Long-term pulmonary sequelae of the Wilson-Mikity syndrome.

Five children born prematurely, eight to ten years ago, who survived the Wilson-Mikity syndrome were compared with six apparently normal prematurely born children and eight normal children born at term, by means of flow volume curves obtained while breathing air and while breathing a mixture of 80% helium and 20% oxygen. The flow rates in air of the group who survived the Wilson-Mikity syndrome were significantly lower than those of the prematurely born normal children (P less than 0.01), and than those of the eight normal children (P less than 0.001). The volume of isoflow while breathing air compared to that while breathing HeO2 was highly variable, but not significantly different in the three groups. Three of the five survivors of the Wilson-Mikity syndrome had a marked concavity in the shape of their flow volume curves. It is concluded that these abnormalities are due to focal increases of compliance or resistances or both of terminal lung units and result in adjacent areas of the lung emptying at different rates. The relationship between physiologic and anatomic abnormalities seen at autopsy in those who die to the disease suggests that they are due to the same pathologic process. Whether or not these abnormalities will disappear with future lung growth remains to be seen.