Anaesthetics

Question 1

What is Bier’s block?

Answer 1

IV Regional anaesthesia. Local anaesthetic is injected IV into extremities that have been exsanguinated by compression/gravity and torniqued to separate it from central circulation.

Question 2

Where is local anaesthetic injected in a transversus abdominal plane nerve block?

Answer 2

Between IO and TA

Question 3

Where is spinal anaesthesia delivered? What does it anaesthetise?

Answer 3

Into the subarachnoid space, L3/L4. Anaesthetises the spinal roots.

Question 4

What should you do if the patient you have just given spinal anaesthesia develops low BP?

Answer 4

Give crystalloid +/- vasopressors (-> constriction)

Question 5

What are the signs of total spinal shock?

Answer 5

Low BP, Low HR, anxiety, apnoea, LOC, headache, urinary retention

Question 6

Where is epidural anaesthesia injected into?

Answer 6

Into the extradural space at L3/L4.

Question 7

When would a blood patch be necessary in someone who has had a dural puncture?

Answer 7

If headache lasts over 24/48 hours

Question 8

Where do you inject caudal (sacral epidural)?

Answer 8

Sacral canal

Question 9

Name 4 absolute contraindications for all neuraxial anaesthesia

Answer 9

1) Anticoagulant states
2) Local sepsis
3) Shock/hypovolaemia
4) High ICP

Question 10

List 8 premedications

Answer 10

1) Analgesia
2) Anxiolysis (benzos)
3) Amnesia
4) Anti-emesis
5) Antibiotics
6) Anti-autonomic
7) Antacids (e.g. Ranitidine)
8) Steroids

Question 11

When should antacids be given to a patient who is going to have surgery?

Answer 11

The night before and 2 hours pre-op

Question 12

Does Propofol have analgesic effects?

Answer 12

NO!

Question 13

What IV anaesthesia would you give to a trauma patient and why?

Answer 13

Etomidate. Avoidance of hypotension is important (Propofol can cause hypotension)

Question 14

Where do neuromuscular blockers work?

Answer 14

Post-synaptic receptors at the NMJ

Question 15

What is suxamethonium?

Answer 15

A partial agonist for acetylcholine receptor - a depolarizing agent

Question 16

Which muscle relaxant causes initial fasciculations and how? How does this lead to paralysis?

Answer 16

Suxamethonium - It depolarizes post-synaptic membranes and then causes paralysis by inhibiting restoration of normal membrane polarity.

Question 17

What rapidly inactivates suxamethonium?

Answer 17

Plasma cholinesterases

Question 18

What is the muscle relaxant of choice in rapid sequence induction?

Answer 18

Suxamethonium

Question 19

Name 3 side effects of suxamethonium

Answer 19

1) Hyperkalaemia
2) Increased intra-ocular pressure
3) Bradycardia (treat with atropine)

Question 20

Why does suxamethonium apnoea occur?

Answer 20

When pt is incapable of metabolising suxamethonium quickly enough due to abnormal cholinesterase - they remain paralysed as there is prolonged drug effect for 2 - 24 hrs.

Question 21

How do non-depolarizing agents work? Do you get fasciculations?

Answer 21

They are competitive antagonists of ACh but without initial depolarisation - so no fasiciculations.

Question 22

What can be used to reverse non-depolarizing?

Answer 22

Anticholinesterases (e.g. neostigmine)

Question 23

Name 2 examples of non-depolarizing agents

Answer 23

Rocuronium

Atracurium (for renal and liver failure - Hoffman elimination)

Question 24

How do patients with Myasthenia Gravis react to muscle relaxants?

Answer 24

They are resistant to suxamethonium BUT v sensitive to non-depolarizing agents so lower doses may be needed.

Question 25

Name 2 drugs that can be used as co-induction agents in IV induction?

Answer 25

Fentanyl/midazolam

Question 26

What gaseous medication is used during gaseous induction?

Answer 26

Sevoflurane in O2 or NO

Question 27

What is the size of endotracheal tube you should use in most men?

Answer 27

8.5 mm

Question 28

What is the size of endotracheal tube you should use in most women?

Answer 28

7.5 mm

Question 29

List at least 4 signs you may see in a patient with a lack/inappropriate levels of general anaesthetic in their blood?

Answer 29

- High heart rate and/ or BP - Dilated pupils - Lacrimations - Movement of laryngospasm

Question 30

When would atelectasis begin after induction? What increases a patient's risk of atelectasis? What is the treatment?

Answer 30

Atelectasis begins within minutes of induction. It is partially caused by using 100% oxygen. TX = analgesia, physio

Question 31

What are the treatment options for bronchospasm?

Answer 31

- Withdraw tube slightly as carina stimulation may be the cause - Check for pneumothorax - Ventilate with 100% oxygen - Increase concentration of volatile agent (e.g. Sevoflurane) - they're good bronchodilators - Salbutamol +/- aminophylline IV - MgSO4 IV - Hydrocortisone IV

Question 32

What treatment would you give for laryngospasm?

Answer 32

100% oxygen. Deepen anaesthesia and attempt to ventilate.

Question 33

Is malignant hyperthermia dominant or recessive? What is it triggered by?

Answer 33

Dominant. | Triggered by suxamethonium or volatile anaesthetics

Question 34

What 4 signs should make you suspect malignant hyperthermia?

Answer 34

1) Unexpected increased oxygen consumption 2) Hypercapnia 3) Tachycardia 4) Rapid temperature increase (late sign)

Question 35

How would you manage a patient with malignant hyperthermia?

Answer 35

- Hyperventilate with 100% oxygen - Maintain anaesthesia with IV agent - Abandon surgery - Non-depolarising muscle relaxant - Dantrolene IV bolus (muscle relaxant) - ITU

Question 36

How would you manage a patient with suxamethonium apnoea?

Answer 36

Ventilate and sedate the patient | Consider FFP

Question 37

What pharmacological treatment can you give to a patient who is shivering during surgery?

Answer 37

Tramadol or nefopam

Question 38

Which form of airway adjunct is aspiration more likely to occur in?

Answer 38

LMA

Question 39

Name 4 risk factors for aspiration during surgery

Answer 39

1) Emergency surgery 2) Pregnancy 3) Diabetes 4) Hiatus hernia

Question 40

How would you manage a patient who has aspirated?

Answer 40

- Apply cricoid pressure - Suction mouth and upper airway - Endotracheal intubation - NGT to empty stomach - Pt head down and left lateral position - Cancel surgery - CXR

Question 41

What medication is used to reverse XS opioids?

Answer 41

Naloxone

Question 42

Describe how pain can lead to delayed wound healing

Answer 42

Pain --> autonomic activation --> increased adrenergic activity --> arteriolar vasoconstriction --> decreased wound perfusion --> decreased tissue oxygenation --> delayed wound healing

Question 43

Where must you not use lignocaine w/ adrenaline?

Answer 43

In areas with an end-arterial supply e.g. fingers

Question 44

What is a normal heart rate?

Answer 44

60 - 100 bpm

Question 45

What is a normal respiratory rate?

Answer 45

12 - 16/ min

Question 46

What is a normal urine output?

Answer 46

800 - 2000mls/day

Question 47

What does an ASA score of 1 mean?

Answer 47

Patient is normally healthy

Question 48

What does an ASA score of 2 mean?

Answer 48

Mild systemic disease but with no limitation of activity

Question 49

What does an ASA score of 3 mean?

Answer 49

Severe systemic disease that limits activity; no incapacitating

Question 50

What does an ASA score of 4 mean?

Answer 50

Incapacitating systemic disease which poses a threat to life.

Question 51

What does an ASA score of 5 mean?

Answer 51

Moribund. Not expected to survive 24 hrs even with operation.

Question 52

What does an ASA score of 6 mean?

Answer 52

Brain-dead patient whose organs are being removed for donor purposes.

Question 53

What are the problems with pulse oximetry?

Answer 53

- Light contamination: finger probe ill-fitting; painted nails - Oximeters detect pulsatile Hb - problem if patient's peripheral circulation is sluggish: shock, local hypothermia, shivering, tremor, finger moving excessively - SpO2 doesn't show how well the patient is ventilating or information on the cellular environment

Question 54

List 3 things that make non-invasive blood pressure monitoring less accurate?

Answer 54

- Patient is dysrhythmic/ hypovolaemic - Cuff is too small --> high BP - Underestimates high blood pressure and overestimates low blood pressure

Question 55

What ASA grade of a patient would you have to do pulmonary function tests +/- arterial blood gas?

Answer 55

If they are ASA grade 3/4

Question 56

How soon before surgery should you stop taking clopidogrel, prasugrel and tixagrelor?

Answer 56

Stop 5 - 7 days before surgery

Question 57

What advice should you give to insulin-dependent diabetics who are due for surgery in regards of their insulin?

Answer 57

Continue their long-acting (basal) insulin, even when on a sliding scale. Omit oral hypoglycaemics on morning of surgery.

Question 58

What should you do in terms of gas given to a patient after anaesthesia?

Answer 58

100% of oxygen

Question 59

How would you check for residual muscle paralysis after surgery? What can you do to reverse this?

Answer 59

Use a peripheral nerve stimulator | Reverse any residual muscle paralysis with neostigmine and an anticholingeric

Question 60

Describe some features of the enhanced recovery programme?

Answer 60

- Carbohydrate drinks 2 hours prior to surgery to avoid metabolic state linked with fasting - Early mobilisation - Prompt return to normal nutrition

Question 61

What should be done regarding a patient on anticoagulation who is due for surgery?

Answer 61

Check their INR and if needed, switch to warfarin to heparin preoperatively

Question 62

Can NSAIDs be continued on the morning of surgery and why?

Answer 62

Discontinue due to renal and anti-pH effects

Question 63

What blood test should you do for patients due for surgery who are on diuretics and what are you looking for?

Answer 63

U&Es and check for hypokalaemia and hypovolaemia