While EMS use of tourniquets and hemostatic dressings have proven effective at increasing survival from trauma, some forms of traumatic hemorrhage shock continue to prove decidedly deadly. Brisk internal hemorrhage from penetrating and blunt trauma can’t always be easily addressed with these solutions. But an old chemical might just make a difference.
That chemical is tranexamic acid (TXA). It won’t replace the ongoing importance of timely, organized on-scene trauma care, in conjunction with rapid, safe transport to an appropriate trauma care destination, but two recent landmark studies are cause for great optimism.
Both studies clearly center on the use of TXA for traumatic hemorrhagic shock. TXA is classified as an “anti-fibrinolytic,” or a clot stabilizer. You can think of it as working in the opposite direction from how thrombolytics work for myocardial infarctions or strokes. Although TXA has existed for decades—being used in cardiovascular surgery, treatment of hemophilia and treatment of difficult uterine bleeding—it is still relatively new in the approach to hemodynamic instability from trauma.
The Clinical Randomization of an Antifibrinolytic in Significant Hemorrhage 2 (CRASH-2) study is the larger of the two studies that deserve our attention. CRASH-2 involved over 20,000 patients across multiple countries—though not the United States. The end result was that in the setting of trauma with significant bleeding—or at great risk for serious bleeding—with tachycardia and hypotension, patients who received TXA had a mortality of 14.5%. Compared to a mortality of 16.0% among those who received a placebo, this proved a statistically significant benefit to receiving TXA. Importantly, when considering a medication that stabilizes clotting—perhaps even promoting it—there were no statistically significant increases in clot complications, such as myocardial infarctions, strokes, pulmonary embolisms or deep venous thromboses. This is an important study and can be read directly at the CRASH-2 website, www.crash2.lshtm.ac.uk.
The smaller of the two studies—but equally important for consideration in EMS—is the Military Application of Tranexamic Acid in Trauma Emergency Resuscitation (MATTERs) Study. This study involved TXA administration in an out-of-hospital setting, on British military medevac helicopters in Afghanistan. Patients were included in this study if hemorrhagic shock was suspected and they were transfused at least one unit of blood. Additional investigation was done in patients who required at least 10 units of blood for stabilization. As in CRASH-2, MATTERs revealed a statistically significant survival benefit when receiving TXA—17.4% in comparison to 23.9% mortality without TXA. MATTERs did cause a note of caution in that there were statistically significant increases in clotting complications of pulmonary embolisms and deep venous thromboses, yet the absolute numbers were quite small.
Both studies should be read thoroughly and EMS medical directors and local trauma specialists must be involved in the considerations of whether TXA is appropriate for the local standard of EMS care.
At present, the cost of TXA in the 1 gram dose that EMS would administer over a 10 minute IV piggyback infusion is approximately $55. It’s clearly not free, but considering its impact it’s quite cost effective when considering the increased survival rate in the most serious of trauma cases.
In metropolitan Oklahoma City and Tulsa, physician medical oversight is provided by the Medical Control Board (MCB) and its Office of the Medical Director. With support from trauma surgeons in both Oklahoma City and Tulsa, the MCB unanimously approved TXA for EMS use on January 16, 2013 with implementation on April 1. Key to ensuring the right patients receive TXA and the wrong ones don’t, a detailed continuing education review of both landmark studies and how TXA is to be used in the local standards of care was created. The program features the system’s medical director and Oklahoma City’s massive transfusion in trauma expert, Dr. Will Havron. Paramedics are required to receive this education and complete real-time patient screening checklists prior to TXA administration. As you can imagine, we’re watching these patients closely in CQI formats and look forward to sharing our impressions over the next several months. We’ll watch these patients and their outcomes carefully and report back.