Trauma lethal triad

Trauma lethal triad

1. MSF MOKHA HOSPITAL THE LETHAL TRIAD OF TRAUMA Materials from the JEMS article: Trauma’s Lethal Triad of Hypothermia, Acidosis & Coagulopathy Create a Deadly Cycle for Trauma Patients Link: https://www.jems.com/articles/print/volume-39/issue-4/features/trauma-s-lethal-triad-hypothermia-acidos.html

2. Learning Objectives: List the individual components of the lethal triad of trauma. Understand the pathophysiology that makes the lethal triad a deadly self-propogating cycle in critically ill trauma patients. Learn simple interventions EMS providers can perform to help prevent or slow the rapid progression of the lethal triad.

3. Key Terms: Acidosis:  Lower than normal pH due to increased hydrogen ion concentration. Coagulation system:  A temperature- and pH-dependent series of complex enzymatic reactions that result in the formation of blood clots to stop both internal and external hemorrhage. Coagulopathy:  Any disorder of the blood that makes it difficult for blood to coagulate. Hypothermia:  Lowered body core temperature. Lethal triad:  A combination of acidosis, coagulopathy and hypothermia that usually leads to death in a patient experiencing trauma.

4. Despite great advancements in trauma care over the past 30 years, trauma is still one of the leading causes of death in any age group. This is especially apparent in the young—for those aged 1–44 years old, trauma is the No. 1 cause of death in the United States. Of these deaths, hemorrhage accounts for up to 40% and remains as the leading preventable cause of trauma-related death. The lethal triad of hypothermia, acidosis and coagulopathy has been recognized as a significant cause of death in patients with traumatic injuries. In 1982, a study described a “bloody vicious cycle” in which hemorrhage and tissue injury cause this predictable triad of complicating factors. Ultimately, this triad resulted in worsening hemorrhage and eventual death. Authors of the research suggested treatment of hypothermia, acidosis and coagulopathy in trauma requires as much attention as the traditionally emphasized surgical management of injuries. Trauma & the Triad:

5. Today, we recognize that to successfully resuscitate the critically ill trauma patient, all emergency providers must have a firm understanding of the lethal triad. This understanding should serve as the cornerstone for all interventions provided to the bleeding trauma patient. Left untreated, hypothermia, acidosis and coagulopathy bring about and propagate each other, eventually resulting in a predictable but irreversible progression toward death. Trauma & the Triad:

6. Normal human body temperature is 35.6–37 degrees C with hypothermia being defined as a core temperature < 35 degrees C. Hypothermia in trauma patients is caused by a multitude of factors. Hemorrhagic shock, traumatic brain injuries impair the body’s ability to regulate its core temperature. Even mild hypothermia in a trauma patient can result in devastating physiologic consequences. Of particular concern is the effect of hypothermia on the coagulation system. Room temperature normal saline (20–25 degrees C) is very hypothermic relative to the desired normal body temperature. Thus, large volume resuscitations with even room temperature IV fluids can significantly contribute to this arm of the lethal triad. Hypothermia:

7. Acidosis is defined as an arterial pH < 7.35 and can result from a variety of disease states. However, in trauma patients the major contributor is poor perfusion to the tissues. Anemia from acute blood loss, peripheral vasoconstriction in response to hypothermia and blood loss, and overall decreased cardiac output severely impair oxygen delivery to the tissues. Lastly, a trauma patient may also have respiratory acidosis. This is a result of hypoventilation due to respiratory depression or obstruction resulting in hypercapnia (increased CO2 levels). Common causes of a respiratory acidosis in trauma include narcotic or alcohol use, traumatic brain injuries, flail chest or preexisting medical conditions such as chronic obstructive pulmonary disease. As a trauma patient’s perfusion worsens, lactic acid rapidly accumulates in the tissues. This causes the body’s pH to drop, resulting in a severe metabolic acidosis. It’s important to note that this process frequently occurs in the presence of normal or only slightly abnormal vital signs. Acidosis:

8. The coagulopathy of trauma occurs not only because of hypothermia and acidosis as previously discussed, but also as a result of losing clotting factors through hemorrhage and hemodilution, and the body’s use and subsequent depletion of both platelets and clotting factors. Dilutional coagulopathy occurs when we resuscitate a bleeding trauma patient with fluid or blood products that don’t contain the same clotting factors lost in the acutely hemorrhaged whole blood. Lastly, EMS providers should be aware of those trauma patients who have a baseline coagulopathy because of preexisting medical conditions. Examples include those patients on anticoagulant therapy such as warfarin (Coumadin) or a novel oral anticoagulant such as dabigatran for stroke prevention in the setting of atrial fibrillation. These patients and those with chronic liver or renal failure have an increased risk of developing a truly life-threatening coagulopathy and hemorrhage after trauma. Coagulopathy:

9. Management of the Lethal Triad: The triad begins and ends with bleeding, so find the bleeding and stop it. Do not stop your search for bleeding with the first source you find, as others may exist. Always assume your patient’s temperature is dropping right before your eyes, because it is, and much faster than you’d expect. If you aren’t sweating, it’s certainly not warm enough. (Ideally, 27 degrees C.). Cover the patient! Promptly remove wet or bloody clothes and replace with a warm blanket. Shivering wastes valuable cellular energy and oxygen in an attempt to stay warm while producing more lactate, contributing to acidosis. Maximaze oxygenation: oxygen mask for all. Monitor: trauma vitals signs running fast. Administer tranexamic acid (TXA)—an antifibrinolytic that prevents clot breakdown and thus decreases blood loss—if your system permits its use. We don’t bleed normal saline, so limit crystalloid infusion as much as possible. It contributes to the patient’s acidosis and dilutes the remaining clotting factors in your patient’s blood. IV fluids may improve a number, but may actually hurt your patient in the long run. Except in those patients with a traumatic brain injury, utilize a permissive hypotension resuscitation strategy. Our goal should be to maintain tissue perfusion typically defined as the presence of a radial pulse or normal mental status. We should avoid overly aggressive fluid administration to normalize blood pressure, which can “pop the clot” and worsen hemorrhage. Whenever possible, administer only warmed fluids. (Ideally 40 degrees C.)