Neuromuscular relaxants

Question 1

What do NMB produce?

Answer 1

paralysis

Question 2

Do NMB produce amnesia or analgesia?

Answer 2

NO

Question 3

What are the pharm effects of NMB?

Answer 3

-interrupt nerve impulses at the NMJ -similar structure to the endogenous neurotransmitter acetylcholine (Ach) - provides muscle relaxation

Question 4

Ca channels and nicotinic receptors are embedded where?

Answer 4

lipid bilayer

Question 5

Are nicotinic receptors presynapic or postsynaptic?

Answer 5

POSTsynaptic

Question 6

Describe the neuromuscular transmission release of Ach from nerve terminal…

Answer 6

AP and depolarizing of nerve terminal Ca channels open ca diffuses down gradient to nerve terminal Ach spills out into synaptic cleft Presynaptic nicotinic receptor responds to Ach by increasing in the synthesis and release of Ache

Question 7

Describe the events at postsynaptic membrane

Answer 7

Ach combines with nicotinic receptors Both nicotinic receptors occupied. Channels open Na, Ca diffuse into cell and K diffuse out. Motor end plate depolarizes AP potentiated Skeletal muscle contracts

Question 8

What is terminated by neurotransmitter action?

Answer 8

acetylcholinesterase (AChe) The choline is transported back to the nerve terminal and reconverted to Ach

Question 9

Acetylcholine receptor _ protein subunits Central core for _ channeling Ach must bind to both _ subunits to open the core A subunits are the site of agonism and antagonism

Answer 9

Acetylochline receptor 5 protein subunits central core for cation channeling Ach must bind to both A subunits to open the core “A” subunits are the site of agonism and antagonism

Question 10

Nondepolarizing BLOCK Nondepolarizing agents are competitive _. _ can not attach to the receptor Channels can not _ _ _ effect on the channel

Answer 10

inhibitors Ach open no direct

Question 11

Depolarizing BLOCK _ binds to _ receptors, channel opens, motor endplate depolarizes _ contraction occurs Sch not metabolized by _ _ _ cannot be initiated

Answer 11

Succs, nicotinic single true acetylcholinesterases - channels stay open until Sch diffuses back into the circulation AP

Question 12

What is a depolarizing muscle relaxant?

Answer 12

Succinylcholine

Question 13

What are nondepolarizing muscle relaxants? (acd mpp rrv)

Answer 13

Mivacurium Rapacuronium Rocuronium Vecuronium Atracurium Cisatracurium Pipecuronium Pancuronium Doxacurium (ACD MPP RRV)

Question 14

Succs: is there a reversal agent?

Answer 14

no

Question 15

Succs: metabolism: rapid hydrolysis by _

Answer 15

pseudocholinesterase = plasma cholinesterase = an enzyme of the liver and plasma

Question 16

How is a Sch block terminated?

Answer 16

by diffusion of Sch away from the neuromuscular junction

Question 17

What are the Sch side effects for pediatrics?

Answer 17

contraindicated in routine mgmt d/t side effects MHAUS strongly advises against Sch use in children IV atropine 0.02mg/kg

Question 18

What does the black box warning about Sch say for pediatrics?

Answer 18

-IV bolus admin may result in Malignant ventricular arrythmias and cardiac arrest 2 to actue rhado with HYPERkalemia. - IV bolus may result in profound bradycardia/asystole. Bradycardia is higher following a 2nd dose of succs. The occurrence of bradyarrhythmias may be reduced by pretreatment with atropine.

Question 19

What are the side effects of Sch?

Answer 19

HYPERkalemia = increased with burns, trauma, nerve damage, neuromuscular disease, renal failure Muscle pains (fasciculations) INCREASED ICP, IOP, IGP =intragastric pressure (IGP) Massester spasm =jaw muscle rigidity in assoc with limb flaccidity Potent MH trigger agent

Question 20

Dibucaine is a _ _ inhibits normal _ # indicates _ makeup of a person with regard to _ # is _ NOT _

Answer 20

Dibucaine is a local anesthetic inhibits normal pseudocholinesterase genetic makeup of a person with regard to pseduocholinesterase is qualitative NOT quanitative

Question 21

Describe the incidence, dibucaine number, duration of homozygous typical…

Answer 21

incidence: normal Dibucaine #: 70-80 duration: 4-6 minutes

Question 22

Describe the incidence, dibucaine number, duration of heterozygous atypical…

Answer 22

incidence: 1/50 patients Dibucaine #: 50-60 duration: 20-30 minutes

Question 23

Describe the incidence, dibucaine number, duration of homozygous atypical…

Answer 23

incidence: 1/3000 Dibucaine #: 20-30 duration: 4-8 hours

Question 24

Chemical properties of NonDepolarMR __ ammonium Steroid derivatives of _ Benzylisoquinolines are _ soluble Principle route of elimination is __ excretion

Answer 24

quaternary ammonium steroid derivatives of benzylisquinolines Benzylisoquinolines are water soluble = inhibits uptake into hepatocytes leads to lack of liver elimination = exception is steroid based relaxants Priniciple route of elimination is urinary excretion

Question 25

DOA if NDMRs Short acting onset duration Route of elimination

Answer 25

Rapacuronium Mivacuronium - metabolism, plasma cholinesterase Rocuronium - biliary excretion (MRR) onset 1 minutes duration \< 30 minutes

Question 26

DOA if NDMRs Intermediate acting onset duration Route of elimination

Answer 26

Vecuronium -biliary excretion Atracurium -metabolism = 2/3 nonspec ester hydrolysis and 1/3 hoffman elimination Cisatracurium - metabolism =hoffman elimination Rocuronium -biliary excretion (Carv) onset: 2 minutes duration: 60 minutes

Question 27

DOA if NDMRs LONg acting onset duration route of elimination

Answer 27

Alcuronium Doxacurium - renal d-tubocurarine -renal Gallamine -renal Metocurine -renal Pancuronium -renal Pipecuronium -renal Onset: 2-6 minutes Duration: 120 minutes

Question 28

Agent Histamine HR BP sux small brady mivacurium small tachy (rapid) atracurium small tachy vecuronium none None rocuronium none None D-tubo mod reflex tachy pancuronium none tachy

Answer 28

## Footnote Agent Histamine HR BP sux small brady decrease mivacurium small tachy (rapid) decrease atracurium small tachy none vecuronium none None none rocuronium none None none D-tubo mod reflex tachy decrease pancuronium none tachy increase

Question 29

Agent Histamine HR BP sux small decrease mivacurium small decrease atracurium small none vecuronium none none rocuronium none none D-tubo mod decrease pancuronium none increase

Answer 29

Agent Histamine HR BP sux small brady decrease mivacurium small tachy (rapid) decrease atracurium small tachy none vecuronium none None none rocuronium none None none D-tubo mod reflex tachy decrease pancuronium none tachy increase

Question 30

## Footnote Agent Histamine HR BP sux brady decrease mivacurium tachy (rapid) decrease atracurium tachy none vecuronium None none rocuronium None none D-tubo reflex tachy decrease pancuronium tachy increase

Answer 30

## Footnote Agent Histamine HR BP sux small brady decrease mivacurium small tachy (rapid) decrease atracurium small tachy none vecuronium none None none rocuronium none None none D-tubo mod reflex tachy decrease pancuronium none tachy increase

Question 31

What are the factors effecting degree of muscle relaxation?

Answer 31

antiHTN renal/hepatic disease cholineseterase inhibitors ketamine lithium

Question 32

Drug Efct: depol block Efct:nondepol block Antibiotic + Cholinesterase inh - Antidysrhythmics + Dantrolene + Inhalational anes + Ketamine + Locals +

Answer 32

## Footnote Drug Efct: depol block Efct:nondepol block Antibiotic + + Cholinesterase inh + - Antidysrhythmics + + Dantrolene ? + Inhalational anes + + Ketamine ? + Locals + +

Question 33

## Footnote Drug : Effect on the nondepol block Antibiotic Cholinesterase inhibitor Antidysrhythmics Dantrolene Inhalational anes Ketamine Locals

Answer 33

## Footnote Drug Efct: depol block Efct:nondepol block Antibiotic + + Cholinesterase inh + - Antidysrhythmics + + Dantrolene ? + Inhalational anes + + Ketamine ? + Locals + +

Question 34

Causes of altered responses to NDMR:

Answer 34

Hypothermia =Prolongs block esp intermed acting NDMR Acidosis =Decrease pH prolongs action of atracurium by inhibiting Hoffman elimination Hypokalemia =Prolongs effect (diuretics) Burns =3rd degree burns \> 30% of body resistance to NDMR (40-60 days post injury)

Question 35

Long acting muscle relaxants Produce paralysis in __ minutes Mainteance of anesthesia for operations \> _ hours Recovery __ minutes Primarily exreted via __ unchanged

Answer 35

3-5 minutes 2 hours 40-70 minutes kidney unchanged

Question 36

Intermediate acting relaxants Useful for \_ half DOA of long acting relaxants onset time varies minimal _ events

Answer 36

intubation circulatory effects

Question 37

Short acting relaxant SCh - _ drip \_ of Ns or D5W \_ mg/min Micacurium Alternative to __ (avoid \_) Onset longer than \_ \_ DOA, _ shorter than intermediates useful for brief _ surgery when used just for \_

Answer 37

Sch -continuous drip 1gm/500ml of NS or D5W 2-4 mg/min Mivacurium - Alternative to succs (avoid myalgia) - onset longer than SCh - short doa, 30-40% SHORTER THAN INTERMIEDIATES useful for brief outpatient surgery when used just for intubation

Question 38

How do you speed the onset of NDMR?

Answer 38

Administer 10% of intubating dose followed in 5 minutes before induction Initial small dose primes spare receptors without producing paralysis the time Onset of larger dose faciliated ALWAYS have emergency airway equipment available

Question 39

Defasciculating dose describe it and the dose of vecuronium and rocuronium

Answer 39

10% of intubating dose of NDMR to prevent Sux induced fasciculation. = Fasciculations increase risk of hyperkalemia, muscle pain, increases introgastric pressure adn aspiration =Temporary increase in ICP with succs =-= Traditionally we still give defasciculating agents when Sch used in head injury patients Vecuronium = .01 mg/kg Rocuronium = .1 mg/kg

Question 40

Doses NMB can be used to _ (full bolus) and to __ \_\_ (reduced bolus after initial bolus and with return of twitces on PNS)

Answer 40

intubate and maintain anesthesia