Nonsurgical causes of pneumoperitoneum.

The radiographic manifestation of free air in the peritoneal cavity suggests serious intra-abdominal disease and the need for urgent surgical management. Yet, about 10% of all cases of pneumoperitoneum are caused by physiologic processes that do not require surgical management. We retrospectively reviewed cases of nonsurgical causes of pneumoperitoneum at the 2 teaching hospitals of a university medical center between January 1990 and December 1995. Successful management by observation and supportive care without surgical intervention was defined as the diagnostic feature of nonperforation. Failure of a laparotomy to delineate a surgical cause or to result in a reparative procedure is congruent with a nonsurgical cause of pneumoperitoneum. During this period, 8 patients (6 men and 2 women; mean age, 61 years) were identified with nonsurgical causes of pneumoperitoneum. Two patients underwent negative laparotomy, and the other 6 were successfully managed nonoperatively and discharged from the hospital. In 6 patients, a cause of the pneumoperitoneum was identified. The causes may be grouped under the following categories: postoperatively retained air, thoracic, abdominal, gynecologic, and idiopathic. In our review of the literature, 61 of 139 reported cases underwent surgical treatment without evidence of perforated viscus. To avoid unnecessary surgical procedures, both primary medicine physicians and surgeons need to recognize nonsurgical causes of pneumoperitoneum. Conservative management is warranted in the absence of symptoms and signs of peritonitis.