Principles of GA

Modern anaesthetists generally use an IV induction agent, inhaled maintenance agents, along with supplementary IV opioids and muscle relaxants.

• However TIVA is also an option

IV agents

• Preferred for most adult patients and many older children
• IV induction is rapid, pleasant, and safe for most patients
  • Propofol
    • Pain on injection
    • Hypotension - be careful with hypovolaemic patients or those that will tolerate hypotension poorly
    • Induces excellent bronchodilation
  • Sodium thiopental
  • Ketamine
    • Increases BP and HR
    • Can be used as the sole anaesthetic for brief procedures
    • However no visceral anaesthesia, no muscle relaxation, doesn't completely control movement
  • Methohixital
  • Etomidate
  • Midazolam

Neuromuscular blockers

• Prevent movement in response to noxious stimuli
• Can mask the signs of inadequate anaesthesia
• Need to be either reversed or checked worn off at the end of anaesthesia
  • Reverse with neostigmine
• Depolarising
  • Succinylcholine
    • Rapid-onset, short duration of action
    • Few contraindications
• Non-depolarising