Neuromuscular blockers 2 Flashcards

1
Q

Identify the statement that demonstrates the MOST accurate understanding of succinylcholine (select 2.):
a. hypertension is a normal side effect
b. it’s an absolute contraindication with an open globe injury
c. severe sepsis increases the risk of hyperkalemia
d. masseter spasm warrants cancellation of the planned procedure

A

a. hypertension is normal side effect
c. severe sepsis increases the risk of hyperkalemia

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2
Q

Succinylcholine can produce a wide variety of side effects including:

A

bradycardia
tachycardia
increased serum K+
increased intraocular pressure
increased intracranial pressure
increased intragastric pressure
malignant hyperthermia

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3
Q

__________ are more susceptible to bradycardia with succinylcholine because of

A

children; because of a higher baseline vagal tone

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4
Q

If a child requires a second dose of succinylcholine, you should administer _________ before administering the second dose of succinlycholine

A

atropine

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5
Q

Succinylcholine is safe in patients with

A

renal failure and a normal serum potassium level

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6
Q

Succinylcholine can cause

A

masseter spasm

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7
Q

If masseter spasm occurs with succinylcholine,

A

it does not warrant cancellation of the planned surgical procedure; this finding in the absence of other s/sx of MH is normal

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8
Q

How does succinylcholine cause bradycardia or asystole?

A

stimulating the M2 receptor in the SA node

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9
Q

How can succinylcholine cause tachycardia and hypertension?

A

by mimicking the action of Ach at the sympathetic ganglia

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10
Q

Succinylcholine transiently intraocular pressure by

A

5-15 mmHg for up to 10 minutes

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11
Q

How can a temporary increase in ICP be prevented when giving succinylcholine?

A

giving a defasciculating dose

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12
Q

Is the risk of aspiration increased with succinylcholine?

A

No because contraction of the abdominal muscle increase intragastric pressure but succinylcholine also raises lower esophageal sphincter tone and they cancel each other out

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13
Q

Which enzymes hydrolyze succinylcholine? Select 3
a. butyrylcholinesterase
b. type 1 cholinesterase
c. true cholinesterase
d. pseudocholinesterase
e. plasma cholinesterase
f. acetylcholinesterase

A

a. butyrylcholinesterase
d. pseudocholinesterase
e. plasma cholinesterase

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14
Q

Acetylcholinesterase is found in

A

the neuromuscular junction

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15
Q

Acetylcholinesterase metabolizes

A

acetylcholine

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16
Q

Pseudocholinesterase is found in the

A

plasma

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17
Q

Pseudocholinesterase metabolizes

A

succinylcholine
mivacurium
ester local anesthetics

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18
Q

Other names for acetylcholinesterase include

A

genuine cholinesterase
type 1 cholinesterase
true cholinesterase
specific cholinesterase

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19
Q

Other names for pseudocholinesterase include

A

butyrylcholinesterase
type 2 cholinesterase
false cholinesterase
plasma cholinesterase

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20
Q

Pseudocholinesterase is produced in the

A

liver and serves as an indicator of hepatic synthetic function

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21
Q

In the plasma, pseudocholinesterase has a reference concentration range of

A

2900-7100 units/L

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22
Q

Pseudocholinesterase is also located in

A

smooth muscles
intestines
white matter of the brain
heart
pancreas
NOT located in the CSF

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23
Q

With pseudocholinesterase, neuromuscular symptoms begin at __ of normal and become serious at ____ of normal

A

60%; 20%

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24
Q

Which factors prolong the duration of succinylcholine? (select 3).
a. metoclopramide
bb. edrophonium
c. obesity
d. late-stage pregnancy
e. myasthenia gravis
f. esmolol

A

a. metoclopramide
d. late-stage pregnancy
f. esmolol

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25
Q

Key drugs that reduce pseudocholinesterase activity include

A

metoclopramide
esmolol
neostigmine

26
Q

Key conditions that reduce pseudocholinesterase activity include:

A

atypical PChe
severe liver disease
burns
neoplasm
pregnancy (late-stage)

27
Q

All co-existing diseases that reduce pseudocholinesterase activity include

A

atypical PChe
severe liver disease
chronic renal disease
organophosphate poisoning
burns
neoplasm
advanced age
malnutrition
pregnancy (late stage)

28
Q

All drugs that prolong the duration of succinylcholine include

A

metoclopramide
esmolol
neostigmine (not edrophonium)
echothiphate
oral contraceptives/estrogen
cyclophosphamide
monoamine oxidase inhibitors
nitrogen mustard

29
Q

A patient with a dibucaine number of 20 received succinylcholine. This patient:
a. is heterozygous for pseudocholinesterase
b. fails to produce pseudocholinesterase in sufficient quantity
c. should receive fresh frozen plasma
d. will be paralyzed for eight hours

A

d. will be paralyzed for eight hours

30
Q

______________ is an amide local anesthetic that is used to diagnose atypical PChE

A

Dibucaine

31
Q

Dibucaine inhibits __________, but has no effect on ______________.

A

normal PChE, no effect on atypical PChe

32
Q

_________________ determines the type of pseudocholinesterase she produces (typical or atypical)

A

A patient’s genetic makeup

33
Q

What does a dibucaine number of 20-30 indicate

A

atypical homozygous

34
Q

What does a dibucaine number of 70-80 indicate?

A

typical homozygous (normal)

35
Q

What does a dibucaine number of 50-60 indicate?

A

heterozygous variant

36
Q

The best treatment for a patient with atypical PChE who has received succinylcholine is

A

mechanical ventilation
sedation
tincture of time

37
Q

Atypical PChE variants cannot _______________ so the duration of succinylcholine will be ________________

A

hydrolyze succinylcholine; prolonged

38
Q

A normal dibucaine number is

A

80

39
Q

A normal dibucaine number of 80 indicates that

A

dibucaine has inhibited 80% of the pseudocholinesterase in the sample

40
Q

A tentative bedside diagnosis of pseduocholinesterase deficiency can be made if

A

the response to train-of-four stimulation is absent for longer than expected

41
Q

With a dibucaine number of 50-60, succinylcholine duration is prolonged by

A

20-30 minutes

42
Q

With a dibucaine number of 20-30, succinylcholine duration is prolonged by

A

4-8 hours

43
Q

Atypical plasma cholinesterase is a

A

qualitative defect; pseudocholinesterase in produced in sufficient quantity however the enzyme that is produced is not functional

44
Q

_______, _______, or ________________ will restore plasma pseudocholinesterase levels in a patient with an atypical variant but it is not necessarily the treatment of choice.

A

whole blood, FFP, or purified human cholinesterase

45
Q

The routine administration of succinylcholine is contraindicated in young children because of the possibility of:
a. malignant hyperthermia
b. hyperkalemic rhabdomyolysis
c. trismus
d. bradycardia

A

b. hyperkalemic rhabdomyolysis

46
Q

Succinylcholine sports a black box warning that details the risk of

A

cardiac arrest and sudden death secondary to hyperkalemia in children with undiagnosed skeletal muscle myopathy

47
Q

The most common cause of skeletal muscle myopathy is

A

Duchenne muscular dystrophy

48
Q

Succinylcholine-induced hyperkalemia typically presents with

A

peaked T waves and sudden cardiac arrest

49
Q

Succinylcholine-induced hyperkalemia most commonly affects

A

males under 8 years old

50
Q

Succinylcholine is generally avoided in

A

children under 8 years of age

51
Q

If a health infant or small child develops cardiac arrest following succinylcholine, treatment should include

A

stabilizing the myocardium
shifting potassium into cells
enhancing potassium elimination

52
Q

What should be given in a succinylcholine induced cardiac arrest to stabilize the myocardium?

A

IV calcium

53
Q

What should be given in a succinylcholine induced cardiac arrest to shift potassium into cells

A

glucose+insulin
sodium bicarbonate
hyperventilation
albuterol

54
Q

What should be given in a succinylcholine induced cardiac arrest to enhance potassium elimination?

A

furosemide
volume resuscitation
hemodialysis
hemofiltration

55
Q

Other forms of skeletal muscle myopathy that can lead to succinylcholine induced cardiac arrest include

A

Becker
Emery-Dreifuss
facioscapuloumeral
limb-girdle muscular dystrophy

56
Q

What is the dose of calcium chloride?

A

20 mg/kg

57
Q

What is the dose of calcium gluconate?

A

60 mg/kg

58
Q

What is the dose of sodium bicarbonate?

A

1-2 mmol/kg

59
Q

What is the dose of furosemide?

A

1mg/kg

60
Q

What is the dose of glucose + insulin?

A

0.3-0.5 g/kg as 10% glucose solution + 1 unit insulin per 4-5 g IV glucose