Fundamentals of Anaesthesia - Chapter 1

Question 1

Definition of one MET?

Answer 1

1 MET equates to 3.5 millilitres of oxygen per kilogram body weight per minute

Question 2

How many METs for the following?

• Walk 100 metres on level ground
• Climb a flight of stairs or walk up a hill
• Strenuous exercise

Answer 2

1 MET - walk 100 metres on level ground
4 MET - climb a flight of stairs or walk up a hill
> 10 MET - strenuous exercise

Question 3

Increased perioperative risk below if functional capacity is below how many METs?

Answer 3

A functional capacity corresponding to < 4 MET (unable to climb a flight of stairs) is associated with increased perioperative risk.

Question 4

Factors associated with difficulty in mask ventilation (5)?

Answer 4

Obesity
Beard
Edentulous
Snoring
Age > 55

Question 5

Grades of laryngoscopy 1-4?

Answer 5

Grade 1: whole of glottis visible
Grade 2: glottis incompletely visible
Grade 3: epiglottis but not glottis visible
Grade 4: epiglottis not visible

Question 6

Frequency of difficult intubations? % not predicted?

Answer 6

1 in 65 are difficult

20% no predicted

Question 7

Mallampati classes 1-4?

Answer 7

Class 1: faucial pillars, soft palate and uvula visible

Class 2: faucial pillars and soft palate visible, uvula
masked by base of tongue

Class 3: only soft palate visible

Class 4: soft palate not visible

Question 8

Wilson risk factors (5)?

Answer 8

Obesity
Restricted head and neck movements  
Restricted jaw movement
Receding mandible
Buck teeth

Question 9

Tests of neck and jaw movement (4)

Answer 9

Flex chin to chest
Limitation of extension - normal >35 degrees
Reduced mouth opening (less that 2 fingers)
Reduced inter-incisor distance (<3.5cm)

Question 10

Normal angle of atlanto-occipital extension?

Answer 10

> 35 degrees

Question 11

Normal mouth opening?

Normal inter-incisor distance?

Answer 11

Normal mouth opening - > 2 fingers

Normal inter-incisor distance- >3.5cm

Question 12

How is thyromental distance measured?

Below what distance predicts a difficult airway?

Answer 12

Distance between the chin and the thyroid notch with the neck fully extended.

A distance of < 6.5 cm (about three finger breadths) predicts difficulty.

Question 13

How is sternomental distance measured?

Below what distance predicts a difficult airway?

Answer 13

It is the distance from the suprasternal notch
to the chin with the neck fully extended.

A distance of < 12 cm predicts difficulty.

Question 14

How is hyomental distance measured?

Below what distance predicts a difficult airway?

Answer 14

The hyomental distance is that from the chin to the hyoid bone. A distance of < 4 cm (about two finger breadths) predicts difficulty.

Question 15

ASA1 definition

Answer 15

A normal healthy patient

Question 16

ASA2 definition

Answer 16

A patient with mild systemic disease

Question 17

ASA3 definition

Answer 17

A patient with severe systemic disease

Question 18

ASA4 definition

Answer 18

A patient with severe systemic disease that is a constant threat to life

Question 19

ASA5 definition

Answer 19

A moribund patient who is not expected to survive without the operation

Question 20

ASA6 definition

Answer 20

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

Question 21

Mendelson’s syndrome?

Answer 21

Pneumonitis secondary to aspiration of gastric acid in pregnant patients

Question 22

Starvation guidelines - adults?

• Clear fluids
• Food/milky drinks

Answer 22

Adults

• Clear fluids and water up to 2 hours preoperatively
• Food, sweets and milky drinks up to 6 hours preoperatively
• No chewing gum on day of surgery

Question 23

Starvation guidelines - children?

• Clear fluids
• Breast milk
• Food/cow’s milk/formula

Answer 23

Children

• Clear fluids and water up to 2 hours preoperatively
• Breast milk up to 4 hours preoperatively
• Formula/cow’s milk up to 6 hours preoperatively
• Food and sweets up to 6 hours preoperatively

Question 24

Why should chewing gum be avoided pre-op?

Answer 24

There is evidence that chewing gum before surgery significantly increases gastric fluid volume, particularly in children.

Question 25

Definition of chronic bronchitis?

Answer 25

Chronic bronchitis is defined as daily cough with sputum production for at least three consecutive months a year for at least two consecutive years.

Question 26

Definition of emphysema?

Answer 26

Emphysema is defined as enlargement of the air spaces distal to the terminal bronchioles with destructive changes in the alveolar wall.

Question 27

Perioperative issues caused by smoking (5)

Answer 27

Smoking causes several perioperative problems:

• Increased airway reactivity
• Increased sputum production and retention
• Bronchospasm
• Coughing
• Atelectasis associated with an increased risk of postoperative chest infection.

Question 28

Perioperative issue caused by URTI?

Management?

Answer 28

Current or recent URTI is also associated with an increased incidence of postoperative chest infection. Hence, unless surgery is urgent, such patients should be postponed for 4 weeks.

Question 29

How does hypertension affect response to induction?

Answer 29

In a hypertensive patient, there is a much greater fall than normal in systemic arterial pressure on induction of anaesthesia, due to a fall in cardiac output resulting from decreases in both heart rate and stroke volume.