Anaesthetics + adjuvants

Question 1

Ketamine

Answer 1

IV General anaesthetic - Opioid

Antagonises N-methyl-D-aspartate (NMDA) receptors; also interacts with muscarinic receptors, descending monoaminergic pain pathways, voltage-sensitive calcium channels and opioid receptors in brain and spinal cord.

Question 2

Midazolam

Answer 2

IV General anaesthetic - Benzodiazepine

Potentiates the inhibitory effects of GABA throughout the CNS, resulting in anxiolytic, sedative, hypnotic, anterograde amnesic, muscle relaxant and antiepileptic effects.

Question 3

Propofol

Answer 3

IV General anaesthetic

Uncertain, but its main CNS depressant action is thought to be via the GABA receptor at a site different to that of barbiturates and benzodiazepines. May also shorten channel opening times at nicotinic acetylcholine receptors and sodium channels in the cerebral cortex.

Question 4

Thiopental

Answer 4

IV general anaesthetics

Potentiates action of the inhibitory neurotransmitter GABA at multiple sites in the CNS, resulting in sedative, hypnotic, anaesthetic and anticonvulsant effects. It also depresses the actions of excitatory neurotransmitters in the CNS. Redistribution of cerebral blood flow to injured areas may also be involved in its neuroprotective effect.

Question 5

Methoxyflurane

Answer 5

Inhaled anaesthetic

Thought to enhance inhibitory ion channel activity and inhibit excitatory activity in the brain to induce hypnosis and amnesia, and in the spinal cord to allow immobility despite painful stimuli.

Question 6

Nitrous oxide

Answer 6

Inhaled anaesthetic

Thought to enhance inhibitory ion channel activity and inhibit excitatory activity in the brain to induce hypnosis and amnesia, and in the spinal cord to allow immobility despite painful stimuli.

Question 7

Atracurium

Answer 7

Non-depolarising neuromuscular blockers

Acetylcholine receptor antagonists, which act at the neuromuscular junction preventing depolarisation of the muscle membrane.

Question 8

Cisatracurium

Answer 8

Non-depolarising neuromuscular blockers

Acetylcholine receptor antagonists, which act at the neuromuscular junction preventing depolarisation of the muscle membrane.

Question 9

Mivacurium

Answer 9

Non-depolarising neuromuscular blockers

Acetylcholine receptor antagonists, which act at the neuromuscular junction preventing depolarisation of the muscle membrane.

Question 10

Rocuronium

Answer 10

Non-depolarising neuromuscular blockers

Acetylcholine receptor antagonists, which act at the neuromuscular junction preventing depolarisation of the muscle membrane.

Question 11

Vecuronium

Answer 11

Non-depolarising neuromuscular blockers

Acetylcholine receptor antagonists, which act at the neuromuscular junction preventing depolarisation of the muscle membrane.

Question 12

Suxamethonium

Answer 12

Depolarizing neuromuscular blocker

Suxamethonium mimics acetylcholine; acts at acetylcholine receptor, depolarising the motor end plate resulting in neuromuscular blockade.

Question 13

Clonidine

Answer 13

Alpha2 and imidazoline agonist

Have sedative, anxiolytic, analgesic and haemodynamic-stabilising effects. They act on alpha2 adrenoreceptors in the CNS to reduce noradrenergic activity, and also on receptors in other tissues. The main site of analgesic action is thought to be the spinal cord.

Stimulation of imidazoline receptors results in a central hypotensive and antiarrhythmic action.

Question 14

Dexmedetomidine

Answer 14

Alpha2 and imidazoline agonist

Have sedative, anxiolytic, analgesic and haemodynamic-stabilising effects. They act on alpha2 adrenoreceptors in the CNS to reduce noradrenergic activity, and also on receptors in other tissues. The main site of analgesic action is thought to be the spinal cord.

Stimulation of imidazoline receptors results in a central hypotensive and antiarrhythmic action.

Question 15

Alfentanil

Answer 15

Potent, short-acting mu-opioid receptor agonists and analogues of fentanyl.

Question 16

Remifentanil

Answer 16

Potent, short-acting mu-opioid receptor agonists and analogues of fentanyl.

Question 17

Atropine

Answer 17

Anticholinergic

preoperatively to reduce salivary and bronchial secretions

perioperatively to treat bradycardia

postoperatively to prevent muscarinic adverse effects of neostigmine.

Question 18

Glycopyrronium

Answer 18

Anticholinergic

preoperatively to reduce salivary and bronchial secretions

perioperatively to treat bradycardia

postoperatively to prevent muscarinic adverse effects of neostigmine.

Question 19

Neostigmine

Answer 19

Anticholinesterase

Reduce breakdown of neuronally released acetylcholine by inhibiting cholinesterase; enhance neuromuscular transmission in skeletal and smooth muscles.

Question 20

Sugammadex

Answer 20

Binds rocuronium or vecuronium to reduce the amount of drug acting at the neuromuscular junction.

Question 21

Bupivacaine

Answer 21

Amide local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.

Question 22

Cocaine

Answer 22

Ester local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.

Question 23

Lidocaine/lignocaine

Answer 23

Amide local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.

Question 24

Prilocaine

Answer 24

Amide local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.

Question 25

Ropivacaine

Answer 25

Amide local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.

Question 26

Tetracaine

Answer 26

Ester local anaesthetic

Reversibly interrupt impulse conduction in peripheral nerves and stabilise excitable cell membranes by blocking sodium channels, thus inhibiting depolarisation.