Anaesthetics

Question 1

What regular medication should be omitted pre-operatively in elective patients?

Answer 1

ACE inhibitors 24-72 hours before

Anti tumour necrosis factor 2 weeks before

DOACs (rivaroxaban and apixaban 3 days prior)

Platelet inhibitors e.g. clopidogrel and aspirin 7-10 days before

Angiotensin receptor blockers (sartans)

Question 2

Inappropriate flexion in GCS?

Answer 2

Flexion of arms below clavicle

Question 3

With what GCS is your airway no longer protected?

Answer 3

<9

Question 4

What are the gastric effects of NSAIDs?

Answer 4

Affects mucosa and gastric acid secretion

Can lead to peptic ulcers

Prevent with omeprazole or misoprostol

Question 5

What are the coagulation effects of NSAIDs?

Answer 5

Prolong bleeding time
Reduce thromboxane production
Displaces warfarin
Do not use in aspirin-sensitive asthma (causes asthma exacerbations)

Question 6

What are the renal effects of NSAIDs?

Answer 6

Reduce prostaglandin release

Vasoconstrict renal arteries and reduce blood flow to kidneys

Risk of kidney failure if during hypotension or blood loss

Precipitates fluid retention

Hyperkalaemia

Question 7

Advantage and disadvantage of desflurane

Answer 7

Rapid recovery in obese - can extubate 5 mins earlier

Contribution to global warming

Question 8

What is propofol used for?

Answer 8

Total Intravenous Anaesthesia

Either starting or maintenance

Question 9

How do muscle relaxants work?

Answer 9

Mimic acetylcholine at neuromuscular junction

Question 10

How does suxamethonium work?

Answer 10

Binds to nicotinic receptors at NMJ

Causes opening of sodium channels and depolarisation leading to fasciculations

Sodium channels then are desensitised leading to muscle relaxation

Question 11

What are the advantages of suxamethonium?

Answer 11

Rapid onset
Short acting
Rapid offset

Question 12

What is suxamethonium broken down by?

Answer 12

Acetylcholinesterase

Question 13

How does rocuronium work?

Answer 13

Binds to nicotinic receptors at NMJ

Competitive inhibitor - only once concentrations higher than acetylcholine will the receptors be blocked and muscle relaxes

Prevents opening of sodium channels in the first place

Once acetylcholine concentrations become higher will effects wear off

Question 14

Onset and duration of rocuronium?

Answer 14

Slow onset
Long duration
Slow offset

Question 15

Give an example of a depolarising and a non-depolarising muscle relaxant

Answer 15

Depolarising: suxamethonium

Non-depolarising: rocuronium

Question 16

What is sugammadex used for?

Answer 16

Reversal of neuromuscular block by rocuronium

Works within 1.5 mins

Expensive so only used in emergencies (e.g. unable to ventilate patient)

Question 17

NSAID contraindications

Answer 17

History of GI bleeds, ulcers or asthma

Question 18

NSAID interactions

Answer 18

Digoxin, warfarin, steroids

Question 19

Weak opioid examples

Answer 19

Codeine
Tramadol (dirty drug with non-opioid effects)
Dihydrocodeine

Question 20

What strong opioid can you use when patient has a low eGFR?

Answer 20

Oxycodone

Question 21

How much stronger is oramorph compared with codeine/tramadol?

Answer 21

10x (therefore divide dose by 10 when changing)