NMB: Part 2 - Reversal Flashcards Preview

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Flashcards in NMB: Part 2 - Reversal Deck (49)
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1
Q

What are the clinical uses of anticholinesterase drugs?

A

REversal of NMBD
Antagonism of CNS effects on other drugs
Treatmetn of MG or glaucoma

2
Q

What is the mechanism of action of anticholinesterase drugs?

A

NMJ effects due to inhibition of acetylcholinesterase

3
Q

What are the three classifications of anticholiesterase drugs?

A

Reversible inhibition
formation of carbamyl esters
Irriversible inactivation

4
Q

How is edrophonium classified?

A

reversible inhibition

5
Q

What is echothiophate and how is it classified?

A

It is an organophosphate used in pesticide. It is classified as irreversible inactivation

6
Q

Neostigmine, Physostigmine and pyridostigmine. How are they classified and which one is different?

A

Formation of carbonyl esters.
Physostigmine is the only one that crosses the blood brain barrier.
(the only one with an H goes to the Head)

7
Q

How do Pyridostigmine, Neostigmine and edrophonium compare in onset and duration of action?

A

Edrophonium is short, neo in the middle and Pyridostigmine is longest onset/duration.

8
Q

How are anticholinesterase drugs eliminated?

A

50-75% of elimination is via renal clearance

9
Q

Could you give anticholinesterase to a pt with renal failure?

A

Yes, it would have prolonged effect, but so would your relaxant, so its cool

10
Q

How does age affect neostigmine?

A

children and infants require less

11
Q

What effects do anticholinesterase drugs have on the cardiovascular system?

A

Bradycardia

12
Q

What effects do anticholinesterase drugs have on the GI/GU systems?

A

Increased secrtion and motility

Tx of paralytic ileus or atonic bladder

13
Q

What effects do anticholinesterase drugs have on the secretory glands/airways?

A

Increased secretions and bronchoconstrictions

Increased secrtions in bronchial, lacrimal, sweat, salivary, gastric and intestinal

14
Q

Which neurologic disorder do anticholinesterase drugs treat?

A

MG

15
Q

What is the treatment for Anticholinesterase OD?

A

Atropine with pralodoxime (cholinesterase reactivator)

16
Q

What are the nicotinic and CNS symptoms of anticholinesterase OD?

A
Nicotinic
-from skeletal muscle weakness to paralysis resulting in apnea
CNS
-confusion
-ataxia
-siezure
-coma
-depression of ventilation
17
Q

What is the dose for Neostigmine?

A

0.04-0.07 mg/kg

18
Q

Is 5 mg the max dose for neostigmine?

A

NO!!! Above 5mg increases the chance PONV, but it is not a max

19
Q

What is the rule for when a pt may be reversed?

A

The absence of any palpable single twitches following 5 s of tetanic stimulation at 50Hz implies very intensive blockade that cannot be reversed

20
Q

What is onset, peak and duration of neostigmine?

A

ONset-5-10 minutes
Peak-10 minutes
duration-1 hour

21
Q

How do anticholinergics work?

A

they prevent Ach binding at muscarinic receptors
reversible bond to Ach receptor
can be overcome with increased Ach

22
Q

What are the effoects of anticholinergics?

A
Sedation (atropine and scopalamine)
Antisialagogue
Increase HR
Relax smooth muscle
Mydiasis
Prevent motion sickness
Decrease gastric ion secretion
23
Q

Why do we use glyco instead of atropine when giving neostigmine?

A

closest onset and duration compared to neo

24
Q

How are anticholinergics cleared?

A

Cleared unchanged in urine. but its not really a big deal for renal pts

25
Q

How do you administer atropine, and glyco?

A

IM or IV. Po is unpredictable

26
Q

What is the lipid solubility of atropine, glyco and scopalamine?

A

scopalamine and atropine are lipid soluble

glyco is not

27
Q

What are clinical uses for anticholinergics?

A
Important
-Pre op med
-tx of bradycardia
-NDNMB reversal
Less common
-Bronchodilation
-Smooth muscle relaxant (biliary and uretal)
-Antagonism of gastric acid secretion (Not used since the dose needed is very high and better drugs are available)
-Prevents nausea and vomiting
28
Q

HOw would anticholinergics affect glaucoma?

A

make it worse

29
Q

Do anticholinergics cross the placenta?

A

Yes, but it’s not a big deal for the baby

30
Q

Which anticholinergic is the most potent sedative? Where does it work?

A

scopalamine
works at reticular activating system
4 mg IV is a good dose. Will cause amnesia

31
Q

Why would atropine be a bad choice for sedation?

A

causes memory deficit and delayed arousal

32
Q

How much glycopyrolate do you give for sedation?

A

glyco has no sedation effects

33
Q

Which anticholinergic is the most potent antisialogogue?

A

Scopalamine

3x more potent than atropine with less HR changes

34
Q

how does glyco compare to atropine as an antisialogogue?

A

2x more potent

Useful when sedative effects are not wanted

35
Q

How do anticholinergic drugs work to treat bradycardia?

A

Blocks Ach @ SA node

36
Q

How does glyco compare to atropine for treating bradycardia?

A

equal in effectiveness, but the onset of glyco is slower

37
Q

What is the mechanism for anticholinergics causing bronchodilation?

A

block the muscarinic receptors of the smooth muscle of medium and large AW leading to decreased resistance and increased deadspace

38
Q

What is the anticholinergic drug used for bronchodilatin? what is it called when its combined with albuterol?

A
ipratropium bromide (atrovent)
combivent
39
Q

Can anticholinergic drugs be used to treat narcotic induced biliary constriction?

A

no

40
Q

What are symptoms of central anticholinergic syndrome?

A

restlessness
hallucinations
somnolence
unconsciousness

41
Q

What is the treatment for central anticholinergic syndrome?

A

Physostigmine-it crosses BBB

42
Q

Which pts are susceptible to central anticholinergic syndrome?

A

Children and elderly

43
Q

What dose of glyco causes central anticholinergic syndrome?

A

It does not cross into the central nervous system, so it wont cause CAS. It is most common with scopalamine, but can be caused by atropine

44
Q

What are the symptoms of anticholinergic OD?

A
Dry mouth
blurred vision
tachycardia
Increased temp
flushing 
irritability
45
Q

What are the effects of anticholinergic OD?

A

Seizures
coma
ventilatory paralysis

46
Q

What is the treatment for anticholinergic OD?

A

physostigmine

47
Q

What are criteria for a pt being reversed?

A
TOF ratio >0.7
tetanus with 100 Hz stimulation
Grip strength
Negative inspiratory pressure > 20 cm H2O
Sustained head lift = 5 seconds
48
Q

What nerves do we use to monitor TOF?

A

Ulnar nerve
Posterior Tibial
Peroneal
Facial nerve

49
Q

What’s so special about Sugammedex?

A

Works independent of Ach level in NMJ-so a profound block with no twitches can be reversed
Cleared renally but speed of reversal is independent of renal function
No need for muscarinic antagonist
Still awaiting approval-some evidence of anaphylactic reaction