Neuromuscular Blockers

Question 1

Neuromuscular blockers

Answer 1

interrupt transmission of nerve impulses at the neuromuscular junction

Question 2

What happens with neuromuscular blockers?

Answer 2

paralysis of striated muscles
Consciousness is retained
no analgesia
spontaneous respiration ceases

Question 3

What are the indications for Neuromuscular blockers?

Answer 3

Postion the eyeball centrally without traction
Relax the respiratory muscles to allow mechanical ventilation
Relax the muscles for neurological or orthopedic surgeries
Aid intubation
An element of balanced anesthesia

Question 4

What is the primary reason for using inhalational anesthetics in veterinary medicine?

Answer 4

Immobility

Question 5

What is the minimum requirement for neuromuscular blockers?

Answer 5

Use mechanical ventilation
Monitor cardio, resp, oxygenation, and neuromuscular function
Monitoring end tidal agent

Question 6

What are some contraindications for neuromuscular blockers?

Answer 6

If there is no possibility too ventilate and monitor the patient
if the animal remain conscious
if there is insufficient analgesia during surgery
if the personnel in charge does not have a complete understanding of NMBDs

Question 7

Functions of NMJ

Answer 7

1. an impulse arrives at the terminal
2. release of acetycholine
3. ACh binds to nicotinic ACh receptors
4. ion flux triggers an action potential that leads to muscle contraction
5. ACh is rapidly metabolized

Question 8

What is the mechanism of action for Depolarizing NMBDs?

Answer 8

act as an agonist on the nicotinic ACh receptors thus causing muscle membrane depolarization

Question 9

What is the mechanism of action for Non-depolarizing NMBDs?

Answer 9

act as competitive antagonist on the nictotinic ACh receptors thus stabilizing muscle membrane

Question 10

What is the most sensitive muscle to relaxation?

Answer 10

Ocular muscles

Question 11

What is the most resistant muscles to relaxation?

Answer 11

Diaphragm

Question 12

What is the typical order of onset of muscle relaxation?

Answer 12

Eyes>Larynx> diaphragm

Question 13

What drugs potentiate NMBD effect?

Answer 13

Inhalational anesthetics

Question 14

What factors influence the depth of NMBD effect?

Answer 14

Hypothermia
Electrolyte abnormalities
Age

Question 15

What are some chemical properties of NMBDs?

Answer 15

Water soluble

Does not cross lipid barriers easily

Question 16

What NMBDs causes Histamine release?

Answer 16

Atracurium

Question 17

What does histamine cause?

Answer 17

Bronchoconstriction
Vasodilation
negative iontropy
tachycardia

Question 18

How do you treat histamine release?

Answer 18

Low dose epinephrine

Question 19

What are the classifications of NMBDs?

Answer 19

Depolarizing NMBDs

Non-depolarizing NMBDs

Question 20

What are some intermediate non-depolarizing NMBDs?

Answer 20

Atracurium
cisatracurium
rocuronium
vecuronium

Question 21

Succinylcholine mechanism of action

Answer 21

causes sustained membrane depolarization on the end plate

Question 22

What are some adverse effects of Succinylcholine?

Answer 22

Cardiac arrhythmias
Hyperkalemia
Fasciculation
myalgia 
myoglobinuria
Elevated intraocular and intragastric pressures
malignant hyperthermia

Question 23

What does Laudanosine cause?

Answer 23

seizures

Question 24

Where do you stimulate peripheral nerves in dogs and cats?

Answer 24

Peroneal nerve

Ulnar nerve

Question 25

Where do you stimulate peripheral nerves in horses?

Answer 25

Facial nerve

Peroneal nerve

Question 26

TOF

Answer 26

Train of Four

Question 27

Sugammadex

Answer 27

reversal of neuromuscular blockade caused by rocuronium

Question 28

What should you keep End Tidal ISO around?

Answer 28

0.9 +/- 0.1%