Rapid diagnosis of the cause of pneumoperitoneum in ventilated asthmatic children.

Two asthmatic children developed a pneumoperitoneum whilst being mechanically ventilated. A quick and accurate diagnosis as to the cause of the pneumoperitoneum was made by analysing the partial pressure of oxygen in the intraperitoneal free gas. This analysis helped to diagnose an intestinal perforation in one child and an air leak from lung barotrauma in the other. There was minimal delay in the surgical treatment of the child with intestinal perforation and in the other, an unnecessary laparotomy was avoided.