Table 1.

The differences between “old” versus “new” bronchopulmonary dysplasia

Contents	Old (or classic) BPD	New BPD
Infants at risk	Moderately preterm infants	Extremely preterm infants
Clinical characteristics	Presurfactant era	Postsurfactant era
	Prolonged invasive ventilation with high inspired oxygen	Gentle or noninvasive ventilation
	Severe airway injury	Interfere with lung development
Pathological aspects	Interstitial and alveolar edema	Arrested acinar development
	Intense airway inflammation	Less prominent inflammation
	Lung parenchymal fibrosis	Less fibrosis
	Metaplasia of the respiratory epithelium	Alveolar hypoplasia with fewer and larger alveoli
	Pulmonary artery smooth muscle hypertrophy	Abnormal and fewer vascular arteries growth
Radiologic findings	Cystic emphysema	Diffuse haziness
	Overinflated lung filed	Decreased lung field
	Alveolar septal fibrosis

BPD, bronchopulmonary dysplasia.