Pancreatitis

Pancreatitis is "inflammation of the pancreas. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of chronic pancreatitis (International Symposium on Acute Pancreatitis, Atlanta, 1992). The two most common forms of acute pancreatitis are alcoholic pancreatitis and gallstone pancreatitis." Management of acute necrotizing pancreatitis has been reviewed.

Classification

Acute pancreatitis

Acute necrotizing pancreatitis

Acute necrotizing pancreatitis is a "severe form of acute inflammation of the pancreas characterized by one or more areas of necrosis in the pancreas with varying degree of involvement of the surrounding tissues or organ systems. Massive pancreatic necrosis may lead to diabetes mellitus, and malabsorption.

Chronic pancreatitis

Chronic pancreatitis is "inflammation of the pancreas that is characterized by recurring or persistent abdominal pain with or without steatorrhea or diabetes mellitus. It is characterized by the irregular destruction of the pancreatic parenchyma which may be focal, segmental, or diffuse.

Etiology/cause

The most common causes are gallstones and alcohol.

Diagnosis

Acute pancreatitis

The diagnostic criteria for pancreatitis are "two of the following three features: 1) abdominal pain characteristic of acute pancreatitis, 2) serum amylase and/or lipase ≥3 times the upper limit of normal, and 3) characteristic findings of acute pancreatitis on a CT scan."

Two clinical practice guidelines state:

"It is usually not necessary to measure both serum amylase and lipase. Serum lipase may be preferable because it remains normal in some nonpancreatic conditions that increase serum amylase includingmacroamylasemia, parotitis, and some carcinomas. In general, serum lipase is thought to be more sensitive and specific than serum amylase in the diagnosis of acute pancreatitis".

"Although amylase is widely available and provides acceptable accuracy of diagnosis, where lipase is available it is preferred for the diagnosis of acute pancreatitis (recommendation grade A)"

Chronic pancreatitis

Chronic pancreatitis may occur without pain, especially patients who first start having symptoms in middle age.

Treatment

Acute pancreatitis

Bowel rest

Approximately 20% of patients have a relapse of pain during acute pancreatitis. Approximately 75% of relapses occur within 48 hours of oral refeeding.

The incidence of relapse after oral refeeding may be reduced by post-pyloric enteral, rather than parenteral, feeding prior to oral refeeding.

Endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) within 72 hours after onset of symptoms may be useful during acute biliary pancreatitis if there are signs of:

• Cholangitis (serum bilirubin level >1.2 mg/dL [20 µmol/L] and/or dilated CBD on ultrasound or CT and temperature >38.5°C)
• Cholestasis (serum bilirubin: >2.3 mg/dL [40 mumol/L] and/or dilated common bile duct)

Necrosectomy

Video-assisted retroperitoneal debridement (VARD) may be better than open necrosectomy.

Prognosis

Short term

Clinical practice guidelines state:

2006: "The two tests that are most helpful at admission in distinguishing mild from severe acute pancreatitis are APACHE-II score and serum hematocrit. It is recommended that APACHE-II scores be generated during the first three days of hospitalization and thereafter as needed to help in this distinction. It is also recommended that serum hematocrit be obtained at admission, 12 h after admission, and 24 h after admission to help gauge adequacy of fluid resuscitation."

2005: "Immediate assessment should include clinical evaluation, particularly of any cardiovascular, respiratory, and renal compromise, body mass index, chest x ray, and APACHE II score"

Risk factors at hospital discharge that predict subsequent hospital admission constitute a clinical prediction rule.

APACHE II score

"Acute Physiology And Chronic Health Evaluation" (APACHE II) score > 8 points predicts 11% to 18% mortality . Online calculator

BISAP Score

The Bedside Index for Severity in Acute Pancreatitis (BISAP) score is a sum of the following signs within 24 hours of presentation:

• Blood urea nitrogen level >25 mg/dL
• Impaired mental status
• Systemic inflammatory response syndrome
• age >60
• Pleural effusion on imaging studies

A BISAP score ≥3 is associated with an increased risk of complications.

The BISAP may not be as accurate as Ranson's and have a lower area under the receiver operating characteristic curve.

Ranson's Score

A score developed by Ranson predicts mortality. At admission:

1. age in years > 55 years
2. white blood cell count > 16000 cells/mm³
3. blood glucose > 11 mmol/L (> 200 mg/dL)
4. serum AST > 250 IU/L
5. serum LDH > 350 IU/L

At 48 hours:

1. Calcium (serum calcium < 2.0 mmol/L (< 8.0 mg/dL)
2. Hematocrit fall > 10%
3. Oxygen PO₂ < 60 mmHg)
4. BUN increased by 1.8 or more mmol/L (5 or more mg/dL) after IV fluid hydration
5. Base deficit (negative base excess) > 4 mEq/L
6. Sequestration of fluids > 6 L

A score of 3 or more suggest severe pancreatitis with a mortality of 15%.

Long term

Chronic pancreatitis is more likely among alcoholic pancreatitis.

Prevention

Cholecystectomy to prevent recurrence should be considered when "significantly elevated liver enzymes (≥threefold increase of alanine aminotransferase or aspartate aminotransferase) on day 1" or "the presence of gallstones/sludge in the gall bladder" is seen with ultrasonography