Anaesthetics Flashcards

1
Q

Which anaesthetic agent is useful in patients who suffer from post-op nausea + vomiting?

A

propofol - is also an anti-emetic

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2
Q

What is thought to be the mechanism of action of volatile liquid anaesthetics (desflurane, isoflurane, sevoflurane)?

A

Exact mechanism of action unknown. May act via a combination of GABA, glycine and NDMA receptors

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3
Q

What are 3 adverse effects of volatile anaesthetic agents (desflurane etc.)?

A
  1. myocardial depression
  2. malignant hyperthermia
  3. halothane (not used comonly any more) hepatotoxic
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4
Q

What is thought to be the mechanism of action of nitrous oxide?

A

exact mechanism of action unknown. May act via a combination of NDMA, nACh, 5-HT3, GABA and glycine receptors

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5
Q

What is an adverse effect and therefore contraindication of nitrous oxide?

A

diffuses into gas filled compartments of the body therefore leading to an increase in pressure; should therefore be avoided in pneumothorax

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6
Q

What are 4 examples of intravenous antibiotics?

A
  1. propofol
  2. thiopental
  3. etomidate
  4. ketamine
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7
Q

What is the mechanism of action of propofol?

A

Potentiates GABA-A

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8
Q

What are 2 adverse effects of propofol?

A
  1. pain on injection - activation of pain receptor TRPA1
  2. hypotension
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9
Q

What are 2 situations when propofol is used?

A
  1. common induction agent
  2. used extensively in intensive care for ventilated patients
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10
Q

What is an additional effect, as well as being an anaesthetic agent, of propofol?

A

anti-emetic effects (useful in post-operative vomiting)

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11
Q

What is the mechanism of thiopental?

A

type of barbiturate - potentiates GABA-A

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12
Q

What is a side-effect of thiopental?

A

laryngospasm

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13
Q

Why does thiopental affect the brain quickly?

A

highly lipid-soluble

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14
Q

What is the mechanism of action of etomidate?

A

potentiates GABA-A

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15
Q

What are 2 adverse effects of etomidate?

A
  1. primary adrenal suppression (seoncdary to reversibly inhibiting 11β-hydroxylase)
  2. myoclonus
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16
Q

In which specific situation may etomidate be the induction agent of choice and why?

A

in cases of haemodynamic instability - causes less hypotension that propofol and thiopental during induction

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17
Q

What is the mechanism of action of ketamine?

A

blocks NMDA receptors

18
Q

What are 2 adverse effects of ketamine?

A

disorientation
hallucinations

19
Q

In what situation may ketamine be a useful anaesthetic / analgesic and why?

A

trauma - doesn’t cause a drop in blood pressure

20
Q

What counts as clear fluids pre-op?

A

water, juice with no bits, coffee/tea without milk, ice lollies

21
Q

What is the guidance for adjustments to metformin on for patients undergoing surgery?

A
  • day prior to admission - take as normal
  • day of surgery, morning op - if OD or BD take as normal, if TDS omit lunchtime dose
  • day of surgery, afternoon op - if OD or BD take as normal, if TDS omit lunchtime dose
22
Q

What is the guidance for adjustments to sulphonylureas on the day of surgery?

A
  • day prior - take as normal
  • day of surgery for morning op - if taken OD in morning, omit dose. if BD - omit morning dose
  • dy of surgery for afternoon op - if OD in morning, omit dose. if BD omit both doses that day
23
Q

What is adjustment to be made to DPP4 inhibitors (gliptins) in patients undergoing surgery?

A
  • day before - take as normal
  • day of (morning op) - take as normal
  • day of (pm op) - take as normal
24
Q

What is adjustment to be made to GLP1 analogues (e.g. exenatide) in patients undergoing surgery?

A
  • day before - take as normal
  • day of (morning op) - take as normal
  • day of (pm op) - take as normal
25
Q

What is adjustment to be made to SGLT2i drugs (-flozins) in patients undergoing surgery?

A
  • day before - take as normal
  • day of (morning op) - omit on day of surgery
  • day of (pm op) - omit on day of surgery
26
Q

What adjustments should be made to twice daily biphasic or ultra-long acting insulins e.g. Novomix 30, Humulin M3 in patients having surgery?

A
  • day before: no dose change
  • day of (am op): halve morning dose, evening dose as normal
  • day of (pm op): halve morning dose, evening dose as normal
27
Q

What special preparation is required for thyroid surgery?

A

vocal cord check

28
Q

What special preparation is required for parathyroid surgery?

A

consider methylene blue to identify gland

29
Q

What special preparation is required for sentinel node biopsy?

A

radioactive marker / patent blue dye

30
Q

What special preparation is required for surgery involving the thoracic duct ?

A

consider administration of cream

31
Q

What special preparation is required for phaeochromocytoma surgery?

A

alpha and beta blockade

32
Q

What special preparation is required for carcinoid tumour surgery?

A

octreotide cover

33
Q

What special preparation is required for colorectal surgery?

A

bowel prep (esp L sided surgery)

34
Q

What special preparation is required for patients with thyrotoxicosis undergoing surgery?

A

lugols iodine/medical therapy

35
Q

What is the commonest reason for desaturation after intubation?

A

oesophageal intubation

36
Q

How does malignant hyperthermia present?

A
  • increased end-tidal CO2
  • increased body temperature, diaphoresis
  • sustained muscular contraction and rhabdomyolysis
  • metabolic acidosis
37
Q

What is the dose of adrenaline for anaphylaxis < 6 months?

A

100 - 150 micrograms (0.1 - 0.15 ml 1 in 1000)

38
Q

What is the dose of adrenaline for anaphylaxis 6 months - 6 years?

A

150 micrograms (0.15 ml 1 in 1000)

39
Q

What is the dose of adrenaline for anaphylaxis in children 6 - 12 years?

A

300 micrograms (0.3 ml 1 in 1000)

40
Q

What is the dose of adrenaline for anaphylaxis in an adult and child > 12 years?

A

500 micrograms (0.5 ml 1 in 1000)

41
Q

What adjustments should be made to once daily insulins e.g. Lantus, Levemir in patients having surgery?

A
  • day before: reduce dose by 20%
  • day of surgery (am op): reduce dose by 20%
  • day of surgery (pm op): reduce dose by 20%