Inhalation Agents Flashcards
Sevoflurane: Class
Inhaled anesthetic : Ether
Sevoflurane: Use
Induction and maintenance of General Anesthesia
Sevoflurane: Mechanism of Action
Brain:
- Stimulates GABA-a receptor
- Increases Cl influx and hyperpolarizes neurons by increasing the amount of time the channel stays open
- Impairs neurons ability to fire
Spinal Cord:
- Stimulates glycine receptor
- Inhibits NMDA receptor
- Inhibits Na channel
Sevoflurane: Dose
MAC: 2.0%
Sevoflurane: B:G Solubility
0.65
Sevoflurane: Vapor Pressure
157
Sevoflurane: Contraindication
Malignant Hyperthermia
Severe liver disease (higher risk of immune mediated hepatitis due to relatively high hepatic metabolism
Sevoflurane: Considerations
Compound A (in hydrated or dessicated)
Needs minimum FGF
Good agent for inhalation inductions in Pediatrics
High concentrations can produce seizure activity
Increase risk for PONV
Sevoflurane: Metabolism
2-5% in liver
Desflurane: Class
Inhaled anesthetic: Ether
Desflurane: Use
Induction and Maintenance of General Anesthesia
Desflurane: Mechanism of Action
Brain:
- Stimulates GABA-a receptor
- Increases Cl influx and hyperpolarizes neurons by increasing the amount of time the channel stays open
- Impairs neurons ability to fire
Spinal Cord:
- Stimulates glycine receptor
- Inhibits NMDA receptor
- Inhibits Na channel
Desflurane: Dose
MAC: 6.6
Desflurane: B:G Solubility
0.42
Desflurane: Vapor Pressure
669
Desflurane: Contraindications
Hx: Malignant Hyperthermia
Desflurane: Considerations
Impairs hypoxic drive the least-> Good choice for COPD/OSA
Least soluble -> Stays in alveoli longer, able to blow off faster
Produces Carbon Monoxide in the presence of Soda Lime
Rapid increases cause Tachycardia
Isoflurane: Class
Inhaled anesthetic: Halogen
Ether
Isoflurane: Use
Induction and maintenance of general anesthesia
Isoflurane: Mechanism of Action
Brain:
- Stimulates GABA-a receptor
- Increases Cl influx and hyperpolarizes neurons by increasing the amount of time the channel stays open
- Impairs neurons ability to fire
Spinal Cord:
- Stimulates glycine receptor
- Inhibits NMDA receptor
- Inhibits Na channel
Isoflurane: Dose
MAC: 1.2
Isoflurane: B:G Solubility
1.46
Isoflurane: Vapor Pressure
238
Isoflurane: Contraindictions
Hx: Malignant Hyperthermia
Patients with severe CAD
Isoflurane: Considerations
Risk for coronary steal
Carbon Monoxide is byproduct in dessicated soda lime
Most severe drop in BP
Nitrous Oxide: Class
Anesthetic Gas
Nitrous Oxide: Use
As an adjunct to other inhaled medications or anesthesia medications
Nitrous Oxide: Mechanism of Action
Antagonizes NMDA receptor
Stimulates potassium 2P channel
Nitrous Oxide: Dose
MAC: 104
Nitrous Oxide: B:G Solubility
0.46
Nitrous Oxide: Vapor Pressure
38,770
Nitrous Oxide: Contraindications
Procedures in the middle ear
Occular Gas bubble placement
Fire Risk
Pre-existing vitamin b12 deficiency
pregnancy
Nitrous Oxide: Considerations
Concentrating Effect (34 x’s more soluble than nitrogen in the blood) fastest FA/FI
Second Gas effect
Is NOT metabolized in the body
Can be absorbed into anesthesia equipment
