Neuromuscular Blockers Flashcards
(155 cards)
1
Q
___________ is a primary neurotransmitter.
A
Acetylcholine (ACh)
2
Q
Alpha Sub-Units
A
- “Ligancated (ACh) Ion (Na) Channels”.
- ACh
3
Q
___ moves in muscle tissue to activate movement.
A
Na
4
Q
Acetylcholine Structure
A
1 N+ binds to alpha sub-unit
5
Q
Acetylcholine
A
- Primary neurotransmitter of parasympathetic system (“Rest and Digest”)
- Choline acetyltransferase
==Ca mediated action potential - Deactivated by acetylcholinesterase
6
Q
What effects do Neuromuscular Blockers have?
A
- Paralysis ONLY
- No pain relief or sedation
7
Q
Depolarizing vs Non-depolarizing
A
D: depolarize muscle fiber leaving it constantly stimulated and unable to be affected by ACh.
ND: Competitively block ACh from binding to receptors post-synaptically.
8
Q
ED95
A
- Dose necessary to produce 95% suppression of SINGLE twitch response.
- Greatly < with IA.
9
Q
Tracheal Intubation Dose is …
A
2x ED95 dose
10
Q
Order of NMB Effect
A
- Effected 1st: Small muscles to Large muscles.
- Recovery: Large muscles (>BF) to Small muscles.
11
Q
Size of Muscle (Sm-Lg) : ____ __ ____
Recovery (< effect) : __ ___
A
: Order of effect
: > BF (Lg muscles - Sm muscles)
12
Q
NDMB structure is either _______________ or ______________.
(PP slides are different than what was said in lecture)
Difference between Benzyl and Aminosteroid?
A
BENZYLisoquinolinium (>histamine release)or
Aminosteroid
13
Q
ACh does not just bind to Skeletal Muscle at Nicotinic Receptor, but also…
A
(Not specific)
- Cardiac muscarinic receptors
- Autonomic ganglia nicotinic receptors
14
Q
Do IA interact (PD interaction) with NMB?
A
No.
15
Q
Succ is ____________.
A
Depolarizing (the only one)
16
Q
Rocc is __________.
A
Non-Depolarizing (and all others)
17
Q
“- onium” = ______________
“- curium” = ______________
A
Aminosteroid
BENZYLisoquinolinium
18
Q
3 long acting NMB
A
- Pancuronium
- Doxacurium
- Pipecuronium
19
Q
4 intermediate acting NMB
A
- Atracurium
- Vecuronium
- Rocuronium
- Cisatracurium
20
Q
1 short acting NMB
A
Mivacurium
21
Q
Succinylcholine
Onset and Duration
A
- “looks and smells like ACh”
- Most rapid onset NMB
- Onset: 30-60 sec
- Duration: 3-5 mins
- The only depolarizing NMB
22
Q
Succ (Structure)
A
N+ ——-N+ (“one molecule combined to both alpha sub-units”)
- “Both alpha units must be bound up to cause depolarization”
23
Q
Succ (Mechanism of Action)
A
- Slower hydrolysis (“Esterases in the blood can’t recognize the Succ molecule to break down = > duration of action than ACh”)
24
Q
Succ has _____ presynaptic effects that are “_______ _____”.
Succ has ______ postsynaptic effects.
A
Minor, feedback loops
Important
25
Hyperdepolarization of Succ causes ...
- Leakage of K out of cell (> K by 0.5)
| - A lot of Na goes in so K goes out.
26
Phase I Blockade
- Depolarizing block (Succ)
| - Fasciculations at onset (pt is still paralyzed)
27
Phase II Blockade
- Desensitization: similar to non-depolarizers
| - tachyphylaxis
28
Succ has one or both phases of blockades?
Both
29
DOSE SLIDE 20
“Do not memorize”
30
Plasma Cholinesterase is > or < in obese patients?
>
31
Plasma Cholinesterase is > or < with > estrogen levels?
<
| meaning > estrogen —> < Plasma Cholinesterase —> > Duration of Succ
32
Raglan __________ Plasma Cholinesterase.
Inhibits
33
Plasma Cholinesterase
Breaks down (hydrolyzes) Succ
34
Neostigmine ____________ Plasma Cholinesterase
Inhibits
35
Some ppl have atypical cholinesterase which ...
> duration of Succ to 1-3 hours rather than 5-9 mins.
36
How to reduce some of the side effects of Succ?
- Prior to giving Succ, give a baby dose of a non-depolarizer
- Can help reduce all side effects except Hyperkalemia.
37
Succ (cardiac)
- Sinus Bradycardia
- Junctional rhythm
- Sinus arrest
-Cardiac muscarinic receptors
- > risk with 2nd does within 5 mins.
“Rest and Digest”
(Can’t cause > HR and >BP in some ppl).
38
If pt’s HR < after giving Succ, give Atropine?
No, Atropine won’t help (atropine is a muscarinic receptor med).
39
Pt Hx that > risk for Hyperkalemia with Succ.(4)
- Muscular dystrophy
- 3rd degree burns
- Upper motor neuron lesions
- Muscle atrophy or severe trauma
40
Is Hyperkalemia an immediate effect?
No, up to 96 hours that can last up to 6 months or more.
41
Pt’s at highest risk of Succ induced hyperkalemia.
Male children with undiagnosed myopathy
42
> rates of Myalgias and where is it found in the body?
- Muscle pain
Young adults, minor surgical procedures, early ambulation > rates of muscle pain.
- Found in Neck, Back, Abdomen
43
In children you could see ___________ from Succ.
Myoglobinuria
44
3 side effect areas caused by Succ.
- Intragastric (> fasiculations —> > aspiration risk)
- Intraocular (2-4 min post admin)
- Intracranial (< risk) (article)
“Article-Succ associated with > mortality when used for RSI of severely injured pt’s in ER when compared with Roc).
45
Succ
- Only depolarizer NMB
- “Looks and smells like ACh”
- Parasympathetic NS
- Short duration of action
- No reversal agent
46
ND NMB what receptors do they target?
-Compete (antagonism) with ACh for alpha subunits at nicotinic receptors (post junctional)
47
Sustained muscle contraction does not occur with _______________.
ND NMB
48
Characteristics of ND NMB
- Posttetanic potentiation
- Potentiation of other nondepolarizers
- Antagonism by anticholinesterases
49
What NMB cause histamine release?
-Atracurium
-Mivacurium
(
50
Pancuronium > or < HR?
| And other ND NMB?
>
| - Cardiac muscarinic receptors are blocked, (blocked rest and digest).
51
ND NMB have a wide _______ __ ______.
Margin of safety.
52
What can long term paralysis for mech ventilation can cause? (>6 days)
Critical Myopathy with an unpredictable duration
- “even if doses are given here and there”
53
There is > risk for critical myopathy in pts who take _________ and ________.
Corticosteroids (highest risk) and aminosteroids.
54
What groups have the least amount of risk than Succ?
Single quaternary ammonium groups
55
Females have _________ __________ of ___________ ____________.
Higher incidence of allergic reactions. (Soaps and cosmetics)
“Case Study not estrogen but soaps” ?
56
What 6 things enhance NMB
- Volatile anesthetics
- Aminoglycosides
- Local anesthetics
- Antiarrhythmics
- Diuretics (Lido and quinidine)
- Mg, Li
57
What can anticonvulsants and NMB can alter?
CYP enzymes
58
What can cyclosporine and NMB affect?
(Poor?) Lung Blockade
59
What can Corticosteroids and NMB cause?
Compound muscle weakness
60
What can sympathomimetics (epi) and NMB cause?
> Onset time due to changes in BF with a faster delivery.
61
What prolongs duration of NMB?
Hypothermia
62
How does < K effect NMB?
- Resistance to Succ
| - Increased sensitivity to ND NMB
63
How does > K effect NMB?
> Succ effects
| < ND NMB effects (thermal injury)
64
Is there gender sensitivities with NMB?
Yes, Women are more sensitive.
| < skeletal muscle?
65
Onset and Duration of Pancuronium
Onset: 3-5 min
Duration: 60-90 min
66
ED95 for Pancuronium
ED95=70mcg/kg (IDW)
67
Metabolite for Pancuronium
- 3-desacetylpancuronium
- Renal and hepatic problems > half life. (Aging reduces clearance)
- 80% eliminated unchanged in urine.
- Total biliary obstruction, hepatic cirrhosis
68
What is Pancuronium is enhanced by?
Respiratory acidosis
69
Does Pancuronium > or < HR, MAP, and CO?
>
| Anti rest and Digest
70
Mechanism of Pancuronium
- Vagal blockade (CN X)
- SNS activation
- Muscarinic interference
71
Can dysrhythmias occur with Pancuronium?
Yes, especially in combo with Digoxin.
72
Onset and Duration of Doxacurium
Onset: 4-6 mins
| Duration 60-90
73
ED95 of Doxacurium
ED95 = 30 mcg/kg
74
Do what when using Doxacurium and IA?
Reduce Doxacurium dose with IA
75
Doxacurium cardiovascular changes
None
“Toxic metabolite that built up esp. with renal failure causing Histamine release”
76
Pipecuronium onset and duration:
Onset: 3-5 mins
Duration: 60-90 mins
77
ED95 of Pipecuronium
ED95 = 50-60 mcg/kg
78
Pipecuronium
Bisquaternary aminosteroid
79
Doxacurium
Benzylisoquinolinium, bisquaternary
80
Pancuronium
Bisquaternary aminosteroid
81
Cardiovascular issues with Pipecuronium
None
82
Infants have __ ______ and __ ______ of effect with Pipecuronium.
> potency and < duration
83
Pipecuronium‘s PK is similar to _____________.
No ________ issues
Pancuronium
Hepatic
84
Intermediate ND NMB have _________ clearance.
Better
85
All Intermediate ND NMB have similar _________.
Onset. (Except for Roc) (Roc is faster).
86
Do intermediate ND NMB have a faster or slower recovery rate than long acting ND NMB?
Faster (1/3 duration of long acting also)
87
Intermediate NDNMB cardiovascular side effects:
None
88
Intermediate ND NMB are _________ reversed by __________________ drugs.
Reliably, anticholinesterase (reversal agents)
89
Priming Principle
- Give a small dose of Roc to bind spare receptors (no clinical effect). 4 mins later give the rest. This deepens the neuromuscular blockade rapidly.
- “or give 4x ED95 of Roc x1 to < onset”.
Goal: to < rate of Roc onset.
90
Atracurium
Bisquaternary benzylisoquinolinium
91
Atracurium onset and duration:
Onset: 3-5 mins
Duration: 20-35 mins (1/2 hour or less than long acting NMB)
92
Atracurium ED95
ED95 = 0.2 mg/kg
93
Atracurium is 82% __________ _________.
Protein bound. (Albumin)
94
What are the cumulative effects of Atracurium?
- None
- Rapid clearance
- “Predictable offset, no lingering effects”.
95
What is the secondary mechanism of action for both Atracurium and Cisatracurium for metabolism beyond the CYP enzymes?
- Hoffman Elimination
| - “So that pts are not sent to the PACU so paralyzed”.
96
Hoffman elimination is ___________ by alkalosis and ___________ by acidosis.
Accelerated, slowed
97
Hoffman elimination followed by ___________ followed by another Hoffman elimination.
hydrolysis
98
What is Laudanosine?
- Metabolite in Hoffman elimination, independent of renal and hepatic function
- Safety net of elimination
99
Laudanosine requires an __________ in MAC of IA.
Increase
100
Laudanosine is a CNS _________ leading to __________ __________.
Stimulant, peripheral vasodilation.
101
What are cardiovascular effects of Atracurium at 3x ED95?
- > HR
- < MAP
- Transient
102
Does histamine release with Atracurium?
Yes, Block both H1 and H2 receptors to get full effect
103
Elderly vs Infants with Atracurium:
Elderly: No effect
Infant: 1/2 dose, > sensitive, > rapid clearance.
104
Cisatracurium
Bisquaternary Benzylisoquinolinium
105
Cisatracurium Onset and Duration:
Onset: 3-5 mins
Duration: 20-35 mins (> duration in obese pts).
106
Cisatracurium ED95:
ED95 = 50 mcg/kg
107
Is it OK to give Cisatracurium to pts with renal and hepatic dysfunction?
Yes
108
Cisatracurium has a slight ________ of _________ for elderly pts.
Delay, onset
109
How is Cisatracurium different from its “sister” Atracurium?
No histamine release
| More safe
110
Vecuronium
MONOquaternary aminosteroid
111
Vecuronium Onset and Duration:
Onset: 3-5 mins
Duration: 20-35 mins
112
Vecuronium ED95
ED95 = 50 mcg/kg
113
Aminosteroids love ________.
Lipids
114
Vecuronium has a _______ lipid solubility to enter ____________.
Higher, hepatocytes
115
Vecuronium‘s lipid solubility allows _________ excretion.
______ metabolism and _________ clearance.
Billiary
Hepatic, renal
116
___________ post inject of Vecuronium enhances effects
Hypercarbia
117
Large cumulative effect of Vecuronium due to > _____________.
Volume of distribution. (Fatty tissues, potential for > duration of action)
118
Does Vecuronium release histamine?
No (rarely)
No vagolytic effects
119
Onset is ______ _______ for infants with Vecuronium.
More rapid
120
With Vecuronium, duration is longest in __________ and shortest in __________.
Infants, children.
121
With Vecuronium, the _________ have a longer recovery rate.
Elderly
122
Rocuronium
MONOquaternary aminosteroid
123
Rocuronium Onset and Duration:
Onset: 1-2 mins
Duration: 20-35 mins
124
Rocuronium ED95
ED95 = 0.3 mg/kg
125
Like Vec, Rocuronium is excreted unchanged in the _______.
Bile
126
Rocuronium has slight ____________ effects.
Vagolytic
127
Does Rocuronium release histamine?
No
128
Mivacurium
Bisquaternary benzylisoquinolinium
129
Mivacurium Onset and Duration
Onset: 2-3 mins
Duration: 12-20 mins
130
Mivacurium ED95
ED95 = 80 mcg/kg
131
Mivacurium is rapidly eliminated because it is _________ by _______ ___________.
Hydrolyzed by plasma cholinesterase
132
Mivacurium has rapid spontaneous _________
Recovery
133
Does Mivacurium release histamine?
Yes, transient histamine release
134
Quaternary Ammonium is > _______ and > ______ ______.
Ionized and water soluble.
135
What are Quaternary Ammonium CNS effects?
None
136
What is volume distribution of Quaternary Ammonium similar to?
ECF volume
137
Do Quaternary Ammonium drugs absorb orally?
No, all are injectable.
138
Do Quaternary Ammonium drugs cross placenta?
No
139
Quaternary Ammonium drugs bind to...
Alpha subunit post-synaptically
140
NMB are not ...
Highly protein bound (Albumin won’t effect med)
141
Mivacurium > or < MAP?
141
There is a risk for __________ with Mivacurium.
Bronchospasm
142
What NMB is associated with Hoffman Elimination?
- Atracurium
| - Cisatracurium
143
What re the NMBs that release histamine?
- Atracurium
- Mivacurium
(NOT Cisatracurium eventhough it is a Bis Benzyl)
144
NMB that are urine eliminated?
- Pancuronium
- Miv (minor)
- Vecuronium (minor)
145
NMB protein bound to...
Atracurium (Hoffman Elimination)
146
What NMB is it ok to give with renal and hepatic dysfunction?
Cisatracurium
147
Hepatic Eliminated NMB:
- Vec
148
What NMB is inactive at the NMJ?
Cisatracurium
| Atracurium
149
What NMB is > risk for Bronchospasm?
Miv
150
4 Side Effects of Succ:
- Arrhythmias
- > K
- Myalgias
- > pressure (gastric, ocular, cranial)
151
NMB that have no CV effects:
Pip
| Dox
152
NMB with slight Vagal effects:
Rocc
153
What is TOF for ND NMB?
< 0.7.
154
What is TOF with Succ?
> 0.7
