Asymptomatic pneumoperitoneum diagnostic and therapeutic dilemma

The most common cause of pneumoperitoneum is iatrogenic postsurgical free air that enters the abdominal cavity during laparotomy. In these patients, pneumoperitoneum usually resolves within the first week of surgery and laparoscopic procedures. In patients who have not had recent laparotomy or laparoscopy, pneumoperitoneum indicates rupture of an intra-abdominal viscus in about 90 per cent of the time. Perforated gastric and duodenal ulcers account for the greatest number of these cases. The other 10 per cent are due to a variety of nonsurgical causes that can often be treated by supportive and non-operative measures. Lack of clinical awareness about these small but significant subset of patients who present with spontaneous benign pneumoperitoneum is a source of needless laparotomies that can at times lead to serious postoperative complications. Benign pneumoperitoneum can be categorized according to the source of the gas as suggested by Gantt. The thoracic cavity is by far the most common source, followed by the GI and female genital tracts and a host of other miscellaneous causes. We report here six patients who presented to Howard University Hospital with nonsurgical pneumoperitoneum. Four of these patients underwent negative laparotomies and one died postoperatively. The most common causes of benign pneumoperitoneum are discussed and a review of the literature is presented.