What are the diagnostic and treatment approaches for acute pancreatitis vs acute appendicitis?

Acute Pancreatitis vs Acute Appendicitis: Diagnostic and Treatment Approaches

Diagnostic Differentiation

Acute pancreatitis requires two of three criteria: characteristic epigastric abdominal pain, serum lipase/amylase ≥3 times normal, and imaging findings of pancreatic inflammation, while acute appendicitis presents with characteristic right lower quadrant pain and localized tenderness, though no single finding is unequivocal. 1, 2

Acute Pancreatitis Diagnosis

• Serum lipase is preferred over amylase due to higher specificity and sensitivity, remaining elevated longer with no other serum sources 1, 2
• Amylase ≥4 times normal is diagnostic when lipase unavailable, though less accurate 1
• Upper abdominal pain with epigastric tenderness and vomiting are typical clinical features 1
• Contrast-enhanced CT is the imaging standard when doubt exists, though ultrasonography is often unhelpful acutely 1
• Diagnosis must be established within 48 hours of admission 1

Acute Appendicitis Diagnosis

• Diagnosis relies on constellation of findings including characteristic abdominal pain, localized right lower quadrant tenderness, and laboratory/imaging findings 1
• No clinical findings are unequivocal for appendicitis identification 1
• Local hospitals should establish standardized clinical pathways involving multidisciplinary teams 1

Severity Assessment (Pancreatitis-Specific)

Severity stratification must occur within 48 hours using clinical impression, obesity, APACHE II score in first 24 hours, and C-reactive protein >150 mg/L. 1, 2

• Severe pancreatitis is defined by persistent organ failure >48 hours, with mortality up to 30% 1
• Mild pancreatitis has minimal organ dysfunction with uneventful recovery, representing 80% of cases with <5% mortality 1
• CT scanning between days 3-10 is indicated for patients with persisting organ failure, sepsis signs, or clinical deterioration 1
• Patients with >30% pancreatic necrosis require specialist unit management 1

Treatment Approaches

Acute Pancreatitis Management

All severe acute pancreatitis patients require high dependency or intensive care unit management with full monitoring and systems support. 1

Initial Management (Mild Cases)

• Manage on general ward with basic monitoring (temperature, pulse, blood pressure, urine output) 1
• Peripheral IV access for fluids, nasogastric tube as needed 1
• Do not routinely administer antibiotics in mild pancreatitis - no evidence of benefit 1, 2
• Pain control with judicious IV opiates is safe 3

Severe Pancreatitis Protocol

• Require HDU/ITU with central venous line, urinary catheter, nasogastric tube, and Swan-Ganz catheter if initial resuscitation fails 1
• Strict asepsis for all invasive monitoring to prevent subsequent sepsis 1
• Enteral nutrition preferred over parenteral, started within 48 hours - reduces infectious complications and mortality 2, 4
• Nasogastric feeding effective in 80% of cases 1

Antibiotic Prophylaxis Controversy

• Evidence is conflicting and difficult to interpret regarding prophylaxis against infected necrosis 1
• If used, limit to maximum 14 days 1
• In severe necrotizing pancreatitis, do not administer prophylactic antibiotics prior to diagnosis of infection 1

Gallstone Pancreatitis

• Urgent therapeutic ERCP within 72 hours for severe gallstone pancreatitis with cholangitis, jaundice, or dilated common bile duct 1, 2
• All patients undergoing early ERCP require endoscopic sphincterotomy regardless of stone presence 1
• Definitive treatment (cholecystectomy) within 2 weeks of discharge, preferably same admission to prevent potentially fatal recurrence 1
• Delay cholecystectomy in severe cases until lung injury and systemic disturbance resolve 1

Infected Necrosis Management

• Image-guided fine needle aspiration for culture at 7-14 days in patients with >30% necrosis and clinical sepsis suspicion 1, 2
• Infected necrosis requires complete debridement of all necrotic material 1
• Surgical intervention increasingly postponed with minimally invasive strategies considered 4

Acute Appendicitis Management

Acute appendicitis without perforation, abscess, or local peritonitis requires only 24-hour prophylactic narrow-spectrum antibiotics covering aerobic, facultative, and obligate anaerobes. 1

Uncomplicated Appendicitis

• Appendectomy is standard treatment 5
• Discontinue prophylactic antibiotics within 24 hours post-operatively 1

Complicated Appendicitis

• Perforated appendicitis with abscess or peritonitis requires 4-7 days antimicrobial therapy unless source control difficult 1
• Longer durations not associated with improved outcomes 1

Special Circumstance

• When appendicitis develops with coexistent severe pancreatitis, surgery may be inappropriate - endoscopic retrograde appendicitis treatment (ERAT) is a minimally invasive alternative 5

Key Pitfalls to Avoid

• Never delay diagnosis beyond 48 hours - both conditions require rapid assessment 1
• Do not use antibiotics routinely in mild pancreatitis - reserve for documented infections 1, 2
• Do not delay cholecystectomy beyond 2 weeks in gallstone pancreatitis - risk of fatal recurrence 1
• Do not use parenteral nutrition when enteral route tolerated in pancreatitis - higher complication rates 1, 4
• Avoid unnecessary laparotomy in pancreatitis - CT should obtain preoperative diagnosis 1

Etiology Determination

Determine etiology in at least 80% of pancreatitis cases, with no more than 20% classified as idiopathic. 1

• All patients with gallstones and pancreatitis require bile duct imaging 1
• Consider bile sampling for microlithiasis in recurrent attacks without identified cause 1