A review in the May 15 issue of American Family Physician highlights the best practices for diagnosing and treating acute pancreatitis, defined as a reversible inflammatory process of the pancreas.
"Acute pancreatitis may occur as an isolated attack or may be recurrent," write Jennifer K. Carroll, MD, MPH, from the University of Rochester School of Medicine in New York, and colleagues. "It has a variety of causes and can range in severity from mild to severe and life threatening. Some patients may require brief hospitalization, whereas others may be critically ill with multiple organ dysfunction requiring intensive care monitoring."
Gallbladder disease (often caused by choledocholithiasis) and long-term alcohol consumption are the most common risk factors for acute pancreatitis. Thanks to recently available imaging modalities, the current guidelines recommend against the diagnosis of "idiopathic acute pancreatitis."
The mortality rate is less than 1% for mild acute pancreatitis, but it can approach 10% to 30% for severe acute pancreatitis, depending on the presence of sterile vs infected necrosis. Although acute pancreatitis may be limited to pancreatic tissue, it may also affect surrounding tissues or more distant organ sites.
The most widely used diagnostic assays for acute pancreatitis are serum amylase and lipase levels. However, other biomarkers and inflammatory mediators such as trypsinogens are being evaluated for clinical use.
Systems for grading the severity of acute pancreatitis are Ranson's criteria, the Imrie scoring system, the Acute Physiology and Chronic Health Evaluation (APACHE II) scale, and the Computed Tomography Severity Index. The Atlanta Classification of Severe Acute Pancreatitis is widely used to compare these systems and to standardize clinical trials.
Recent developments in diagnostic modalities, including endoscopic ultrasonography and magnetic resonance cholangiopancreatography, have increased available options to determine the cause of pancreatitis and to determine the presence of complications.
For improving patient outcomes, enteral nutrition is preferred over parenteral nutrition. Clinical trials are underway to assess the role, selection, and optimal timing of antibiotics in patients with infected necrosis.
Key recommendations for practice are as follows:
Total enteral nutrition is as good as or more effective than total parenteral nutrition for nutritional management of severe pancreatitis (evidence level, A).
Urgent endoscopic retrograde cholangiopancreatography (ERCP) is indicated in patients with or at risk for biliary sepsis or obstruction, cholangitis, or worsening or persistent jaundice (evidence level, A).
Endoscopic retrograde cholangiopancreatography is useful to evaluate for less common causes of pancreatitis (including sphincter of Oddi dysfunction, pancreas divisum, and pancreatic duct strictures; evidence level, C).
Contrast-enhanced computed tomography (CT) is useful to diagnose acute pancreatitis (evidence level, C).
Whether antibiotics improve survival in patients with necrotic pancreatitis remains controversial (evidence level, B).
Subjective symptoms and historical features suggesting the diagnosis of acute pancreatitis include acute-onset, steady, intense epigastric abdominal pain radiating to the back with nausea and vomiting. Leaning forward may relieve this pain. Medical history may be positive for chronic alcoholism and/or gallstones.
Objective signs suggesting the diagnosis of mild acute pancreatitis include restlessness, low-grade fever, tachycardia, and/or mild epigastric tenderness.
When acute pancreatitis is severe, there may also be marked tenderness with guarding and abdominal distension, absent bowel sounds, systemic signs of hypotension, possible shock, jaundice, and pulmonary findings such as rales and/or pulmonary edema.
Laboratory results suggesting the diagnosis of acute pancreatitis include elevated serum and/or urinary levels of pancreatic enzymes (amylase, lipase, C-reactive protein, or trypsinogen activation peptide). Other tests that may be useful include liver function tests and tests for calcium triglycerides, albumin, complete blood count, arterial blood gases, and glucose.
Imaging modalities that may assist in diagnosis are ultrasonography, contrast-enhanced CT or magnetic resonance imaging (with elevated serum creatinine level), and magnetic resonance cholangiopancreatography (MRCP) or ERCP if there is a high suspicion of common bile duct stones.
The differential diagnosis of acute pancreatitis includes short-term or long-term alcohol consumption, gallstones, peptic ulcer disease, perforated ulcer, early appendicitis, bowel obstruction, and mesenteric ischemia. Use of various medications may also mimic some of the findings of acute pancreatitis. Other conditions to consider are hypertriglyceridemia, hypercalcemia, infection, posttraumatic injury, pregnancy, or pulmonary, renal, or cardiovascular disorders.
Various rating scales and indices can be used to rate the severity of acute pancreatitis. Mild pancreatitis is defined as scores of 3 or less for Ranson's Criteria, less than 8 for APACHE II, and less than 7 for the Computed Tomography Severity Index. For severe pancreatitis, the corresponding scores are greater than 3, 8 or greater, and 7 or greater, respectively.
Management of mild pancreatitis includes aggressive rehydration with dextrose in normal saline, 1 L/hour until urine output is adequate; pain relief with morphine; and enteral nutritional support once pain improves and laboratory results normalize. Hemodynamic and laboratory/serum parameters should be monitored.
For management of severe pancreatitis, intensive care unit admission may be preferable. For the first 48 hours, the patient should take nothing by mouth. Other measures include aggressive volume replacement, nutritional support (enteral preferred), and pain relief with morphine.
If gallstones and obstructive jaundice are suspected, emergent ERCP should be considered and pancreatic or peripancreatic necrosis should be identified or ruled out. Antibiotics should be considered in cases of possible infection. Consultation with gastroenterology, surgery, and/or interventional radiology subspecialists may be helpful.
"Physicians often find the decision about nutritional management in patients with acute pancreatitis challenging because historically it was believed that pancreatic rest was needed," the authors conclude. "However, total enteral nutrition, when compared with total parenteral nutrition, has been shown to have clear benefits in patients with severe acute pancreatitis."
The authors have disclosed no relevant financial relationships.
Am Fam Physician. 2007;75:1513-1520.
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