Current literature suggests that about one to two-thirds of trauma patients are hypothermic upon presentation to the emergency department. The mortality of hypothermic patients is approximately twice that of similarly injured normothermic patients.7-10 In another large study of trauma patients requiring massive transfusion, hypothermia (< 36 deg C) on arrival was an independent predictor of mortality and associated with increased blood product consumption.11-13 Furthermore, studies in civilian trauma have shown >80% of non-surviving patients arrived hypothermic with a core temperature < 34 deg C.12 In both civilian and military trauma, 100% mortality has been demonstrated when core temperature reached < 32 deg C.14,15 When hypothermic patients fall below the thermoregulatory threshold for shivering (around 30 deg C), shivering heat production ceases. Therefore, these patients have lost the ability to generate heat and will continue to cool unless actively rewarmed by external sources.16 This can be further exacerbated by pharmacologic treatment with sedatives and paralytics.17,18
Innovation and improved outcomes-based research over the past two decades have improved survivability via addressing coagulopathy and acidosis .1,5,19–22 Early recognition and treatment of hypothermia is an equally important consideration that begins at the point of injury and should be implemented for all combat casualties, particularly patients at risk of experiencing shock. As it is labor and resource intensive to re-warm a casualty, measures to prevent hypothermia should begin as soon as possible with thermal wraps and warmed resuscitation products.5,23,24 There are varying degrees of abilities and resources availability at each echelon role of care, which are discussed in the following sections.