The enigma of asymptomatic idiopathic pneumoperitoneum: A dangerous trap for general surgeons

INTRODUCTION: Idiopathic pneumoperitoneum is an extremely rare condition that can easily be misdiagnosed as an acute abdomen. Awareness of this phenomenon can help avoid unnecessary surgical intervention and the potential associated morbidities. PRESENTATION OF CASE: A 76 year old man presented to hospital with dyspnoea and productive cough and was diagnosed with an infective exacerbation of COPD. He subsequently had a CTPA which showed a significant amount of free intraperitoneal gas in the upper abdomen. He was completely asymptomatic from this with no abdominal pain, distension, or significant rise in inflammatory markers. Of note, he had never had previous abdominal surgery or endoscopic procedures. He showed no signs of peritonism and was closely observed with serial abdominal examinations for 24 h. He subsequently tolerated oral intake and was discharged 8 days after admission. DISCUSSION: Spontaneous pneumoperitoneum can be due to a variety of intrathoracic, gynaecologic, intra-abdominal and iatrogenic causes. This is a rare case of asymptomatic idiopathic pneumoperitoneum where no clear aetiology or risk factors were found for his free intraperitoneal gas. To the best of our knowledge there have only been two published case reports in the English literature describing idiopathic pneumoperitoneum in a patient that was completely asymptomatic from it. CONCLUSION: As a general surgeon it is important to be aware of the non-surgical causes of pneumoperitoneum. Knowledge of this uncommon condition may help reduce the risk of unnecessary laparotomy.