[Accidental hypothermia in multiple trauma patients].

BACKGROUND: Hypothermia, defined as a body core temperature below 35 °C, could be divided into an endogeneous, therapeutic and accidental hypothermia. At admission in the emergency room multiple trauma patients show a hypothermic core temperature in up to 66 %. A core temperature below 34 °C seems to be critical in these patients as this temperature limit has been demonstrated to be associated with an increased risk for post-traumatic complications and a decreased survival. In polytraumatised patients with a core temperature below 32 °C a mortality rate of 100 % has been described.

MATERIAL AND METHODS: The main pathophysiological effects of hypothermia concern the haemo-dynamic, coagulatory and immune systems. Mild hypothermia (35-32 °C) leads to a vasoconstriction, tachycardia and increased cardiac output. After an increasing arrhythmia and bradycardia severe hypothermia (< 32 °C) finally results in a cardiac arrest. Hypothermia-induced coagulopathy comprises a dysfunction of the cellular and plasmatic coagulation with an increased blood loss. Due to the attenuation of the post-traumatic, pro-inflammatory immune response and enhancement of anti-inflammatory reactions, hypothermia counteracts an overwhelming systemic inflammation, concomitantly resulting in an increased susceptibility for infectious complications.

RESULTS: Because of the negative effects of the -accidental hypothermia, effective rewarming is essential for adequate bleeding control and successful resuscitation. As aggressive rewarming (> 0.5 °C / h) has been reported to be associated with an increased mortality during the further course, this procedure should only be applied in hypothermic multiple trauma patients with haemorrhagic shock.

CONCLUSION: Accidental hypothermia represents a serious problem in multiple trauma patients due to its frequency and negative pathophysiological effects. Therefore, early and effective re-warm-ing is essential in the treatment of hypothermic trauma patients. Possible protective effects of a therapeutic hypothermia in the treatment of trauma patients after initial resuscitation and operative bleeding control have to be clarified in further experimental and clinical studies.