What is the treatment and workup for gallstone pancreatitis?

Treatment and Workup for Gallstone Pancreatitis

Initial Diagnosis and Workup

All patients with suspected gallstone pancreatitis should have serum lipase (preferred over amylase), liver function tests (AST, ALT, bilirubin, alkaline phosphatase), triglycerides, and calcium measured at admission, along with immediate abdominal ultrasonography to identify gallstones and assess for common bile duct stones. 1, 2

Diagnostic Laboratory Findings

• Lipase is preferred over amylase for diagnosis when available, as it provides superior accuracy 1
• Early elevation of serum aminotransferases (AST/ALT) or bilirubin strongly suggests gallstone etiology 1, 2
• If initial ultrasound is inadequate or suspicion remains high, repeat ultrasonography after recovery or use endoscopic ultrasound (EUS) as an accurate alternative 1, 2

Severity Assessment

Assess severity within the first 24-48 hours using clinical impression, APACHE II score, obesity, or C-reactive protein >150 mg/L at 48 hours, as this determines the urgency and intensity of intervention. 1, 3

• Severe pancreatitis is defined by persistent organ failure beyond 48 hours 1
• Glasgow score ≥3 or persisting organ failure after 48 hours predicts complications 1
• Dynamic CT with non-ionic contrast should be obtained within 3-10 days to assess for necrosis, but is not needed initially in mild cases 1, 3, 4

Treatment Algorithm Based on Clinical Presentation

Immediate ERCP (Within 24 Hours)

Perform urgent therapeutic ERCP with sphincterotomy immediately in patients with concomitant cholangitis (fever, rigors, positive blood cultures, deranged liver function tests), as delay increases morbidity and mortality. 1, 3, 4

• All ERCPs must be performed under antibiotic cover 1, 4
• Endoscopic sphincterotomy or duct drainage by stenting is required to ensure relief of biliary obstruction 1

Early ERCP (Within 72 Hours)

Perform early ERCP within 72 hours in patients with high suspicion of persistent common bile duct stone (visible stone on imaging, persistently dilated common bile duct, jaundice) or in those with severe pancreatitis who fail to improve despite intensive resuscitation within 48 hours. 1, 3

• All patients undergoing early ERCP for severe gallstone pancreatitis require endoscopic sphincterotomy whether or not stones are found 1
• The evidence for early ERCP in severe pancreatitis without cholangitis or confirmed bile duct obstruction is controversial, with practice varying between centers 1

No Urgent ERCP Needed

In mild gallstone pancreatitis without cholangitis, jaundice, or dilated common bile duct, proceed directly to supportive care and plan for cholecystectomy during the same admission. 1, 4, 5

General Supportive Care

All patients require vigorous fluid resuscitation, supplemental oxygen as needed, correction of electrolyte and metabolic abnormalities, and adequate pain control. 1

Severe Cases

• Manage all severe cases in HDU or ITU with full monitoring including CVP, arterial blood gases, hourly vital signs, oxygen saturation, and urine output 1, 3, 4
• Swan-Ganz catheterization is indicated when cardiocirculatory compromise exists or initial resuscitation fails 1, 3, 4

Nutritional Support

• Provide nutritional support in patients likely to remain NPO for more than 7 days 1
• Nasojejunal tube feeding with elemental or semi-elemental formula is preferred over total parenteral nutrition 1
• The nasogastric route is effective in 80% of cases 1

Antibiotic Prophylaxis

The evidence for prophylactic antibiotics is conflicting, but if used, intravenous cefuroxime for a maximum of 14 days represents a reasonable balance between efficacy and cost in severe pancreatitis. 1, 3, 4

• Routine prophylactic antibiotics are generally limited, with no clear consensus 1, 5
• Confirmed infections require treatment in their own right 1

Definitive Management: Cholecystectomy

All patients with gallbladder in situ should undergo laparoscopic cholecystectomy during the same hospital admission if possible, and otherwise no later than 2-4 weeks after discharge, as delaying beyond this significantly increases risk of recurrent biliary events including potentially fatal repeat pancreatitis. 1, 3, 4

Timing Considerations

• In mild pancreatitis, perform cholecystectomy within 2-4 weeks, preferably during initial hospitalization 4, 6, 7, 8
• Delaying cholecystectomy beyond 2-4 weeks significantly increases recurrent biliary events 3, 4
• If local complications develop, defer surgery until complications are treated or resolved 4

Preoperative Assessment

• Perform preoperative liver biochemistry and ultrasound examination of the common bile duct 1, 4
• The role of routine preoperative ERCP in the absence of CBD dilatation, detected stones, or abnormal liver function tests is debatable, as ERCP carries intrinsic risks (3-5% procedure-induced pancreatitis, 2% bleeding, 1% cholangitis, 0.4% mortality) 1, 4
• Operative cholangiography should be obtained at time of laparoscopic cholecystectomy 8

Special Populations

For patients unfit for surgery, ERCP with sphincterotomy alone provides adequate long-term therapy, though with slightly higher risk of biliary complications during follow-up. 1, 4

Management of Necrosis

Sterile necrosis does not usually require therapy and can be closely monitored unless the patient's clinical status deteriorates. 1, 6

• All patients with persistent symptoms and >30% pancreatic necrosis, or those with smaller areas and clinical suspicion of sepsis, should undergo image-guided fine needle aspiration 1
• Patients with infected necrosis require intervention to completely debride all cavities containing necrotic material 1, 6
• Recognize that necrosis evolves and liquefies over time, producing organized or "walled-off" necrosis 1

Critical Pitfalls to Avoid

• Never delay ERCP in patients with cholangitis, as this leads to increased morbidity and mortality 3
• Never delay cholecystectomy beyond 2-4 weeks in patients fit for surgery, as this significantly increases recurrent biliary events 3, 4
• Do not perform routine preoperative ERCP in mild cases without CBD dilatation, detected stones, or abnormal liver function tests, as the risks may outweigh benefits 1, 4
• Do not mistake walled-off necrosis as a simple pseudocyst 1
• Ensure facilities and expertise are available to perform ERCP at any time, particularly for severe gallstone pancreatitis with jaundice or cholangitis 1