Anaesthetic Drugs Flashcards
What is anaesthesia and what part of the brain get depressed during it?
The removal of awareness and sensation in an individual
- Cortex
- Midbrain
- Spinal Cord
- Medulla
What receptors do anaesthetic drugs stimulate?
Inhibitory receptors:
- GABA
- Glycine
What receptors do anaesthetic drugs inhibit?
Excitatory receptors:
- Serotonergic
- Nicotinic
- Glutamate
What shape are GABAa receptors and what do they allow the influx of when open - and what effect does this have on their cell?
Pentameric (made up of 5 monomers)
Allows for the influx of Cl- which hyper polarises cells
What is nitrous oxide (N2O) and what kind of analgesic and anaesthetic is it?
An odourless gas with a rapid onset and offset that can be a cardiorespiratory depressant.
It is a strong analgesic agent but a poor analgesic agent.
How are anaesthetic agents usually administered to patients?
Via inhalation of IV
What physical properties are considered when deciding what inhalation agent to use?
- Cost
- Stability
- Flammability
- Ability to vaporise
- Environmental stability
What chemical properties are considered when deciding what inhalation agent to use?
- Toxicity
- Blood solubility
- Non-irritant
- Side effects
What is isoflurane and what are its side effects?
A cheap halogenated ether used as an anaesthetic that is both stable and non-flammable.
- Impacts CVS/RS
- Irritable to the airways
What is seroflurane and its main limitation?
Halogenated ether used as an anaesthetic with a rapid onset and offset
Main limitation is that it is expensive
What is desflurane and its limitations?
Halogenated ether with a quick onset/offset
- Expensive
- Irritant
- Requires a special vaporiser
What solubility property do IV anaesthetic drugs need to have?
Need to be lipid-soluble
What do muscle relaxants cause and what can they be used for?
They cause muscle paralysis and are used for?
- Facilitation of intubation (insertion of a tube into body)
- Maintenance of paralysis for ventilation and/or surgery
What are the two types of muscle relaxants and where do they both act on?
Depolarising and non-depolarising
Act on the neuromuscular junction (NMJ)
What is an example of a depolarising muscle relaxant, and how does it work?
Suxamethonium
Acts on post-synaptic membrane and acts as an agonist by mimicing ACh. However, it can’t be broken down by AChE so muscle remains contracted for a short time then loses the contraction as the drug stays on the receptor so it can’t get stimulated again.
