Pancreatitis, Acute

Diagnosis

Indications for Testing

• Abdominal pain in epigastrium

Laboratory Testing

• Amylase, lipase – ≥3 times normal level
  • Lipase more sensitive and specific for pancreatic disease
  • No role in assessing severity; not helpful when measured on a daily basis
• CBC – leukocytosis common in severe disease
• Metabolic panel (sodium, potassium, BUN, creatinine, calcium, glucose, HCO3)
  • Calcium, BUN and glucose may be associated with prognosis
• C-reactive protein – concentration ≥150 mg/dL within the first 72 hours after presentation indicates acute necrotizing pancreatitis (sensitivity 80-85%, specificity 90%)
  • Recommend waiting 48 hours after illness before obtaining (to prevent false negatives)
• Procalcitonin – may have value in differentiating between mild and severe disease
  • Should be obtained at admission

Imaging Studies

• US/CT/ERCP – all used to confirm diagnosis or to assess local complications such as fluid collections and neurosis

Prognosis

• Prognostic criteria
  • Ranson criteria  
    • At admission or diagnosis
      • Age <55 years
      • WBC count <16,000/mm³ (16.0x10⁹/L)
      • Blood glucose <200 mg/dL (11.1 mmol/L)
      • Serum lactate dehydrogenase <350 U/L
      • AST <250 U/L
    • During initial 48 hours
      • Hematocrit decrease <10%
      • BUN increase <5 mg/dL (1.8 mmol/L)
      • Serum calcium <8 mg/dL (2 mmol/L)
      • Base deficit <4 mmol/L (4 mEq/L)
      • Fluid sequestration <6,000 mL
      • Partial arterial oxygen tension (PaO2) <60 mm HG
      • Scoring: one point for each criterion met
  • APACHE II scale
    • Equation includes the following factors: age, rectal temperature, mean arterial pressure, heart rate, PaO2, arterial pH, serum potassium, serum sodium, serum creatinine, hematocrit, WBC count, chronic health status, and Glasgow Coma Scale score
  • CT severity index (Balthazar criteria)
    • CT grade
      • A – normal pancreas (0 points)
      • B – edematous pancreas (1 point)
      • C – B plus mild extrapancreatic changes (2 points)
      • D – severe extrapancreatic changes plus one fluid collection (3 points)
      • E – multiple of extensive fluid collections (4 points)
      • Necrosis score:
        • None (0 points)
        • <One-third (2 points)
        • >One-third but <one-half (4 points)
        • >One-half (6 points)
      • Scoring: CT grade + necrosis score
  • Glasgow prognostic criteria (Imrie scoring system)
    • Age <55 years
    • WBC count <15,000/mm³ (15.0x10⁹/L)
    • Blood glucose <180 mg/dL (10 mmol/L) in patients without diabetes
    • Serum lactate dehydrogenase <600 U/L
    • Serum aspartate transaminase (AST) or alanine transaminase (ALT) <100 U/L
    • Serum calcium <8 mg/dL
    • PaO2 <60 mm Hg
    • Serum albumin <3.2 g/dL (32 g/L)
    • Serum urea <45 mg/dL (16.0 mmol/L)
    • Scoring: one point for each criterion met 48 hours after admission
  • Predictions of adverse outcome in severe pancreatitis
    • Organ dysfunction – APACHE II score ≥8 (60% sensitive, 85% specific)
    • Multiple organ dysfunction score (MODS) at 72 hours >3
    • Sequential organ failure assessment (SOFA) score at 48 hours >4
    • Ranson score at 48 hours >3
    • Modified Glasgow score at 48 hours ≥3
  • Prediction of local complications
    • Hematocrit – >44%
    • Body mass index (BMI) – >30
    • Balthazar CT grade of C–E at 1 week (85% sensitive, 100% specific)

Differential Diagnosis

• Acute cholecystitis
• Perforated duodenal/gastric ulcer
• Mesenteric ischemia
• Aortic dissection
• Acute coronary syndromes
• Intestinal obstructions
• Nephrolithiasis
• Appendicitis
• Ectopic pregnancy

Clinical Background

Acute pancreatitis is a reversible inflammatory process of the pancreas.

Epidemiology

• Incidence – 30-40/100,000 in the U.S.
• Age – peaks in 40s
• Sex
  • Gallstone-induced pancreatitis, M<F
  • Alcohol-induced pancreatitis, M>F

Risk Factors

• Hepatobiliary
  • Gallstones/choledocholithiasis
  • Chronic alcohol consumption
  • Hepatobiliary tumors (rare)
• Drug-induced – estrogen, corticosteroids, isoniazid, metronidazole, azathioprine  
• Iatrogenic – surgery, post endoscopic retrograde cholangiopancreatography (ERCP)
• Infection – viral, bacterial, fungal
• Metabolic
  • Hyperlipidemia
  • Hypercalcemia, hyperparathyroidism
• Autoimmune – eg, systemic lupus erythematosus
• Genetic – cystic fibrosis, mitochondrial disease, mutations in PRSS1 or SPINK1 genes
• Congenital anomalies – pancreas divisum
• Tumor
• Trauma/ischemia

Pathophysiology

• Inappropriate or premature activation of trypsinogen thought to be the initiating event
• Early stages are characterized by interstitial edema of pancreatic parenchyma and necrosis of peripancreatic fat
• In 20% of patients, pancreatitis progresses to coagulation necrosis of glandular elements

Clinical Presentation

• Gastrointestinal
  • Sudden upper abdominal pain – may radiate to flank, lower abdomen
  • Nausea, emesis
  • Retroperitoneal hemorrhage – indicates poorer prognosis
    • Grey Turner sign – grey discoloration over flank
    • Cullen sign – bruising in and around umbilicus
  • Constitutional – fever
  • Cardiopulmonary – respiratory distress, hypotension, and tachycardia
  • Neurologic – encephalopathy
  • Renal – diminished urine output
• Potential complications
  • Pancreatic – acute fluid collection, necrosis, pseudocyst, abscess, ascites
  • Intestinal – paralytic ileus, GI hemorrhage
  • Hepatobiliary – jaundice, obstruction of the common bile duct, portal vein thrombosis
  • Systemic
    • Metabolic
      • Malnutrition
      • Hypocalcemia
      • Hypoglycemia
    • Hematological
      • Disseminated intravascular coagulation
      • Portal vein thrombosis
  • Renal – acute renal failure
  • Cardiovascular – circulatory failure (shock)
  • Respiratory – hypoxic acute respiratory failure

Treatment

• Hospitalization with intravenous fluids
• Remove anatomic causes (eg, gallstones)
• Antibiotics in severe pancreatitis

Indications for Laboratory Testing

• Tests generally appear in the order most useful for common clinical situations
• Click on number for test-specific information in the ARUP Laboratory Test Directory

Click the plus sign to expand the table of additional tests.

Test Name and Number	Comments
Urea Nitrogen, Serum or Plasma 0020023 Method: Quantitative Spectrophotometry	Prognostic score in Ranson criteria
Bilirubin, Direct & Total, Serum or Plasma 0020426 Method: Quantitative Spectrophotometry	Diagnose biliary etiology for acute pancreatitis
Bilirubin, Direct, Serum or Plasma 0020033 Method: Quantitative Spectrophotometry	Bilirubin component test
Bilirubin, Total, Serum or Plasma 0020032 Method: Spectrophotometry	Bilirubin component test
Amylase, Urine 0020471 Method: Quantitative Enzymatic	Rule out macroamylasemia as cause of elevated amylase
Amylase, Body Fluid 0020506 Method: Quantitative Enzymatic	Not useful in diagnosis of disease; however, may help identify pancreatitis as a cause
Lipase, Fluid 0020715 Method: Quantitative Enzymatic	Not useful in diagnosis of disease; however, may help identify pancreatitis as a cause
Amylase, Isoenzymes 0020804 Method: Quantitative Enzymatic	Rule out salivary amylase as cause of elevated amylase
Pancreatitis, Idiopathic (CFTR, PRSS1, SPINK1) Sequencing 2002005 Method: Polymerase Chain Reaction/Sequencing	Order in idiopathic recurrent pancreatitis to determine genetic predisposition to the condition Clinical sensitivity 45% for idiopathic chronic pancreatitis
Pancreatitis, Hereditary (PRSS1) Sequencing 2002016 Method: Polymerase Chain Reaction/Sequencing	Order in children with pancreatitis or in affected adults with a positive family history Sensitivity 80% for hereditary pancreatitis
Pancreatitis, Idiopathic (SPINK1) Sequencing 2002012 Method: Polymerase Chain Reaction/Sequencing	Order in adults with idiopathic pancreatitis if other components of the panel have already been performed (eg, CFTR, PRSS sequencing) Clinical sensitivity 17% for idiopathic chronic pancreatitis
Macroamylase Determination 2004464 Method: Quantitative Ultrafiltration/Quantitative Enzymatic