In bronchopulmonary dysplasia, which factor is associated with fluid accumulation in the lungs?

• A. Decreased pulmonary vascular pressure
• B. Increased capillary permeability
• C. Increased plasma oncotic pressure
• D. Decreased capillary permeability

Answer: (B)

In bronchopulmonary dysplasia, fluid accumulation in the lungs is best explained by injury to the pulmonary capillary endothelium that increases capillary permeability. This leak allows protein-rich fluid to escape into the interstitial and alveolar spaces, producing edema that worsens gas exchange and contributes to respiratory distress.

Why this fits: inflammation and injury from prematurity, oxygen exposure, and ventilation disrupt the alveolar-capillary barrier, so fluids seep out rather than being kept in the vessels.

Why the others don’t fit: lower pulmonary vascular pressure would tend to reduce edema; higher plasma oncotic pressure would pull fluid into the vessels rather than leak out; decreased capillary permeability would limit fluid movement into the lung tissue.