Diagnosis and causes of acute pancreatitis

Diagnosis of acute pancreatitis (based on the revised Atlanta ClassificationBanks, 2013) is made if the patient has at least 2 of the following:

• characteristic abdominal pain (usually central and epigastric, often described as intense boring pain that radiates to the back), which occurs regardless of the severity
• biochemical evidence of pancreatitis (serum amylase or lipase elevated more than 3 times the upper limit of normal)
• radiographic evidence of pancreatitis on imaging.

Acute pancreatitis can be classified as:

• mild acute pancreatitis—no local or systemic complications
• moderate acute pancreatitis—local or systemic complications or organ failure that resolves within 48 hours
• severe acute pancreatitis—organ failure that persists for more than 48 hoursBanks, 2013.

Identifying patients likely to develop severe acute pancreatitis is difficult because early clinical findings, laboratory tests and imaging lack sensitivity and specificity for development of severe disease. Therefore, regular reassessment is essential.

The recognition of persistent complications and acute (ascending) cholangitis in patients with acute pancreatitis is important. The cause of acute pancreatitis should be determined because it can influence early management and the follow-up strategy, as well as prognosis. Causes include:

• gallstones (40 to 50% of cases)Frey, 2006
• prolonged excessive alcohol consumption (approximately 20% of cases)Frey, 2006
• drugs (eg azathioprine, antiretroviral or chemotherapeutic drugs)—an under-recognised cause; if suspected, consider every drug the patient is taking as a possible cause
• complication of endoscopic retrograde cholangiopancreatography (ERCP)
• other causes—infections (particularly viral), hyperlipidaemia, hypercalcaemia, trauma, genetic mutations or congenital anomalies, vasculitis or cancer.