There are very few laboratory tests that can be depended upon per se to make a clinical diagnosis, and indeed the man who is wont to make a diagnosis on such evidence alone is certain to rue the day. However, there are a few tests which, when properly and competently executed, are reliable in clinching a differential diagnosis among several clinical possibilities. Such a test in our experience has been the serum amylase test in establishing a differential diagnosis between perforated ulcer and acute pancreatitis. Bockus1 has said:
An immediate determination of the serum amylase may be helpful if acute pancreatitis is to be considered. If the serum amylase is markedly elevated, a primary diagnosis of acute pancreatitis is justified since perforated peptic ulcers rarely increase the concentration of the pancreatic enzymes in the blood.
In our laboratory, the Somogyi test is used, and the limit of normal has
ROSENBURG SA, AKGUN S. Serum Amylase Test in Differential Diagnosis of Freely Perforated Ulcer and Acute PancreatitisA Reevaluation. AMA Arch Surg. 1957;75(1):41-43. doi:10.1001/archsurg.1957.01280130045009