Inhalational Anesthetic Agents Flashcards
What was the first ever inhalational anesthetic?
Nitrous oxide
Whats the difference between vapor and gas?
Vapor: liquid at STP, stored in bottles, and delivered via vaporizer
Gas: Gas at STP, stored in tanks, and delivered via flow meter
What is the saturated vapor pressure?
Maximum achievable concentration of molecules in a gaseous phase at a specific temperature
What affects saturated vapor pressure?
Agent specific, temperature specific
T/F Saturated vapor pressure is unaffected by altitude
TRUE
What is the definition of boiling point?
Temperature at which the saturated vapor pressure = atmospheric pressure
T/F Boiling point is unaffected by altitude
FALSE; boiling point decreases with altitude
T/F Isoflurane’s boiling point is near room temperature
FALSE; Desflurane is
What is gas movement driven by?
Partial pressure gradient across tissues
Chemical affinity for tissue (lipid solubility)
What is the partition coefficient?
indicates gas affinity for adjacent tissue at equilibrium
Gases relatively insoluble in blood have a LOW PC.
What are two ways that a vaporizer compensates for temperature differentiation?
1: Made of copper or bronze that has a high thermal conductivity
2: Device that alters carrier gas flow ratio (bimetallic strip)
A high MAC =
Low potency
What are things that will decrease MAC
Sedatives, analgesic, N2O (MAC sparing effect)
Old age, hypothermia, hypotension
What are factors that will increase MAC?
Hyperthermia, pediatric
What % of N2O needs to be used to see effects?
50%
