Keyword
Hypothermia
Definition
< 36° C
Advantages
- metabolic O2 requirements
- protective during cerebral or cardiac ischemia
Adverse effects
- Cardiac arrhythmias and ischemia
- Increased peripheral vascular resisitance
- Lt. Shift of the Hb-O2 saturation curve
- Reversible coagulopathy(PLT dysfunction)
- Increased postop. protein catabolism and stress response
- Altered mental status
- Impaired renal function
- Delayed drug metabolism
- Impaired wound healing
- Increased risk of infection
Unintentional hypothermia during general anesthesia
- Phase I : Redistribution of heat from warm “central” compartment to cooler peripheral tissues by anesthetic-induced vasodilation (1-2° C during the 1st hour)
- Phase II : Continuous heat loss to the envirnment (gradual decline during the next 3-4hours)
- Phase III : Equilibrium ; heat loss equals metabolic heat production (reaching a steady state)
Reference
Morgan and Mikhail's Clinical Anesthesiology, 5th edition, Ch.52, P.1184-