title: Extensive investigation of patients with mild elevations of serum amylase and/or lipase is 'low yield'.
abstract: BACKGROUND
  Serum amylase and lipase levels are widely used as markers of pancreatic inflammation. However, it would seem that mild elevations of amylase and lipase rarely predict significant pancreatic pathology. Pancreatic imaging tests are expensive. The gold standard, endoscopic retrograde cholangiopancreatography, carries risk of morbidity and mortality.
  
  
  OBJECTIVE
  To determine whether extensive investigation of patients with mild, nonspecific abdominal symptoms and mild elevations of amylase and/or lipase results in a significant diagnostic yield.
  
  
  METHODS
  Outpatient evaluations were retrospectively analyzed over 12 months. Inclusion criteria were nonspecific abdominal pain, and mild elevations (less than three times the upper limit of normal) of serum amylase or lipase, or both. Exclusion criteria included a history of chronic pancreatitis, elevation of liver tests and acute pain syndromes.
  
  
  RESULTS
  Nineteen patients over the study period met the criteria. Of the nineteen patients, 58% had elevation of lipase alone, 21% amylase alone and 21% had elevations of both. In addition, 89.5% of the patients had nonspecific abdominal pain. After imaging with one or more of ultrasound, computed tomography, magnetic resonance cholangiopancreatography, endoscopic ultrasound and endoscopic retrograde cholangiopancreatography, small bowel follow through or hepatobiliary scanning, 78.9% patients were thought to have a normal pancreas. Of the remaining patients, 15.8% had mild or equivocal changes of chronic pancreatitis, and one patient was found to have a pancreatic tail pseudocyst. The average cost of investigation was US$2,255, taking only direct procedural costs into account. No patient was found to have malignancy.
  
  
  CONCLUSIONS
  The majority of patients with nonspecific abdominal pain and isolated elevations of amylase and/or lipase (less than three times the upper limit of normal) had no identifiable pancreatic pathology. The diagnostic yield in patients with mild elevations of lipase alone was particularly poor. The cost effectiveness and risk-benefit ratio of extensive investigation of this group of patients warrants further study.
authors.affiliation: Department of Gastroenterology, Duke University Medical Center, Durham, North Carolina 27710, USA. byrne006@mc.duke.edu
authors.forename: Michael F
authors.initials: MF
authors.lastname: Byrne
authors.forename: Robert M
authors.initials: RM
authors.lastname: Mitchell
authors.forename: Helen
authors.initials: H
authors.lastname: Stiffler
authors.forename: Paul S
authors.initials: PS
authors.lastname: Jowell
authors.forename: Malcolm S
authors.initials: MS
authors.lastname: Branch
authors.forename: Theodore N
authors.initials: TN
authors.lastname: Pappas
authors.forename: Doug
authors.initials: D
authors.lastname: Tyler
authors.forename: John
authors.initials: J
authors.lastname: Baillie
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000681:Amylases / Q000097:blood*; D003362:Cost-Benefit Analysis; D003365:Costs and Cost Analysis; D003952:Diagnostic Imaging; D005260:Female; D006801:Humans; D008049:Lipase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010182:Pancreatic Diseases / Q000175:diagnosis* / Q000191:economics*; D012189:Retrospective Studies
chemical_list: D008049:Lipase; D000681:Amylases