Acute pancreatitis

Abstract

Acute pancreatitis affects 300 to 600 new patients per million population per year and is most commonly caused by gallstones or alcohol. Careful imaging reveals that most so-called idiopathic acute pancreatitis is due to small (1–3-mm diameter) gallstones. Diagnosis is made by a combination of a typical presentation (upper abdominal pain and vomiting) in conjunction with raised serum amylase (more than three times the upper limit of normal) and/or lipase (more than twice the upper limit of normal). Several other acute abdominal emergencies can mimic acute pancreatitis and may be associated with a raised serum amylase. In equivocal cases, a CT scan is indicated to exclude other causes and confirm the diagnosis. Initial management is with (1) analgesia, (2) ensuring adequate oxygenation, and (3) intravenous fluid administration. The revision of the Atlanta classification separates patients clinically into (1) mild—with early resolution without complications, (2) moderate—local complications without organ failure, and (3) severe—complications associated with organ failure. Mild acute pancreatitis responds to analgesia and intravenous fluids. If gallstones have been identified, then cholecystectomy (or endoscopic retrograde cholangiopancreatography (ERCP) sphincterotomy where clinically appropriate) should be performed during the same admission, or at least within 2 to 4 weeks to prevent recurrent attacks. Severe acute pancreatitis carries a high mortality (up to 20%). Management in the early stages is centred on organ support (respiratory, circulatory, and renal failure). Later management involves surgical or radiological intervention for sepsis, usually within a specialist pancreatic unit.