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
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
Nitrous oxide• “ Laughing Gas”• Gaseous anaesthetic.• Piped gas supply or blue cylinders.
Isoflurane• Volatile anaesthetic• Require vaporiser• Isoflurane commonly used• Faster recovery compared to halothane and enflurane• Irritating vapour, therefore not commonly used for induction.
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
Older agents• Halothane - May cause arrhythmias intraoperatively and hepatitis postoperatively• Enflurane - May cause seizures and renal impairment
Muscle relaxants• Useful for aiding insertion of Endotracheal tube and ventilation• Will cause apnoea, therefore assisted ventilation mandatory.
Muscle relaxants• Suxamethonium - Rapid onset of action - Used in rapid sequence induction - Potential problems include arrhythmias
Muscle relaxants• Non-depolarising muscle relaxants - - Atracurium - Vecuronium - Mivacurium - Rocuronium• Fast onset with intermediate duration of action
Reversal of neuromuscularblockade• Neostigmine : - Anticholinesterase - Used for reversal of muscle relaxation by non-depolarising muscle relaxants - Atropine given together to counter bradycardia
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
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