principles of anaesthetics

Question 1

what is the triad of anaesthesia ?

Answer 1

analgesia
relaxation
hypnosis

Question 2

how do general anaesthetic agents work ?

Answer 2

GABA receptor agonists - open chlorine channels

hyperpolarise neurones so less likely to fire

Question 3

where is the initial surge in IV anaesthetics ?

Answer 3

viscera

Question 4

what is the usual sequence of general anaesthesia ?

Answer 4

IV induction

inhalation maintainance

Question 5

what are central CVS effects of general anaesthetic ?

Answer 5

depress CV centre
reduce sympathetic outflow
negative inotropic/chronotropic effect on heart
reduced vasoconstrictor tone

Question 6

what are the effect of GA on the respiratory system ?

Answer 6

reduce hypoxic and hypercarbic drive
decrease tidal volume and increase rate
paralyse cilia

Question 7

what are indications for muscle relaxant ?

Answer 7

ventilation and intubation
immobility essential
body cavity surgery

Question 8

what are problems with muscle relaxants ?

Answer 8

awareness
incomplete reversal - airway obstruction and ventilatory insufficiency in post op
apnoea

Question 9

what are signs and symptoms of local anaesthetic toxicity ?

Answer 9

lingual numbness and tingling
light-headedness
tinnitus, visual disturbance
muscular twitching
drowsiness
CV depression
convulsions
coma
cardiorespiratory arrest