From the Guidelines
Elevated amylase and lipase levels, specifically three times the upper limit, strongly suggest acute pancreatitis, with lipase being the more specific marker. Amylase and lipase are enzymes that help diagnose pancreatic disorders, with elevated levels in the blood typically indicating pancreatic inflammation or damage 1. Lipase is more specific to pancreatic issues than amylase and stays elevated longer, making it the preferred diagnostic marker.
Key Points to Consider
- Normal amylase levels are typically 30-110 U/L, while normal lipase levels range from 10-60 U/L 1.
- Levels three times the upper limit strongly suggest acute pancreatitis 1.
- These enzymes can also be elevated in other conditions like kidney disease, intestinal obstruction, or certain medications.
- When interpreting these tests, it's essential to consider clinical symptoms and other diagnostic findings 1.
- The degree of elevation doesn't necessarily correlate with disease severity, and monitoring these enzymes can help track recovery from pancreatic inflammation.
Diagnostic Approach
- The diagnosis of acute pancreatitis should be established within 48 hours of admission, based on compatible clinical features and elevations in amylase or lipase levels 1.
- Confirmation of the diagnosis, if required, is best achieved by computed tomography (CT) of the abdomen using intravenous contrast enhancement 1.
- Clinicians should be aware that an early CT (within 72 hours of illness onset) might underestimate the amount of pancreatic necrosis 1.
From the Research
Amylase and Lipase Tests
- Amylase and lipase tests are used to diagnose various conditions, including acute pancreatitis, chronic pancreatitis, and non-pancreatic conditions 2, 3.
- Elevated serum levels of amylase and lipase can be caused by several factors, such as gastrointestinal tract obstruction, malignancies, and other disease conditions 2.
- Serum lipase levels can be elevated in many intra-abdominal inflammatory conditions, and are not sufficient to diagnose acute pancreatitis in patients with abdominal pain 3.
Diagnostic Accuracy
- Serum lipase offers a higher sensitivity than serum amylase in diagnosing acute pancreatitis 4.
- Lipase also offers a larger diagnostic window than amylase, as it is elevated for a longer time, making it a useful diagnostic biomarker in early and late stages of acute pancreatitis 4.
- However, both lipase and amylase alone lack the ability to determine the severity and etiology of acute pancreatitis 4.
Clinical Scenarios
- Isolated elevation of lipase can be related to non-pancreatic sources of lipolytic enzymes, such as malignant tumors, acute cholecystitis, or esophagitis 5.
- An elevated lipase should not be equated with evidence for pancreatitis if the amylase is normal, and a simultaneous determination of both amylase and lipase is recommended for the evaluation of patients with abdominal pain 5.
Diagnosis and Treatment of Acute Pancreatitis
- The diagnosis of acute pancreatitis requires two of upper abdominal pain, amylase/lipase ≥ 3 × upper limit of normal, and/or cross-sectional imaging findings 6.
- Initial priorities in the treatment of acute pancreatitis include intravenous fluid resuscitation, analgesia, and enteral nutrition, and when necessary, critical care and organ support, parenteral nutrition, antibiotics, pancreatic exocrine and endocrine replacement therapy 6.