Relation of diagnostic serum amylase levels to aetiology and severity of acute pancreatitis.

The sensitivity of diagnostic serum amylase (greater than 1000 iu/l) was assessed in 417 patients with acute pancreatitis as a result of gall stones (258), alcohol (104), or miscellaneous causes (55), of whom 111 (27%) had a clinically severe attack (including 34 deaths). On hospital admission, an amylase value diagnostic of pancreatitis was found in 96.1% of all mild cases and in 87.4% of severe cases (p less than 0.001); at 48 hours these values were 33.3% and 48.2% respectively (p = 0.026). Diagnostic amylase levels for alcoholic patients were found in 86% of mild cases on admission and in 76% of severe cases (p less than 0.001, compared with other groups). The diagnostic levels were also significantly lower at 24 hours for both the alcoholic and miscellaneous groups compared with the gall stone group (p less than 0.001). Eight of 27 (30%) patients with a serum amylase activity less than 1000 iu/l had pancreatic necrosis compared with 12 of the remaining 390 (3.1%) patients (p less than 0.001); the mortality was also significantly different (44% v 5.6% respectively, p less than 0.001). These data support the view that more sensitive tests for acute pancreatitis are needed for routine use especially in those whose disease has an alcoholic aetiology.