A tactical medic must understand the physiology and the progression of trauma. During the progression of trauma, there are multiple variables that accelerate the deterioration of the casualty. In the medical worlds, there are many “triads” that help a provider remember the tenets of a certain condition. The Trauma Triad of Death is a triad that must be understood by a tactical medic. A traumatic patient will more than likely succumb to this triad if one of the variables is not treated for. The Trauma Triad of Death is unique as each of the three “legs” of the triad complement and work on each other further raising mortality rate. There are three main factors in the Trauma Triad of Death: hypothermia; metabolic acidosis; coagulopathy. All of these, if not treated promptly, continue to work on each other to create a downward spiral and ultimately the death of your casualty.
A core temperature of 90°F in an environmental exposure raises mortality rate to 21%. A core temperature of 90°F in a multisystem trauma patient raises mortality rate to nearly 100% (Navarro, 2011). The time for a core temperature to drop 8.6°F is faster than you may expect (as you seasoned medics may already know). As the casualty loses blood and shivers against the cold floor exposed to the wind, he loses body heat through radiation, conduction and convection. As the warm blood flows out of the casualty, the body loses the ability to regulate the core temperature. When the casualty falls to 95°F, the body begins to shiver, attempting to bring the temperature up. This use of major muscle groups to warm the body releases more waste products, raising acidosis (pH levels in the body and acidity) and consumes oxygen that the body greatly needs in order to survive the traumatic event. It is extremely important to keep the casualty warm as soon as possible. A casualty will can and will go hypothermic in temperatures and conditions that you may consider warm. Make sure you keep an emergency/space blanket in your med bag. These small blankets take up minimal space and reflect the casualty’s body heat. Be wary with only using a space blanket, insulation is also key and a thin blanket may not be all the casualty needs but is better than nothing. Blizzard blankets or North American Rescue’s Hypothermia Prevention and Management Kits (HPMK) are excellent to keep inside the vehicle. If you have nothing else, use parts of uniforms or sheets to warm the casualty. Ensure you insulate the casualty from the ground or stretcher because the body will lose heat through conduction as well. Cover up the head and feet as much body heat is lost through these parts of the body. Remember that pushing room temperature intravenous fluids can quickly lower body temperature. Use fluid warmers like the Thermal Angel to keep fluids warm. Fluids should be warmed to at LEAST 100°F, and between 104°F-108°F for a hypothermic patient (Alaska Guidelines, 2005). If nothing is available, attempt to warm the fluids by placing the bag between your armpits before administering them.
When the casualty receives a traumatic injury, a myriad of physiological processes occur to salvage the body. Most traumatic injuries include some degree of blood loss. The body uses fibrinogen and other clotting factors to create a primary clot and then initiates a complex clotting cascade to strengthen the clots and prevent further bleeding. Hypothermia interferes with the clotting cascade and impairs platelet function. The altered enzymatic activity leading to a 33% reduction in clotting factor IV can be seen at 91°F (Rensburg, 2005). In order to correct coagulation issues and avoid the disastrous and lethal Disseminated Intravascular Coagulopathy (DIC) you must treat for hypothermia immediately. Treatments that have been used in the past to combat coagulopathy is the administration of recombinant activated factor VII (rFVIIa) and fresh whole blood with an early transfusion of plasma with PRBCs (LTC Niven, 2012). The military has paved the way of antifibrinolytic therapy with Tranexamic Acid (TXA) reducing mortality rates in traumatic patients over 30 days (LTC Niven, 2012). TXA administered at the point of injury may be more useful in situations when there is a prolonged evacuation time (rural settings, combat settings). While training at a hospital in Florida, our medics gave TXA multiple times in the ED, though the staff considered it a very new treatment. Nevertheless, it is a good idea to at least talk to your medical officer about the new trauma drugs that are being used in the field.
Acidosis begins to occur because of the hypothermia as well. Hypothermia causes vasoconstriction, reducing the body’s ability to perfuse the organs and clear the lactic acid that builds up from the shivering. Hypothermia alters the sodium-potassium pump function during hypothermia and results in hyperkalemia (excess Potassium in the body), which in severe hypothermic cases can result in heart dysrhythmias. Pre-hospital care for acidosis is limited to preventing it by keeping the patient warm.
Knowing how to prevent the trauma triad of death is easy. Treating it is not. The best possibly way to reduce casualty mortality is covering up your patient and controlling the ABCs immediately.
B. Tsuei (2004). Hypothermia in the Traumatic Patient. Injury. 35(1), 7-15.
K. Navarro (2011). Hypothermia and Trauma: A Deadly Combination. The Research Review. Retrieved from http://www.ems1.com/trauma/articles/1189729-Hypothermia-and-trauma-A-deadly-combination/
L. Rosenburg (2005) Hypothermia in the Traumatic Patient. RCSED. Retrieved from http://www.rcsed.ac.uk/fellows/lvanrensburg/classification/commonfiles/hypothermia%20trauma%20patient.htm
Murphy, P. (2012) Understanding the Trauma Triad of Death. EMS World. Retrieved from http://www.emsworld.com/article/10565011/understand-the-trauma-triad-of-death?page=6
Niven, A. (2012) Management of Trauma-Associated Coagulopathy: News Strategies and Controversies. American College of Chest Physicians. Retrieved from http://www.chestnet.org/accp/article/chest-physician/management-trauma-associated-coagulopathy-new-strategies-and-controversies
State of Alaska (2003). Cold Injuries Guidelines. Retrieved from http://www.hypothermia.org/Hypothermia_Ed_pdf/Alaska-Cold-Injuries.pdf
Picture Courtesy of Paramedicine 101
About Hank V.
Hank is a 6-year veteran currently serving in the U.S. Army Special Operations Forces as a Combat Medic. He has deployed to East Asia and the Middle East.