NMB

Question 0

depolarizers mimic __

the only depolarizer left __

Answer 0

acetylcholine

succinycholine

Question 1

Can NMB’s cross the bbb?

Answer 1

no, thus cannot produce anesthesia, only work at the neuromuscular junctions

Question 2

do non depolarizers mimic or block acetylcholine at the neuromuscular junction?

Answer 2

non depolarizers block

depolarizers (succs) mimics

Question 3

name some aminosteroid non-depolarizers

Answer 3

anything the ends in -onium like:
vecurONIUM
rocurONIUM
pancurONIUM

onium kind of looks like onion, so onions must be aminosteroids

Question 4

name some benzylisoquinoliniums

Answer 4

anything that ends in -curium:
atraCURIUM
cisatraCURIUM

Question 5

what are the characteristics of a phase 1 block?

Answer 5

reduction in amplitude of single twitch, NO FADE WITH TETANY OR TOF

Question 6

what are the characteristics of a phase 2 block?

Answer 6

reduction in amplitude of single twitch, FADE with tetany and TOF

Question 7

how is potency of NMBs measured?

Answer 7

the dose required to reduce the amplitude of single twitch 95%, measured under nitrous-barb-opioid anesthesia

Question 8

the ED95 is not enough to intubate on, so typically we give __x the ED95 to intubate

Answer 8

2x

Question 9

since the cords are fast twitch, which is a more accurate indicator of optimal NMB, adductor pollicis or obicularis oculi?

Answer 9

obicularis oculi, blinking is a fast-twitch muscle movement

Question 10

do NMB affect fast or slow twitch muscles first?

why?

Answer 10

fast, fortunately for us there are more receptors at fast muscles, so the NMB equilibrates more quickly there

Question 11

fortunately for us, to paralyze the diaphragm requires __x the dose required to paralyze the adductor pollicis or obicularis oculi

Answer 11

2x

Question 12

single twitch gives __-junctional data

Answer 12

post

Question 13

tetanus and TOF gives __-junctional data

Answer 13

pre

Question 14

trick question, do depolarizers exhibit Wedensky inhibition?

Answer 14

no, depolarizers (succs) do not exhibit fade with TOF (wedensky)

Question 15

if your clueless attending injects an unlabeled syringe of clear medication into a patient who subsequently develops paralysis, how can you determine if it was a depolarizer or a non-depolarizer?

Answer 15

do TOF, non-depolarizer will exhibit fade, whereas depolarizing succs does not exhibit fade.

single twitch won’t tell you because you can’t see fade with a single twitch.

Question 16

why can’t NMBs cross the BBB and cause CNS effects, cross the placenta, etc?

Answer 16

because they are quaternary ammonium groups, highly ionized, water soluble, and poorly lipid soluble, thus they have a small volume of distribution

Question 17

what is the INITIAL reason for decreased concentrations on NMBs

Answer 17

redistribution

Question 18

are NMBs highly protein bound?

Answer 18

nope, but with reduced vD such as in hypovolemia, greater effects will be seen due to increased plasma concentrations

Question 19

for laryngospasm, doses of succs as low as ___mg/kg may be sufficient

Answer 19

0.1

Question 20

patients should have a TOF >0.7 for spontaneous ventilation. what the heck does that mean?

Answer 20

it means that your fourth twitch is at least 70% of the amplitude of the first twitch.

Question 21

concentration and dosage of succs

Answer 21

20 mg/ml

1-1.5 mg/kg

Question 22

concentration and dose of vec

Answer 22

concentration 1 mg/ml

dose 0.1 mg/kg

Question 23

concentration and dosing roc

Answer 23

concentration 10 mg/ml

dose 0.6-1 mg/kg (1mg/kg to intubate in 1 minute)

Question 24

concentration and dose of nimbex/cisatracurium

Answer 24

concentration 2 mg/kg dose 0.1 mg/kg don't let the concentration of nimbex trip you up, it has twice the concentration of vec because it's got such a long drug class name - benzylisoquinolinium

Question 25

what does a molecule of succs consist of?

Answer 25

two molecules of ACH linked by acetate methyl groups

Question 26

what is the difference between succs and the other NMBs?

Answer 26

succs actually binds to and ACTIVATES the receptor (thus fasciculations), whereas benzylisoquinoliniums and aminosteroids BLOCK BUT DON'T ACTIVATE the receptor (thus no fasciculations)

Question 27

why don't NMBs work on cardiac, GI, and other smooth muscle junctions?

Answer 27

NMBs only work on cholinergic receptors, not muscarinic or nicotinic receptors

Question 28

what is common to all NMBs?

Answer 28

quaternary ammonium group with at least 1 charged nitrogen atom

Question 29

the five post-junctional subunits are:

Answer 29

2 alphas 1 beta 1 gamma 1 delta the sorority that Paul Meadows was in during his college days

Question 30

how wide is the synaptic cleft?

Answer 30

20-30 nm

Question 31

are pre-junctional nerve endings myelinated or non-myelinated?

Answer 31

NON-myelinated

Question 32

what class is acetylcholine? how is it synthesized? how many molecules of ACH in a quanta?

Answer 32

- quaternary ammonium ESTER - acetylation of choline, controlled by enzyme choline acetylase - 1000 molecules in a quanta

Question 33

do non-depolarizers cause a conformational change in the alpha subunits?

Answer 33

no, only succs (depolarizer) causes the conformational change and opens ion channels, fasciculations, etc. Non-depolarizers block one or the other alpha subunit

Question 34

why should you pretty much always reverse your patients?

Answer 34

because occupation (or blockade) of up to 70% of receptors will not show any evidence of block by single twitch test, thus your patient will be weak but you wouldn't know it by testing with nerve stimulator

Question 35

how many alpha subunits do you gotta block before neurotransmission fails?

Answer 35

80-90%

Question 36

paralysis is complete at __ to __ % occupancy, but adequate muscle relaxation is __ to __%

Answer 36

90-95% occupancy is complete | 85-90% is adequate

Question 37

If you do a TOF and the fourth twitch is absent, that equals approximately __-__% suppression of a single twitch

Answer 37

70-75%

Question 38

Let's say your patient recently had a stroke and is hemiplegic, which side should you place your nerve stimulator? what about a patient with parkinsons, MS, or muscular dystrophy? -what about para/quadriplegic?

Answer 38

- the UNaffected side for stroke - no change for Michael J Fox (parkinsons) or MS, or muscular dystrophy - para/quad will have increased sensitivity to NDNMBs

Question 39

burn patients and NDNMBs?

Answer 39

resistance to NDNMBs, begins at 10 days, peaks at 40 days, declines after 60 days, >30% BSA

Question 40

what is the autonomic margin of safety?

Answer 40

the difference between the NMB dose and the dose producing circulatory effects the greater the margin, the safer the drug

Question 41

what is critical illness myopathy?

Answer 41

patients who received prolonged NMB for mechanical ventilation >6 days may have significant weakness persisting for several months

Question 42

what factors enhance NDNMB activity? sevo at 2, just got some gentamycin abx, had a regional block with LA, is on digoxin and lasix, got some mag in the unit, takes lithium and just got a ganglionic blocker for autonomic dysreflexia. Also is hypothermic

Answer 42

``` volatiles aminoglycosides LA anti-dysrhythmics diuretics Mg++ lithium ganglionic blockers hypothermia ```

Question 43

what does hypotension do to NDNMB?

Answer 43

slow onset, prolong duration

Question 44

let's say you decide not to reverse your patient, take them to the PACU where they get too much morphine and develop respiratory acidosis, what happens to their NDNMB?

Answer 44

increases it, re-curarization

Question 45

how do volatiles enhance NDNMB?

Answer 45

volatile induced depression of CNS

Question 46

Ester LA's compete for plasma cholinesterases and therefore prolong the effects of __

Answer 46

succs

Question 47

gorillacillin

Answer 47

a medical slang term for any of the big bad antibiotics with very broad coverage