Principles of anaesthetics Flashcards
What are the drug categories in anaesthetics?
Inhalation anaesthetics IV anaesthetics Muscle relaxants Locala anaesthetics Analgesics
What is the triad of anaesthetics?
Hyponosis
Analgesia
Musle relaxation
What is the mechanism of action of general anaesthetics?
Interfere with neuronal ion channels
How to inhaled general anaesthetics act?
Dissolve in membranes
What drugs are used as inhaled general anaesthetics?
Halogenated hydrocarbons
What speed is the induction of general anaesthesia?
Inhaled- slow
IV- rapid
What drugs are used as IV anaesthetics?
Propofol
Opiates
What is the mechanism of action of IV anaesthetics?
Allosteric ending to GABA receptors opens chloride channels
What is the process of loss of consciousness with general anaesthetics?
Top down
Most complex processes interrupted first
What are the effects of general anaesthetics on CVS system?
Depress CV centre-
- reduce sympathetic outflow,
- negative ionotropic effect on heart- weaker contractions
- vasodilation and venodilation
What are the effects of general anaesthetics on the rest system?
Depressants- reduce hypoxic and hypercarbic drive, decrease tidal volume and increase rate
Paralyse cilia
Decrease functional residual capacity- lower lung volumes, V/Q mismatch
What are the indications for muscle relaxants?
Ventilation an intubation
Immobility essential
Body cavity surgery
What are the purposes of analgesia in surgery?
Prevent arousal
Hypnotic effect
Suppression of reflex response to painful stimuli
