A 61-year-old woman was diagnosed with common bile duct stones and acute biliary pancreatitis. She had previously undergone cholecystectomy 5 years ago. A planed endoscopic retrograde cholangio-pancreatography （ERCP） was arranged under general anesthesia. The patient was posed at prone position without bronchial intubation. Endoscopic access was achieved smoothly and cholangiography revealed mild dilation of the extrahepatic bile duct with mild graduate taper at ampullary region. Some filling defects were found inside lower CBD. A moderate sphincterotomy was made unremarkably

and some tiny stones were retrieved using a Dormia basket. A retrieval balloon was advanced into bile duct to make occlusion cholangiogram. At this moment

the endoscope lost its location into part one of duodenum. When the scope reaches back to descending duodenum

active bleeding was found coming out from orifice of papilla

accompanied with decreased oxygen saturation and arrhythmia. X-ray examination demonstrated gas within hepatic vein and inferior cava vein

although no free gas was observed in the renal region or subphrenic area. The endoscope was removed immediatelyand patient was changed to supine position. Vigorous cardiopulmonary resuscitation was begun immediately

unfortunately the patient did not response to all the efforts. The causes of death were thought to be systemic air embolism with cardiopulmonary failure.