Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (695 page)

   The ratio between amylase and creatinine in serum and urine. Also referred as fractional excreted of amylase. ALCR is calculated as:

   
Normal range:

   Amylase urine: 1–17 U/hour

   ALCR: 1–4%

   Use

   Differential diagnosis of pancreatitis

   Diagnosis of pseudocyst of the pancreas, where the urine amylase may remain elevated for weeks after the serum amylase has returned to normal, after a bout of acute pancreatitis.

   Interpretation

Increased In

   Pancreatitis (>6%)

   DKA

   Renal insufficiency

   Duodenal perforation

   Large doses of corticosteroids