Sterility of Tranexamic Acid Syringes Prefilled by Tactical Combat Medics in a Garrison Setting

Tranexamic acid (TXA) is an antifibrinolytic agent that confers a significant mortality benefit in the treatment of hemorrhagic trauma. The benefit of TXA is timedependent; Special Operations Tactical Medics (SOTM) and Special Operations Independent Duty Corpsmen (SOIDC) commonly prefill TXA syringes prior to a mission. However, the sterility of prefilled TXA syringes remains unclear.

SOTMs (n=40) and SOIDCs (n=11) each filled two syringes with TXA in a garrison-type training setting using their customary preparation technique. As controls, a trained clinical research coordinator (CRC) filled 51 TXA syringes in the garrison setting and 51 in a Level-II Biosafety Lab (n=204 syringes total). In all cases, TXA was drawn from a glass vial into a 10cc syringe. TXA syringes were stored at room temperature, plated on chocolate agar at 0-, 3-, 6-, and 9-day intervals from collection (n=816 plates total), incubated for 7 days, then observed for bacterial growth.

The observed positivity rate of 0.6% (5 of 816 plates) was statistically similar to the published false positive rate of 0.5% for chocolate agar (P=.68). Positivity rates did not significantly differ by garrison setting versus lab setting (P=.20), SOTM/SOIDC versus CRC (P=.18), or day of testing (P=.26). One TXA syringe demonstrated contamination on Day 9.

Present findings suggest that TXA syringes prepared in a simulated operational environment can maintain sterility up to 6 days when stored at room temperature. These results directly inform the Committee on Tactical Combat Casualty Care (CoTCCC) regarding the safe storage duration of prefilled TXA syringes.