.

Global emergency medicine: A scoping review of the literature from 2020

OBJECTIVE

The objective was to identify, screen, highlight, review, and summarize some of the most rigorously conducted and impactful original research (OR) and review articles (RE) in global emergency medicine (EM) published in 2020 in the peer-reviewed and gray literature.

METHODS

A broad systematic search of peer-reviewed publications related to global EM indexed on PubMed and in the gray literature was conducted. The titles and abstracts of the articles on this list were screened by members of the Global Emergency Medicine Literature Review (GEMLR) Group to identify those that met our criteria of OR or RE in the domains of disaster and humanitarian response (DHR), emergency care in resource-limited settings (ECRLS), and EM development. Those articles that met these screening criteria were then scored using one of three scoring templates appropriate to the article type. Those articles that scored in the top 5% then underwent in-depth narrative summarization.

RESULTS

The 2020 GEMLR search initially identified 35,970 articles, more than 50% more than last year's search. From these, 364 were scored based on their full text. Nearly three-fourths of the scored articles constituted OR, of which nearly three-fourths employed quantitative research methods. Nearly 10% of the articles identified this year were directly related to COVID-19. Research involving ECRLS again constituted most of the articles in this year's review, accounting for more than 60% of the literature scored. A total of 20 articles underwent in-depth narrative critiques.

CONCLUSIONS

The number of studies relevant to global EM identified by our search was very similar to that of last year. Revisions to our methodology to identify a broader range of research were successful in identifying more qualitative research and studies related to DHR. The number of COVID-19-related articles is likely to continue to increase in subsequent years.

A high-dose 24-hour tranexamic acid infusion for the treatment of significant gastrointestinal bleeding: HALT-IT RCT

BACKGROUND

Tranexamic acid reduces blood loss in surgery and the risk of death in trauma patients. Meta-analyses of small trials suggest that tranexamic acid decreases the number of deaths from gastrointestinal bleeding, but these meta-analyses are prone to selection bias.

OBJECTIVE

The trial provides reliable evidence of the effect of tranexamic acid on mortality, rebleeding and complications in significant acute gastrointestinal bleeding.

DESIGN

A multicentre, randomised, placebo-controlled trial and economic analysis. Patients were assigned by selecting one treatment pack from a box of eight, which were identical apart from the pack number. Patients, caregivers and outcome assessors were masked to allocation. The main analyses were by intention to treat.

SETTING

The setting was 164 hospitals in 15 countries, co-ordinated from the London School of Hygiene & Tropical Medicine.

PARTICIPANTS

Adults with significant upper or lower gastrointestinal bleeding (n = 12,009) were eligible if the responsible clinician was substantially uncertain about whether or not to use tranexamic acid. The clinical diagnosis of significant bleeding implied a risk of bleeding to death, including hypotension, tachycardia or signs of shock, or urgent transfusion, endoscopy or surgery.

INTERVENTION

Tranexamic acid (a 1-g loading dose over 10 minutes, then a 3-g maintenance dose over 24 hours) or matching placebo.

MAIN OUTCOME MEASURES

The primary outcome was death due to bleeding within 5 days of randomisation. Secondary outcomes were all-cause and cause-specific mortality; rebleeding; need for endoscopy, surgery or radiological intervention; blood product transfusion; complications; disability; and days spent in intensive care or a high-dependency unit.

RESULTS

A total of 12,009 patients were allocated to receive tranexamic acid (n = 5994, 49.9%) or the matching placebo (n = 6015, 50.1%), of whom 11,952 (99.5%) received the first dose. Death due to bleeding within 5 days of randomisation occurred in 222 (3.7%) patients in the tranexamic acid group and in 226 (3.8%) patients in the placebo group (risk ratio 0.99, 95% confidence interval 0.82 to 1.18). Thromboembolic events occurred in 86 (1.4%) patients in the tranexamic acid group and 72 (1.2%) patients in the placebo group (risk ratio 1.20, 95% confidence interval 0.88 to 1.64). The risk of arterial thromboembolic events (myocardial infarction or stroke) was similar in both groups (0.7% in the tranexamic acid group vs. 0.8% in the placebo group; risk ratio 0.92, 95% confidence interval 0.60 to 1.39), but the risk of venous thromboembolic events (deep-vein thrombosis or pulmonary embolism) was higher in tranexamic acid-treated patients than in placebo-treated patients (0.8% vs. 0.4%; risk ratio 1.85, 95% confidence interval 1.15 to 2.98). Seizures occurred in 38 patients who received tranexamic acid and in 22 patients who received placebo (0.6% vs. 0.4%, respectively; risk ratio 1.73, 95% confidence interval 1.03 to 2.93). In the base-case economic analysis, tranexamic acid was not cost-effective and resulted in slightly poorer health outcomes than no tranexamic acid.

CONCLUSIONS

Tranexamic acid did not reduce death from gastrointestinal bleeding and, although inexpensive, it is not cost-effective in adults with acute gastrointestinal bleeding.

FUTURE WORK

These results caution against a uniform approach to the management of patients with major haemorrhage and highlight the need for randomised trials targeted at specific pathophysiological processes.

LIMITATIONS

Although this is one of the largest randomised trials in gastrointestinal bleeding, we cannot rule out a modest increase or decrease in death due to bleeding with tranexamic acid.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN11225767, ClinicalTrials.gov NCT01658124 and EudraCT 2012-003192-19.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 58. See the NIHR Journals Library website for further project information.

Tranexamic acid to reduce head injury death in people with traumatic brain injury: the CRASH-3 international RCT

BACKGROUND

Tranexamic acid safely reduces mortality in traumatic extracranial bleeding. Intracranial bleeding is common after traumatic brain injury and can cause brain herniation and death. We assessed the effects of tranexamic acid in traumatic brain injury patients.

OBJECTIVE

To assess the effects of tranexamic acid on death, disability and vascular occlusive events in traumatic brain injury patients. We also assessed cost-effectiveness.

DESIGN

Randomised trial and economic evaluation. Patients were assigned by selecting a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients, caregivers and those assessing outcomes were masked to allocation. All analyses were by intention to treat. We assessed the cost-effectiveness of tranexamic acid versus no treatment from a UK NHS perspective using the trial results and a Markov model.

SETTING

175 hospitals in 29 countries.

PARTICIPANTS

Adults with traumatic brain injury within 3 hours of injury with a Glasgow Coma Scale score of ≤ 12 or any intracranial bleeding on computerised tomography scan, and no major extracranial bleeding, were eligible.

INTERVENTION

Tranexamic acid (loading dose 1 g over 10 minutes then infusion of 1 g over 8 hours) or matching placebo.

MAIN OUTCOME MEASURES

Head injury death in hospital within 28 days of injury in patients treated within 3 hours of injury. Secondary outcomes were early head injury deaths, all-cause and cause-specific mortality, disability, vascular occlusive events, seizures, complications and adverse events.

RESULTS

Among patients treated within 3 hours of injury (n = 9127), the risk of head injury death was 18.5% in the tranexamic acid group versus 19.8% in the placebo group (855/4613 vs. 892/4514; risk ratio 0.94, 95% confidence interval 0.86 to 1.02). In a prespecified analysis excluding patients with a Glasgow Coma Scale score of 3 or bilateral unreactive pupils at baseline, the results were 12.5% in the tranexamic acid group versus 14.0% in the placebo group (485/3880 vs. 525/3757; risk ratio 0.89, 95% confidence interval 0.80 to 1.00). There was a reduction in the risk of head injury death with tranexamic acid in those with mild to moderate head injury (166/2846 vs. 207/2769; risk ratio 0.78, 95% confidence interval 0.64 to 0.95), but in those with severe head injury (689/1739 vs. 685/1710; risk ratio 0.99, 95% confidence interval 0.91 to 1.07) there was no apparent reduction (p-value for heterogeneity = 0.030). Early treatment was more effective in mild and moderate head injury (p = 0.005), but there was no obvious impact of time to treatment in cases of severe head injury (p = 0.73). The risk of disability, vascular occlusive events and seizures was similar in both groups. Tranexamic acid is highly cost-effective for mild and moderate traumatic brain injury (base case of £4288 per quality-adjusted life-year gained).

CONCLUSION

Early tranexamic acid treatment reduces head injury deaths. Treatment is cost-effective for patients with mild or moderate traumatic brain injury, or those with both pupils reactive.

FUTURE WORK

Further trials should examine early tranexamic acid treatment in mild head injury. Research on alternative routes of administration is needed.

LIMITATIONS

Time to treatment may have been underestimated.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN15088122, ClinicalTrials.gov NCT01402882, EudraCT 2011-003669-14, Pan African Clinical Trial Registry PACTR20121000441277.

FUNDING

The project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 26. See the NIHR Journals Library website for further project information. In addition, funding was provided by JP Moulton Charitable Trust, Joint Global Health Trials (Medical Research Council, Department for International Development and the Wellcome Trust). This project was funded by the NIHR Global Health Trials programme.