The role of tranexamic acid in traumatic brain injury

Evidence from recent trials evaluating efficacy of antifibrinolytic agents in the context of traumatic brain injury may lead to changes in the management of patients with traumatic brain injury. Tranexamic acid (TXA) reduces the proteolytic action of plasmin on fibrin clots, resulting in an inhibition of fibrinolysis and stabilisation of established blood clots. There has been significant interest in use of the drug as a therapeutic agent in the context of severe haemorrhage; however, considerable controversies regarding its efficacy remain. A number of trials have demonstrated a small but significant decrease in mortality following its administration, but the results have been somewhat inconsistent and may not be generalisable. The results of the CRASH-3 trial were that there was no statistical difference in the number of traumatic brain injury related deaths (18.5% with TXA and 19.8% with placebo; relative risk [RR] 0·94; 95% confidence interval [CI] 0·86-1·02). Nonetheless, there was a subgroup of patients for whom TXA appeared to provide benefit, and this was in patients with mild and moderate injury (with a Glasgow Coma Score > 8). This is potentially a very important finding that may have huge potential implications; however, we believe it does not currently provide indisputable evidence to support the administration of TXA to all patients with TBI. Further work is required to better define the subset of patients who may benefit as well as to evaluate the long-term functional benefit in order to determine which types of severe traumatic brain injury patients would derive more benefits than harms from TXA.