Thermoregulatory vasoconstriction does not impede core warming during cutaneous heating

Area of Science:

• Anesthesiology
• Physiology
• Thermoregulation

Background:

• Perioperative hypothermia is a common complication.
• Cutaneous-to-core heat transfer significantly influences core body temperature.
• Anesthesia alters thermoregulatory mechanisms, including vasomotor tone.

Purpose of the Study:

• To evaluate the role of thermoregulatory vasoconstriction in perioperative heat transfer.
• To determine the impact of anesthesia on thermoregulation during mild and vigorous thermal stress.
• To assess the effectiveness of postanesthetic cutaneous warming.

Main Methods:

• Investigated heat transfer between skin and core in anesthetized subjects.
• Assessed thermoregulatory vasoconstriction during mild and vigorous cooling.
• Evaluated core rewarming rates with and without active cutaneous warming.

Main Results:

• Thermoregulatory vasoconstriction effectively reduces core cooling during mild thermal stress.
• Vasoconstriction offers only slight protection against core cooling during vigorous cooling.
• Anesthetic-induced alterations in vasomotor tone are critical for maintaining core temperature.
• Active cutaneous warming significantly accelerates core rewarming post-anesthesia.

Conclusions:

• Thermoregulatory vasoconstriction protects core temperature by limiting heat loss during mild cooling.
• Anesthetic effects on vasomotor tone are a key determinant of perioperative temperature.
• Thermoregulatory mechanisms are insufficient to prevent significant temperature changes during vigorous cooling or warming.