What are the INSPIRE (International Study Group of Pediatric Pancreatitis: In Search for a Cure) criteria for diagnosing and managing pediatric pancreatitis?

INSPIRE Criteria for Pediatric Pancreatitis

The INSPPIRE (International Study Group of Pediatric Pancreatitis: In Search for a Cure) consortium established standardized diagnostic criteria requiring 2 of 3 findings: abdominal pain compatible with acute pancreatitis, serum amylase and/or lipase ≥3 times upper limits of normal, and imaging findings consistent with acute pancreatitis. 1

Diagnostic Criteria by Disease Category

Acute Pancreatitis (AP)

The diagnosis requires at least 2 of the following 3 criteria: 1

• Abdominal pain compatible with acute pancreatitis (epigastric pain radiating to the back, sudden onset, persistent)
• Serum amylase and/or lipase values ≥3 times upper limits of normal
• Imaging findings characteristic of acute pancreatitis (pancreatic edema, peripancreatic fluid collections, or necrosis)

Lipase is preferred over amylase as it has higher specificity for pancreatic tissue and remains elevated longer (rises within 4-8 hours, peaks at 24 hours). 2 Amylase rises within 6-24 hours and peaks at 48 hours but normalizes faster. 2

Acute Recurrent Pancreatitis (ARP)

ARP is defined as ≥2 distinct episodes of acute pancreatitis with complete intervening return to baseline (clinical symptoms resolve and pancreatic enzymes normalize between episodes). 1

Chronic Pancreatitis (CP)

CP diagnosis requires typical abdominal pain PLUS one of the following: 1

• Characteristic imaging findings (pancreatic calcifications, ductal dilation, parenchymal atrophy, or irregular main pancreatic duct)
• Exocrine pancreatic insufficiency (steatorrhea, low fecal elastase) plus imaging findings
• Endocrine insufficiency (diabetes mellitus) plus imaging findings

Initial Diagnostic Workup

Laboratory Testing at Admission

All patients should have serum obtained for: 3, 1

• Amylase or lipase level (diagnostic threshold >3× upper limit of normal)
• Liver chemistries (bilirubin, AST, ALT, alkaline phosphatase) to evaluate biliary etiology
• Triglyceride level (if not obtained at admission, measure fasting levels after recovery)
• Serum calcium level

Imaging Approach

Abdominal ultrasound should be obtained at admission primarily to identify gallstones or choledocholithiasis as the etiology, not for diagnosis of pancreatitis itself. 3, 2, 1

Contrast-enhanced CT is reserved for: 2

• Uncertain diagnosis when clinical and biochemical criteria are equivocal
• Predicted severe disease based on clinical assessment
• Evidence of organ failure or clinical deterioration

In pediatric patients, ultrasound or contrast-enhanced ultrasound is the preferred follow-up imaging modality, with MRI preferred over CT if cross-sectional imaging is required to minimize radiation exposure. 3

Severity Assessment

Clinical Severity Stratification

Severity stratification should be completed within 48 hours of admission using: 3, 2

• Glasgow scoring system (≥3 positive criteria indicates severe disease)
• C-reactive protein (peak level >210 mg/L in first 4 days or >120 mg/L at end of first week indicates severe disease) 3
• APACHE II score (≥8-9 indicates severe disease) 3, 2

Persistent organ failure (>48 hours) is the most reliable marker of severe disease and mortality risk, including cardiovascular, respiratory, or renal insufficiency. 4, 2

Prognostic Markers

Corrected serum calcium <2 mmol/L is a well-established negative prognostic factor requiring ICU admission for continuous monitoring. 4

Management Based on INSPPIRE Framework

Etiology Investigation

The etiology should be established in at least three-fourths of patients. 3 For recurrent or unexplained pancreatitis in children, further evaluation includes: 1

• Magnetic resonance cholangiopancreatography (MRCP)
• Sweat chloride testing (cystic fibrosis screening)
• Genetic testing (PRSS1, SPINK1, CFTR mutations)
• Endoscopic ultrasound for structural abnormalities

Nutritional Support

Nasojejunal tube feeding using elemental or semi-elemental formula is preferred over total parenteral nutrition in patients likely to remain NPO for more than 7 days. 3 Total parenteral nutrition should only be used in those unable to tolerate enteral nutrition. 3

Gallstone Pancreatitis Management

Urgent ERCP (within 24 hours) is required for concomitant cholangitis. 3, 4 Early ERCP (within 72 hours) should be performed with high suspicion of persistent common bile duct stone (visible stone on imaging, persistently dilated common bile duct, jaundice). 3

Clinical Pitfalls

The INSPPIRE criteria are more useful than the 2011 International Consensus Diagnostic Criteria (ICDC) in pediatric populations, as they avoid unnecessary invasive biopsies in patients who respond well to corticosteroids for autoimmune pancreatitis. 5 Using adult criteria (ICDC) can delay diagnosis and result in unnecessary invasive testing. 5

Clinical assessment alone is unreliable and will misclassify approximately 50% of patients, necessitating objective scoring systems for severity stratification. 3