C H A P T E R 2 8
Neuromuscular junction blocking agents
441
CHAPTER SUMMARY
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The nerves communicate with muscles at a point
called the neuromuscular junction (NMJ), using
acetylcholine (ACh) as the neurotransmitter.
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NMJ blockers interfere with muscle function. The
two groups of NMJ blockers are non-depolarising
and depolarising agents.
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The non-depolarising NMJs include those agents that
act as antagonists to ACh at the NMJ and prevent
depolarisation of muscle cells. The depolarising
NMJs act as an ACh agonist at the junction, causing
stimulation of the muscle cell and then preventing it
from repolarising.
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NMJ blockers are primarily used as adjuncts to
general anaesthesia, to facilitate endotracheal
intubation, to facilitate mechanical ventilation and to
prevent injury during electroconvulsive therapy.
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Adverse effects of NMJ blockers, such as prolonged
paralysis, inability to breathe, weakness, muscle pain
and soreness, and effects of immobility are related to
muscle function blocking.
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Care of people receiving NMJ blockers must include:
support and reassurance because communication
is decreased with paralysis; vigilant maintenance
of airways and respiration; prevention of skin
breakdown; and monitoring for return of function.
Knowing your strengths and weaknesses helps you to
study more effectively. Take a PrepU Practice Quiz
to find out how you measure up!
ONLINE RESOURCES
An extensive range of additional resources to enhance teaching
and learning and to facilitate understanding of this chapter may
be found online at the text’s accompanying website, located on
thePoint at
These include Watch and
Learn videos, Concepts in Action animations, journal articles,
review questions, case studies, discussion topics and quizzes.
WEB LINKS
Healthcare providers and students may want to consult
the following Internet sources:
Information about anaesthesia and anaesthetics.
Home page of the Australian and New Zealand College
of Anaesthetists.
Home page of the Society for Paediatric Anaesthesia in
New Zealand and Australia.
Implementation
Provide comfort and safety measures: positioning, skin care,
temperature control, pain medication as needed, maintain
airway, ventilate person, have antidotes on standby.
Provide support and reassurance to deal with paralysis and
inability to communicate.
Provide teaching about procedure being performed and
what to expect.
Assist with life support as needed.
Evaluation
Evaluate drug effects: muscle paralysis.
Monitor for adverse effects: cardiovascular effects
(tachycardia, hypotension, respiratory distress, increased
respiratory secretions), GI effects (constipation, nausea),
skin breakdown, anxiety, fear.
Monitor for drug–drug interactions as indicated.
Evaluate the effectiveness of the teaching program and
comfort and safety measures.
Constantly monitor vital signs and watch for return of
normal muscular function.
TEACHING FOR S.N.
• Before the surgery is performed, you will be given a
drug to paralyse your muscles called a neuromuscular
blocking agent. It is important that your muscles do not
move at this time because it could interfere with the
procedure.
• Common effects of these drugs include complete
paralysis:
• You will not be able to move or to speak while you are
receiving this drug.
• You will not be able to breathe on your own, and you
will receive assistance in breathing.
• This drug may not affect your level of consciousness, and
it can be very frightening to be unable to communicate
with anyone around you. Someone will be with you, will
try to anticipate your needs, and will explain what is going
on at all times.
• This drug may have no effect on your pain perception.
Every effort will be made to make sure that you do not
experience pain.
• You will be receiving suxamethonium; with this drug, you
may experience back and throat pain related to muscle
contractions that occur. You will be able to take aspirin to
relieve this discomfort.
• Recovery of your muscle function may take 2 to 3 hours
and someone will be nearby at all times until you have
recovered from the paralysis.
