2. General Anaesthesia
An artificial state of
unresponsiveness, followed by
amnesia, maintained by the
continuing presence of
chemical agents in the brain
6. Thiopentone
• Proven track record
• Rapid onset of action with fast recovery
due to redistribution
• Repeated doses need to be smaller as
accumulation occurs
• Extravasation may cause necrosis
• Potent anticonvulsant
7. Propofol
• Fast onset of action with rapid recovery
due to redistribution and high clearance
• Clear headed recovery
• Low incidence of nausea and vomiting
• Suitable for short procedures especially
day surgery
• Pain on injection and occasional
involuntary movements
12. Nitrous oxide
• “ Laughing Gas”
• Gaseous anaesthetic.
• Piped gas supply or blue cylinders.
13. Isoflurane
• Volatile anaesthetic
• Require vaporiser
• Isoflurane commonly used
• Faster recovery compared to halothane
and enflurane
• Irritating vapour, therefore not commonly
used for induction.
14.
15. Newer agents
• Sevoflurane
- Fast onset and offset of effect
- Non-irritating, useful for
inhalational induction,
especially in children.
• Desflurane
- Boiling point near room temperature
- Need special vaporiser
16. Older agents
• Halothane
- May cause arrhythmias
intraoperatively and hepatitis
postoperatively
• Enflurane
- May cause seizures and renal
impairment
17.
18. Muscle relaxants
• Useful for aiding insertion of
Endotracheal tube and ventilation
• Will cause apnoea, therefore assisted
ventilation mandatory.
19. Muscle relaxants
• Suxamethonium
- Rapid onset of action
- Used in rapid sequence induction
- Potential problems include
arrhythmias
20. Muscle relaxants
• Non-depolarising muscle relaxants -
- Atracurium
- Vecuronium
- Mivacurium
- Rocuronium
• Fast onset with intermediate duration of
action
21. Reversal of neuromuscular
blockade
• Neostigmine :
- Anticholinesterase
- Used for reversal of muscle
relaxation by non-depolarising
muscle relaxants
- Atropine given together to counter
bradycardia
23. Induction of Anaesthesia
• Intravenous hypnotic ± narcotic, or
• Inhalational anaesthetic ± narcotic
± Muscle relaxant if required
24. Maintenance of
Anaesthesia
• Inhalational anaesthetic ± analgesic,
or
• Intravenous anaesthetic ± analgesic,
or
• Inhalational anaesthetic + Intravenous
anaesthetic ± analgesic
± Muscle relaxant if required
25. Reversal of Anaesthetic
• Switch off Inhalational /
Intravenous
Anaesthetic
• Reverse neuromuscular blockage
• Consider other specific antagonists if
necessary - Naloxone,
Flumazenil
36. Ventilation - IPPV
• Requires endotracheal intubation in most
cases
• Useful when needed to:
- protect the lungs from aspiration of
material from stomach or
upper airways
- ensure adequate ventilation of the
lungs
37. Ventilation - IPPV
• Ventilator generates a positive pressure
which drives gas / oxygen mixture into
lungs
• Dangers include:
- failure of intubation / ventilation
leading to hypoxia
- injury to lungs if airway pressure is
excessive