A man with drowsiness and abdominal pain.

A 26 year old man with abdominal pain and drowsiness was brought to the emergency department by a group of young men who left before any further questioning. He said that he had flown to New York from Equador the previous day and had a party with his friends, where he drank some alcohol but denied using any illicit substances. His physical examination revealed pinpoint pupils. He had no focal neurological deficits and his abdominal examination was benign. Within an hour he went into respiratory distress and slipped into coma, necessitating intubation. His blood work was essentially normal and his urine toxicology was positive for opiates. Chest radiography was normal. Arterial blood gases before intubation showed pH 7.2, carbon dioxide pressure 6.93 kPa (52 mm Hg), oxygen pressure 9.86 kPa (74 mm Hg), bicarbonate 20 mmol/l, and oxygen saturation 94%. Abdominal radiography (fig 1) and computed tomography of the abdomen (fig 2) were done.