Anaesthetics Flashcards
What are the types of drugs that are used in anaesthetics?
Inhalational anaesthetics Intravenous anaesthetics Muscle relaxants Local anaesthetics Analgesics
What techniques and equipment are used in anaesthetics?
Tracheal intubation Ventilation Fluid therapy Regional anaesthesia Monitoring
What is the triad of anaesthesia?
Analgesia
Hypnosis
Relaxation
Which parts of the triad are used with general anaesthetics?
All three but mainly hypnosis
Which parts of the triad are used with local anaesthetics?
Mainly analgesia but also relaxation
Which parts of the triad are used with opiates?
Mainly analgesia but also hypnosis
Which parts of the triad are used with muscle relaxants?
Relaxation
How do all general anaesthetics work?
By suppressing neuronal activity in a dose dependant fashion. This is largely done by opening chloride channels which hyperpolarise the neurones or suppressing excitatory synaptic activity
How is cerebral function affected by general anaesthetics?
Most complex processes lost first followed by primitive reflexes last
How quickly is IV anaesthesia effective?
1 arm - brain circulation time
What IV agents are used in general anaesthesia and why are they so fast acting?
Thiopentone and propofol
Highly fat soluble and so can cross membranes very quickly
What are inhalational anaesthetics?
Halogenated hydrocarbons
What is MAC?
Minimum alveolar concentration
What does MAC measure and what does a lower value mean?
Measures potency
A lower number = higher potency as it takes less of the drug to produce the same effect
What is the most common sequence of general anaesthesia?
Intravenous induction followed by inhalational maintenance
More modern agents with more sophisticated infusion techniques (computer controlled infusions) allow use of intravenous maintenance
