Neuromuscular Blockers - Quiz 7 Flashcards Preview

Spring 2020 - Pharmacology 1 > Neuromuscular Blockers - Quiz 7 > Flashcards

Flashcards in Neuromuscular Blockers - Quiz 7 Deck (75)
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1

How does Acetylcholine bind to the Nicotinic Receptor?

The positively charged Nitrogen binds to both alpha subunits of the nicotinic receptor, allowing Sodium to enter. 

2

Which enzyme is responsible for the synthesis of Acetylcholine?

Choline Acetyltransferase

Choline + Acetyl CoA --> Acetylcholine

3

Which Autonomic System does Acetylcholine Activate?

Both

Primarily Rest & Digest, but also Kick starts the Sympathethic Nervous System

4

What deactivates Acetylcholine?

Acetylcholinesterase break down ACh into choline & acetate

5

Why are Neuromuscular Blockades used?

Cause paralysis to reduce complications d/t movement & help with intubation

6

What percentage of Suppression of Single Twitch Response is adequate for Surgery?

90%

7

What is the difference b/t Depolarizing & Non-Depolarizing Agents?

Depolarizing: constantly stimulates muscle fiber and cant respond to ACh

Non-Depolarizing: Competetively blocks ACh from receptor

8

What is ED95

NMB dose with non volatile anesthetic needed for 95% supression of single twitch during

ED95 is much less when used w/ gas

9

How much NMB is needed for Tracheal Intubation in terms of ED95?

2x ED95

10

What is the Order of Effect of NMBs?

Small quick moving muscles first (Eyes, Fingers)

then

Abdomen (Diaphragm) last

Reverses in reverse order d/t blood flow

11

What is the effect of NMBs at the Laryngeal Muscles vs Peripheral Muscles?

More Rapid & Less Intense @ Laryngeal Muscles

12

What are indicators of Laryngeal Relaxation when using NMBs?

Orbicularis Oculi - good indicator

Adductor Pollicis - poor indicator

13

What do the Non-Depolarizing NMBs break down into?

Benzylisoquinolinium - Histamine Release

Aminosteroid

14

What does the Quarternary Ammonium part of the NMB do?

Makes NMB highly ionized & water soluble - stays in blood

Does not cross into CNS or Placenta

Cant Give Orally

Binds to Alpha Subunits

15

What does it mean for NMBs to be non selective?

They will effects at both  Autonomic Nicotinic & Cardiac Muscarinic receptors

16

Which Non-Depolarizing NMBs are Benzylisoquinoliniums?

NMBs that end with -curium

17

Which Non-Depolarizing NMBs are Aminosteroids?

NMBs that end with -curonium

18

Which Non-Depolarizing NMBs are Long Acting?

Pancuronium

Pipercuronium

Doxacurium

19

Which Non-Depolarizing NMBs are Intermediate Acting?

Vecuronium

Rocuronium

Atracurium

Cisatracurium

20

Which Non-Depolarizing NMBs are Short Acting?

Mivacurium

21

What is the only Depolarizing NMB used?

Succinylcholine

Intense Rapid Paralysis

Onset: 30-60 seconds

Duration: 3-5 minutes

22

What is the Mechansim of Action of Succinylcholine?

Binds to one or both alpha subunits @ Nicotinic receptor

Mimics ACh

23

What is the Mechansim of Action of Succinylcholine?

  • Binds to one or both alpha subunits @ Nicotinic receptor
  • Mimics ACh, but longer duration d/t slower hyrdrolysis
  • Hyperpolarizes Receptor & no more ACh can activate the receptor
  • Big Na+ influx causes Efflux of K+

24

What happens in Phase I of Block w/ Succinylcholine?

  • Depolarizing receptor stimulation
  • ↓Contraction to single twich
  • ↓Ampltidude of continuous stimulation
  • TOF > 0.7
  • Muscle twitches @ onset

25

What happens in Phase II of Block w/ Succinylcholine?

Acts like Non-Depolarizer

ACh can no longer act

26

How do Plasma Cholinesterase affect Succinylcholine?

Break SCh down to weak metabolite

Give Neostigmine to reverse for pts w/ liver disease

27

How does High Estrogen & Reglan affect Succinylcholine?

High Estrogen reduces Cholinesterase levels

Reglan Inhibits Cholinsterase

Build up of Succinylcholine

28

How does Obesity affect Succinylcholine?

Obese pt's have more Cholinesterase and may reduce effects of SCh

29

How does Atypical Cholinesterase affect Succinylcholine?

May increase Duration of SCh from 10 minutes to 3+ hours

Test w/ Dibucaine

30

How can side effects of Succinylcholine be reduced?

Pretreat with small dose of Non-Depolarizing NMB

Non effective for Hyperkalemia