Anesthetics - IV

Question 1

4 goals of balanced anesthesia

Answer 1

1. relieve anxiety
2. relax muscles
3. prevent secretions
4. induce unconsciousness

Question 2

transmitters in cortical stimulation

Answer 2

cholinergic - PPT & LDT activate the thalamus

monoaminergic - H, 5HT3, GABA activate cortex via thalamic inputs

Question 3

induction agents

Answer 3

thiopental, propofol, etomidate

Question 4

MOA of thiopental

Answer 4

∙ ↑GABA & Glycine binding to receptor

∙ Barbiturates prolong GABA binding

Question 5

AE of thiopental

Answer 5

AE: ↓CBF, ICP, MAP, CO, RR & VE and ↑HR

∙ Porphyria, enzyme induction

Question 6

Admin & half-life of thiopental

Answer 6

A: in Na2CO3

↑half-life

Question 7

MOA of propofol

Answer 7

∙ ↑GABA & Glycine binding to receptor
∙ @ ↑conc acts like GABA itself
∙ ↓NMDA binding
∙ ↓glutamate binding to receptor

Question 8

AE of propofol

Answer 8

AE: ↓CBF, ICP, MAP, CO, RR & VE and ↑HR
∙ Antiemetic
∙ Propofol infusion syndrome

Question 9

Admin of propofol

Answer 9

A: glycerol, EDTA (lipophilic)

Question 10

MOA of etomidate

Answer 10

∙ ↑GABA & Glycine binding to receptor

Question 11

AE of etomidate

Answer 11

AE: ↓CBF, ICP, RR, VE. None on HR, MAP, CO
∙ Inhibition of steroidogenesis
∙ Not used in ICU

Question 12

Admin & half-life of etomidate

Answer 12

A: propylene glycol (surfactant)

↓half-life

Question 13

NMDA blocker

Answer 13

ketamine

Question 14

ketamine MOA

Answer 14

∙ ↑GABA & Glycine binding to receptor
∙ ↓NMDA binding
∙ ↓glutamate binding to receptor

Question 15

ketamine AE

Answer 15

AE: ↑CF, ICP, MAP, HR, CO. None on RR, VE
∙ Analgesic (IM route)
∙ Preserves protective reflexes
∙ Hallucination on emergence (tx w/ benzos)

Question 16

clinical utility for ketamine

Answer 16

Clinical utility: dissociative anesthetic, produces selective neuronal depression

Question 17

benzos for analgesia

Answer 17

diazepam, midazolam

Question 18

MOA for benzos

Answer 18

produce an allosteric change in receptor activity & shift dose curve for GABA binding to left, ↑potency but NOT efficacy

Question 19

AE for benzos

Answer 19

∙ ↑therapeutic safety margin
∙ CV & respiratory depression alone (↓)
∙ death on OD if combined with EtOH

Question 20

specific antagonist for benzo OD

Answer 20

flumanezil

Question 21

rank the half-lifes of benzos from longest to shortes

Answer 21

diazepam (20-40hr) > > midazolam (2-4)

Question 22

metabolism of diazepam

Answer 22

3 active metabolites

Question 23

metabolism of midazolam

Answer 23

rapidly inactivated

Question 24

opioids for analgesia

Answer 24

morphine, fentanyl

Question 25

AE of opioids

Answer 25

∙ Bradycardia
 ∙ Hypotension (2nd to H release)
 ∙ HTN (reflex)
 ∙ Respiratory depression (dose-dependent)
      ∙ anesthetic + opioid = severe
 ∙ Muscle rigidity
 ∙ n/v, constipation, miosis
 ∙ ↑ICP & cranial bloodflow (↑PaCO2)

Question 26

best opioid for long-lasting analgesia?

Answer 26

morhpine (peak in 15-30 min)

Question 27

PK fentanyl

Answer 27

More lipid soluble, onset in <30 sec, peak effect in 2-3 min (n/v rare)

Question 28

signs & symptoms of malignant hyperthermia

Answer 28

↑in end tidal CO2, total body rigidity, ↑HR & ↑RR, respiratory & metabolic acidosis, unexpected MI

Question 29

causative agents of malignant hyperthermia

Answer 29

succinylcholine, but also all volatile anesthetic agents (desflurane & sevoflurane)

Question 30

treatment for malignant hyperthermia

Answer 30

dantrolene (avoid CCB with dantrolene), stop agent, hyperventilate with O2 & correct hyperkalemia & acidosis