General Anesthesia

Question 1

desflurane

Answer 1

Volatile General Anesthetic

Volume % producing 1 MAC: 7.25 (less potent as go higher)

Blood-gas Partition Coefficient: 0.42 (Fast on Fast Off)

Metabolized at only 0.02%

• Irritates Airways
• Myocardial Depression MInimal
• Produces prompt Recovery

Example of combination with N2O
- 0.5 MAC desflurane (3.0%) + 0.7 MAC nitrous Oxide (70%)= 1.2 MAC Desflurane
- Due to N2O adjunct to
anesthetic agents

Volatile anesthetics can cause
malignant hyperthermia.

Volatile anesthetics are respiratory
depressants

Volatile anesthetics decrease arterial
blood pressure

Volatile anesthetics appear to produce the
predominance of their central nervous
system effects: - amnesia, sedation, and
muscle relaxation-

By facilitating inhibitory neurotransmission
at GABA and glycine receptors. Excitatory
glutamate transmission is also reduced.

Question 2

isoflurane

Answer 2

Volatile General Anesthetic

Volume% producing 1 MAC: 1.15
- Most potent

Blood-gas Partition Coefficient: 1.4

Oldest and Highest blood gas coefficient

Irritates airways

Undergoes metabolism at 0.2%

Myocardial Depression is minimal

Volatile anesthetics can cause
malignant hyperthermia.

Volatile anesthetics are respiratory
depressants

Volatile anesthetics decrease arterial
blood pressure

Volatile anesthetics appear to produce the
predominance of their central nervous
system effects: - amnesia, sedation, and
muscle relaxation-

By facilitating inhibitory neurotransmission
at GABA and glycine receptors. Excitatory
glutamate transmission is also reduced.

Question 3

nitrous oxide

Answer 3

Volatile General Anesthetic Adjuvant

Volume % producing 1 MAC: 105-110

Blood-gas Partial Coeffcient: 0.46

Reduces MAC requirements for other volatile anesthetics

Very insoluble

Has little side effects

Question 4

sevoflurane

Answer 4

Volatile General Anesthetic

Volume% producing 1 MAC: 2.05

Blood-gas Partition Coefficient: 0.68

Non-irritating

Undergoes metabolism at 2-5%

Myocardial Depression is minimal

Produces Prompt Recovery

Volatile anesthetics can cause
malignant hyperthermia.

Volatile anesthetics are respiratory
depressants

Volatile anesthetics decrease arterial
blood pressure

Volatile anesthetics appear to produce the
predominance of their central nervous
system effects: - amnesia, sedation, and
muscle relaxation-

By facilitating inhibitory neurotransmission
at GABA and glycine receptors. Excitatory
glutamate transmission is also reduced.

Question 5

dantrolene

Answer 5

Treats Malignant Hypothermia

Question 6

succinylcholine

Answer 6

Causes Malignant Hyperthermia

Question 7

etomidate

Answer 7

Intravenous Induction Agent

Produces Respiratory Depression

Does not produce cardiovascular depression

Cannot be ANTAGONIZED (must be careful)

Question 8

ketamine

Answer 8

Induction Agent

A phencyclidine
derivative

NMDA receptor
antagonist

Dissociative
anesthetic

• Used in induction for general
anesthesia

• Produces sedation, amnesia and
analgesia

• Does not produce respiratory
depression or cardiovascular
depression

• Cannot be antagonized
• Emergence delirium

Question 9

methohexital

Answer 9

Induction Agent

Oxybarbiturate

Used for intravenous induction of
general anesthesia

• Highly lipid soluble

• Produce rapid, profound
unconsciousness due to rapid
uptake into the brain

• Produce marked respiratory depression
• Recovery occurs in 5-8 min

• Prompt recovery is due to
redistribution from the brain to
other tissues

• No drugs are available to reverse
barbiturates

• Decrease sympathetic outflow from the brain

Works on Beta Subunit of GABA

Question 10

propofol

Answer 10

Induction Agent

Newest anesthetic induction agent

Dissolved in intralipid

• Used in induction for general
anesthesia

• Can also be used for maintenance

• Produces cardiovascular and
respiratory depression

• Cannot be antagonized
• Least “hangover effect”

Works on Alpha subunit of GABA receptor

Question 11

thiopental

Answer 11

Induction Agent

Thiobarbituate

Used for intravenous induction of
general anesthesia

• Highly lipid soluble

• Produce rapid, profound
unconsciousness due to rapid
uptake into the brain

• Produce marked respiratory depression
• Recovery occurs in 5-8 min

• Prompt recovery is due to
redistribution from the brain to
other tissues

• No drugs are available to reverse
barbiturates

• Decrease sympathetic outflow from the brain

Works on Beta Subunit of GABA

Question 12

alfentanil

Answer 12

Analgesic

Fast onset, short acting

• Useful for premedication

• Reduce the MAC of volatile
anesthetics

• Produces marked respiratory
depression

• Usually not much effects on
blood pressure

Question 13

fentanyl

Answer 13

Analgesic

Highly lipid soluble

High potency

Fast onset

Shorter action of duration

Part of premedication

Fast onset, short acting

• Useful for premedication

• Reduce the MAC of volatile
anesthetics

• Produces marked respiratory
depression

• Usually not much effects on
blood pressure

Question 14

remifentanil

Answer 14

Analgesic

Remifentanil is metabolized by plasma esterase;
it can be used as an infusion.

Question 15

sufentanil

Answer 15

Analgesic

Fast onset, short acting

• Useful for premedication

• Reduce the MAC of volatile
anesthetics

• Produces marked respiratory
depression

• Usually not much effects on
blood pressure

Question 16

flumazenil

Answer 16

Premedication Agent

Antagonizes Benzodiazepines

Opposes effect of sedation and amnesia brought on by benzos, as well as reversing respiratory depression

Question 17

midazolam (others include diazepam and lorazepam

Answer 17

Premedication Agent

Benzodiazepine

Used in premedication for general
anesthesia

• Highly lipid soluble
• Produce sedation and amnesia

• Intravenous benzodiazepines can
produce respiratory depression

• Can be antagonized by flumazenil

Dangerous especially in sleep apnea