Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (693 page)

   Esophageal rupture

   Perforated or penetrating peptic ulcer

   Postoperative upper abdominal surgery, especially partial gastrectomy (≤2 times normal in one third of patients)

   Acute alcohol ingestion or poisoning.

   Salivary gland disease (mumps, suppurative inflammation, duct obstruction due to calculus, radiation).

   Malignant tumors (especially pancreas, lung, ovary, esophagus; also breast, colon); usually >25 times upper reference limit, which is rarely seen in pancreatitis.

   Advanced renal insufficiency; often increased even without pancreatitis.

   Macroamylasemia.

   Others, such as chronic liver disease (e.g., cirrhosis; ≤2 times normal), burns, pregnancy (including ruptured tubal pregnancy), ovarian cyst, diabetic ketoacidosis, recent thoracic surgery, myoglobinuria, presence of myeloma proteins, some cases of intracranial bleeding (unknown mechanism), splenic rupture, and dissecting aneurysm.

   It has been suggested that a level >1,000 Somogyi units is usually due to surgically correctable lesions (most frequently stones in biliary tree), the pancreas being negative or showing only edema; but 200–500 U is usually associated with pancreatic lesions that are not surgically correctable (e.g., hemorrhagic pancreatitis, necrosis of pancreas).

   Increased serum amylase with low urine amylase may be seen in renal insufficiency and macroamylasemia. Serum amylase ≤4 times normal in renal disease only when creatinine clearance is <50 mL/minute due to pancreatic or salivary isoamylase; but rarely more than four times normal in the absence of acute pancreatitis.

Decreased In

   Extensive marked destruction of the pancreas (e.g., acute fulminant pancreatitis, advanced chronic pancreatitis, advanced cystic fibrosis). Decreased levels are clinically significant only in occasional cases of fulminant pancreatitis.

   Severe liver damage (e.g., hepatitis, poisoning, toxemia of pregnancy, severe thyrotoxicosis, severe burns).