Persistent pulmonary interstitial emphysema in an unventilated neonate.

Persistent pulmonary interstitial emphysema (PPIE) is a chronic form of pulmonary interstitial emphysema. The disease is histologically distinguished by large cysts and giant cells. Our patient was a female twin who was born at 31 weeks of gestation with a birth weight of 1,450 g. A chest X-ray at 2 hr after delivery was normal. At 12 hr, respiratory distress developed, and nasal continuous positive airway pressure (CPAP) was initiated. A chest film revealed left-sided pneumothorax. A chest tube was inserted, and the baby continued on nasal CPAP for 5 days. Her chest X-ray on postnatal day 4 showed diffuse cystic changes in the left lung. Thoracic computed tomography revealed multiple thick-walled cysts, the largest measuring 3 cm in diameter. Our case confirms that localized PIE may occur in preterm infants who have been treated with nasal CPAP only. Since this method is being used increasingly to avoid mechanical ventilation and in the postextubation period, it is very important that clinicians be aware of its complications.