Large sub-pleural air cysts: an extreme form of pulmonary interstitial emphysema.

Pulmonary interstitial emphysema is a well-documented complication of positive-pressure ventilation. However, the occurrence of large sub-pleural air cysts is a less well-known, extreme manifestation of this entity. We present here an infant who developed this complication of pulmonary barotrauma during cardiopulmonary resuscitative efforts.