NMBs

Question 1

Succs MOA?

Answer 1

Succs binds to alpha subunit of Ach nicotinic receptors, channel opens, motor endplate depolarizes, one single contraction occurs, channels stay open and another action potential can’t be initiated (due to inactivated Na channels) until succs diffuses back into circulation

Question 2

What is the reversal of succs?

Answer 2

There isn’t one!

Sucks block is terminated by diffusion of succs away from the NMJ

Question 3

What is the black box warning of succs having to do with pediatric administration?

Answer 3

May result in profound bradycardia or asystole

Question 4

What is a dibucaine number? What does it indicate? What does this have to do with succs?

Answer 4

Indicates genetic make-up of a person with regard to pseudocholinesterase
If you have a low dibucaine number, succs will act longer

Question 5

Which NMBs release histamine?

Answer 5

D-tubo - moderate amount
Mivacurium - small amount
Atracurium - small amount
Succs- small amount

Question 6

Which NMBs cause increase/decrease in BP?

Answer 6

Decrease- mivacurium, D-tubo, succs

Increase- pancuronium

Question 7

Which NMBs cause increase/decrease in HR?

Answer 7

Decrease- succs
Increase- mivacurium, atracurium, D-tubo, pancuronium
(None- roc, vec)

Question 8

What drugs have an effect on depolarizer or non-depolarizer NMBs

Answer 8

Antibiotics
Cholinesterase inhibitor (succs only)
Antidysrhythmics
Dantrolene, ketamine (NDMRs only, not sure about succs)
Inhalational agents
Locals

Question 9

What is the priming principle? (AKA the defasciculating dose)

Answer 9

Speeds onset of NDMRs; prevents succs-induced fasciculations
Give 10% of intubating dose 5 min before induction
The initial small dose primes spare receptors without producing paralysis the time

Question 10

What class of drugs will reverse nondepolarizing NMBs? How does it work?

Answer 10

Anticholinesterases, they competitively binds to and inhibits AChE in the NMJ, increasing availability of ACh

Question 11

Which NMB reversal is most reliable in a deep block (over 90% receptors)

Answer 11

Neostigmine

Note: Nothing can block a profound block (100%)

Question 12

What anticholinergic has a similar onset and duration to Neostigmine, and is mixed together to decrease side effects? It is also used with pyridostigmine.

Answer 12

Glycopyrrolate

Question 13

Due to similar onset times, which anticholinergic is endrophonium administered with?

Answer 13

Atropine

Question 14

Side effects of anticholinesterases?

Answer 14

Bradycardia
Bronchospasm
N/V
Increased secretions and peristalsis

Question 15

Which would you use succhs for, a bronchospasm or laryngospasm?

Answer 15

Laryngospasm
Succs can actually make the bronchospasm worse
Note: use more gas or ketamine to break the bronchospasm

Question 16

In order to reverse the patient, they must have how many twitches present, if any?

Answer 16

One twitch at least

Question 17

What are clinical signs of adequate reversal?

Answer 17

Head lift, cough, swallow
Spontaneous ventilation
Open eyes, protrude tongue

Question 18

What does physostigmine reverse?

Answer 18

Reverses confusion/disorientation following atropine/scopalamine
Reverses somnolence with opioids/valium/versed/IA/ketamine
Usually only used bc provider error

Question 19

Which drug is the only organophosphate anticholinesterase drug used clinically, lowers IOP, useful in treating glaucoma, and may prolong DOA of succs?

Answer 19

Echothiopate

Question 20

What is the preferred nerve and correlating muscle used for peripheral nerve stimulation (PNS) to detect twitches?

Answer 20

Ulnar nerve

Adductor pollicis muscle