Potentially lethal enteric bleeding in the ED.

Spontaneous or primary aortoduodenal fistula (PADF) is an uncommon etiology of upper gastrointestinal bleeding and may potentially cause sudden and unexpected death. Early diagnosis of this disease is difficult, and the mortality rate was reported near 100% when surgery is delayed. The emergency physician (EP) plays a major role in the early diagnosis of aortoduodenal fistula. A PADF should be included in the differential diagnosis when EPs treated emergency department patients with gastrointestinal bleeding, especially those in combination with known abdominal aortic aneurysm or palpable pulsating abdominal mass. Besides, abdominal computed tomography should be considered in patients with recurrent large amount of gastrointestinal bleeding without significant endoscopic findings. Prompt diagnosis and surgical intervention may preserve the life of these patients.