HYPOTHERMIA IN TRAUMA: FLUID AND BLOOD WARMING

Adverse consequences of perioperative hypothermia include myocardial ischemia, cardiac arrhythmias, coagulopathy, shivering, increased oxygen consumption during rewarming, alteration in drug metabolism, impaired offloading of oxygen from hemoglobin, and increased wound infection. Administration of cold or inadequately warmed IV fluids contributes to hypothermia, whereas administration of normothermic fluids may reduce both the incidence and complications of hypothermia. Therefore, infusion of adequately warmed fluids is important in order to minimize thermal stress and maintain thermal homeostasis. Trauma in itself, as well as bleeding with tissue hypoperfusion, alters thermoregulation and results in hypothermia. Some of the preventable factors that contribute to the high incidence of hypothermia in the trauma population are prolonged exposure in the field and administration of cold intravenous fluids.1 Patients requiring emergency surgical intervention may suffer additional hypothermic insults from cold surgical preparation solutions and heat loss in the cold operating room environment. Administration of anesthetic agents impairs the ability to maintain thermal homeostasis and causes internal redistribution of body heat from the warmer core to the cooler peripheral tissue, thereby further reducing core temperature in the exposed patient. Although hypothermia decreases metabolic function of the body and is neuroprotective, hypothermia is deleterious in traumatized patients because of coagulopathy, metabolic acidosis, and impaired immune response2. Injured patients with hypothermia are more likely to die than normothermic patients with a similar injury severity score.