anesthesia

Question 1

which inhaled anesthetic produces analgesia? which maintains protective CO2 reflex?

Answer 1

nitrous oxide for both

Question 2

which inhaled anesthetic is not as lipid soluble as the others? what is the result? how is that taken advantage of?

Answer 2

nitrous oxide
reaches saturation rapidly
mass effect: coformulated with other agents

Question 3

which inhaled anesthetic has no effects on CV system? what is the exception to that?

Answer 3

nitrous oxide

opioids can block reflexive sympathetic effects and unmask depressive effects

Question 4

which inhaled anesthetic is most responsible for diffusional hypoxia on termination?

Answer 4

nitrous oxide

Question 5

what does the initial administration of anesthetics show?

Answer 5

period of delirium:
exaggerated mechanics of respiration, breath holding
increased muscle tone and BP, mydriasis

Question 6

why would analgesics be routinely used in anesthesia?

Answer 6

loss of memory and perceptive awareness may precede analgesia

Question 7

which inhaled anesthetic has greatest potency? why?

Answer 7

halothane: lowest MAC

Question 8

why can’t nitrous oxide be used alone?

Answer 8

MAC = 105%

incomplete anesthetic: requires supra-atmospheric pressures to work on own

Question 9

which inhaled drugs work fastest? why?

Answer 9

N2O>desflurane>sevoflurane

less lipid soluble->lower blood:gas partition coefficient

Question 10

besides lower blood:gas partition coefficients, why else do the newer inhaled drugs work faster?

Answer 10

lower brain:blood partition coefficients

enter brain faster

Question 11

irritating odor is adverse effect of which anesthetics?

Answer 11

enflurane, isoflurane, desflurane

Question 12

which inhaled anesthetics produce muscle relaxation?

Answer 12

enflurane and isoflurane

Question 13

which inhaled anesthetic is pro-arrhythmogenic? why?

Answer 13

halothane: sensitizes heart to catecholamines

Question 14

what is a unique toxicity of halothane?

Answer 14

halothane hepatitis

Question 15

which inhaled anesthetic is pro-epileptic in susceptible individuals?

Answer 15

enflurane

Question 16

what are two unique adverse effects of N2O?

Answer 16

diffusional hypoxia

increased pressure in gas-containing areas of body

Question 17

which drugs cause malignant hyperthermia? what is the antidote?

Answer 17

volatile anesthetics (not N2O)
dantrolene

Question 18

what is thiopental and what is it used for?

Answer 18

barbiturate

IV induction of anesthesia

Question 19

what is propofol and what is it used for? what is worrying about its MOA?

Answer 19

IV induction of anesthesia
blocks NMDA glutamate receptors, GABA agonist
at high concentrations, acts in place of GABA

Question 20

what is unique about ketamine? what is its mechanism of action?

Answer 20

dissociative anesthetic: dissociates cortex from external environment
NMDA glutamate antagonist

Question 21

what are the longest and shortest acting benzodiazepines used in IV anesthesia?

Answer 21

longest: diazepam
shortest: midazolam

Question 22

which opioid used in anesthesia produces ultra-short acting analgesia? long-acting? just short?

Answer 22

remifentanil
morphine
fentanyl

Question 23

what is the risk with the formation of lipid-soluble IV anesthetics?

Answer 23

surfactants can cause thrombophlebitis

Question 24

which IV anesthetics act on glutamate NMDA receptors?

Answer 24

propofol and ketamine

Question 25

etomidate

Answer 25

GABA agonist

Question 26

which IV anesthetic's are most and least stored in fat?

Answer 26

most: diazepam, thiopental least: etomidate

Question 27

what are the effects of thiopental, etomidate, and propofol on CBF, oxygen requirements, and ICP? exception?

Answer 27

decrease them all | ketamine: increases CBF and ICP, no effects on O2 requirements

Question 28

which IV anesthetics increase HR? what is their effect on CO and MAP?

Answer 28

propofol and thiopental | decrease CO and MAP

Question 29

which IV anesthetic is good for cardiac patients? why?

Answer 29

etomidate | no effects on heart of vasculature

Question 30

what drug causes a fatal CV and multi-organ failure of unknown etiology?

Answer 30

propofol infusion syndrome

Question 31

what drug inhibits steroidogenesis, potentially fatally?

Answer 31

etomidate

Question 32

what IV anesthetic preserves important protective reflexes and is an analgesic?

Answer 32

ketamine

Question 33

what drug produces hallucinations when awakening?

Answer 33

ketamine

Question 34

what local anesthetic is used in dental procedures with epi? why?

Answer 34

articaine | supposed better penetration of bone

Question 35

what topical anesthetics can be applied to mucous membranes? which can't?

Answer 35

benzocaine and dyclonine | dibucaine and pramoxine

Question 36

what drugs might be administered with local anesthetics to increase efficacy?

Answer 36

epinephrine or levnordefrin | vasoconstrictors

Question 37

what drug might be administered to speed recovery from local anesthesia? why?

Answer 37

phentolamine | alpha-blocker->dilate vasculature

Question 38

methemoglobinemia is primarily seen with which anesthetic? what other drug? how can it be reversed?

Answer 38

prilocaine and benzocaine to lesser extent | methylene blue or ascorbic acid

Question 39

what local anesthetics have greatest and least chance of cardiotoxicity and why?

Answer 39

greatest: bupivacaine, long-acting least: ropivacaine, short-acting