What is the workup for gallstone pancreatitis?

Workup for Gallstone Pancreatitis

The workup for gallstone pancreatitis should include laboratory tests, imaging studies, and assessment of disease severity, with urgent ERCP indicated for patients with severe disease who fail to improve within 48 hours of intensive resuscitation or who have cholangitis. 1

Initial Assessment and Diagnosis

Laboratory Tests

• Serum amylase and lipase (elevated in pancreatitis)
• Liver function tests (elevated in biliary obstruction)
  • ALT, AST, alkaline phosphatase, bilirubin
• Complete blood count
• Electrolytes, BUN, creatinine
• Triglycerides (to rule out hypertriglyceridemia as cause)
• Arterial blood gas analysis (in severe cases)
• Procalcitonin (most sensitive test for detecting pancreatic infection) 2

Imaging Studies

• Abdominal ultrasound (first-line imaging to detect gallstones)
• Dynamic CT scan with non-ionic contrast (should be obtained within 3-10 days of admission) 1
  • Assesses for pancreatic necrosis
  • Identifies peripancreatic fluid collections
  • Detects gas in retroperitoneal area (strongly suggests infection) 2

Severity Assessment

Determine severity using clinical criteria and scoring systems:

• Clinical signs of severe disease:
  • Organ failure
  • Local complications
  • Systemic inflammatory response
• Scoring systems:
  • Ranson criteria
  • APACHE II score
  • CT-Balthazar score 2

Management Based on Severity

Mild Gallstone Pancreatitis

• Supportive care
• Preoperative assessment of common bile duct by:
  • Liver biochemistry
  • Ultrasound examination 1
• Consider early laparoscopic cholecystectomy (within 24 hours of admission)
  • Reduces length of stay and ERCP rates 3
  • May have slightly higher complication rates

Severe Gallstone Pancreatitis

• Admit to ICU/HDU with full monitoring 1
• Aggressive fluid resuscitation
• Monitoring requirements:
  • Peripheral venous access
  • Central venous line for CVP monitoring
  • Urinary catheter
  • Nasogastric tube
  • Hourly vital signs including respiratory rate and oxygen saturation 1
• Consider Swan-Ganz catheter if cardiocirculatory compromise exists 1
• Consider prophylactic antibiotics (IV cefuroxime recommended) 1

Indications for ERCP

ERCP with sphincterotomy is indicated in the following scenarios:

• Severe gallstone pancreatitis failing to improve within 48 hours despite intensive resuscitation 1
• Increasingly deranged liver function tests with signs of cholangitis (fever, rigors, positive blood cultures) - requires immediate ERCP 1
• Persistent biliary obstruction 2

ERCP should always be performed under antibiotic cover 1

Timing of Cholecystectomy

• For mild gallstone pancreatitis:

  • Laparoscopic cholecystectomy within 2-4 weeks ideally 1
  • Consider same-stay cholecystectomy to prevent recurrence 4, 5
  • Delaying cholecystectomy increases risk of recurrent biliary-pancreatic complications 6

• For severe gallstone pancreatitis:

  • Defer cholecystectomy until clinical improvement
  • If peripancreatic fluid collections present, follow with serial CT scans
  • Perform cholecystectomy once fluid collections resolve 4

Common Pitfalls to Avoid

1. Delaying cholecystectomy unnecessarily - Patients admitted to surgical services are more likely to receive definitive treatment with same-stay cholecystectomy, resulting in fewer readmissions for recurrent disease 5

2. Overuse of ERCP - Routine ERCP is not necessary in all cases; selective use based on specific criteria (cholangitis, persistent obstruction) is preferred 1, 6

3. Inadequate monitoring in severe cases - Severe gallstone pancreatitis requires ICU/HDU care with full monitoring and systems support 1

4. Failure to recognize cholangitis - Patients with cholangitis (fever, jaundice, right upper quadrant pain) require immediate ERCP and antibiotic treatment 7

5. Missing common bile duct stones - Intraoperative cholangiography during cholecystectomy helps identify common bile duct stones that may cause recurrent pancreatitis 6