Atelectasis associated with mechanical ventilation for hyaline membrane disease.

The occurrence of atelectasis among infants, who were intubated and mechanically ventilated for hyaline membrane disease and who survived the neonatal period, was examined after omitting atelectasis associated with obvious malposition of the endotracheal tube. Atelectasis occurred both while intubated and after extubation. There was a pronounced effect of birth weight. The incidence among 131 surviving infants increased from 9% while intubated and 15% after extubation in infants with birth weights > 2000 g to 50% while intubated and 56% after extubation in those with birth weights < 1000 g. Although in general, the incidence fell as the duration of intubation diminished, postextubation atelectasis was a problem even in larger infants with comparatively short intubations. The pattern of atelectasis showed a disproportionate involvement of all lobes of the right lung, both while intubated and after extubation. This suggests that the incidence of atelectasis might be lowered by minimizing traumatic damage to the mucosa of the right sided bronchi.