8.2: Anaesthesia Flashcards
What channel do anaesthetic drugs mostly work on?
Effect GABA channels to increase sensitivity to GABA
This increases chloride currents and hyperpolarises the neurone to decrease its excitability
Some also inhibit NACh receptors
Nitrous oxides and ketamine affect NMDA receptors (for glutamate)
What is the MAC value?
The minimal alveolar concentration
% of inhaled anaesthetic that abolished response to surgical incision in 50% of patients
Used to describe potently for inhalational anaesthetics
(MAC closely refers to lipid solubility ie potency. So the lower the MAC value, the more potent the inhaled anaesthetic is)
Which is nitrous oxides often added to other volatile agent anaesthetics?
To reduce the MAC value so a reduced dose is required
What are some examples of inhalational anaesthetics?
Nitrous oxide
Isoflurane
Desflurane
What are some examples of IV anaesthetics and what are their target sites?
Profolol, target GABA receptors
Barbiturates, target GABA receptors
Ketamine, targets NMDA receptors
How does the lipid solubility affect the potency of an anaesthetic?
More soluble = more potent
What are some main anaesthetic side effects?
Hypotension CNS/ CVS/ respiratory depression Chest infection Allergic reaction Malignant hyperthermia
How does % of protein binding indicate the duration of an anaesthetic?
A higher protein binding means it will act longer
What are some examples of local anaesthetics?
Lidocaine
Procaine
Bupivacaine
What are the reversible effect of anaesthesia?
Amnesia Analgesia Muscle relaxation Depression of spinal reflexes Loss of consciousness Anxiolytic
A higher blood: gas efficient for an inhaled anaesthetic indicates what?
The more readily it will enter the bloodstream (passing down its concentration from the alveoli)
