Anaesthetics + Peri-operative care

Question 1

In which patients are nasopharyngeal airways ideal? In which patients are they contraindicated?

Answer 1

Ideal: Seizure

CI: Base of skull fracture- rare risk of inserting into cranial cavity

Question 2

What are the pre-op fasting recommendatios?

Answer 2

Food >6h
Clear fluids >2h

Also applkies to pregnant women not in labour + diabetics

Question 3

What can be used for emergency surgery in a non-pregnant adult who has not fasted?

Answer 3

Rapid sequence induction to reduce risk of gastro-oesophageal reflux

Question 4

What does rapid sequence induction involve?

Answer 4

Optimal preoxygenation
Induction agent + suxamethonium
Application of cricoid force at the onset of unconsciousness.

Question 5

How are diabetics treated with insulin with good glycaemic control managed during minor procedures?

Answer 5

Adjustment of usual insulin regimen

Question 6

How are diabetics with surgery requiring a long asting period >1 missed meal/ poorly controlled diabetics managed during surgery?

Answer 6

Variable rate IV insulin infusion

Question 7

How are most diabetics taking oral drugs managed for surgery?

Answer 7

Manipulating medication on day of surgery

Question 8

Give 3 exceptions where diabetics on oral drugs should be managed with variable rate IV insulin infusion

Answer 8

> 1 meal to be missed
Poor glycaemic control
Risk of renal injury (low eGFR, contrast use)

Question 9

How shold diabetics on metformin with a morning or afternoon op be managed?

Answer 9

Day prior: normal dose
OD-BD: normal
TD: omit lunchtime dose

Question 10

How shold diabetics on sulfonylureas with a morning op be managed?

Answer 10

Day prior: normal dose
OD in AM: omit
BD: omit AM dose

Question 11

How should diabetics on DPP IV inhibitors (-gliptins) or GLP-1 analogues (-tides) be managed for surgery?

Answer 11

Day prior: normal dose
AM or PM surgery: normal dose

Question 12

How should diabetics on SGLT-2 inhibitors (-flozins) be managed for surgery?

Answer 12

Day prior: normal dose
AM or PM surgery: omit

Question 13

How should diabetics on OD insulins e.g. Lantus, Levemir be managed for surgery?

Answer 13

Dar prior: reduce dose by 20%
AM or PM surgery: reduce dose by 20%

Question 14

How should diabetics on BD biphasic or ultra-long acting insulins e.g. Novomix 30 be managed for surgery?

Answer 14

Day prior: normal dose
AM or PM surgery: halve usual AM dose, normal evening dose

Question 15

How shold diabetics on sulfonylureas with a afternoon op be managed?

Answer 15

Day prior: normal dose
OD in AM: omit
BD: omit both doses

Question 16

4 stages of wound healing

Answer 16

Haemostasis: mins-hours
Inflammation: 1-5d
Regeneration: 1-8w
Remodeling: 6w-1y

Question 17

Which phase of wound healing is the longest?

Answer 17

Remodeling

Question 18

Name a condition that impairs fibroblast synthetic function and immunity with detrimental effect in healing process

Answer 18

Jaundice

Question 19

3 conditions that can compromise microvascular flow and impair healing

Answer 19

Vascular disease
Shock
Sepsis

Question 20

List 4 drugs that impair wound healing

Answer 20

NSAIDs
Steroids
Immunosuppressive agents
Anti-neoplastic drugs

Question 21

What is closure?

Answer 21

Delayed primary closure: anatomically precise closure that is delayed for a few days before granulation tissue becomes macroscopically evident

Secondary closure: spontaneous closure/ surgical closure after granulation tissue has formed

Question 22

What are hypertrophic scars?

Answer 22

Abnormal, fibroproliferative scars with excess collagen
DONT progress beyond margins of original injury.

Question 23

5 features of hypertrophic scars

Answer 23

Pink-red
Slightly raised
Uncomfortable + itchy
Occur within weeks of injury
Limited to confines of initiating wound

Question 24

What usually causes hypertrophic scars?

Answer 24

Full thickness dermal injury

Question 25

What are keloid scars?

Answer 25

Tumour-like lesions arising from connective tissue of a scar/ spontaneously Extend beyond the margins of the original wound

Question 26

Give 3 predisposing factors for keloid scars

Answer 26

Dark skin Young adults Sites: sternum, shoulder, neck, face

Question 27

Management of keloid scars

Answer 27

Early: intra-lesional steroids e.g. Triamcinolone Excision (risk further keloid scarring/ recurrence)

Question 28

Give 5 features of keloid scars

Answer 28

Purplish-red Firm, smooth + raised Uncomfortable + itchy Can occur years after injury + don't regress Grow beyond initiating wound area

Question 29

Which abnormal form of scar contains nodules?

Answer 29

Hypertrophic scars

Question 30

Describe the MOA of Suxamdthonium

Answer 30

Non-competitive (or depolarising) muscle relaxant Induces prolonged depolarisation of skeletal muscle membrane

Question 31

How does the use of suxamethonium manifest in a patient?

Answer 31

Fasciculations lasting a few seconds before profound paralysis

Question 32

What is suxamethonium aka?

Answer 32

Succinylcholine

Question 33

When is suxamethonium usually used/

Answer 33

Rapid sequence intubation in emergency settings due to fast onset + short duration of action

Question 34

Give 2 adverse effects of suxamethonium

Answer 34

Malignant hyperthermia Hyperkalaemia (norm transient)

Question 35

In which patients is suxamethonium contraindicated? Why?

Answer 35

Penetrating eye injuries + acute closed angle glaucoma It increases intra-ocular pressure

Question 36

Name 4 competitive (non-depolarising) muscle relaxants

Answer 36

Atracurium Tubcurarine Vecuronium Pancuronium

Question 37

How do competitive (non depolarising) muscle relaxants work?

Answer 37

Competitive antagonism of acetylcholine at nicotinic receptors at NMJ

Question 38

Name 1 adverse effect of competitive muscle relaxants

Answer 38

Hypotension

Question 39

What drug can be used for reversal of competitive muscle relaxants?

Answer 39

Acetycholinesterase inhibitors e.g. Neostigmine

Question 40

What is the MOA of Glycopyrrolate? How does this work?

Answer 40

Competitive antagonist of ACh at peripheral muscarinic receptors Profound anti-secretory action

Question 41

When is Glycopyrrolate used?

Answer 41

In conjunction with other anti-cholinesterases e.g. neostigmine to reverse muscle relaxation at end of surgery if required

Question 42

What is postoperative ileus aka?

Answer 42

Paralytic ileus

Question 43

What is the common cause of postoperative ileus?

Answer 43

Surgery involving the bowel Reduced bowel peristalsis resulting in pseudo-obstruction

Question 44

Give 5 S/S of postoperative ileus

Answer 44

Abdo distension/ bloating Abdo pain N+V Inability to pass flatus Inability to tolerate oral diet

Question 45

What may contribute to development of post-operative ileus?

Answer 45

Deranged electrolytes Check potassium, magnesium + phosphate

Question 46

Describe management of post-op ileus

Answer 46

NBM initially, may progress to small sips clear fluid NG tube if vomiting IV fluids to maintain normovolaemia TPN for prolonged/ severe cases

Question 47

ASA 1

Answer 47

Normal healthy patient Non-smoker No/ minimal alcohol use

Question 48

ASA 2

Answer 48

Mild systemic disease w/o substantive functional limits e.g. current smoker, social alcohol drinker, pregnancy, obesity (BMI 30-40), well-controlled DM/ HTN, mild lung disease

Question 49

ASA 3

Answer 49

Severe systemic disease Substantive funcitonal limitations >,1 severe diseases

Question 50

ASA 4

Answer 50

Severe systemic disease that is a constant threat to life

Question 51

ASA 5

Answer 51

Moribund patient who is not expected to survive w/o the operation

Question 52

ASA 6

Answer 52

Declared brain-dead patient whose organs are being removed for donor purposes

Question 53

When is the gold standard for stopping the OCP prior to surgery under GA?

Answer 53

4w Due to increased risk thromboembolism | No need to stop if LA