[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.