Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anesthesia pharm > Nondepolarizing NMBDs - test 3 > Flashcards

Nondepolarizing NMBDs - test 3 Flashcards

1
Q

Selection for nondeloparizing NMBDs is influenced by what factors?

A
  • Onset
  • duration of action
  • Rate of recovery
  • Metabolism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

MOA for non-depolarizing NMBDs:

A
  • Act at prejunctional sites to block Ach release
  • Compete for alpha subunits of post-junctional nAchRs with Ach
  • No conformational change
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Characteristics of Non-depolarizer Blockade.
-Decrease twitch response to _________.
-__________ response to a continuous stimulus.
- TOF ratio _________

A

-Decrease twitch response to single twitch.
- Unsustained (fade) response to a continuous stimulus.
- TOF ratio <0.7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Characteristics of Non-depolarizer Blockade.
Post-tetanic potentiation
Potentiation of other ___________.
Antagonism by ___________
No _________ during onset.

A

Potentiation of other non-depolarizing drugs.
Antagonism by anticholinesterase
No fasciculations during onset.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why is there a fade with non-depolarizing NMBDs?

A

Suggests that SOME fibers are contracting while some are blocked
- some are more susceptible to NMBDs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What causes the cardiovascular effects in non-depolarizing NMBDs?

A
  • release of histamine
  • effects at cardiac muscarinic receptors
  • effects on nAchRs at autonomic ganglia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cardiovascular effects from non-depolarizing NMBD are __________ clinically significant.

A

rarely

The patient often is already on drugs to counter the cardiovascular effects. Fentanyl to counter the tachycardic effects of histamine or pressors to treat the hypotension.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the autonomic margin of safety for NMBDs?

A
  • Difference between dose that produces blockade (ED95) and dose that creates circulatory effects
  • Same dose for pancuronium (the dose you give is also the dose that causes CV effects)
  • Very different dose for vec, roc, cis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is critical illness myopathy?

A

Skeletal muscle weakness that occurs weeks to months after NMBD is discontinued

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some risk factors for critical illness myopathy?

A
  • Patients with MSOF who were ventilated > 6 days
  • Usually an aminosteroid blocker
  • Glucocorticoids prior to NMBD
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are some things that could be beneficial for patients with critical illness myopathy?

A
  • Nerve monitoring
  • Sedation
  • Analgesia
  • Small doses of NMBD beneficial?
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the altered response if a non-depolarizing NMBD and a volatile anesthetics are concurrently used?

What is the MOA?

A

There will be a dose-dependent enhancement to the NMBD.
(Desflurane will have the most enhancement > Sevo > Iso)

MOA: Dose-dependent inhibition nAChR - not completely understood

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the altered response if a non-depolarizing NMBD was given concurrently with loop diuretics, corticosteroids, metoclopramide, and local anesthetics?

A

Enhances or antagonizes blockade
- Increase acetylcholine release
- Depression of cholinesterase activity
- Depression of nerve conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the altered response if a NMBD or sux is given with magnesium?

A
  • Enhances blockade
  • MOA for non-depol: decreases prejunctional release of Ach, decreases sensitivity to postjunctional membranes
  • MOA for sux is unclear
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the altered response if a non-depolarizing NMBD is given with ephedrine (SNS drug)?

A

Faster onset time d/t increased CO and skeletal muscle flow.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the altered response if esmolol is given before induction with a non-depolarizing NMBD?

A

If esmolol is given before induction, there will be a delayed onset.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What altered response in non-depolarizing NMBD if there is hypothermia?

MOA?

A

Even with mild hypothermia, Vec and Pancuronium will double in duration.

MOA: Temperature slows down hepatic enzyme activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which non-depolarizing NMBD is not metabolized by the liver but is pH and temperature dependent?

What is the MOA?

A

Atracurium and Cisatracurium

MOA: temperature-dependent elimination process through Hoffman elimination (need normal temperature and pH) and ester hydrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Acute hypokalemia with NMBDs:

A
  • Hyperpolarizes cell membrane (increased transmembrane potential)
  • Resistance to depolarizing NMBDs
  • Increased sensitivity to non-depolarizing NMBDs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Acute hyperkalemia with NMBDs:

A
  • Decreases membrane potential (partially depolarizes cell membrane)
  • Increases effects of depolarizing NMBDs
  • Resistance to non-depolarizing NMBDs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Burns are resistant to non-depolarizing NMBD ______ days post-injury.

When does the resistance go away?

What non-depolarizing drug is the exception to burns, and what is the dose?

A

Ten days

Resistance goes away in 60 days.

Rocuronium 1.2mg/kg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

MOA for altered responses of NMBDs with burn patients:

A
  • Altered affinity of nAchRs?
  • Not related to altered density (# of receptors)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

NMBD on stroke patients:
Paretic Arm
Unaffected Side
MOA

A

Paretic arm: Resistance compared to unaffected side

Unaffected side: Resistance compared to normal patients

MOA: Proliferation of extrajunctional nAChRs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Which NMBD is more likely to cause an allergic reaction?

A

Succinylcholine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Which NMBD is least likely to cause an allergic reaction?

A

Cisatracurium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What group is it possible to have cross-sensitivity with NMBDs?

A

Quaternary ammonium group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Altered responses: Gender and NMBDs

A
  • Women are more sensitive
  • Need 22% less vec
  • Need 30% less roc
  • Duration of block greater in women
28
Q

What is the long acting NMBD?
What groups is it?

A

Pancuronium

Bisquaternary aminosteroid

29
Q

Pancuronium Dose:
Onset:
Duration:

A

Intubating dose = 0.1 mg/kg
Onset = 3-5 minutes
Duration = 60-90 minutes

30
Q

How is pancuronium metabolized?

A

80% eliminated unchanged in the urine

31
Q

How does metabolism for pancuronium change in renal failure?

A
  • 30-50% decreased plasma clearance
  • 10-14% desacetylpancuronium metabolite 1/2 as active (by liver)
32
Q

How does metabolism for pancuronium change in liver disease?

A
  • Increased Vd
  • Larger initial dose is needed
  • Prolonged elimination 1/2 time
33
Q

How does metabolism for pancuronium change with aging?

A

Decreased plasma clearance d/t renal function

34
Q

What causes increased heart rate, MAP, and CO with pancuronium?

A

Vagal blockade
- mostly at SA node
- BP increase d/t HR

SNS activation
- Release of NE presynaptically
- Bloackade of NE reuptake

35
Q

What are other CV effects of pancuronium?

A
  • No changes in SVR or inotropy
  • No histamine release
36
Q

What are the 4 intermediate acting NMBDs?

A
  • Vecuronium
  • Rocuronium
  • Cisatracurium
  • Atracurium
37
Q

How do intermediate NMBDs compare to long acting?

A
  • Similar onset maximum blockade (except high dose roc)
  • Approximately 1/3 duration of action
  • Minimal/absent CV effects
  • Antagonized by anticholinesterase drugs in about 20 minutes
38
Q

What group is Vec in?

A

Aminosteroid

39
Q

Vecuronium dose:
Onset:
Duration:

A

Intubating dose = 0.1 mg/kg
Onset = 3-5 minutes
Duration = 20-35 minutes to be reversible (not completely out of your system)

40
Q

Metabolism of Vecuronium:

A

Hepatic metabolism
- Principle organ of elimination
- 3-desacetylvecuronium 50-80% as potent (but rapidly converted to metabolite with 1/10 the effects)

41
Q

Excretion of vecuronium:

A

Renal excretion
- approx 30% appears unchanged (70% metabolized in liver)
- Renal dysfunction = eliminated 1/2 time prolonged

42
Q

Why isn’t vecuronium used as a drip very often?

A

It has cumulative effects - d/t metabolite 3-desacetylvecuronium 50 to 80% as potent

43
Q

How does metabolism for vec change in the elderly?

A
  • Decreased volume of. distribution (less muscle mass)
  • Decreased plasma clearance (less hepatic flow)
  • Single dose mechanics unchanged
  • Delayed recovery with infusions
44
Q

How does metabolism of vecuronium change in obstetrics?

A
  • Insignificant effects to fetus
  • Increased clearance in 3rd trimester (progesterone)
  • Prolonged duration early postpartum (give IBW)
45
Q

Acid base changes with vecuronium:

A

Dependent on when the acid-base status changes
- Prior to NMBD = no prolonged blockade
- Following NMBD = prolongs blockage

46
Q

Respiratory acidosis with vecuronium:

A
  • Activity inversely proportional to bound drug - acidosis increases bound amount
  • Changes in ionization at receptor increases attachment time
  • Concern postop with hypoventilation
47
Q

Are there any CV effects with vecuronium?
Histamine release?

A
  • Essentially no CV effects
  • No histamine release
48
Q

What group is Rocuronium?

A

Aminosteroid

49
Q

Rocuronium Dose:
Onset:
Duration:

A

Dose = 0.6 mg/kg or 1.2 mg/kg
- larger doses parallel onset of Sux but offset of pancuronium

Onset = 3-5 minutes; 1-2 minutes

Duration = 20-35 minutes; 60-90 minutes

50
Q

Metabolism of Rocuronium:

A
  • Excreted unchanged in bile - longer duration of action in liver failure and eldery
  • d/t decreased clearance and an increased Vd
  • 10-30% renal excretion - only marginally affected in renal failure
51
Q

CV effects for rocuronium:

A
  • No histamine release
  • No cardiac effects - slight vagolytic effects?
52
Q

What group is cisatracurium?

A

Benzylisoquinolone

53
Q

Cis dose:
Onset:
Duration of action:

A

Intubating dose = 0.1 mg/kg
Onset = 3-5 minutes
Duation of action = 20-35 minutes

54
Q

Is recovery from a cis infusion affected by time?

55
Q

Cistatracurium is a cis- isomer of what??

A

Atracurium

56
Q

How is Cis degraded?

A

Hoffman elimination (temperature dependent)
- Doesn’t use non-specific plasma cholinesterase as much as atracurium

57
Q

Metabolism of Cis for elderly:
Obese patients:

A

Elderly = slight delay (1 min) in onset d/t CO

Obese = Duration of action prolonged if dosed at actual body weight d/t Vd

58
Q

CV effects for Cis:

A
  • No histamine release
  • CV stability
59
Q

What is the only clinically useful short acting non-depolarizer?
What group is it?

A

Mivacurium
- Benzylisoquinolone

60
Q

Mivacurium Dose:
Onset:
Duration of action:

A

Intubating dose = 0.15 mg/kg

Onset = 2-3 minutes - conditions less desirable

Duration of action = 12-20 minutes

61
Q

What are the 3 stereoisomers of mivacurium?

A
  • Cis-cis
  • Cis-trans**
  • Trans-trans**

** = NM blocking ability

62
Q

How is mivacurium cleared?

A

Cleared by plasma cholinesterase

63
Q

Is mivacurium currently on the market?

64
Q

CV effects of mivacurium:

A

Minimal effects

Anesthesia pharm (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions