Nondepolarizing NMB

Question 1

Structurally similar to ACh with one or two quaternary nitrogens

• high polar, highly ionized (H2O soluble)
• cannot cross lipid barries (no CNS effects, no placental cross, poor oral absorption)

Answer 1

chemical characteristics of nondepolarizing NMB

Question 2

• d-tubocurarine (curare)
• astracurium (tracrium)
• cisatracurium (nimbex)
• doxacurium (nuromax)
• mivacurium (mivacron)

Answer 2

benzylisoquinoline class NMB

Question 3

• pancuronium (pavulon)
• vecuronium (norcuron)
• pipecuronium (arduan)
• rocuronium (zemuron)
• rapacuronium (raplon)

Answer 3

steroidal class NMB

Question 4

NMB that end with “urium”

-except for one that ends with urarine

Answer 4

benzylisoquinoline class

Question 5

NMB that end with ronium

Answer 5

steroidal class

Question 6

competes with ACh to bind with alpha subunits on the postjunctional AChReceptor, which, prevents the ion channel from opening…which prevents depolarization (no muscle movement)

Answer 6

MOA of nondepolarizing NMB

Question 7

• small, rapidly contracting muscles (eye, fingers, toes)
• long muscles (adductor pollicis, intercostals)
• diaphragm *first to recover

Answer 7

sequence of relaxation after dose of NMB

Question 8

• decreased twitch response to single stimulus
• fade with tetanus, TOF
• enhanced by other nondepolarizing NMB
• antagonized by anticholinesterase drugs

Answer 8

characteristics of nondepolarizing NMB

Question 9

• onset
• duration
• side effects
• metabolism

Answer 9

agent related determinants of NMB

Question 10

• co-existing diseases (renal, hepatic, cardiac, neurom)
• current medical therapy
• surgical procedure

Answer 10

patient related determinants of NMB

Question 11

cost

Answer 11

determinants of NMB selection

Question 12

The less potent the drug, the ____ the ED95, and the more ____ onset

Answer 12

higher, rapid

more molecules must be given per dose, resulting in more molecules reaching the NMJ

Question 13

What drug is the least potent and has the highest ED95

Answer 13

rocuronium

Question 14

facilitates rapid intubating conditions by giving a small dose (1/10 intubating dose or 1/3 ED95) of the NMB prior to induction which allows some receptors to be occupied and minimizes the time required for the remaining receptors to be blocked by intubating dose

Answer 14

priming principle

Question 15

What happens when you increase dose of NMB?

Answer 15

speed up onset, increase side effects, and prolong duration

Question 16

What is the one short acting nondepolarizing NMB?

Answer 16

mivacurium (mivacron)

Question 17

• astracurium (tracrium)
• cisatracurium (nimbex)
• vecuronium (norcuron)
• rocuronium (zemeron)

Answer 17

intermediate acting nondep NMB

Question 18

• pancuronium (pavulon)
• doxacurium (nuromax)
• pipecuronium (arduan)

Answer 18

long acting nondep NMB

Question 19

if nondep excreted by kidneys, do they have longer half lives and duration or shorter?

Answer 19

longer half lives, longer duration (>60 mins)

Question 20

if nondep NMB excreted by liver, does that mean shorter half lives and duration or longer? and what family is this?

Answer 20

shorter half lives, shorter duration and steroid family

Question 21

how is atracurium eliminated

Answer 21

primarily by hofmann elimination and a bit hepatic

Question 22

how is mivacurium eliminated?

Answer 22

plasma cholinesterase

just like SCh, which is a depolarizing NMB

Question 23

• naturally occurring benzylisoquinoline obtained from the plant chondodendrum tomentosum
• horrific histamine release
• LONG ACTING - eliminated renal and hepatic

Answer 23

d-tubocurarine (curare)

Question 24

• ED95: 0.07 mg/kg (potent)
• intubating: 0.1 mg/kg
• onset: 3-5 mins
• duration: 60-90 mins
• elimination: renal and liver (10-40%)

Answer 24

pancuronium (pavulon)

Question 25

- cards - vagolytic effect due to vagal blockade at cardiac muscarinic receptors and stimulation of sympathetic nervous system (norepi release) - increase HR, CO, BP, MAP (especially when AV conduction is altered, think afib)

Answer 25

pancuronium (pavulon) side effects

Question 26

- ED95: 0.030 mg/kg - intubating: 0.05-0.08 mg/kg - onset: 4 to 6 mins - duration: 60 - 90 mins - elimination: mostly kidneys, some liver

Answer 26

doxacurium (nuromax)

Question 27

- decreased renal/hepatic function causes prolonged duration - elderly have prolonged effect - indicated for long cases where extubation immediately post-op is not necessary, or for ventilated patients in the unit - NO CARDS EFFECT

Answer 27

doxacurium (nuromax)

Question 28

- ED95: 0.050 mg/kg - intubating: 0.085 mg/kg - onset: 3-5 mins - duration 60 to 90 mins - elimination: renal (unchanged)

Answer 28

pipecuronium (arduan)

Question 29

- no cards effects - no histamine release - prolonged duration in renal failure - used for prolonged ventilation, cards stability, liver patients

Answer 29

pipecuronium (arduan)

Question 30

ED95: 0.05 mg/kg intubating: .1 mg/kg onset: 2.3 mins duration: 45 to 60 mins elimination: hepatic (40% in bile), urine

Answer 30

vecuronium (norcuron)

Question 31

metabolizes by deacetylation in the hepatocytes to two metabolites which have less than one-tenth of the NMB properties of drug

Answer 31

vecuronium (norcuron)

Question 32

- more lipid soluble allowing greater passage into hepatocytes for clearance - do not give to infants (>duration) - rarely histamine release - no vagolytic effect

Answer 32

vecuronium (norcuron)

Question 33

- ED95: 0.3 mg/kg - intubating: 0.6 mg/kg - onset: 1 to 2 mins - duration: 20 to 35 mins - elimination: unchanged in bile and urine

Answer 33

rocuronium (zemuron)

Question 34

- priming dose no impact - > duration in liver/kidney patients - no histamine release - anaphylactoid reactions - rapid sequence - NO DIFFICULT AIRWAYS

Answer 34

rocuronium (zemuron)

Question 35

``` ED95: 0.2 mg/kg (not super potent) Intubating: 0.5 mg/kg onset: 2 to 3 mins duration: 20-35 mins elimination: hoffman elimination, plasma esterases ```

Answer 35

atracurium (tracrium)

Question 36

- elimination independent of organ function - laudanosine (metabolite) causes seizures - histamine release (can be avoided by slow admin, h1/2 blockers) - increased HR - decreased MAP, SVR, flushing

Answer 36

atracurium (tracrium)

Question 37

ED95: 0.05 mg/kg intubating: 0.2 mg/kg onset: 2 to 3 mins duration: 20 - 35 mins elimination: hofmann elimination, no ester hydrolysis

Answer 37

cisatracurium (nimbex)

Question 38

- elimination independent of organ function - good for infusions - minimal histamine release - minimal CV effects (really none) - indicated: organ failure, intermediate length case, the need to avoid histamine release, infusion

Answer 38

cisatracurium (nimbex)

Question 39

what two drugs are used for rapid sequence

Answer 39

SCh and rocuronium

Question 40

ED95: 0.08 mg/kg intubating: 0.15 to 0.2 mg/kg onset: 1.5 to 3 mins duration: 12 to 20 mins elimination: plasma cholinesterase (slower than SCh)

Answer 40

mivacurium (mivacron)

Question 41

- good bigger peds pt - laryngeal muscles relax and recover quicker than long muscles - histamine release, avoid by dividing doses - CV effects at 3x ED95 - neostigmine can slow recovery - use edrophonium

Answer 41

mivacurium (mivacron)

Question 42

- will cause prolonged blockade in pts with atypical plasma cholinesterase - monitor oo - not organ dependent, > duration renal/liver

Answer 42

mivacurium (mivacron)

Question 43

vagolytic, tachycardia, htn, dysrhythmias, enhanced av conduction

Answer 43

pancuronium (pavulon)

Question 44

histamine release from mast cells causes hypotension and tachycardia

Answer 44

mivacurium (mivacron) atracurium (tracurium)

Question 45

doesn't release histamine, may interfere with catabolism of it causing more to remain active (inhibits histamine-n-methyl-transferase)

Answer 45

vercuronium (norcuron)