Paediatric Respiratory 2

Question 1

What respiratory anomalies are associated with Trisomy 21?

Answer 1

• Pulmonary hypertension
• Bronchial stenosis
• Subpleural cysts
• Alveolar simplification

Question 2

What happens to the FEF50%:FIF50% with

• variable extra-thoracic lesions
• variable intra-thoracic lesions
• fixed obstruction

Answer 2

• variable extrathoracic lesions INCREASE ratio (>1)
• variable intrathoracic lesions DECREASE ratio (<0.2)
• fixed obstructions (intrathoracic or extrathoracic) ratio ~1

Question 3

The mechanism of action of inhaled nitric oxide is:

Answer 3

upregulation of cyclic guanosine monophosphate (cGMP)

Question 4

Pulmonary function tests in diffuse interstitial

pulmonary fibrosis typically show:

Answer 4

• Increased FEV1/FVC %
• FEV, FVC and TLC decrease
• FRC increases due to air trapping

Question 5

What happens to alveolar and arterial PCO2 if you double ventilation rate?

Answer 5

Doubling the rate of ventilation halves alveolar and arterial PC02

Question 6

What do Type 1 pneumocytes do?

Answer 6

Gas exchange

Question 7

What is ABCA3?

Answer 7

Transporter on the limiting membrane of lamellar bodies (storage organelle for surfactant) in alveolar type II pneumocytes. Mutation causes surfactant deficiency

Question 8

Which surfactant deficiency is the most likely to present early and kill you within 1 year?

Answer 8

Surfactant protein B deficiency

Question 9

What happens to chest wall COMPLIANCE in Morquio syndrome?

Answer 9

Generally related to scoliosis/skeletal issues - DECREASED compliance due to restrictive chest wall abnormality, restrictive pattern on PFTs

Question 10

What symptoms would you expect from someone with a flattened/rectangular inspiratory curve?

Answer 10

Extra-thoracic obstruction:

• Bi/unilateral vocal cord paralysis (weak cry, aspiration, resp distress)
• Tracheomalacia (cough, stridor)
• Airway burns

Worse on inspiration because negative pressure narrows/collapses airway inwards; PEEP reduces the obstruction

Question 11

When is specific lung compliance measured?

Answer 11

Expiration at functional residual capacity

Compliance is affected by FRC

Question 12

Ivacaftor is used for which class of CF mutation?

Answer 12

Class 3

G551D

Question 13

What are the cutoffs for respiratory failure?

Answer 13

The definition of respiratory failure is PaO2 <8

kPa (60mmHg) or PaCO2 >7 kPa (55mmHg)