Inhaled Anesthetics Flashcards
Nephrotoxic inhalational agent that causes vasopressin-resistant, high-output renal failure with prolonged use
Methoxyflurane
Inhalational agent associated with hepatitis
Halothane
Inhalational agent that decreases myocardial contractility, increases CSF production, and resistance to CSF outflow
Enflurane
Inhalational agent that can cause tonic-clonic seizures
Enflurane
Fresh Gas Flow: Factors affecting Fi (inspired gas) - 3
- FGF rate
- Breathing circuit volume
- Circuit absorption
Fresh Gas Flow: Factors affecting FA (alveolar gas concentration) - 4
- Uptake (blood-gas coefficient x C(A-V) x Q)
- Ventilation
- Concentration effect
A. Concentrating effect
B. Second gas effect/Augmented inflow effect
Dr. Keneally’s PPT: Fi, minute vent [hyper/hypoventilation], rate of uptake into bloodstream
Fresh Gas Flow: Factors affecting Fa (arterial gas concentration)
Ventilation/perfusion mismatching
Fresh Gas Flow: Factors affecting anesthetic uptake
- Solubility in blood
- Alveolar blood flow
- Difference in alveolar and venous blood partial pressures
Will increased cardiac output have a greater affect on alveolar concentration of soluble or insoluble agents?
Soluble; low output states predispose patients to overdose w soluble agents due to increased rate of alveolar concentration rise
What factors speed induction and recovery from inhalational anesthesia? - 7
- Elimination of rebreathing
- High fresh gas flow
- Low anesthetic-circuit volume
- Low absorption by circuit
- Decreases solubility
- High CBF
- Increased ventilation
Nitrous oxide:
B/G Partition coefficient
MAC%
Vapor pressure
PC: 0.47
MAC: 105
VP: -
Halothane:
B/G Partition coefficient
MAC%
Vapor pressure
PC: 2.4
MAC%: 0.75
VP: 243
Isoflurane:
B/G Partition coefficient
MAC%
Vapor pressure
PC: 1.4
MAC: 1.2
VP: 240
Desflurane:
B/G Partition coefficient
MAC%
Vapor pressure
PC: 0.42
MAC: 6.0
VP: 681
Sevoflurane:
B/G Partition coefficient
MAC%
Vapor pressure
PC: 0.65
MAC: 2.0
VP: 160
