Neuromuscular Blocking Agents

Front 1

perioperative uses of NMBAs?

Back 1

-NEVER used as substitutes for safe and adequate levels of general anesthesia
-have NO effect on consciousness or pain threshold

Front 2

use of NMBAs in ICUs

Back 2

-never used without adequate sedation

Front 3

depolarizing (noncompetitive) NMBA

Back 3

succinylcholine

Front 4

MOA of succinylcholine

Back 4

-initial depolarization (twitch)
-depolarization spreads causing disorganized contractions of nearby motor units (fasciculations)
--produces site of sustained depolarization and muscle cannot repolarize
-referred to as "depolarization blockade"

Front 5

the depolarization blockade of succinylcholine is also referred to as?

Back 5

phase 1 blockade

Front 6

prolonged/repeated/high doses of succinylcholine causes neuromuscular blockade to __________

Back 6

pass from Phase 1 to Phase 2

Front 7

what occurs during Phase 2 blockade

Back 7

the post-junctinal muscle membrane has becomerepolarized but still does not respond to ACh or any nicotinic cholinergic agonist molecule
-associated with delayed recovery of neuromuscular transmission

Front 8

Phase 2 Blockade is AKA?

Back 8

desensitization blockade

Front 9

name four nondepolarizing (competitive) NMBAs

Back 9

-atracurium and cistracurium (benzylisoquinolones)
-pancuronium and rocuronium (steroids)

Front 10

MOA of nondepolarizing (competitive) NMBAs

Back 10

-compete reversibly with ACh for the nicotinic chalineergic rec. site
-nerve impulse transmission is interrupted and the muscle is effectively paralyzed

Front 11

how can the paralysis caused by nondepolarizing (competitive) NMBAs be overcome?

Back 11

-by increasing the amt of ACh at the receptor site with a reversible cholinesterase inhibitor

Front 12

name three reversible cholinesterase inhibitors?

Back 12

-edrophonium
-neostigmine
-pyridostigmine

Front 13

why does succinylcholine have the shortest duration of action of all NMBAs?

Back 13

-it is hydrolyzed in the plasma by the enzyme plasma cholinesterase (pseudocholinesterase)

Front 14

what type of genetic variation is there in the pharmacodynamic response?

Back 14

-the homozygous atypical group cannot easily metabolize succinylcholine and experience prolonged blockade

Front 15

FHx of prolonged paralysis after surgery may indicate?

Back 15

pseudocholinesterase deficiency

Front 16

most serious ADR for succinylcholine

Back 16

-triggering agent for malignant hyperthermia
-succinylcholine contraindicated in FHx of malignant hyperthermia during anesthesia
-

Front 17

malignant hyperthermia occurs with succinlycholine use in pts that are genetically susceptible following exposure to?

Back 17

-halogenated anesthetics (mainly halothane) or succinylcholine

Front 18

Sx of malignant hyperthermia?

Back 18

-muscle rigidity, acidosis, hyperkalemia, and extreme hyperthermia

Front 19

Tx of malignant hyprethermia

Back 19

-surface cooling
-dantrolene sodium

Front 20

autonomic ADR of succinlycholine

Back 20

-stimulation of nicotinic rec. in ganglia and adrenal medulla

Front 21

ADR of succinylcholine

Back 21

-malignant hyperthermia
-autonomic actions
-hyperkalemia
-myalgia
-increased intraocular pressure (IOP)

Front 22

which nondepolarizing NMBAs have no alterations in renal and hepatic dz?

Back 22

atracurium and cistracurium

Front 23

which nondepolarizing NMBA has the fastest onset time, intermediate duration, and is indicated for rapid sequence induction anesthesia?

Back 23

rocuronium

Front 24

which nondepolarizing NMBA has a slow onset and has a long duration?

Back 24

pancuronium

Front 25

which nondepolarizing NMBA has a generic that is less expensive than intermediate duration agents for prolonged procedures, but has CV ADR?

Back 25

pancuronium

Front 26

which nondepolarizing NMBA is not dependent on organs of elimination and has an absence of CV ADR?

Back 26

atracurium

Front 27

which nondepolarizing NMBA is used as an alternative to succinylcholine for rapid tracheal intubation?

Back 27

rocuronium

Front 28

ADR of pancuronium

Back 28

-sympathomimetic; increased transmission through sympathetic ganglion (tachycardia, HTN)
-vagolytic: blockade of peripheral muscarinic rec. in the SA node; increased HR
-release of histamine from mast cells; skin flushing, hypotension

Front 29

use of NMBA for tracheal intubation

Back 29

-rapid sequence induction
-NMBA and IV induction agent given simultaneously
-use a NMBA with fastest onset time: succinylcholine

Front 30

contraindications for succinylcholine use

Back 30

-skeletal muscle myopathies
-pts susceptible to malignant hyperthermia
-atypical plasma cholinesterase (pseudocholinesterase)
-following acute injury phase for major burns, trauma, extensive muscle denervation,upper motor neuron injury

Front 31

if succinylcholine cannot be used for tracheal intubation, ________________ is used

Back 31

-nondepolarizing NMBA
-rocuronium is agent of choice and indicated for this procedure

Front 32

NMBA use in ICU

Back 32

-inadequate analgesia and sedation
-very little data available to support their use in ICU