C H A P T E R 2 7
General and local anaesthetic agents
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CHAPTER SUMMARY
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General anaesthetics result in analgesia, amnesia and
unconsciousness; they also block muscle reflexes that
could interfere with a surgical procedure or put the
person at risk for harm.
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The use of general anaesthetics involves a widespread
CNS depression that could be harmful, especially
in people with underlying CNS, cardiovascular or
respiratory diseases.
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Anaesthesia proceeds through four predictable stages
from loss of sensation to total CNS depression and
death.
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Induction of anaesthesia is the period of time from
the beginning of anaesthesia administration until the
person reaches surgical anaesthesia.
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Balanced anaesthesia involves giving a variety of
drugs, including anticholinergics, rapid intravenous
anaesthetics, inhaled anaesthetics, NMJ blockers and
opioids.
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People receiving general anaesthetics should be
monitored for any adverse effects; they need
reassurance and safety measures until the recovery of
sensation, mobility and the ability to communicate.
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Local anaesthetics block the depolarisation of nerve
membranes, preventing the transmission of pain
sensations and motor stimuli.
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Local anaesthetics are administered to deliver the
drug directly to the desired area and to prevent
systemic absorption, which could lead to serious
interruption of nerve impulses and response.
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Ester-type local anaesthetics are immediately
destroyed by plasma esterases. Amide local
anaesthetics are destroyed in the liver and have a
greater risk of accumulation and systemic toxicity.
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Care of people receiving general or local anaesthetics
should include safety precautions to prevent injury
and skin breakdown; support and reassurance to deal
with the loss of sensation and mobility; and teaching
regarding what to expect, to decrease stress and
anxiety.
Knowing your strengths and weaknesses helps you to
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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.
Focus physical examination on the following:
CV: blood pressure, pulse, peripheral perfusion, ECG
CNS: orientation, affect, reflexes, vision
Skin: colour, lesions, texture, sweating
Respiratory: respiration, adventitious sounds
Laboratory tests: liver function tests, plasma esterases
Implementation
Provide comfort and safety measures: positioning, skin care,
side rails, pain medication as needed, maintain airway,
antidotes on standby.
Provide support and reassurance to deal with loss of
sensation and mobility.
Provide teaching about procedure being performed and
what to expect.
Provide life support as needed.
Evaluation
Evaluate drug effects: loss of sensation, loss of movement.
Monitor for adverse effects: cardiovascular effects (blood
pressure changes, arrhythmias), respiratory depression,
GI upset, CNS alterations, skin breakdown, anxiety and
fear.
Monitor for drug–drug interactions as indicated for each
drug.
Evaluate the effectiveness of the teaching program and
comfort and safety measures.
Constantly monitor vital signs and muscular function and
sensation as it returns.
TEACHING FOR A.M.
Teaching about local anaesthetics is usually incorporated
into the overall teaching plan about the procedure that the
man will undergo. Things to highlight with the man would
include the following:
• Discussion of the overall procedure:
• What it will feel like (any numbness, tingling, inability to
move, pressure, pain, choking?)
• Any anticipated discomfort
• How long it will last
• Concerns during the procedure: Report any discomfort
and ask any questions as they arise
• Discussion of the recovery:
• How long it will take
• Feelings to expect: tingling, numbness, pressure, itching
• Pain that will be felt as the anaesthesia wears off
• Measures to reduce pain in the area
• Signs and symptoms to report (e.g. pain along a nerve
route, palpitations, feeling faint, disorientation)
