Wilson Mikity Syndrome.

In 1960, Wilson and Mikity  described a new form of respiratory disease of unknown cause in five premature infants with a mean birth  weight of 1342 g. 

Chest radiographs demonstrated \"coarse, streaky infiltration with small areas of emphysema, occasionally appearing cystic.\" Histologic findings included alveolar overdistention, septal fibrosis, and interstitial mononuclear infiltration. The original description of this constellation of abnormalities, which became known as the Wilson-Mikity syndrome, predated the widespread use of mechanical assisted ventilation to treat RDS. 

In 1967, the term bronchopulmonary dysplasia (BPD) was introduced by Northway et al to describe a chronic lung disease occurring in premature infants with RDS who were treated with positive-pressure mechanical ventilation and supplemental oxygen and who developed radiographic abnormalities indistinguishable from those seen in Wilson-Mikity syndrome. 

Traditionally, the diagnosis of BPD was assigned to infants who received mechanical ventilation and oxygen delivery for a minimum of 3 days during the first 2 weeks of life, who exhibited clinical signs of respiratory compromise beyond 28 days, who required supplemental oxygen beyond 28 days of age to maintain a PaO2 above 50 mm Hg, and who developed the characteristic radiographic abnormalities. 

Chest radiographs findings: 

Stage I BPD (2–3 days after birth) : typical granular opacities of RDS are seen.  

Stage II BPD (4–10 days): near complete opacification of the lungs is identified in the most severe examples. 

Stage III BPD (10–20 days) : small round cystic lucencies alternating with regions of irregular opacity are seen. 

Stage IV BPD (beyond 1 month) : demonstrates further enlargement of lucent regions alternating with thin strands of increased opacity, an appearance that has come to be called \"bubbly lungs\"