Duration of pneumoperitoneum on chest radiograph after open colorectal surgery

Postoperative pneumoperitoneum on a plain chest radiograph is a potentially important medicolegal document of possible complication. However, pneumoperitoneum may be observed without significance after intra-abdominal procedures.

Between April 2001 and March 2002, 204 consecutive open laparotomies for colorectal surgery were studied. Sixty-three patients had 97 chest radiographs taken before the twenty-fifth postoperative day.

Only one patient had subdiaphragmatic air (height >20 mm) on the tenth postoperative day associated with a visceral perforation. Normal subdiaphragmatic pneumoperitoneum was observed on 11 films in 8 patients (13%). Small amounts of air (<15 mm high) were observed in 7 (15%) of 47 radiographs on days 0-5, in 4 (18%) of 25 radiographs on days 6-10, but in no radiograph of 24 after day 10.

Subdiaphragmatic pneumoperitoneum less than 20 mm high is often observed between the sixth and tenth postoperative days, without clinical importance.