[Free air below the diaphragm: not always an acute surgical problem]

In three patients, two males aged 66 and 67 years with among other disorders chronic obstructive pulmonary disease (COPD) and one woman aged 24 years with a history of intestinal surgery and current abdominal pain, the chest X-ray showed free air below the diaphragm. The two males had no major abdominal symptoms, but they did have pneumonia. All were treated conservatively. Of the males, one died from pneumonia, the other recovered. The woman presented recurrent symptoms and was subjected to extensive diagnostic examinations. This revealed a marked sigmoid perforation which was repaired, after which the symptoms did not recur. Pneumoperitoneum indicates rupture or perforation of a hollow viscus in up to 90%. In these cases, prompt surgical management is the therapy of choice. In at least 10% free air under the diaphragm is due to causes which do not require surgical treatment. These causes can be divided into intra-abdominal, intrathoracic, gynaecological and iatrogenic diseases. Conservative management should only be considered if followed by frequent and intensive evaluation of the patient's condition.