NMB, Reversal agents, antimuscarinic PPT

Question 1

what kind of receptors are at the NMJ?

Answer 1

post synaptic nicotinic receptors

Question 2

type of receptor found on PRESYNAPTIC membrane

Answer 2

alpha 3

Question 3

how much do you need to get an initial action potential

Answer 3

10%

Question 4

how much to produce fade? (percentage)

Answer 4

75%

Question 5

how do you prolong the effects of succinylcholine? (3)

Answer 5

1. high dose
2. continuous infusion
3. reduced rate of metabolism

Question 6

how is succinlycholine metabolized?

Answer 6

by pseudocholinesterase

Question 7

Factors that may impact duration of action of succinylcholine (3)

Answer 7

1. hypothermia
2. low enzyme- pseudocholinesterase
3. genetic

Question 8

things that inhibit pseudocholinesterase activity (9)

Answer 8

1. echothiophate
2. neostigmine, pyridostigmine
3. phenelzine
4. cyclophosphamide
5. metoclopramide
6. esmolol
7. pancuronium
8. oral contraceptives
9. dibucaine

Question 9

usual adult dose for intubation of succinylcholine

Answer 9

1-1.5 mg/kg IV

Question 10

Will neonates have a lower or higher ECF/volume of distribution wt based dose?

Answer 10

higher/larger

Question 11

when would you see a cardiovascular effect with sux in adults?

Answer 11

when you give SECOND dose of sux

Question 12

how do you prevent fasciculations from sux?

Answer 12

pretreatment with small dose nondepolarizing agent

Question 13

sux can increase serum potassium by how much ?

Answer 13

0.5 mEq/L

Question 14

short term effect on hyperkalemia management

Answer 14

insulin (drives K+ intracellular) + glucose to prevent hypoglycemia

Question 15

if someone has high enough K+ extracellularly it can lead to ___

Answer 15

cardiac arrest

Question 16

describe the 4 things that happen when there is denervation injury.

Answer 16

1. immature isoform (epsilon subunit)
2. more receptors spread out (extrajunctional receptors)
3. widespread depolarization and extensive K release
4. Risk peak 7-10 days after injury (minimal after 2 days)

Question 17

Sux adverse effects (10)

Answer 17

1. ) bradycardia
2. AV node arrhythmia
3. ventricular arrhythmia
4. increased pressure: IC, IO, IG
5. hyperkalemia
6. myalgia
7. masseter spasm
8. malignant hyperthermia
9. precurarization
10. allergic rxns

Question 18

When should you NOT use sux? (6)

Answer 18

1. underlying neuromuscular disease
2. risk of MH
3. hx of ax to sux
4. homozygous for atypical plasma cholinesterase
5. [K+] > 5.5 mEq/L
6. after 2-3 days; denervation, immobilization, burns

Question 19

how can you quicken the effect of NONDEPOLARIZING NMB?

Answer 19

larger dose

Question 20

True/False: potency leads to a faster onset

Answer 20

FALSE; potency =slower onset; smaller dose

Question 21

how to enhance nondepolarizing NMB?

Answer 21

increase dose, risk AE’s and prolonged duration of action

Question 22

a repeated dose of nondepolarizing NMB would rely on ___

Answer 22

elimination

Question 23

which nondepolarizing nmb is metabolized by plasma cholinesterase?

Answer 23

mivacurium

Question 24

Which nondepolarizing drugs are eliminated renally?

Answer 24

pancuronium and doxacurium

Question 25

drugs that are intermediate acting

Answer 25

1. atracurium 2. rocuronium 3. vecuronium

Question 26

short acting duration of action nondepolarizing nmb

Answer 26

mivacurium

Question 27

long acting duration of action nondepolarizing nmb

Answer 27

pancuronium

Question 28

how much (percentage) of the initial dose do you need to prevent fasciculations with sux?

Answer 28

10-15% of dose

Question 29

what agents are likely to cause a histamine release?

Answer 29

atracurium

Question 30

which drug is more likely to cause a vagal blockade?

Answer 30

rocuronium and pancuronium (panc ++)

Question 31

Factors that prolong Nondepolarizing NMB agent (4)

Answer 31

1. hypothermia 2. respiratory acidosis could potentiate blockade and antagonize reversal agent effects 3. electrolytes (hypo kalemia and calcemia augment ND block) ; hypermagnesemia potentiates ND block 4. ) age (bigger dose due to increased ECF?)

Question 32

which drug does NOT effect histamine release?

Answer 32

cisatracurium

Question 33

offset speed to recover from 25% to 75% twitch ht

Answer 33

recovery index

Question 34

percentage for full block of neurotransmission

Answer 34

95%

Question 35

complications for someone with a residual block (2)

Answer 35

1.) hypoventilation 2.) aspiration | monitor duration of reversal agent vs. NMB

Question 36

reduction of evoked response indicative of ND block

Answer 36

fade

Question 37

when does a single twitch stimulation disappear?

Answer 37

when 90-95% receptors are occupied by neuromuscular blocker

Question 38

determined by response to peripheral nerve stimulation

Answer 38

NMB reversal (sugammadex, neostigmine)

Question 39

Factors that affect dose and response for NM reversal (5)

Answer 39

1. shorter acting; faster onset vs. longer acting 2. larger doses vs. smaller doses 3. duration of action of NMB 4. clearance 5. faster reversal- fewer complications

Question 40

fastest onset and shortest duration of action NM reversal and less muscarinic effect

Answer 40

edrophonium

Question 41

selective for aminosteroid non depolarizing relaxants

Answer 41

sugammadex

Question 42

dose for sugammadex for routine deep block

Answer 42

4 mg/kg

Question 43

what can happen to sugammadex if under dosed?

Answer 43

may wear off before NM blocker is completely cleared