If you find a pneumoperitoneum in your patients who have any evidence of peritonitis, it means that they have a perforated viscus and it means that they go to your surgical colleagues because they need to go to the Operating Room. Iatrogenic is probably the biggest cause. If the patient was just in the OR a day earlier and had a laparotomy, it s not at all uncommon to see a pneumoperitoneum. The thing to remember about the postoperative pneumoperitoneum is it should go away within seven days. So if you have a patient who is seven or eight days postop who pops up with a pneumoperitoneum and you hadn t seen one previously, then suspect that there may be a complication postoperative or that there s a perforated viscus.
Some patients can develop spontaneous pneumoperitoneum.
That patient I showed you who had the pneumatosis intestinalis, that can perforate and cause extra-elementary air. But that patient is going to be not clinically sick and you can probably just kind of watch and see what happens. There can be gynecologic causes of pneumoperitoneum. I think the classic one is the woman who is just maybe newly pregnant and goes waterskiing and just isn t maybe very good at it and spends a lot of time dragging her bottom end through the water. She can develop a pneumoperitoneum because she has really direct communication between the outside via the fallopian tubes, so just remember that as a possibility.