Bronchopulmonary dysplasia etiology: which statement is true?

• A. It is caused by long-term supplemental oxygen and mechanical ventilation
• B. It occurs only in term infants
• C. It is prevented by high oxygen concentrations
• D. It is unrelated to ventilation

Answer: (A)

Bronchopulmonary dysplasia arises from injury to the immature lung of very preterm infants who require prolonged respiratory support. Prolonged mechanical ventilation can cause volutrauma and barotrauma, while extended exposure to high oxygen levels leads to oxidative stress and inflammation. Together, these injuries disrupt normal alveolar and vascular development, producing the chronic lung changes seen in BPD. This is why the statement about long-term oxygen and mechanical ventilation being involved is true. It also explains why BPD occurs in preterm infants who need extended ventilation, not only in term infants; and why simply using high oxygen concentrations does not prevent it—excess oxygen contributes to injury.