M5 L4: Anesthetics

Question 1

components of general anesthesia

Answer 1

1. hypnosis (loss of consciousness)
2. amnesia (loss of memory)
3. analgesia (loss of response to pain)
4. areflexia (loss of autonomic response)
5. relaxation (skeletal muscle relaxation)

Question 2

general anesthesia mech of action

Answer 2

• facilitation of GABA-mediated inhibition at GABAa receptor: strengthens the inhibitory function of GABA, increasing CNS depression
• antagonism of glutamic acid excitation of NMDA receptor: decreases excitation in CNS, enhancing CNS depression

Question 3

2 ways general anesthesia is administered

Answer 3

• inhaled
• IV

Question 4

commonly used inhaled anesthesias

Answer 4

• nitrous oxide
• volatile anesthetics:HALOTHANE

Question 5

what is nitrous oxide (N2O)

Answer 5

laughing gas!
- low-potency, incomplete anesthesia
- rapid onset and offset
- prominent analgesic effect

Question 6

nitrous oxide (N2O) adverse effects

Answer 6

hypotension, respiratory depression (usually minimal)

Question 7

what are volatile general anesthetics

Answer 7

• liquid @ room temp so you have to aerosolize them for inhalation
• potent drugs produce: unconsciousness, analgesia, muscle relaxation, bronchodilation

Question 8

what are volatile anesthetics adverse effects

Answer 8

• hypotension, respiratory depression

Question 9

minimum alveolar concentration (MAC)

Answer 9

• concentration of inhaled anesthetic required to prevent 50% of ppl from responding to painful surgical stim w “gross purposeful movements”
• if u need higher amount, the weaker the anesthetic
• determines anesthetic potency, inverse relationship (increased MAC = decreased potency)

Question 10

what are commonly used IV general anesthetics

Answer 10

• propofol
• ketamine
• etomidate

Question 11

what is propofol

Answer 11

• very rapid offset despite prolonged infusions
• ideal ambulatory anesthetic
• prevents nausea and vomiting
• dose not change HR
  adverse effects: hypotension, apnea

Question 12

what is ketamine

Answer 12

• often in pediatric anesthesia
• used as rec street drug
• anesthetic of choice for compromised blood flow
• provides analgesia
• does not usually cause apnea

Question 13

adverse effects of ketamine

Answer 13

• hypertension
• tachycardia
• elevated intracranial pressure
• dysphoria

Question 14

what is local anesthetics

Answer 14

• loss of sensation confined to a discrete area of the body

Question 15

how do local anesthetics work?

Answer 15

• block voltage-gated sodium channels
• decreased action potential
• blocks sensory nerve conduction

Question 16

what is the effect of local anesthetics

Answer 16

block pain sensation
- autonomic function
- temp sensation
- light touch
- proprioception
- motor function

Question 17

how do local anesthetics terminate the effect

Answer 17

• systemic absorption -> distribution -> elimination

Question 18

uses and administration of local anesthetics

Answer 18

nerve block, spinal or epidural
topical, local infiltration (like if a tooth is being pulled)

Question 19

local anesthetic adverse effects and toxicity

Answer 19

allergy:
- mostly due to additives effects, rare
systemic toxicity:
- due to overdose or accidental IV injection
- sedation, light-headedness, visual and auditory disturbances, restlessness, convulsions, and CVS depression

Question 20

ex of local anesthetic

Answer 20

lidocaine