1.2.1 IV: Induction with propofol, thiopental or etomidate. Pt is
pre-oxygenated and monitored. Maintenance with oxygen +
nitrous oxide + continuous propofol with
additional muscle relaxants when required.
1.2.2 Inhalation: Either for induction
or maintenance. Potency
calculated by MAC (minimum
alveolar concentration): the
amount of gas required in the
lungs to prevent 50% of
humans moving when given a
painful stimulus. Isoflurane,
sevoflurane, desflurane. For
maintenance they are given
with O2, muscle relaxants and
1.2.3 Preferably IV for
induction and inhaled
1.3 Rapid sequence induction
1.3.1 For emergency situation: rapidly
acting muscle relaxant given
immediately after induction
agent. Risk of inability to intubate
and ventilate pt.
1.4 Acts on the brain
1.5 Effect on cardio and respiratory systems: CVS:
reduced myocardial contractility, reduced cardiac
output, hypotension, arrythmias, increased
myocardial sensitivity to catecholamines. RS:
reduced ventilation, laryngospasm/airway
obstruction, reduced ventilatory response to
hypoxia and hypercapnia, bronchodilation.
2.1.1 Local anaesthetic into epidural space
either via single dose, intermittent
top-up or continuously via a pump.
Unlike a spinal it can be topped-up so
prolongued action, but slower onset (up
to 45 mins). Can also be used as a
PCA system. Must monitor ECG, BP,
RR & O2 sats. May become
2.1.2 Risks: respiratory
failure, total spinal
effect from dural
2.2.1 Blocks sacral and lumbar
nerve roots. Mainly in children.
2.3.1 Solution directly into CSF. Complete sensory
block, may also be loss of power. Usually lower
body, can extend from nipples (T10) to toes. Level
measured using ice/light touch. Fast onset lasting
1-4 hrs. Must monitor ECG, BP, RR & O2 sats.
May become hypotensive (sympathetic blockade)
so may need fluid.
2.3.2 Effect on cardio and respiratory
systems: reduced ventilation (if
opiates) , bradycardia,
hypotension (vasodilation caused
by anaesthetic blocking
sympathetic nerves to blood
2.3.3 Risks: Failure, localised bruising/pain, infection, respiratory
depression with opiates, PONV, bladder distension,
bradycardia, hypotension, high spinal block (depression of
cervical spine and brainstem, spinal headache.
3.2 Topical (skin/mucous membranes ie
before injection), local infiltration (for
minor procedures ie suturing),
(minor/major nerve blockade ie
ulnar/brachial plexus). Can also be
used for treatment of pain in combi
with opioids, NSAIDS etc.
3.3 Vasodilator effect so often given with vasoconstrictor to increase potency. But
do not use adrenaline around end-arteries (ie penis/finger ring-block) - can