General anesthetic agents

Question 1

Therapeutic use of IV anesthetics

Answer 1

induction of anesthesia

Question 2

What is the therapeutic use of benzodiazepines for anesthetics

Answer 2

for sedation and anxiolysis

Question 3

Main contributor to IV anesthetics duration of action

Answer 3

redistribution out of CNS

Question 4

MOA of Methohexital

Answer 4

short acting barbituate, acts on GABA-A receptors

Question 5

Pharmacokinetics of methohexital

Answer 5

onset 30sec, duration 10 min

Question 6

Therapeutic use of methohexital

Answer 6

induction of anesthesia and procedural sedation

Question 7

MOA of propofol

Answer 7

GABA-A agonist, sedative and amnestic, but not analgesic

Question 8

Therapeutic use of propofol

Answer 8

most commonly used in US. general anesthesia induction and maintenance, procedural sedation, post-op anti-emetic

Question 9

Pharmacokinetics of propofol

Answer 9

onset 40sec duration 6 min

Question 10

Side effects of propofol

Answer 10

hypotension and respiratory depression

Pain at injection site

Question 11

MOA of etomidate

Answer 11

potentiation of GABA-A currents. Minimal cardiovascular and respiratory effects, not analgesic

Question 12

Therapeutic use of etomidate

Answer 12

commonly used for induction and maitenance of general anesthesia, patients with hypotension

Question 13

Side effects of etomidate

Answer 13

injection site pain, myoclonic movements, post-op nausea and vomiting, adrenal insufficiency with continuous infusion

Question 14

Ketamine MOA

Answer 14

NMDA receptor antagonist, produces dissociative sedation, analgesia and bronchodilation. Minimal cardiovascular effects

Question 15

Therapeutic use of ketamine

Answer 15

less often used due to emergence phenomenon. Usefull for induction of pediatric anesthesia.
procedural sedation for brief, painful procedures
patients with airway disease

Question 16

Side effects of ketamine

Answer 16

CNS psychotomimetic-vivid dreams and hallucinations, can be countered in adults with benzodiazapines
Some nausea/vomiting, tachycardia and hypersalivation

Question 17

7 properties of an ideal general anesthetic

Answer 17

anesthesia
analgesic and anxiolytic
amnesia
muscle relaxation
inhibition of reflex response to trauma
rapid, smooth onset and recovery
little or no systemic toxicity or hazard to healthcare personenel

Question 18

Cardivascular effects of anesthesia

Answer 18

decreases mean arterial blood pressure

Question 19

Respiratory effect of general anesthesia

Answer 19

reduced or eliminated ventilory drive

Question 20

Emergence effects

Answer 20

vomiting, treated with 5-HT3 antagonists
return of sympathetic tone- tachycardia and hypertension
shivering

Question 21

MOA of inhalation anesthetics

Answer 21

Enhances GABA-A activity
Inhibition of excitatory glutamate, nicotinic, 5-HT3 receptors
inhibits action potential propagation by Boltage gated ion channels
GPCRs

Question 22

Factors affecting anesthetic uptake (3)

Answer 22

blood solubility
aveolar blood flow
difference in PP of agent in aveolar gas vs blood

Question 23

A high blood:gas partition coefficient results in:

Answer 23

slow induction rate

Question 24

Mixture for second gas effect

Answer 24

70% nitrous oxide and 1% halothane

Question 25

What factors affect MAC in patients

Answer 25

increase mac in infancy and chronic alcohol intake | decreae MAC in elderly and acute alcohol intake

Question 26

Therapeutic use of Nitrous oxide

Answer 26

``` alone as a sedative/analgesic for outpatient dental in combination (70%) for secondary gas effect ```

Question 27

Advantages of NO (4)

Answer 27

good analgesia and amnesia rapid induction and recovery minimal cardiovascular effects reduced side effect of other inhalation agents

Question 28

Disadvantages of NO (5)

Answer 28

``` Not a complete anesthetic not a good muscle relaxant can cause diffusion hypoxia myelosuppression- not good for chronic use possible teratogen ```

Question 29

Therapeutic use of halothane

Answer 29

rarely used in US, low cost in developing countries | Used for children in US due to lack of pungency

Question 30

Advantages of halothane (4)

Answer 30

Non-pungent rapid induction and recovery muscle relaxant bronchodilator

Question 31

Disadvantages of halothane (5)

Answer 31

``` poor analgesic slow elimination significant cardiac depression increased intracranial pressure halothane hepatitis ```

Question 32

Isoflurane therapeutic use

Answer 32

comonly used for maintenance at 1-2%

Question 33

Advantages of isoflurane

Answer 33

good cardiovascular profile, maintains cardiac function

Question 34

Disadvantages of isoflurane

Answer 34

pungent

Question 35

Therapeutic use of desflurane

Answer 35

widely used for maintenance 6-8% during outpatient surgery

Question 36

Advantages of desflurane

Answer 36

very rapid induction and emergence | good cardiovascular profile

Question 37

Disadvantages of desflurane

Answer 37

pungent, bronchial irritation, used with IV agent for induction

Question 38

Therapeutic use of sevoflurane

Answer 38

widely used 2-4%

Question 39

Advantages of sevoflurane

Answer 39

low pungency - good for pediatric patients | good cardiovascular profile