A Case of Duodenocaval Fistula in the Setting of Respiratory Failure Initially Confused for Transfusion-Related Acute Lung Injury.

Background: A duodenocaval fistula is seen when a connection exists between the duodenum and the inferior vena cava. It is a rare entity that presents a diagnostic challenge due to its nonspecific presenting symptoms and often is found only during a laparotomy or autopsy.

Case presentation: A 37-year-old man initially presented to the hospital for melena but went into cardiac arrest before undergoing an esophagogastroduodenoscopy. Unfortunately, a duodenocaval fistula was only found during the autopsy.

Conclusions: Duodenocaval fistula is a diagnostic challenge as it may present with nonspecific findings concerning for other etiologies. We want to highlight that although rare, duodenocaval fistula should be considered for patients who present with gastrointestinal bleeding and hypoxic respiratory failure.