Anesthesia

Question 1

-from administration to loss of consciousness, decreased awareness of pain, may have some amnesia and decreased consciousness

Answer 1

stage1 - analgesia stage

Question 2

• from loss of consciousness to regular respiration
• excitation and delirium may occur
• amnesia occurs
• vomiting and incontinence possible

Answer 2

stage 2 - disinhibition

Question 3

• from regular respiration to respiratory arrest
• patient unconscious, no pain reflexes
• respiration and blood pressure maintained

Answer 3

stage 3 -surgical

Question 4

• from respiratory arrest to death

- requires mechanical and pharmacological support

Answer 4

stage 4 - medullary paralysis stage

Question 5

• very controllable, readily reversible
• induction not as fact or smooth as with fixed agents
• depress spontaneous and evoked neuronal activity
• act at voltage gated K channels, GABAa receptor chloride channels resulting in hyperpolarization

Answer 5

inhalable anesthetics

Question 6

• insufficient potency for surgical anesthesia
• has analgesic activity
• can be used as carrier for volatile anesthetics
• decreases methionine synthetase with chronic exposure and can cause megaloblastic anemia

Answer 6

nitrous oxide

Question 7

halothan, enflurance, desflurane, isoflurane, sevoflurane

Answer 7

volatile inhaled anesthetics

Question 8

anesthetic concentration in the inspired air is proportional to _________, with higher resulting in more rapid achievement of anesthetic concentrations in blood

Answer 8

partial pressure

Question 9

blood:gas partition coefficient?

Answer 9

Otswald

Question 10

lower Otswald coefficient leads to _______ equilibrium with the rbain

Answer 10

faster

Question 11

the partial pressure of anesthetics with _______ solubility in blood are more affected by ventilation rate

Answer 11

higher

Question 12

the concentration of anesthetic in the inspired air at equilibrium when there is no response to a skin incision in 50% of patients

Answer 12

minimum alveolar concentration (MAC)

Question 13

higher MAC = ______ potent

Answer 13

less

Question 14

inhaled anesthetic that depresses myocardium, has liver toxicity

Answer 14

halothane

Question 15

• barbiturates, IV/fixed anesthetics
• rapid induction
• no analgesia*, pain on injection
• decrease in respiration, difficult to control level of anesthesia
• redistributes, accumulates in adipose

Answer 15

thiopental, methohexital

Question 16

• IV/fixed anesthetic
• acts at GABAa receptors, increase channel open time
• more rapid recovery than barbiturates, 10X faster hepatic metabolism
• maintenance and induction anesthesia
• used for OP procedures
• significant decrease in BP and blunts baroreceptor reflex, decreases respiration

Answer 16

propofol

Question 17

• used for induction and balanced anesthesia, esp in patients at risk for hypotension
• minimal CV/resp depression
• no analgesic activity
• not recommended for long term infusion
• high incidence of nausea, vomiting, pain on injection, myoclonus

Answer 17

etomidate

Question 18

• dissociative anesthesia, catatonia, analgesia, amnesia w/o loss of consciousness
• blocks NMDA glutamate receptor ion channel
• short duration of action
• excellent analgesia and amnesia
• mydriasis, salivation, lacrimation, spontaneous limb movements
• cardiac stimulation
• increases cerebral blood flow
• emergence phenomenon - hallucinations and disorientation, can decrease w/ benzodiazepines
• use limited mainly to small children, patients at risk for hypotension and bronchospasm

Answer 18

ketamine

Question 19

• shortest acting benzo, least irritating for IV admin
• used in combo with inhaled agent or IV opioids
• can be used for maintenance of anesthesia with other agents as part of general or conscious sedation
• rapid onset and recovery
• good amnestic effects
• antagonist flumazenil can accelerate recovery
• induction too slow to induce anesthesia

Answer 19

midazolam

Question 20

• opioid, can achieve anesthesia with sufficient dose or in combo with benzodiazepines
• useful in patients with compromised CV function
• provides excellent post op analgesia
• can cause truncal rigidity, impair ventilation

Answer 20

fentanyl

Question 21

• minimize anesthetic use
• good for ortho procedures
• short acting good for intubations, ECT
• should never be used as substitute for inadequate anesthesia

Answer 21

neuromuscular blocking agents (paralytics)

Question 22

• d-tobucurarine, mivacarium, rocuronium

- potency altered by pH, increases in histamine release

Answer 22

competitive nicotinic antagonists

Question 23

• depolarizing nicotinic agonist
• short duration of action
• desensitization follows with long term exposure

Answer 23

succinylcholine

Question 24

• no effect on motor end plate depolarization
• no effect on striated muscle
• small muscles affected first
• additive w/ d-tobucurarine
• reversal of block with physostigmine
• increased potency w/ inhaled anesthetics and antibiotics

Answer 24

competitive neuromuscular blockers

Question 25

- partial persistent depolarization at motor end plate - fasciculations of striated muscle - skeletal muscle affected first - antagonistic effect with d-tobucurarine - no antagonism w/ physostigmine - no effect with inhaled anesthetics or antibiotics

Answer 25

depolarizing neuromuscular blockers

Question 26

-most paralytics cause _______ release leading to hypotension and bronchospasm, most pronounced with d-tobucurarine

Answer 26

histamine

Question 27

succinylcholine cause muscle pain due to ________

Answer 27

fasciculations

Question 28

- opioids - local anesthetics - increase potency of both competitive and depolarizing agents - anticonvulsants - CV drugs - antibiotics (esp. aminoglycosides, increase potency and duration of competitive antagonists) - inhalable anesthetics esp isoflurance increase potency and duration

Answer 28

drug interactions with neuromuscular blockers

Question 29

- block nerve conduction by blocking voltage gated sodium channels, thus preventing depolarization and conduction of the cation potential - charged anesthetic molecules gain access to the channel when it is open - efficacy is use dependent, - also block K channels at higher concentrations

Answer 29

local anesthetics

Question 30

local anesthetics order of block?

Answer 30

pain --> cold/warm/touch/deep pressure --> muscle tone/proprioception/motor function

Question 31

- penetrates membranes, vasoconstrictor, medium acting | - ester, used topically for nasal and opthalmic procedures

Answer 31

cocaine

Question 32

- ester, surface use only, very lipophilic | - burns, bites, hemorrhoids, cather, endoscope placement

Answer 32

benzocaine

Question 33

-amide, most widely used, medium acting

Answer 33

lidocaine

Question 34

- amide, medium acting | - vasoconstricts, slightly longer lasting

Answer 34

mepivicaine

Question 35

long acting amides

Answer 35

bupivicaine, ropivicaine

Question 36

potency of local anesthetics affected by ______

Answer 36

pH

Question 37

local anesthetics are weak bases, the _______ form is required to penetrate the membrane to gain access to the channel inside the cell membrane -potency decreased at low pH (infected tissues)

Answer 37

unprotonated

Question 38

- duration of action of local anesthetics proportional to time drug is in contact with the nerve - more ________ leads to shorter action, greater systemic absorptin - use epi to increase duration

Answer 38

vascularization

Question 39

- CNS: sleepiness, lightheaded, restlessness, nystagmus and myoclonus, tonic clonic seizures with esters, direct neurotoxicity with spinal admin due to pooling in cauda equina - CV: depression, hypotension, cocaine can cause HTN, arrythmias, myocardial failure - allergic rxns with esters

Answer 39

local anesthetic adverse effects

Question 40

______ syndrome tends to occur with continuous spinal anesthesia

Answer 40

cauda equina