Bronchopulmonary Dysplasia ✅

Question 1

How is bronchopulmonary dysplasia defined clinically?

Answer 1

On the basis of clinic signs and dependence on ambient oxygen either at 28 days, or more usually at 36 weeks post menstrual age

Question 2

What is the limitation of using oxygen requirement as a measure of severity of bronchopulmonary dysplasia?

Answer 2

It is a subjective measure and leads to marked variation in prevalence of BPD between units

Question 3

What has been proposed as a result of difficulties arising from using oxygen requirement to measure severity of BPD?

Answer 3

A stricter physiologic definition

Question 4

How is BPD identified using the stricter physiologic definition?

Answer 4

Undergo an oxygen challenge test

Question 5

What happens in the oxygen challenge test?

Answer 5

Infants receiving less than 30% supplemental oxygen undergo a stepwise 2% reduction of supplemental oxygen until they are breathing room air

Question 6

When are babies classified as having no BPD after the oxygen challenge test?

Answer 6

Oxygen saturation >90% for 60 minutes in room air

Question 7

When are babies classified as having BPD after the oxygen challenge test?

Answer 7

If saturation <90% during the observation period

Question 8

What are babies undergoing an oxygen challenge test monitored for?

Answer 8

• Apnoea
• Bradycardia
• Increased oxygen requirements

Question 9

What happens if apnoea, bradycardia, or increased oxygen requirement occurs during the oxygen challenge test?

Answer 9

It is considered a test failure and categorised as BPD

Question 10

What is the advantage of using the oxygen challenge test to identify BPD?

Answer 10

It provides an objective assessment of the presence and severity of underlying lung disease

Question 11

How does the incidence of BPD in VLBW infants differ when using the oxygen challenge test compared to standard criteria?

Answer 11

10% compared to 25%

Question 12

What does the pathogenesis of BPD involve?

Answer 12

• Underdeveloped lungs due to prematurity
• Initial injury to the lung due to primary disease process, e.g. RDS
• Ventilator-induced lung injury mediated through barotrauma (high pressure)
• Volutrauma
• Oxygen toxicity
• Inflammatory cascade
• Inadequate nutrition

Question 13

What causes volutrauma?

Answer 13

Inappropriately high or low tidal delivery

Question 14

What is the underlying problem with pulmonary mechanics in BPD?

Answer 14

• Reduction in lung compliance

- Increased airway resistance

Question 15

What does a reduction in lung compliance and increased airway resistance lead to in BPD?

Answer 15

Increased work of breathing

Question 16

What change in pulmonary mechanics may become more significant in later BPD?

Answer 16

Expiratory flow limitation

Question 17

What happens to functional residual capacity in BPD?

Answer 17

May be reduced initially, but can increase in later stages

Question 18

Why is functional residual capacity initially reduced in BPD?

Answer 18

Due to atelectasis

Question 19

Why can functional residual capacity increase in later stages of BPD?

Answer 19

Due to air trapping and hyperinflation

Question 20

What changes are found in the lungs of extremely premature infants?

Answer 20

• Alveolar simplification
• Reduction in overall surface area for gas exchange
• Failure of secondary alveolar crest to form normal alveoli (epithelial and endothelial cell growth abnormalities)

Question 21

What is the treatment for BPD once it has developed?

Answer 21

Supportive

Question 22

What is the prognosis for BPD?

Answer 22

Most infants ultimately achieve normal lung function

Question 23

What does BPD increase the risk of?

Answer 23

• Death in the first year of life
• Reactive airway disease
• Viral infection
• Growth failure
• Neurodevelopmental abnormalities

Question 24

Which viral infection are patients with BPD particularly susceptible to?

Answer 24

RSV