What is the best initial diagnostic step for a male patient in his 20s with severe epigastric pain, diffuse tenderness, sluggish bowel sounds, hyperleukocytosis (high White Blood Cell (WBC) count), and elevated amylase levels?

Best Initial Diagnostic Step for Suspected Acute Pancreatitis

Abdominal CT with IV contrast is the best initial diagnostic step for this patient with suspected acute pancreatitis presenting with severe epigastric pain, diffuse tenderness, sluggish bowel sounds, elevated WBC count, and amylase of 300. 1

Rationale for CT as First-Line Imaging

• The American College of Radiology recommends CT with IV contrast as the initial imaging modality for suspected acute abdominal conditions, including acute pancreatitis, due to its superior diagnostic capability with high sensitivity (90-95%) and specificity 1
• CT provides comprehensive evaluation of all abdominal organs and can detect pancreatic inflammation, necrosis, fluid collections, and potential complications 1
• Early CT (within 48-72 hours) provides valuable information about severity and potential complications, guiding subsequent management decisions 1

Why Other Options Are Inferior

1. Erect Chest X-ray (Option A):

   • Limited sensitivity (30-85%) for detecting perforations 1
   • Cannot adequately evaluate other potential causes of acute abdominal pain 1
   • Unable to detect pancreatic inflammation or early complications

2. Abdominal X-ray (Option B):

   • Low sensitivity and specificity for most acute abdominal conditions 1
   • Limited value in detecting early signs of pancreatitis or mesenteric ischemia 1
   • Cannot adequately assess pancreatic inflammation or complications

3. Abdominal Ultrasound (Option D):

   • Operator-dependent with limited visualization in patients with bowel gas or obesity 1
   • Less sensitive than CT for detecting pancreatic inflammation 1
   • While useful for biliary evaluation, not the best initial test for suspected pancreatitis 1

Clinical Considerations

• The patient's presentation with sudden-onset severe epigastric pain, diffuse tenderness, sluggish bowel sounds, leukocytosis, and elevated amylase (300) strongly suggests acute pancreatitis 1, 2
• The diagnosis of acute pancreatitis requires two of three criteria: characteristic abdominal pain, elevated amylase/lipase (>3x normal), and characteristic imaging findings 3
• This patient meets at least two criteria: characteristic pain and elevated amylase

Management Following Diagnosis

• If CT confirms pancreatitis, assess for severity markers (necrosis, fluid collections) to guide management decisions 1
• Initial management includes:
  • Pain management
  • Early fluid resuscitation (150-250 ml/h of crystalloid solution) 2
  • Early enteral nutrition, which has been shown to improve outcomes 2
  • Avoidance of prophylactic antibiotics in mild cases 2

Important Caveats

• While ultrasound is not the best initial test, it may be useful as a follow-up to evaluate for biliary causes of pancreatitis 1
• CT with IV contrast is contraindicated in patients with renal dysfunction or contrast allergy, in which case alternative imaging should be considered 1
• The World Journal of Emergency Surgery guidelines strongly recommend CT as first-line imaging for suspected perforated peptic ulcer, which is in the differential diagnosis for this patient 1