Intravenous Anaesthetic Agents Flashcards
What are intravenous (IV) anaesthetic agents?
IV anaesthetic agents are drugs that cause a rapid loss of consciousness when given intravenously.
How quickly do IV anaesthetic agents typically cause loss of consciousness?
IV anaesthetic agents typically cause loss of consciousness within 10-20 seconds.
What are two physical/chemical properties of an ideal IV induction drug?
Water-soluble and stable in solution; long shelf-life.
Name two pharmacokinetic properties of an ideal IV induction drug.
Rapid onset in one arm-brain circulation time; rapid clearance and metabolism.
List two pharmacodynamic properties of an ideal IV induction drug.
High therapeutic ratio; minimal cardiovascular and respiratory effects.
Why is there no ideal intravenous anaesthetic agent?
No IV anaesthetic agent possesses all the ideal properties.
Name two advantages of using IV anaesthetic agents.
Rapid and smooth induction of anaesthesia; little equipment requirement.
List two disadvantages of using IV anaesthetic agents.
Difficult retrieval of the drug once administered; less control of depth and duration of anaesthesia.
What are the two main classifications of IV anaesthetic agents?
Rapidly acting induction agents and slower-acting basal narcotic agents.
Name two barbiturates used as IV induction agents.
Methohexital and Thiopental.
What is the most commonly used alkyl phenol IV anaesthetic agent?
Propofol.
Name a phencyclidine derivative used as a slower-acting IV anaesthetic.
Ketamine.
List two general uses of IV anaesthetic agents.
Induction agents; ICU sedation.
What is the mechanism of action of Thiopentone?
Thiopentone acts primarily at synapses by depressing post-synaptic sensitivity to neurotransmitters.
List two systemic effects of Thiopentone on the cardiovascular system.
Decreases cardiac output and peripheral vascular resistance.
