체온조절과 마취 = Thermoregulatory Control and Anesthesia

다국어 초록 (Multilingual Abstract)

The temperature of the body is regulated almost entirely by nervous feedback mechanisms, and almost all of these operate through temperature-regulating centers located in the hypothalamus. The anterior hypothalmic-preoptic area has been found to contain large numbers of heat-sensitive neurons and about a third as many cold-sensitive neurons that seem to function as temperature sensors for controlling body temperature. When the skin is chilled over the entire body, immediate reflex effects are invoked to increase the temperature of the body in several ways: A) by providing a strong stimulus to cause shivering. with resultant increase in the rate of body heat production, B) by inhibiting the process of sweating if this should be occuring, and C) by promoting skin vasoconstriction to diminish the transfer of body heat to the skin.
The thermoregulatory system usually maintains core body temperature within 0.2℃ of normal, which Is about 37℃ in humans. Anesthetic-induced inhibition of thermoregulation combines with exposure to a cold operating room environment to make most unwarmed patients hypothermic. Clinical doses of all tested general anesthetics decrease the threshold for response to hypothermia from approximately 37℃ (normal) to 33 to 35℃.
Mild intraoperative hypothermia provides significant protection against tissue ischemia and hypoxia. Major adverse effects include morbid myocardial outcomes, reduced resistance to surgical wound infections, impaired coagulation, prolonged duration of drug action, shivering, and decreased postoperative therm at comfort.