Kragh JF Jr., Parsons DL, Kotwal RS, et al. Testing of junctional tourniquets by military medics to control simulated groin hemorrhage. J Spec Oper Med. 2014;14(3):58–63.
Happy New Year, JEMS readers! In November 2014, the National Association of EMTs rolled out the 8th edition of Pre-Hospital Trauma Life Support (PHTLS). We strongly recommend EMS providers review this update and we’re focusing this column on the science behind some new concepts described in the text.
Rapid placement of tourniquets is again emphasized, including new junctional tourniquets. These devices are designed for pelvic, inguinal, axillary and even abdominal bleeding where standard tourniquets don’t fit. These junctional tourniquets have made their way onto the civilian market by way of military applications and research from the U.S. Army Institute of Surgical Research.
Four different commercially available devices were evaluated by the military on their ability to stop blood flow distal to the application site. The four devices varied from true tourniquets, metal clamps, and pneumatic devices.
Using a Doppler to assess distal blood flow, all four devices were applied to the groin area of healthy, uninjured combat medics.
Despite going through training on each device, several medics had difficulties providing true occlusion of blood flow with several of the devices. Medics rated the SAM Junctional Tourniquet device among the easiest and fastest to apply—at 78 seconds. The SAM Junctional Tourniquet was also the second cheapest and the only device to reach 100% effectiveness in stopping blood flow distal to the groin.
It’s worth noting the SAM Junctional Tourniquet was listed as a 2014 JEMS Hot Product from EMS Today.
Tranexamic Acid (TXA)
Valle EJ, Allen CJ, Van Haren RM, et al. Do all trauma patients benefit from tranexamic acid? J Trauma Acute Care Surg. 2014;76(6):1373–1378.
Used for years in orthopedic surgery to prevent excessive hemorrhage, TXA may also have some use in EMS. TXA is an inexpensive derivative of the amino acid lysine, given in a 1 g bolus followed by 1 g infusion over eight hours. TXA doesn’t promote clotting; rather, it’s an antifibrinolytic, preventing the breakdown of clots formed through the natural clotting cascade in the body.
Evidence for use of TXA in EMS is inconclusive. A new study out of Ryder Trauma Center and the University of Miami may only muddy the waters, as it conflicts with the more favored MATTERS study and the controversial CRASH-2 trial. Retrospectively reviewing a subset of 150 patients over 3.5 years, researchers noted the patients who received TXA at their facility were quite different than the ones enrolled in the CRASH-2 study. Unlike the MATTERS study, with a younger military population experiencing prolonged transport times, and the CRASH-2 trial, with a median patient age of 35 years and an injury time over two hours, the TXA study had a median patient age of 42 years and an average injury time of less than one hour.
The authors took 150 patients who received TXA and compared them to a similar population of 150 patients with similar injuries who didn’t receive TXA. In their study, patients who received TXA required double the amount of blood to be transfused compared to the non-TXA group. Mortality, excluding patients who arrived in the ED deceased, was 27% in the TXA group compared to 17% in the non-TXA group.
The raw numbers suggest use of TXA in an older population is detrimental to overall survivability, but this is a small study. When researchers excluded patients who died within two hours, there was a reduction in death if TXA was used.
This leads us to think TXA’s role may be more useful in prolonged transport situations, involving younger populations with limited access to definitive care.
In a November 2014 presentation, Corey M. Slovis, MD, eloquently said: “The smartest, most informed clinicians could successfully argue for or against this drug.” We look forward to ongoing trials investigating TXA use in air medical services and on ground ambulances.