Anaesthetics

Question 1

Important things to ask pre-anaesthetic consultation (8)

Answer 1

1. Recent/current illnesses
2. Baseline exercise tolerance
3. Symptoms of sleep apnoea
4. Smoking
5. Past medical history
6. Drug history incl. allergies
7. Previous anaesthetics and reactions
8. Family anaesthetic history

Question 2

General anaesthetic assessment (5)

Answer 2

1. Neck movement limitation
2. Jaw opening (inter-incisor distance, more than 3 cm = good)
3. Dentures
4. Airway assessment (Mallampati + note BMI)
5. Back examination if having spinal/epidural

Question 3

What is the Mallampati score?

Answer 3

Used to predict ease of intubation

1. see all of soft palate and uvula
2. see half of uvula
3. see a small gap at end of soft palate
4. can only see hard palate

Question 4

What are the fasting guidelines pre-surgery?

Answer 4

No eating for 6 hours pre-op (clear fluids allowed), complete NBM for 2 hours pre-op

Question 5

How are Type 1 diabetics on the AM list prepared for surgery? (3)

Answer 5

1. Take insulin as normal on day before surgery.
2. Nil orally from midnight, take 1/2 normal dose of long-acting insulin and withhold short-actin insulin
3. Should ideally be first on list

Question 6

How are Type 1 diabetics on the PM list prepared for surgery? (3)

Answer 6

1. Take insulin as normal on day before surgery
2. Nil orally after a light breakfast before 7:30am, take 1/2 normal dose of long-acting insullin and withhold short-acting insulin
3. Early admission for glucose monitoring +/- dextrose/insulin/K+ infusion

Question 7

How are those on oral anti-hyperglycaemic agents prepared for surgery? (2)

Answer 7

Try to do first on list!

Stop meds on day of surgery

Question 8

Managing low risk patient on long-term warfarin therapy before surgery

Answer 8

1. Withhold warfarin 4-5 days before surgery
2. Check INR day before surgery: if INR 2-3, administer 3 mg VIT K IV
3. Day of surgery: if INR = 1.5, surgery can proceed
   If INR more than 1.5, defer surgery or if urgent use prothrombinex or FFP (check protocol)
4. Consider pre-op thromboprophylaxis with LMWH if immobilisied
5. For procedures with a low risk of bleeding, continue warfarin

Question 9

Managing low risk patient on long-term warfarin therapy after surgery

Answer 9

Recommence warfarin on night of surgery at previous maintenance dose

Thromboprophylaxis

Question 10

What constitutes a high-risk patient in those undergoing invasive procedures and on long-term warfarin therapy?

Answer 10

Mechanical Heart Valve
CHADS2 more than 2
Episode of VTE within last 3 months

Question 11

Managing a high-risk patient on long-term warfarin therapy before surgery

Answer 11

1. Withhold warfarin 4-5 days before surgery
2. Once INR below 2.0 start LMWH or UFH infusion. If LMWH is used, last dose should be 24h before surgery. If UFH, cease 4-6 hours before surgery.

Question 12

Managing a high-risk patient on long-term warfarin therapy after surgery

Answer 12

1. Recommence warfarin the night of surgery at previous maintenance dose
2. Start LMWH or UFH 12-24h post-op
3. Continue LMWH or UFH for minimum of 5 days and cease 48h after target INR is reached

Question 13

What is the thyromental distance?

Answer 13

Measured from the thyroid notch to the tip of the jaw with the head extended - used to measure ease of intubation. Less than 6 cm is good.

Question 14

Describe the ASA classification system

Answer 14

I - No systemic disease (normal healthy patient for age)
II - Mild systemic disease
III - More severe compensated systemic disease limiting activity, but not acutely incapacitating
IV - uncompensated and incapacitating systemic disease - a constant threat to life
V - patient not expected to survive 24h with or without operation