Misc. Topics Flashcards
Best method of preventing heat loss in OR
Forced air warming
Modes of heat loss in OR
Radiation > Convection > Evaporation > Conduction
Body’s temp control is regulated by
Brainstem
Hypothalamus (pre-optic area)
Radiation
#1 source of heat loss (60%) Protect by covering the skin
Convection
20-30% of heat loss
Happens from movement of air over the patient (wind chill)
Evaporation
20% of heat loss
Happens from respiration, wounds, and exposure of internal organs
Conduction
Only 5% of heat loss
Ex- OR table, IV fluids, and irrigation fluids
Phase I of intra-op heat transfer
D/t redistribution of fluids from the central to peripheral compartments
Anesthetic agents cause vasodilation and prevent shivering
Placing warm blankets on the patient BEFORE inducing GA can minimize the peripheral temperature gradient
Phase II of intra-op heat transfer
Heat loss to the environment EXCEEDS heat production
Phase III of intra-op heat transfer
Heat loss to the environment equals heat production (equilibrium)
CV and pharmacologic consequences of hypothermia
CV
- SNS stimulation
- Vasoconstriction + decreased tissue PO2
- Shits O2-Hgb curve to the left
- Coagulopathy and plt dysfunction
- Sickling of HgbS
Pharm:
- Slowed drug metabolism
- Increased solubility of VAs (prolonged emergence)
Shivering and O2 Consumption
Increases O2 consumption by 400-500%!!
- Risk of MI!
Drugs that can be used to treat shivering
Meperidine
Clonidine
Precedex
Steps if Airway Fire
Remove the ETT and stop flow of all gases
Remove anything else combustable from the airway
Pour cold saline into the airway
If fire still isn’t extinguished, use CO2 extinguisher
After fire under control:
1) Go back to ventilating the patient (avoid nitrous and high O2)
2) Check ETT for damage (any fragments missing?)
3) Perform bronchoscopy to look for airway injury or ETT fragments
This med is the gold standard induction med for ECT
Methohexital
