Evidence of abdominal free air not explained by paracentesis or recent surgical procedure Evidence of abdominal free air not explained by paracentesis or recent surgical procedure Evidence of abdominal free air not explained by paracentesis or recent surgical procedure Evidence of abdominal free air not explained by paracentesis or recent surgical procedure Patients with evidence of abdominal free air not explained by paracentesis Evidence of abdominal free air not explained by paracentesis or recent surgical procedure Evidence of abdominal free air that is not explained by paracentesis or recent surgical procedure Evidence of abdominal free air not explained by paracentesis or recent surgical procedure