Anaesthetics Flashcards
What are the three components that define anaesthesia?
Hypnosis, amnesia and immobility
What is the definition of hypnosis?
Loss of consciousness
What is the definition of amnesia?
No memory formation
What is the definition of immobility?
No movement in response to painful stimulus
What are the four stages of anaesthesia?
Analgesia (dream like state)
Excitement (increased muscle tone, heart rate and blood pressure)
Anaesthesia (satisfying hypnosis, amnesia and immobility)
Cessation of breathing
What intravenous anaesthetics?
Etomidate, alphaxolone, propofol, ketamine, pentobarbitol and thiopental
What are inhalant anaesthetics?
Nitrous oxide, halothane, xenon, isofluorane, desfluorane, sevofluorane and enfluorane
What is the unitary theory of anaesthesia?
All anaesthetics have a hydrophobic site of action - all act on hydrophobic sites of proteins or on lipid membranes.
What are the problems with the unitary theory of anaesthesia?
More recently discovered anaesthetics are less potent than predicted by their lipid solubility.
Anaesthetics can bind to proteins.
Mutations in some proteins impair anaesthetic effects.
Enantiomer pairs have different potencies.
Propofol is routinely used for induction due to…
its rapid effect and ability to be rapidly eliminated
Anaesthetic potency of propofol correlates with its ability to what?
Potentiate GABA A receptor mediated Cl- currents
Which volatile anaesthetics are the only ones currently used?
Isofluorane, desfluorane and sevofluorane
Volatile anaesthetics are often used during what stage of anaesthesia alongside nitrous oxide and oxygen?
Maintenance
Volatile anaesthetics have what effect?
Strong immobilisation, amnesic and hypnotic effects.
Potentiation of which receptor by volatile anaesthetics contributes to immobilisation?
Glycine receptors
