3.7 General Anesthesia

Question 1

What is anesthesia?

Answer 1

Drug-induced reversible depression of CNS losing all physical perception

Question 2

What are the 5 goals of surgical anesthesia?

Answer 2

1. Unconciousness/prevent awareness
2. Amnesia
3. Analgesia
4. Immobility/muscle relaxation
5. Attenuation of ANS pain responses

Question 3

What must be maintained in pursuit of the goals of surgical anesthesia?

Answer 3

Hemodynamic (BP) and respiratory stability (+temperature)

Question 4

What are the 3 types of anesthesia?

Answer 4

General, procedural, and local

Question 5

Induction of anesthesia is done via…

Answer 5

IV

Question 6

Maintenance of anesthesia is done via…

Answer 6

Inhalation

Question 7

What is procedural sedation?

Answer 7

Analgesic and anxiogenic drug induction while maintaining individual breath control (concious), ANS reflexes, and hemodynamics

Question 8

What is the ideal volatile anesthetic?

Answer 8

1. Fast induction and recovery
2. Minimal CV and respiratory effects
3. Pleasant to inhale, odourless
4. Safe for people and environment

Question 9

What is minimum alveolar concentration (MAC)?

Answer 9

The alveolar partial pressure of a gas where 50% of people don’t feel an incision

Question 10

T/F: A high MAC value is an effective gas

Answer 10

False, it’s less potent and requires more gas

Question 11

MAC is ____ related to dosage

Answer 11

Directly

Question 12

What factors cause an increase in MAC in a person?

Answer 12

Alcoholism, infants, high metabolism, cocaine
Increase dosage

Question 13

What factors cause a decrease in MAC in a person?

Answer 13

Elderly, pregnancy, opioids

Question 14

Blood:gas coefficient determines…

Answer 14

Drug solubility, inverse to speed of drug onset

Question 15

Blood:gas coefficient is ____ related to speed of drug onset

Answer 15

Indirectly

Question 16

What is the Meyer-Overton rule?

Answer 16

Denotes a linear relationship between lipid solubility (oil/gas coeff) and anesthetic potency (MAC)

Question 17

What are IV anesthetics?

Answer 17

Propofol, barbituates, ketamine

Question 18

What is the MOA of (most) IV anesthetics?

Answer 18

GABA(A) receptor agonists
Increased Cl- through GABA(A) receptor channel = firing of an inhibitory neuron = decreased activity

Question 19

Why is ketamine uncommonly used as an anesthetic?

Answer 19

CV and hemodynamic instability

Question 20

A rapidly onset IV drug means it is highly ____

Answer 20

Lipophilic

Question 21

What is the MOA of dexmedetomidine?

Answer 21

+ a2 receptors –> - norephinephrine –> - arousal

Question 22

Where does dexmedetomidine act?

Answer 22

a2 receptors in the locus ceruleus

Question 23

T/F: Inhalants decrease cerebral blood flow

Answer 23

False, they increase it

Question 24

T/F: IV anesthetics decrease CBF and CMR(O2)

Answer 24

True, shutting everything down

Question 25

What can reverse the effects of benzodiazepines?

Answer 25

Flumazenil

Question 26

Is NO2 an ideal inhalant?

Answer 26

No, it causes blood and respiratory increase