J Trauma Acute Care Surg. 2019 Mar 22;Epub ahead of print]

# Tranexamic Acid (TXA) Administration Following Head Trauma in a Combat Setting: Does TXA Result in Improved Neurologic Outcomes?

Morte D, Lammers D, Bingham J, Kuckelman J, Eckert M, Martin M

BACKGROUND: Tranexamic acid (TXA) has been shown to decrease mortality and blood product requirements in severely injured patients. TXA has also been hypothesized to prevent secondary brain injury in patients with TBI. While prior studies have demonstrated improved neurologic outcomes associated with TXA administration in severely injured pediatric patients, no such studies have been performed in adults.

METHODS: A retrospective review of all adult trauma admissions to North Atlantic Treaty Organization hospitals in Iraq and Afghanistan between 2008-2015. Univariate and multivariate analysis was used to identify factors associated with TXA administration. Patients without a documented head abbreviated injury scale (AIS) were excluded. Patients were propensity matched based on demographics, mechanism of injury, injury scores (AIS/ISS), presenting Glasgow Coma Score (GCS), initial vitals/labs, and initial transfusion requirement. Primary outcomes were in-hospital mortality and neurologic outcomes measured by discharge GCS scores. Secondary outcomes were respiratory failure and rates of thromboembolic events.

RESULTS: 4476 injured patients 18 years or older were evaluated. 265 (5.9%) of these patients required a massive transfusion in the first 24 hours and 174 (3.9%) received TXA. TXA patients had significantly higher ISS, more penetrating injuries, lower presenting GCS, higher incidence of severe head injury (AIS>3), and higher transfusion requirements. 92 patients were included in the propensity matched cohort. Of these, patients who received TXA had significantly lower mortality rate (0% vs 10.1%, p=0.02) and improvement of GCS to 14-15 irrespective of admission GCS compared to patients who did not receive TXA (100% vs 87%, p=0.01). There were no significant differences in number of thromboembolic events recorded between the two groups.

CONCLUSIONS: TXA administration in adult combat trauma patients was independently associated with decreased mortality and improved neurologic outcomes, with no increase in thromboembolic events. Further study of the possible mechanisms and effect of TXA on brain injury and neurologic outcomes is warranted.

LEVEL OF EVIDENCE: Level IV; Therapeutic.