Elevated serum amylase activity in the absence of clinical pancreatic or salivary gland disease: possible role of acute hypoxemia.

Elevated serum amylase activity, in the absence of clinically apparent pancreatic or salivary gland disease, has been observed in many seemingly unrelated conditions. In a search for common etiological factors to account for hyperamylasemia in these conditions, a retrospective analysis was performed. Eighty-four episodes of hyperamylasemia (greater than 300 I.U./l. Phadebas method) occurring in 75 patients over a one-year period ending in June, 1975 were assigned to one of two groups. Group 1 consisted of 56 (67%) episodes of hyperamylasemia with clinical pancreatitis. Group 2 consisted of 28 (33%) episodes of hyperamylasemia in the absence of clinical pancreatitis. Hypoxemia (pO2 less than 75 mm. Hg.) was found in 9/15 patients in Group 2 who had arterial blood gases measured. To assess the possible relationship between acute hypoxemia and amylase activity, a prospective study was initiated. Patients with known causes of pancreatitis or renal failure were eliminated. Hyperamylasemia was found in 3/8 hypoxemic patients. This raises the possibility that acute hypoxemia alone or in combination with other factors may raise serum amylase activity, possibly through ischemic injury to the pancreas or salivary glands or other amylase containing tissues.