Inhalant Anesthetics

Question 1

Halothane

Answer 1

• Inhalant Anesthetic
• Aliphatic
• requires preservatives, causes cardiac dysrhythmias, more potent then isoflurane (MAC 0.9%)

Question 2

Nitrous Oxide

Answer 2

• Inhalant Anesthetic
• only inorganic one
• GAS
• MAC is over 200 … cannot be used alone, usually given to lower potency of other agents

Question 3

Isoflurane

Answer 3

• Inhalant Anesthetic
• Ether
• does not need preservatives, does not cause dysrhythmias, less potent then Halothane (MAC 1.3%)
• VAPOR
• MAC is about 1.3
• most soluble, slower onset
• most liver friendly

Question 4

Sevoflurane

Answer 4

• Inhalant Anesthetic
• Ether
• VAPOR
• MAC is 2.2

Question 5

Desflurane

Answer 5

• Inhalant Anesthetic
• Ether
• VAPOR
• MAC is from 7-10!!!!!
• lest soluble, fastest onset
• boiling point close to room temperature, high vapor pressure
• low potency
• needs high heat and pressure to maintain constant infusion

Question 6

Halogenation of Inhalant Anesthetic

Answer 6

• bromide and chloride increase potency
• fluorine increases stability
• > increase potency, decrease reactivity, makes them non-flammable

Question 7

Properties determining how inhalants are administered and travel around the body

Answer 7

Administered:
-vapor pressure
-boiling point
-specific gravity
Travel:
-SOLUBILITY (total number of gas molecules dissolved into a solvent) and blood/gas coefficient
-> lower blood/gas coefficient = faster onset and recovery
-> more soluble = takes longer to act because likes to hangout in the blood, less soluble ones leave blood fast to act in tissues

Question 8

Gas VS Vapor

Answer 8

Gas: exists in gas form at room temp, can be administered from 0-100%
vapor: exists in liquid form at room temp, maximum delivery concentration depends on its saturated vapor pressure (saturated vapor pressure / atmospheric pressure= max % we can use)

Question 9

ways to quantify inhalants

Answer 9

• pressure
• concentration (most common)
• mass

Question 10

potency definition

Answer 10

• DOSE needed for a desired effect
• MAC = minimal alveolar concentration
• MAC of anesthetic that prevents gross movement in 50% of patients (ED 50% = MAC)
• MAC and potency are inversely correlated

Question 11

3 factors that influence alveolar uptake

Answer 11

• solubility
• cardiac output
• alveolar / venous anesthetic partial pressure difference

Question 12

malignant hyperthermia

Answer 12

• most commonly seen in swine
• muscle contractions
• treatment: stop inhalant and give muscle relaxant