The Lancet 2019: October 14. DOI:https://doi.org/10.1016/S0140-6736(19)32233-0
Aim of Study
Assess the effects of tranexamic acid in patients with traumatic brain injury (TBI).
Design and Location
Randomised, placebo-controlled trial was done in 175 hospitals in 29 countries.
Adults with TBI who were within 3 h of injury, had a Glasgow Coma Scale (GCS) score of 12 or lower or any intracranial bleeding on CT scan, and no major extracranial bleeding were eligible.
The time-window for eligibility was originally 8 h but in 2016 the protocol was changed to limit recruitment to patients within 3 h of injury. They randomly assigned (1:1) patients to receive tranexamic acid (loading dose 1 g over 10 min then infusion of 1 g over 8 h) or matching placebo.
Head injury-related death in hospital within 28 days of injury in patients randomly assigned within 3 h of injury.
Early head injury-related death (within 24 h after injury), all-cause and cause-specific mortality, disability, vascular occlusive events (myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism), seizures, complications, neurosurgery, days in intensive care unit, and adverse events within 28 days of randomization.
All analyses were on an intention-to-treat basis. For each binary outcome, they calculated RRs and 95% CIs.
The effects of tranexamic acid on the primary outcome were stratified by three baseline characteristics: severity of head injury, time to treatment, and age. Severity of head injury was assessed using the baseline GCS score.
Effect of severity was assessed in a regression analysis that included continuous terms for GCS and its square.
Effect of treatment on time was assessed in a subgroup analysis of the effect of tranexamic acid according to the estimated time interval between injury and treatment (≤1, >1 to ≤3, >3 h). Variables were controlled in a multivariable model.
Lastly they examined the effect of tranexamic acid on head injury-related death stratified by age. For subgroup analyses, they reported p-values for the test for heterogeneity.
Reduction in the risk of head injury-related death with tranexamic acid in patients with mild-to-moderate head injury (RR 0·78 [95% CI 0·64–0·95]).
Early treatment was more effective than later treatment in patients with mild and moderate head injury (p=0·005).
The RR of head injury-related death was 0·81 (95% CI 0·69–0·95) within 24 h.
The prevalence of disability among survivors was similar between groups.
The risk of vascular occlusive events and other complications was similar in the tranexamic acid and placebo groups.
This trial provides evidence that the administration of tranexamic acid to patients with TBI within 3 h of injury reduces head injury-related death, with no evidence of adverse effects or complications.
Stated Limitations from the Study
- Underestimated risk of venous thromboembolism
- Patients with unilateral non reactive pupils were not excluded
- Wide confidence intervals
- Narrowing down the group to get significant benefit
- Haemodynamically stable patients
Discussion from Journal Club Meeting (?Change of Practice)
The point of the study is that the administration of the tranexamic acid in TBI is safe as it does not cause any significant adverse effects, especially thromboembolytic events.
Summary by Dr L Mumelj. Journal Club Meeting 24 October 2019.