NMBA Dosages

Question 1

Succinylcholine (alternate name):

Answer 1

Anectine

Question 2

Succinylcholine structure:

Answer 2

2 Ach molecules
depolarizing neuromuscular blocking agent
highly ionized, water soluble

Question 3

Succinylcholine MOA:

Answer 3

1. Mimics Ach
2. Produces a sustained depolarization of post junctional membrane causing a single contraction
3. Causes skeletal muscle paralysis, inactivates Na+ channels
4. Succ blocks Ach from being able to bind to receptor
5. Will not be metabolized by acetylcholinesterase

Question 4

Succinylcholine Onset:

Answer 4

IV: 30-60 sec IM: 1-3 min

Question 5

Succinylcholine Duration of action:

Answer 5

IV: 3-10 min IM: 5-10 min

Question 6

Succinylcholine Metabolism:

Answer 6

Plasma Cholinesterase

Question 7

Succinylcholine IV intubation dose:

Answer 7

IV: 1 mg/kg (intubation)

Question 8

Succinylcholine IM intubation dose:

Answer 8

1.5-3 mg/kg + anticholinergic

Question 9

Succinylcholine side effects:

Answer 9

1. Myalgias
2. Increase IOP
3. Increase ICP
4. Hyperkalemia
5. Bradycardia

Question 10

Succinylcholine Contraindications / cautions

Answer 10

1. Avoid in Neuro patients (upregulation of receptors)
2. Avoid in high K
3. Malignant Hyperthermia trigger
4. Avoid in burn patients, sepsis
5. No reversal
6. Inhalational anesthetics decrease dose needed (25-50%)

Question 11

Rocuronium (alternate name)

Answer 11

Zemuron

Question 12

Rocuronium Structure:

Answer 12

Nondepolarizing neuromuscular blocking agent
Aminosteroid
Quaternary ammoinum group
Hydroxyl group

Question 13

Rocuronium MOA:

Answer 13

1. Competitive antagonist, binds to alpha subunit of nicotinic receptor
2. Only needs to bind to 1 alpha subunit
3. Channels will not open
4. Action potential will not propagate
5. Skeletal muscle paralysis

Question 14

Rocuronium Onset:

Answer 14

30-60 sec (RSI dose)

Question 15

Rocuronium Duration of action:

Answer 15

30-60 min

Question 16

Rocuronium PB:

Answer 16

30%

Question 17

Rocuronium Metabolism:

Answer 17

60% biliary,
30-40% really,
Minimal hepatic

Question 18

Rocuronium IV induction dose:

Answer 18

IV: 0.6-1 mg/kg (generally 1 mg/kg, induction)

Question 19

Rocuronium IV RSI dose:

Answer 19

IV: 1.2 mg/kg (RSI)

Question 20

Rocuronium IV maintenance dose:

Answer 20

IV: 0.06-0.6 mg/kg (maintenance)

Question 21

Rocuronium IV defasiculating dose:

Answer 21

IV: 5-10 mg (defasiculating)

Question 22

Rocuronium Side effects:

Answer 22

1. CV stable
2. Does not cross placenta
3. Does not cross BBB
4. Paralysis
5. Transient hypotension

Question 23

Rocuronium Contraindications / cautions:

Answer 23

1. Previous Allergic rxn
2. Do not administer without sedating patient
3. Caution in renal disease
4. Caution in hepatic disease
5. Inhalational anesthetics decrease dose needed (25-50%)

Question 24

Vecuronium (alternate name):

Answer 24

Norcuron

Question 25

Vecuronium structure:

Answer 25

Nondepolarizing neuromuscular blocking agent
Amino steroid
Quaternary ammonium group

Question 26

Vecuronium MOA:

Answer 26

1. Antagonist
2. Competitively binds to alpha subunit of nicotinic receptor
3. Blocks Ach from attaching
4. Channels cannot open
5. Action potential cannot occur

Question 27

Vecuronium Onset:

Answer 27

3 min

Question 28

Vecuronium duration of action:

Answer 28

30-60 min

Question 29

Vecuronium PB:

Answer 29

60-80%

Question 30

Vecuronium Metabolism:

Answer 30

40-80% hepatic,
20-30% in bile unchanged,
20-30% really

Question 31

Vecuronium IV induction dose:

Answer 31

IV: 0.08-0.1 mg/kg (up to 20 mg)

Question 32

Vecuronium IV maintenance dose:

Answer 32

IV: 0.01-0.05 mg/kg (maintenance)

Question 33

Vecuronium IV defasiculating dose:

Answer 33

IV: 0.5 mg (defasiculating)

Question 34

Vecuronium side effects:

Answer 34

1. CV stable
2. Does not cross placenta
3. Does not cross BBB
4. Paralysis
5. ED95 = 0.03mg/kg

Question 35

Vecuronium Contraindications / cautions:

Answer 35

1. Do not administer without sedation
2. Do not give if previous allergic reaction
3. Caution in hepatic disease
4. Caution in renal disease
5. Inhalational anesthetics decrease dose needed (25-50%)

Question 36

Cisatracurium (alternate name):

Answer 36

Nimbex

Question 37

Cisatracurium structure:

Answer 37

Benzoisoquinolinium
Quaternary ammonium group
Stereoisomer of atricurium

Question 38

Cisatracurium MOA:

Answer 38

1. Antagonist
2. Competitively binds to alpha subunit of nicotinic receptor
3. Blocks Ach from attaching
4. Channels cannot open
5. Action potential cannot occur

Question 39

Cisatracurium Onset:

Answer 39

3 min

Question 40

Cisatracurium duration of action:

Answer 40

30-60 min

Question 41

Cisatracurium PB:

Answer 41

not successfully studied - rapid degredation

Question 42

Cisatracurium Metabolism:

Answer 42

Hoffman elimination and plasma esterases

Question 43

Cisatracurium IV intubation dose:

Answer 43

IV: 0.1-0.2 mg/kg (intubation)

Question 44

Cisatracurium IV maintenance dose:

Answer 44

IV: 0.05-0.1 mg/kg (maintenance)

Question 45

Cisatracurium IV defasiculating dose:

Answer 45

IV: 1-2 mg (defasiculating )

Question 46

Cisatracurium side effects:

Answer 46

1. CV stable
2. Does not cross placenta
3. Does not cross BBB
4. Paralysis
5. Degrades without renal or hepatic intervention

Question 47

Cisatracurium Contraindications / cautions:

Answer 47

1. Do not administer without sedating patient
2. Do not give if previous allergic rxn
3. Lithium decreases dose needed
4. Thermoregulation important (hoffmans)
5. Inhalational anesthetics decrease dose needed (25-50%)