Pneumoperitoneumi

Pneumoperitoneumi refers to the presence of free gas within the peritoneal cavity. It is most often detected as a sign of a perforated hollow viscus and is frequently a surgical emergency. However, free intraperitoneal air can also occur after abdominal procedures or instrumentation, following trauma, from thoracic sources, or spontaneously in certain populations, such as neonates or patients receiving mechanical ventilation.

Causes are commonly categorized as iatrogenic, traumatic, or spontaneous. Iatrogenic causes include laparoscopy, endoscopy with insufflation, peritoneal dialysis exchanges, and other abdominal interventions. Traumatic causes encompass blunt or penetrating abdominal injuries that perforate a viscus. Perforation from conditions such as peptic ulcers, diverticulitis, appendicitis, Crohn disease, or malignancy are typical surgical etiologies. Spontaneous or non-surgical pneumoperitoneum can occur due to thoracic barotrauma, alveolar rupture with mediastinal air tracking into the peritoneum, or air introduced during invasive procedures without perforation. In neonates, pneumoperitoneumi is often associated with necrotizing enterocolitis or other inflammatory/infectious processes.

Diagnosis relies on imaging and clinical assessment. Upright chest radiography or abdominal radiographs can reveal free air under the diaphragms or in the peritoneal cavity; computed tomography is more sensitive and can help identify the source. Clinical presentation ranges from acute abdomen with peritoneal signs to minimal symptoms when air is incidental or non-perforative. In stable patients with a clear iatrogenic cause and no signs of peritonitis, conservative management may be appropriate; in suspected perforation with peritonitis or sepsis, urgent surgical intervention is typically required. The prognosis depends on the underlying cause and the timeliness of treatment.