From the Guidelines
The diagnosis of acute pancreatitis requires at least two of the following three criteria: abdominal pain consistent with the disease, biochemical evidence of pancreatitis (serum amylase and/or lipase greater than three times the upper limit of normal), and characteristic findings from abdominal imaging. The abdominal pain associated with acute pancreatitis is usually sudden in onset, located in the epigastrium, and may be accompanied by nausea and vomiting. Laboratory tests should be obtained promptly when pancreatitis is suspected, with lipase generally preferred over amylase due to its greater specificity and longer elevation period 1. Imaging is not required for diagnosis if the first two criteria are met but is often performed to assess severity, identify complications, or rule out other causes of abdominal pain. Early diagnosis is crucial as it allows for prompt initiation of supportive care including intravenous fluids, pain management, and nutritional support.
Key Diagnostic Criteria
- Abdominal pain consistent with acute pancreatitis
- Biochemical evidence of pancreatitis (serum amylase and/or lipase greater than three times the upper limit of normal)
- Characteristic findings from abdominal imaging
The diagnostic approach is based on the pathophysiology of pancreatic inflammation, which leads to enzyme release into the bloodstream and structural changes visible on imaging 1. It is essential to consider acute pancreatitis among the differential diagnoses in patients admitted with unexplained multiorgan failure or the systemic inflammatory response syndrome. Confirmation of the diagnosis, if required, is best achieved by computed tomography (CT) of the abdomen using intravenous contrast enhancement. Clinicians should be aware that an early CT (within 72 hours of illness onset) might underestimate the amount of pancreatic necrosis.
Importance of Early Diagnosis
Early diagnosis of acute pancreatitis is critical to reduce morbidity, mortality, and improve quality of life. Prompt initiation of supportive care can help prevent complications and improve outcomes. The 2019 WSES guidelines for the management of severe acute pancreatitis emphasize the importance of early diagnosis and treatment 1.
Laboratory Tests and Imaging
Laboratory tests, including serum amylase and lipase levels, should be obtained promptly when acute pancreatitis is suspected. Lipase is generally preferred over amylase due to its greater specificity and longer elevation period 1. Imaging studies, such as contrast-enhanced CT, MRI, or ultrasound, can help assess severity, identify complications, and rule out other causes of abdominal pain. However, imaging is not required for diagnosis if the first two criteria are met.
Clinical Considerations
Clinicians should be aware of the clinical features and elevations in amylase or lipase levels that are consistent with acute pancreatitis. Elevations in amylase or lipase levels greater than 3 times the upper limit of normal, in the absence of renal failure, are most consistent with acute pancreatitis 1. Acute pancreatitis should be considered among the differential diagnoses in patients admitted with unexplained multiorgan failure or the systemic inflammatory response syndrome.
From the Research
Diagnostic Criteria for Acute Pancreatitis
The diagnostic criteria for acute pancreatitis require the satisfaction of at least two out of three criteria, which include:
- Abdominal pain radiating to the back
- Serum lipase or amylase levels three or more times the upper limit of the normal level 2, 3, 4, 5
- Findings indicating pancreatitis obtained via a computed tomography (CT) scan or magnetic resonance imaging (MRI) 2, 3, 5
Laboratory Tests
Laboratory tests play a crucial role in the diagnosis of acute pancreatitis, with serum amylase and lipase being the most commonly used tests 4, 6.
- Serum lipase is now the preferred test due to its improved sensitivity, particularly in alcohol-induced pancreatitis 4
- A threshold concentration 2-4 times the upper limit of normal is recommended for diagnosis 4
- New biomarkers, including trypsinogen and elastase, have no significant advantage over amylase or lipase 4
Imaging Studies
Imaging studies, such as CT and MRI, can be useful in assessing the severity of acute pancreatitis or if the diagnosis is uncertain 3, 5.