Pneumoperitoneum without ruptured viscus in the neonate: a case report and review of the literature.

A premature infant with severe respiratory distress developed the clinical and radiologic signs of pneumoperitoneum. At operation, free intraperitoneal air without visceral perforation was found. This case is unique in that pneumothorax was never observed and that interstitial emphysema or ischemic gastrointestinal lesions were not present at autopsy. The patient, however, was on a positive pressure ventilator for some time because of hyaline membrane disease and early pulmonary oxygen toxicity. Reduced parenchymal compliance could predispose to alveolar rupture. Although there was no clinical or anatomic evidence to point to a source of the intraperitoneal air, an undetectable pulmonary rupture with prompt dissection into the peritoneal cavity is the most likely explanation for the pneumoperitoneum.