DIAGNOSIS: PNEUMOPERITONEUM / HYDROPNEUMOPERITONEUM This is a surgical emergency. The bilateral subdiaphragmatic free air with non-anatomical horizontal air-fluid levels is the classic radiological sign of a perforated hollow viscus.
| Cause | Notes |
|---|---|
| Perforated peptic ulcer (duodenal or gastric) | Most common cause in this age group |
| Perforated sigmoid diverticulitis | Common in elderly males |
| Perforated appendix | Less likely given age and bilateral free air |
| Perforated gastric/colonic malignancy | Must be excluded, especially at 65 years |
| Post-procedural perforation | Prior surgical clips noted - relevant history |
⚠️ This is a time-sensitive finding. Mortality from hollow viscus perforation rises significantly with delay in surgical intervention.