Consequences of hypothermia

Virtually all anaesthetics render patients poikilothermic and body temperature invariably decreases during surgery. For selected surgical procedures, hypothermia can protect vital organs from ischaemic injury. Hypothermia, however, is not without consequences as hypothermia-related complications are well known. As little as 2°C of core hypothermia impairs coagulation and predisposes to bleeding. Hypothermia slows emergence from general anaesthesia by both pharmacokinetic and pharmacodynamic mechanisms. Thermal discomfort is another commonly recognized perioperative problem. In the postoperative setting, even mild hypothermia exacerbates the stress response by activation of the sympathetic nervous system resulting in increased catecholamines. By this mechanism, hypothermia can precipitate myocardial ischaemia and cardiac morbidity in awake patients. In surgical patients, body temperature should be carefully monitored and controlled with the same level of attention that is given to the other vital signs. By controlling body temperature in the perioperative period, improved outcomes can be achieved.