Prehospital Tranexamic Acid and First 24-Hour Blood Product Transfusion in Patients with Isolated Traumatic Brain Injury.

Background: Tranexamic acid (TXA) is an antifibrinolytic drug known to reduce mortality in bleeding trauma patients, yet the evidence of TXAs impact on blood product use within this population is conflicting. In patients with traumatic brain injury (TBI), the impact of TXA on transfusion remains unclear.

Study design: This is a secondary analysis of the prehospital TXA for TBI trial that enrolled patients in the prehospital setting with a Glasgow Coma Scale score of 3 to 12 and not in shock (systolic blood pressure < 90 mmHg) before enrollment within 2 hours of injury. Subjects with isolated TBI (iTBI; Abbreviated Injury Scale Head score 3 or greater and Abbreviated Injury Scale 2 or less in any other category) were included. Factors associated with transfusion were characterized using logistic regression.

Results: Of 966 patients enrolled in the primary trial, 306 subjects met the definition of iTBI and were included (101 in the 2-g prehospital TXA bolus arm, 97 in the 1-g prehospital TXA bolus or 1-g in-hospital TXA infusion arm, and 108 in the placebo arm). In multivariable regression analysis, receipt of a 1-g TXA bolus or 1-g TXA infusion (odds ratio 0.27, p = 0.03) and receipt of TXA after combining TXA treatment arms (odds ratio 0.32, p = 0.02) were associated with decreased odds of red cell transfusion.

Conclusions: In subjects with iTBI, prehospital TXA may be associated with lower odds of red cell transfusion compared with placebo. This effect was likely mediated by treatment group imbalances in the percentage of subjects with a penetrating mechanism of injury, as well as the need for emergent neurosurgical intervention.