Principles of Anaesthetics

Question 1

what do GA interfere with?

Answer 1

neuronal ion channels

Question 2

what do GA do?

Answer 2

hyperpolarise neurones making them less likely to fire

Question 3

pharmacology of IV agents?

Answer 3

allosteric binding to GABA receptors which open chloride ion channels

Question 4

cerebral function in GA?

Answer 4

lost from top down with most complex processes lost first - hearing is last

Question 5

reflexes in GA?

Answer 5

spared as small number of synapses

Question 6

wha is in inhalational anaesthetics?

Answer 6

halogenated hydrocarbons

Question 7

what does MAC mean?

Answer 7

minimum alveolar concentration

Question 8

what is MAC?

Answer 8

measure of potency - lower the MAC the more potent

Question 9

GA effects on the central CVS? (2)

Answer 9

depress cardiovascular centre

reduce sympathetic outflow

Question 10

GA effects directly on CVS?

Answer 10

negatively inotropic
vasodilation
venodilation

Question 11

GA effect on MAP?

MAP = CO X SVR

Answer 11

negative inotropic and venodilation decrease CO

vasodilation decreases SVR

Question 12

what do GA agents do to respiratory system? (4)

Answer 12

reduce hypoxic and hypercarbic drive
decreases tidal volume and increases rate
paralyse cilia
decrease FRC

Question 13

what do muscle relaxants cause?

Answer 13

apnoea

Question 14

why give intraoperative anaesthesia? (3)

Answer 14

prevention of arousal
opiates contribute to hypnotic effect of GA
suppression of reflex responses to painful stimuli