Pneumoperitoneum: A review of nonsurgical causes

Objective: To review causes of nonsurgical pneumoperitoneum (NSP), identify nonsurgical etiologies, and guide conservative management where appropriat e. Data Source: We conducted a computerized MEDLINE database search from 1970 to 1999 by using key words pneumoperitoneum and benign, nonsurgical, sponta neous, iatrogenic, barotrauma, pneumatosis, diaphragmatic defects, free air , mechanical ventilation, gynecologic, and pelvic. We identified 482 articl es by using these keywords and reviewed all articles. Additional articles w ere identified and selectively reviewed by using key words laparotomy, lapa roscopy: and complications. Study Selection: We reviewed all case reports and reviews of NSP, defined a s pneumoperitoneum that was successfully managed by observation and support ive care alone or that required a nondiagnostic laparotomy. Data Synthesis: Each unique cause of nonsurgical pneumoperitoneum was recor ded. When available, data on nondiagnostic exploratory laparotomies were no ted. Case reports were organized by route of introduction of air into the a bdominal cavity: abdominal, thoracic, gynecologic, and idiopathic. Conclusions: Most Gases of NSP occurred as a procedural complication or as a complication of medical intervention. The most common abdominal etiology of NSP was retained postoperative air (prevalence 25% to 60%). NSP occurred frequently after peritoneal dialysis catheter placement (prevalence 10% to 34%) and after gastrointestinal endoscopic procedures (prevalence 0.3% to 25%, varying by procedure). The most common thoracic causes included mechan ical ventilation, cardiopulmonary resuscitation, and pneumothorax. One hund red ninety-six case reports of NSP were recorded, of which 45 involved surg ical exploration without evidence of perforated viscus. The clinician shoul d maintain a high index of suspicion for nonsurgical causes of pneumoperito neum and should recognize that conservative management may be indicated in many cases.