Acute pancreatitis

Background

• Acute inflammatory process that may involve surrounding tissue and remote organ systems
• Disease can range from mild inflammation to severe necrosis and multi-organ failure

Etiology

1. Gallstone (including microlithiasis) - 35-40% of cases
2. Alcohol (acute and chronic consumption)
3. Hypertriglyceridemia
4. ERCP
5. Drugs
   1. Azathioprine, cisplatin, furosemide, tetracycline, thiazides, sulfa
6. Autoimmune disease
   1. SLE, Sjögren
7. Abdominal trauma
8. Postoperative complications
9. Infection
   1. Bacterial: Legionella, Leptospira, Mycoplasma, Salmonella
   2. Viral: mumps,coxsackie, CMV, echo, Hep B
   3. Parasitic: Ascaris, cryptosporidium, toxoplasma
10. Hypercalcemia
11. Hyperparathyroidism
12. Ischemia
13. Posterior penetrating ulcer
14. Scorpion venom
15. Organophosphate insecticide
16. Pancreatic or ampullary tumor
17. Pancreas divisum with ductular narrowing on pancreatogram
18. Oddi sphincter dysfunction
19. Idiopathic (15-20% of cases)

DDX

• Abdominal Pain#Epigastric
• Abdominal Pain#Diffuse

Clinical Features

• Pain
  • Persistent
  • Localizes to epigastric area, around waist, RUQ, or occasionally LUQ
  • Radiates to back
• N/V noted in most
• Abd distention is frequent complaint
• Cullen sign (ecchymosis of periumbilical region) - intrabdominal hemorrhage
• Turner sign (ecchymosis of flanks) - retroperitoneal hemorrhage
• Pulmonary Findings
  • Hypoxemia, ARDS, tachypnea
  • Indicates severe pancreatitis
    • Diaphragmatic inflammation, pancreatico-pleural fistula

Diagnosis

• Two of the following 3 features:
  • 1. Characteristic abdominal pain
  • 2. Lipase level 3x upper limit of normal
    • Negative lipase does not exclude pancreatitis in chronic/recurrent disease
      • Absolute value not associated w/ prognosis or severity
  • 3. Characteristic findings on US or CT
• Imaging
  • Ultrasound
    • Edematous, swollen pancreas
    • Gallstones
    • Pseudocyst / pancreatic abscess
  • CT w/ IV contrast
    • Helpful to exclude alternative diagnoses, assess severity, identify complications
  • ERCP
    • Indicated for pts w/ severe biliary pancreatitis w/ retained CBD stone or cholangitis

Work-Up

1. Lipase
2. CBC
3. Chemistry
4. LFT
5. ?Lactate
6. ?Triglyceride

Treatment

"Place the pancreas at rest"

1. NPO (clears is probably ok for mild/moderate cases)
2. IVF
   1. Maintain urine output at 0.5 mL/kg
3. Analgesia
4. Antiemetics
5. Hypocalcemia
   1. Treat if symptomatic
6. Glycemic control
7. Albumin
   1. Consider if level <2
8. NGT if ileus is present
9. Abx
   1. Only indicated for necrosis, abscess, or infected pseudocyst / peripancreatic fluid
   2. Imipenem-cilastatin, meropenem, or (fluoroquinolone + metronidazole)
10. ERCP
    1. Indicated for retained CBD stones or cholangitis

Complications

1. Local
   1. Pancreatic necrosis
   2. Pancreatic pseudocyst / abscess
   3. Portal vein thrombosis
2. Systemic
   1. Cardiac dysfunction
   2. Renal failure
   3. Respiratory failure
   4. Shock
   5. Hypocalcemia (due to sequestration in necrotic fat)
   6. Hyperglycemia

Prognosis

1. APACHE-II
   1. Highest sensitivity and specificity in distinguishing mild from severe pancreatitis
   2. Can be used to estimate risk of hospital death at admission
   3. http://www.globalrph.com/apacheii.htm
2. CT Severity Index
3. Ranson criteria
   1. Consist of 11 parameters. Five of the factors are assessed at admission, and six of the factors are assessed during the next 48 hours.
   2. On admission:
      1. Age > 55
      2. WBC > 16,000
      3. Blood glucose >200mg/dL
      4. Lactate dehydrogenase >350 U/L
      5. Aspartate aminotransferase (AST) >250 U/L
   3. 48 hours:
      1. Hematocrit fall by > 10%
      2. BUN increase by >5 mg/dL
      3. Serum Calcium <8 mg/dL
      4. pO2 < 60mmHg
      5. Base deficit >4 MEq/L
      6. Fluid Sequestation > 6L

Disposition

1. Discharge
   1. Mild case + no biliary disease + no systemic complication + tolerating clears
2. All other patients should be admitted

References

Tintinalli