Acute pancreatitis

Toxicological	• Chronic ethanol abuse • Toxic alcohols • Azathioprine • Mercaptopurine • Valproic acid • Didanosine • Corticosteroids • Sulfa drugs • Scorpion venom
Obstructive	• Gallstones • Pancreatic tumors • External compression • Pancreatic divisum • Parasites: clonorchiasis, ascariasis
Trauma	• Classic etiology is blunt trauma of bicycle handlebars to the epigastrium
Metabolic	• Hypertriglyceridemia • Hypercalcemia
Infectious	• CMV • HIV • Mumps • Coxsackie • Hepatitis A and B • Cryptococcus • Toxoplasma • Mycobacteria

Presentation

Classic and critical presentations

Historical features of pancreatitis include its characteristic abdominal pain, classically described as epigastric in location and radiating to the back. This is typically associated with nausea and vomiting.
- Painless disease in awake patients is uncommon but, for reasons that are unclear, painless pancreatitis may be seen more frequently in peritoneal dialysis patients or patients who have undergone renal transplantation.
- The location of pain may be quite variable depending on which part of the pancreas has the most severe inflammation.
Findings on physical examination include upper abdominal tenderness, sometimes associated with rebound and guarding.
- The physical examination in the patient with suspected pancreatitis should involve a thorough search for findings suggestive of severe disease (discussed below): tachycardia, hypotension, acute abdominal findings, including severe tenderness, guarding, and periumbilical and flank ecchymoses (Cullen’s and Grey–Turner’s signs, respectively), and an abnormal lung examination, including dyspnea and basilar rales.
Predicting severe illness
- Severe pancreatitis (which is essentially synonymous with necrotizing pancreatitis) is typically defined using the Atlanta classification, which was developed in 1992.

Atlanta classification

Severe pancreatitis is present if any of the following are present:

Local complications
• Necrosis
• Abscess
• Pseudocyst

Organ damage
• Shock: systolic blood pressure <90 mmHg
• Pulmonary insufficiency: PaO₂ U+2264

60 mmHg
• Renal failure: creatinine >2.0 mg/dL (after rehydration)
• Gastrointestinal bleeding: >500 mL in 24 hours

Prognostic scores
- Multiple scoring systems have been developed to predict the severity of illness in acute pancreatitis, but none of them should replace regular reassessment of the patient’s clinical condition.
- The most commonly used scoring system is the Ranson score, but the utility of this tool for the emergency physician is limited by the fact that its appropriate use requires data that is not available until 48 hours after admission.
  - Ranson criteria: One point if any of the following are present on admission:
    - Age >55 years
    - Blood glucose levels >200 mg/dL
    - WBC count >16 000/microliter
    - LDH >350 IU/L
    - AST/SGOT >250U.
  - Ranson criteria: One point if any of the following are present within 48 hours of admission:
    - Calcium <8 mg/dL
    - PaO₂ <60 mmHg
    - Base deficit >4 mEq/L
    - Decrease in hematocrit of more than 10 percentage points
    - Need for >6 L IVF resuscitation.
  - Scoring: The presence of three or more of the above Ranson criteria is associated with more severe disease and a higher risk of morbidity and mortality.
- An APACHE II score 8 at the time of admission has been shown in multiple studies to be predictive of mortality and has been recommended by the American Gastroenterological Association (AGA) to predict severe illness in pancreatitis.
  - Unfortunately, its use in the emergency department is limited by the fact that its appropriate use requires data that is not available until 24 hours after admission. Additionally, because of its complexity, it typically requires imputing the values into a computer for calculation.
- Several other scoring systems are available.
  - The harmless acute pancreatitis score is the easiest to apply in the emergency department. Patients with a normal serum creatinine, normal hematocrit, and no abdominal rebound or guarding almost universally have a benign course of illness.
  - The bedside index of severity in acute pancreatitis (BISAP) is a scoring system that uses data generally available upon admission to predict in-hospital mortality. It has been prospectively validated in multisite study for the prediction of mortality in patients with acute pancreatitis (Table 37.2). Criteria include the following:
    - BUN >25 mg/dL
    - Altered mental status
    - >2 SIRS criteria
    - Age >60
    - Pleural effusion.
- Radiological assessment of severity can be aided by use of the graded CT Severity Index; a low severity index score at 4 days has a sensitivity near 100% for ruling out pancreatic necrosis.
  - The CT Severity Index is based on the amount of necrosis found on CT scan. A score of 0–1 is associated with a 0% mortality and morbidity, whereas a score of 7–10 is associated with a 17% mortality and 92% complication rate.
- Patients whose initial presentation is suggestive of a severe course of disease should be managed in a critical care unit.