The nurse is handling a client with chronic pancreatitis. Upon reviewing the client’s record, which of the following serum amylase levels is to be expected?
A. 50 units/L.
B. 150 units/L.
C. 350 units/L.
D. 650 units/L.
Correct Answer: C. 350 units/L.
The normal serum amylase level is 25 to 151 unit/L. Clients with chronic pancreatitis have an increased level of serum amylase which does not exceed three times the normal value. Serum amylase and lipase levels may be slightly elevated in chronic pancreatitis; high levels are found only during acute attacks of pancreatitis.
Option A: 50 units/L is a low serum amylase level. Low serum amylase (hypoamylasemia) has been reported in certain common cardiometabolic conditions such as obesity, diabetes (regardless of type), and metabolic syndrome, all of which appear to have a common etiology of insufficient insulin action due to insulin resistance and/or diminished insulin secretion.
Option B: 150 units/L is within the normal values. However, in the later stages of chronic pancreatitis, atrophy of the pancreatic parenchyma can result in normal serum enzyme levels because of significant fibrosis of the pancreas, resulting in decreased concentrations of these enzymes within the pancreas.
Option D: 650 units/L is seen with acute pancreatitis since the value may exceed five times the normal value. The sensitivity and specificity of amylase as a diagnostic test for acute pancreatitis depends on the chosen threshold value. By raising the cut-off level to 1000 IU/l (more than three times the upper limit of normal), amylase has a specificity approaching 95%, but sensitivity as low as 61% in some studies.