What are the diagnostic criteria and treatment options for a patient with suspected pancreatitis, presenting with acute abdominal pain, nausea, vomiting, and a history of gallstones, hypertriglyceridemia, or alcohol abuse?

Diagnostic Criteria for Pancreatitis

Acute pancreatitis is diagnosed when at least 2 of the following 3 criteria are met: (1) characteristic upper abdominal pain radiating to the back with nausea/vomiting, (2) serum lipase or amylase ≥3 times the upper limit of normal, and (3) characteristic findings on cross-sectional imaging. 1

Biochemical Diagnosis

Serum lipase is the preferred first-line diagnostic test over amylase, with a diagnostic threshold of ≥3 times the upper limit of normal. 2, 3 Lipase offers superior specificity because there are no other significant sources of lipase reaching the serum, and it remains elevated longer than amylase—particularly valuable in alcohol-induced pancreatitis and delayed presentations. 4, 3, 5

• The British Society of Gastroenterology accepts serum amylase ≥4 times normal as diagnostic, though this is less preferred than lipase. 4
• The degree of enzyme elevation does not correlate with disease severity—patients can have severe pancreatitis with modest enzyme elevations. 3
• When serum values are equivocal, urinary amylase activity may provide diagnostic confirmation. 4

Clinical Presentation

The characteristic clinical picture includes:

• Upper abdominal pain radiating to the back, accompanied by nausea and vomiting 2
• Epigastric or diffuse abdominal tenderness on examination 4
• Body wall ecchymoses (Cullen's sign at umbilicus, Grey-Turner's sign in flanks) in severe cases 4, 2

Clinical findings alone are unreliable for diagnosis and must be confirmed biochemically or radiologically. 4

Imaging Strategy

Initial Imaging

• Abdominal ultrasound should be performed at admission to detect gallstones (the most common etiology), biliary duct dilation, and free peritoneal fluid. 4, 2, 3 However, the pancreas itself is poorly visualized in 25-50% of cases, so ultrasound cannot definitively diagnose pancreatitis. 4
• Chest and abdominal plain radiographs should be obtained routinely to exclude other pathology (perforated viscus, intestinal obstruction) and provide baseline assessment. 4, 3

Confirmatory CT Imaging

• Contrast-enhanced CT is the preferred confirmatory test when diagnosis is uncertain, but must be delayed until 72 hours after symptom onset to avoid underestimating pancreatic necrosis. 2, 6
• Early CT (within 72 hours) is unreliable for assessing necrosis and should be avoided unless diagnostic uncertainty persists. 6

Mandatory Initial Laboratory Workup

At admission, obtain the following to establish etiology:

• Liver chemistries (bilirubin, AST, ALT, alkaline phosphatase): Elevated aminotransferases or bilirubin strongly suggest gallstone etiology. 4, 2, 6
• Serum triglycerides: Levels >1000 mg/dL indicate hypertriglyceridemia-induced pancreatitis. 3, 7, 1
• Serum calcium: To identify hypercalcemia as a potential cause. 4, 3, 6
• Serum glucose and renal function: Diabetic ketoacidosis with hypertriglyceridemia can induce pancreatitis. 8

Severity Assessment

All patients require immediate severity stratification to guide triage and management:

• APACHE II score >8 predicts severe disease and mandates ICU/intermediate care consideration. 4, 2, 3, 6
• C-reactive protein >150 mg/L at 48 hours is the preferred laboratory marker for severity assessment. 4, 2, 3
• Patients with predicted severe disease (APACHE II >8) or evidence of organ failure during the initial 72 hours require contrast-enhanced CT after 72 hours to assess pancreatic necrosis. 4, 6

Etiological Investigation

The etiology should be established in at least 75-80% of cases—"idiopathic" pancreatitis should not be accepted without vigorous investigation. 4, 2, 6

History Must Include:

• Alcohol use quantified in units per week 4, 2, 6
• Previous symptoms or documentation of gallstones 4
• History of hypertriglyceridemia or hypercalcemia 4
• Family history of pancreatic disease 4, 6
• Detailed prescription and nonprescription drug history 4
• History of trauma 4, 6

Advanced Investigation for Unexplained Cases:

• For patients >40 years with unexplained pancreatitis, perform CT or endoscopic ultrasound (EUS) to exclude pancreatic malignancy, even after a single episode. 4, 3, 6
• For recurrent unexplained pancreatitis, EUS is preferred as the initial advanced test over ERCP, uncovering etiology in 29-88% of patients. 4, 3
• Extensive invasive evaluation is not recommended in patients <40 years with a single episode of unexplained pancreatitis. 4, 6

Diagnostic Timeline

The correct diagnosis must be established within 48 hours of admission to avoid missing alternative life-threatening intra-abdominal catastrophes (mesenteric ischemia, perforated viscus, leaking abdominal aortic aneurysm). 4, 3

Common Pitfalls

• Never perform CT before 72 hours for severity assessment—it will underestimate necrosis. 6
• Do not rely on clinical findings alone—they overlap with multiple acute abdominal conditions. 4
• Do not accept normal or mildly elevated enzymes as excluding pancreatitis in delayed presentations—lipase remains elevated longer than amylase. 3, 5
• Lactescent (milky) serum suggests severe hypertriglyceridemia and may be visible on admission in 45% of hypertriglyceridemic pancreatitis cases. 7