Anaesthetics Flashcards
Name 4 volatile/inhaled anaesthetics
Nitrous Oxide, Isoflurane, Desiflurane, Sevoflurane
Name 2 IV anaesthetics
Ketamine and propofol
What is general anaesthesia?
Inhaled anaesthetics, causing an unconscious state with reversible sensory, motor and sympathetic suppression.
What is regional anaesthesia?
An epidural or spinal injection, causing blocked transmission in the spinal cord, eliminating feeling in certain areas.
What is local anaesthesia?
A peripheral nerve block in the extremeties.
What is dissociative anaesthesia?
Use of ketamine to dissociate higher and lower brain centres, usable in children and the elderly.
How does propofol work?
Increases post-synaptic GABA sensitivity, causing GABA to open chloride channels, allow influx and hyperpolarise the neurone.
How does ketamine and nitrous oxide work?
Antagonises excitatory NMDA post-synpatic receptors, blocking the binding of glutamate, subsequently reducing the transmission of action potentials and calcium currents.
What is the minimum alveolar concentration?
The alveolar concentration of inhaled anaesthesia, at 1atm of pressure, whereby 50% of patients will no longer respond to surgical stimuli.
What is the Blood:Gas Co-efficient?
A measure of how many litres of gaseous anaesthesia can enter 1 litre of blood.
What is the Tissue:Blood Co-efficient?
A measure of how readily anaesthesia exits blood and enters tissue.
Why would you use propofol as an adjuvant for inhaled fluranes?
Lowers the minimum alveolar concentration of fluranes (positive allosteric modulator).
Name 3 types (other than propofol of anaesthetic adjuvants
Opioids, benzodiazapines (GABA agonist), and neuromuscular blocking agents (NAChR antagonists or depolarising agonists - tubocurarine).
What are the three anaesthetic stages?
Induction, maintenance and recovery (where drugs have been withdrawn).
What are the four depths of anaesthesia?
Analgesia, Excitement (delirium and aggression), Surgical Anaesthesia (MAC 1.2-1.5), Respiratory Paralysis (2.2 MAC).
