What is diagnosis?

A 52-year-old man with alcoholism is brought to the emergency department because of a 2-day history of
nausea, vomiting, and increasingly severe abdominal pain that radiates to his left shoulder and back.
He appears extremely dehydrated and is short of breath. His temperature is 37.8°C (100°F), pulse is 120/min,
respirations are 18/min, and blood pressure is 80/60 mm Hg. Abdominal examination shows distention with
epigastric tenderness. Bowel sounds are decreased. Rectal examination shows no abnormalities. Test of the
stool for occult blood is negative. Laboratory studies show:
Hemoglobin 5.5 g/dL
Leukocyte count 15,500/mm3
Serum
Ca2+ 7.5 mg/dL
Amylase 750 U/L
A CT scan of the abdomen is shown.