J Spec Oper Med. Spring 2018;18(1):62-68.

# Intramuscular tranexamic acid in tactical and combat settings.

Vu EN, Wan WCY, Yeung TC, Callaway DW.

BACKGROUND: Uncontrolled hemorrhage remains a leading cause of preventable death in tactical and combat settings. Alternate routes of delivery of tranexamic acid (TXA), an adjunct in the management of hemorrhagic shock, are being studied. A working group for the Committee for Tactical Emergency Casualty Care reviewed the available evidence on the potential role for intramuscular (IM) administration of TXA in nonhospital settings as soon as possible from the point of injury.

METHODS: EMBASE and MEDLINE/PubMed databases were sequentially searched by medical librarians for evidence of TXA use in the following contexts and/or using the following keywords: prehospital, trauma, hemorrhagic shock, optimal timing, optimal dose, safe volume, incidence of venous thromboembolism (VTE), IM bioavailability.

RESULTS: A total of 183 studies were reviewed. The strength of the available data was variable, generally weak in quality, and included laboratory research, case reports, retrospective observational reviews, and few prospective studies. Current volume and concentrations of available formulations of TXA make it, in theory, amenable to IM injection. Current best practice guidelines for large-volume injection (i.e., 5mL) support IM administration in four locations in the adult human body. One case series suggests complete bioavailability of IM TXA in healthy patients. Data are lacking on the efficacy and safety of IM TXA in hemorrhagic shock.

CONCLUSION: There is currently insufficient evidence to support a strong recommendation for or against IM administration of TXA in the combat setting; however, there is an abundance of literature demonstrating efficacy and safety of TXA use in a broad range of patient populations. Balancing the available data and risk- benefit ratio, IM TXA should be considered a viable treatment option for tactical and combat applications. Additional studies should focus on the optimal dose and bioavailability of IM dosing of patients in hemorrhagic shock, with assessment of potential downstream sequelae.