Am Fam Physician. 2022;106(1):44-50
Author disclosure: No relevant financial relationships.
Acute pancreatitis is the most common gastrointestinal-related reason for hospitalization in the United States. It is diagnosed based on the revised Atlanta classification, with the presence of at least two of three criteria (upper abdominal pain, serum amylase or lipase level greater than three times the upper limit of normal, or characteristic findings on imaging studies). Although computed tomography and other imaging studies can be useful to assess severity or if the diagnosis is uncertain, imaging is not required to diagnose acute pancreatitis. Based on limited studies, several scoring systems have comparable effectiveness for predicting disease severity. The presence of systemic inflammatory response syndrome on day 1 of hospital admission is highly sensitive in predicting severe disease. Treatment of acute pancreatitis involves goal-directed fluid resuscitation, analgesics, and oral feedings as tolerated on admission. If oral feedings are not tolerated, nasogastric or nasojejunal feedings are preferred over parenteral nutrition. Cholecystectomy is recommended during the initial admission for patients with mild acute biliary pancreatitis. Medical management is usually sufficient for necrotizing pancreatitis; however, if surgical intervention is needed, a minimally invasive approach is advised over direct endoscopic or open surgical debridement (necrosectomy) because of lower complication rates.
Acute pancreatitis is the most common gastrointestinal condition requiring hospital admission in the United States. This article summarizes the best available patient-oriented evidence for the diagnosis and treatment of acute pancreatitis.
| Clinical recommendation | Evidence rating | Comments |
|---|---|---|
| Routine imaging is not recommended for patients with mild pancreatitis.14,25,32,34 | C | Expert opinion and consensus guidelines suggesting that computed tomography does not change management or clinical outcomes when used in mild cases |
| Contrast-enhanced computed tomography is the preferred imaging modality in cases of diagnostic uncertainty associated with equivocal clinical markers.25 | C | Expert opinion and consensus guidelines |
| Compared with parenteral nutrition, enteral feeding is associated with shorter hospitalizations and reductions in mortality, multiorgan failure, infection, and other complications in patients with acute pancreatitis.40–42 | A | Consistent evidence from meta-analyses of randomized controlled trials |
| Early enteral feeding as tolerated is recommended over restricting oral intake in patients with acute pancreatitis.4,34,41–45 | A | Consensus guidelines, systematic reviews, and randomized controlled trials |
| In the absence of infection, prophylactic antibiotics are not recommended for patients with pancreatic necrosis.48,49 | B | Meta-analyses of randomized controlled trials suggesting that prophylaxis is not associated with a significant decrease in mortality |
| Cholecystectomy for mild acute biliary pancreatitis should be considered during the initial admission.51,52 | B | Meta-analyses suggesting that early cholecystectomy leads to significant reduction in recurrent biliary complications and hospital readmission rates compared with delayed cholecystectomy; early cholecystectomy showed no increases in surgical complications and a decrease in length of hospitalization |
| Recommendation | Sponsoring organization |
|---|---|
| Do not test for amylase in cases of suspected acute pancreatitis. Instead, test for lipase. | American Society for Clinical Pathology |
Epidemiology
The incidence of acute pancreatitis is approximately 5 to 80 cases per 100,000 people per year.1–4
Between the years 2001 and 2014, hospitalizations and costs related to acute pancreatitis steadily increased, likely because of the increased prevalence of obesity, an aging population, and gallstone-related disorders.1–5
| More common | Uncommon |
|---|---|
| Choledocholithiasis (38% to 70%) Chronic alcohol use (25% to 41%) Hypertriglyceridemia (10%) Endoscopic retrograde cholangiopan-creatography (4%) Pancreatic ductal carcinoma (1% to 4%) Medication use (< 2%): aminosalicylates, anticonvulsants, antimicrobials, hormone therapy, oral contraceptives, loop diuretics, nonsteroidal anti-inflammatory drugs, opiates, reverse transcriptase inhibitors, steroids, glucagon-like peptide 1 antagonists | Abnormalities of the pancreas: annular pancreas, pancreas divisum, sphincter of Oddi dysfunction Autoimmune disorders Genetic factors:: variation in CFTR, CTRC, PRSS1, SPINK1, or CASR gene Hypercalcemia: excessive vitamin D supplementation, hyperparathyroidism, total parenteral nutrition Infections: viral, bacterial, fungal, parasitic Surgical procedures and trauma Toxins: scorpion and snake bites Vascular abnormalities: ischemia, vasculitis |
Diagnosis
Acute pancreatitis is diagnosed based on the revised Atlanta classification, which includes the presence of at least two of the following criteria: (1) upper abdominal pain, (2) serum amylase or lipase level more than three times the upper limit of normal, or (3) characteristic imaging findings.14
The differential diagnosis of acute pancreatitis is shown in Table 2.
| Acute myocardial infarction Aortic dissection Appendicitis Cholangitis Cholecystitis Cholelithiasis/choledocholithiasis Diabetic ketoacidosis Gastric outlet obstruction | Gastroenteritis Gastroparesis Hepatitis Intestinal infarction/ischemia Pancreatic cancer Peptic ulcer disease Small bowel obstruction Tubo-ovarian abscess |
SIGNS AND SYMPTOMS
Acute pancreatitis should be suspected in patients with sudden onset of left upper quadrant or epigastric abdominal pain, although it is sometimes painless. Pain often radiates to the back, worsens with eating or drinking, and is associated with nausea and vomiting.10
Physical examination findings may include tenderness on palpation of the upper abdomen, decreased bowel sounds, fever, tachycardia, hypotension, or jaundice.10
Overall, the history and physical examination have moderate accuracy when findings are abnormal (positive likelihood ratio = 3.2; negative likelihood ratio = 0.8).10
Ecchymosis around the umbilicus (Cullen sign) or on the flank (Grey Turner sign) is present in only 3% of patients with acute pancreatitis and may occur with other diseases. Therefore, the diagnostic significance of these findings is low.15,16
DIAGNOSTIC TESTING
The accuracy of laboratory and imaging tests in the diagnosis of acute pancreatitis is summarized in Table 3.6,10,17–19
Serum lipase measurement should be the initial test in suspected acute pancreatitis, although serial measurements are not indicated. Amylase and lipase levels increase rapidly in pancreatitis, but serum amylase normalizes more quickly. Elevation of amylase or lipase that is more than three times the upper limit of normal strongly suggests acute pancreatitis.18,20–22
A urinary trypsinogen-2 level of more than 50 ng per mL on dipstick testing also suggests pancreatitis, but this test is not as widely available as serum amylase testing.18
Laboratory evaluation should include a comprehensive metabolic panel, complete blood count, and triglyceride levels to aid in diagnosis and severity assessment. An aspartate transaminase level of more than 60 U per L (1.00 μkat per L) and an alkaline phosphatase level of more than 12 U per L (0.20 μkat per L) are helpful in the diagnosis of acute biliary pancreatitis, with positive predictive values of 90.2 and 81.9, respectively.10,23
Imaging is not required for the diagnosis of acute pancreatitis, although computed tomography can be useful to assess severity or in cases of diagnostic uncertainty, failure of conservative treatment, or clinical deterioration.14,19,24
Ultrasonography is useful in patients with suspected acute biliary pancreatitis; however, sensitivity for detection of gallstones is only 67% to 78%. Sensitivity of ultrasonography for choledocholithiasis is between 50% and 80%. Endoscopic ultrasonography is more accurate for choledocholithiasis, with a sensitivity of more than 90%, but it is more invasive.25–27
Magnetic resonance cholangiopancreatography is recommended when there is concern for acute biliary pancreatitis and the common bile duct is not adequately visualized or appears normal on ultrasonography. Magnetic resonance cholangiopancreatography has a similar sensitivity to endoscopic ultrasonography for detection of common bile duct stones that are 6 mm or larger.25,28,29
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