Spontaneous pneumoperitoneum without peritonitis.

Spontaneous pneumoperitoneum without peritonitis is a rare phenomenon which poses a dilemma to the surgeon faced with this problem. Two such cases and their outcome are presented. The first case was caused by barotrauma during positive pressure ventilation and was treated by laparotomy. No perforated viscus was found. The second case was caused by tracheal rupture during emergency intubation and was treated by observation until complete resolution. Both patients died for reasons unrelated to the pneumoperitoneum. The mechanisms for passage of air from the chest into the abdominal cavity were through the diaphragm in the first case and along the great vessels in the second. A compilation of other etiologies of pneumoperitoneum without peritonitis as extracted from the literature is presented. In the presence of pneumoperitoneum without peritonitis and when the clinical history does not suggest perforation of a viscus, we advise performing an abdominal tap. If negative, continued observation is advised.