NMB: Part 2 - Reversal Flashcards Preview

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

What are the clinical uses of anticholinesterase drugs?

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

2

What is the mechanism of action of anticholinesterase drugs?

NMJ effects due to inhibition of acetylcholinesterase

3

What are the three classifications of anticholiesterase drugs?

Reversible inhibition
formation of carbamyl esters
Irriversible inactivation

4

How is edrophonium classified?

reversible inhibition

5

What is echothiophate and how is it classified?

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

6

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

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

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

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

8

How are anticholinesterase drugs eliminated?

50-75% of elimination is via renal clearance

9

Could you give anticholinesterase to a pt with renal failure?

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

10

How does age affect neostigmine?

children and infants require less

11

What effects do anticholinesterase drugs have on the cardiovascular system?

Bradycardia

12

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

Increased secrtion and motility
Tx of paralytic ileus or atonic bladder

13

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

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

14

Which neurologic disorder do anticholinesterase drugs treat?

MG

15

What is the treatment for Anticholinesterase OD?

Atropine with pralodoxime (cholinesterase reactivator)

16

What are the nicotinic and CNS symptoms of anticholinesterase OD?

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

17

What is the dose for Neostigmine?

0.04-0.07 mg/kg

18

Is 5 mg the max dose for neostigmine?

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

19

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

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

20

What is onset, peak and duration of neostigmine?

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

21

How do anticholinergics work?

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

22

What are the effoects of anticholinergics?

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

23

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

closest onset and duration compared to neo

24

How are anticholinergics cleared?

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

25

How do you administer atropine, and glyco?

IM or IV. Po is unpredictable

26

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

scopalamine and atropine are lipid soluble
glyco is not

27

What are clinical uses for anticholinergics?

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

HOw would anticholinergics affect glaucoma?

make it worse

29

Do anticholinergics cross the placenta?

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

30

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

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

31

Why would atropine be a bad choice for sedation?

causes memory deficit and delayed arousal

32

How much glycopyrolate do you give for sedation?

glyco has no sedation effects

33

Which anticholinergic is the most potent antisialogogue?

Scopalamine
3x more potent than atropine with less HR changes

34

how does glyco compare to atropine as an antisialogogue?

2x more potent
Useful when sedative effects are not wanted

35

How do anticholinergic drugs work to treat bradycardia?

Blocks Ach @ SA node

36

How does glyco compare to atropine for treating bradycardia?

equal in effectiveness, but the onset of glyco is slower

37

What is the mechanism for anticholinergics causing bronchodilation?

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

38

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

ipratropium bromide (atrovent)
combivent

39

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

no

40

What are symptoms of central anticholinergic syndrome?

restlessness
hallucinations
somnolence
unconsciousness

41

What is the treatment for central anticholinergic syndrome?

Physostigmine-it crosses BBB

42

Which pts are susceptible to central anticholinergic syndrome?

Children and elderly

43

What dose of glyco causes central anticholinergic syndrome?

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

What are the symptoms of anticholinergic OD?

Dry mouth
blurred vision
tachycardia
Increased temp
flushing
irritability

45

What are the effects of anticholinergic OD?

Seizures
coma
ventilatory paralysis

46

What is the treatment for anticholinergic OD?

physostigmine

47

What are criteria for a pt being reversed?

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

48

What nerves do we use to monitor TOF?

Ulnar nerve
Posterior Tibial
Peroneal
Facial nerve

49

What's so special about Sugammedex?

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