GA + LA

Question 1

Factors affecting rate of onset of GA (fast onset)

Answer 1

1) Solubility in blood (low)
2) Conc in inspired air (high)
3) Rate and depth of pulmonary ventilation (high)
4) Arteriovenous conc gradient (high)

Question 2

Factors affecting rate of recovery (fast)

Answer 2

1) Solubility in blood (low)
2) Duration of exposure (low)
3) Rate of pulmonary ventilation and blood flow (high)

4) Hepatic metabolism of halothane
5) Bacteria in GIT break down NO

Question 3

GA effects on organ systems
- CVS
- Respiratory
- Brain
- Liver

Answer 3

CVS: Decrease mean arterial pressure
Respiratory: Decrease minute ventilation, bronchodilation
Brain: Increase cerebral blood flow, increase intracranial pressure
Liver: Decrease hepatic blood flow

Question 4

Rate of onset and recovery of halothane

Answer 4

Medium

Question 5

Halothane is used for induction of anaesthesia

Answer 5

No, used to maintain anesthesia (induction for children)

Question 6

Onset and Recovery rate of nitrous oxide

Answer 6

Fast

Question 7

Nitrous oxide is potent.

Answer 7

FALSE not potent used as adjunct w others

Question 8

Nitrous oxide used as analgesic for labour pain

Answer 8

YES

Question 9

IV Anesthetics usually lack analgesic effects

Answer 9

YES except ketamine

Question 10

IV Anesthetics has rapid onset and recovery aka short acting

Answer 10

YES

Question 11

Thiopentone has low lipid solubility

Answer 11

No, it has high lipid solubility, allowing it to rapidly cross BBB and our of blood and brain to muscle and fat

Question 12

Thiopentone mechanism of action

Answer 12

Increase duration of GABA gated CL- channels

Question 13

Benzodiazepines have a faster onset of CNS depressant than Thiopentone

Answer 13

NO, slower (inadequate for surgery)

Question 14

Flumazenil increases rate of recovery of benzodiazepines

Answer 14

Yes

Question 15

Benzodiazepines mechanism of action

Answer 15

Increase frequency of GABA gated CL- channel opening

Question 16

Propofol rate of onset and recovery is faster than thiopentone

Answer 16

Rate of onset = thiopentone but recovery is faster

Question 17

Propofol mechanism of action

Answer 17

Potentials GABA by slowing channel closing time aka longer duration of opening CL- channels
AND
Na+ channel blocker

Question 18

Ketamine increase cerebral blood flow

Answer 18

Yes

Question 19

Ketamine is a NMDA receptor agonist

Answer 19

NO it is NMDA receptor antagonist > produces dissociative anesthesia

Question 20

Describe conscious sedation In GA

Answer 20

Patent airway and responds to command

Question 21

Charged form of LA have more rapid onset time

Answer 21

Uncharged form > less dissociation > closer to tissue pH > more rapid onset

Question 22

Butyrylcholinesterases..

Answer 22

Rapidly hydrolyses ester types LA

Question 23

What prolongs action of LA

Answer 23

Vasoconstrictors (eg epinephrine)

Question 24

How is amide LA metabolites

Answer 24

Metabolised in liver by CYP450 enzymes

Question 25

LA Pain fibres are sensory/motor, small/large diameter, unmyelinated/myelinated

Answer 25

Sensory, small, unmyelinated

Question 26

Injection of LA into inflamed tissues is more effective

Answer 26

NO, pH Low at inflamed tissues > small proportion uncharged and enter cell > less effective

Question 27

Sodium bicarbonate increases onset of LA

Answer 27

Yes, increase pH increase onset