Serum Amylase Added Value to Non-Diagnostic Serum Lipase in Acute Pancreatitis: Retrospective Study

Abstract

Introduction: It is widely accepted that serum lipase is more sensitive than serum amylase in diagnosing acute pancreatitis. However, since the sensitivity of serum lipase is not 100%, serum amylase may have an added value when serum lipase level is not diagnostic. Methods: We retrospectively reviewed all lipase and amylase tests that were simultaneously performed over a 6-month period at a university-affiliated teaching hospital in Florida. We considered amylase and lipase levels to be diagnostic if they were >3 times upper normal limit. We determined the percentage of simultaneous tests that showed normal or borderline lipase level but diagnostic amylase level. Abdominal computed tomography reports were reviewed when available. Results: Out of 3716 simultaneous serum lipase and amylase tests, 171 had diagnostic and 3545 normal or borderline lipase results, respectively. Out of the later, 21 (0.6%) tests had diagnostic amylase results. Abdominal computed tomography was available in association with 13 of the 21 tests with diagnostic amylase and normal or borderline lipase results, none showed evidence of acute pancreatitis. Five of the remaining 8 tests were associated with cardiac arrest, two with diagnostic serum lipase results on presentation, and one with pancreatic cancer and obstructive jaundice. Conclusion: We conclude that serum amylase has no added value to serum lipase in the setting of acute pancreatitis. Simultaneous amylase and lipase tests in this setting should be abandoned to avoid unnecessary healthcare spending.