MCQ 4 (Medicine)

Q) Which of the following is not true about serum amylase in a case of acute pancreatitis?
a) It is widely used as a screening test
b) Remains elevated for weeks
c) 85% have elevated levels
d) Maybe normal with coexisting hypertrigyceridemia
Ans: b) (Harrison’s 16th Ed., 1891)

The serum Amylase is widely used as screening test for acute pancreatitis.
· A value >65U/L should raise the question of acute pancreatitis. Levels >130U/L make the diagnosis more likely, and values greater than three times normal virtually clinch the diagnosis if gut perforation or infarction is excluded.
· It is elevated within 24 hrs of onset and remains so for 1-3 days. Levels return to normal within 3-5 days unless there is extensive pancreatic necrosis, incomplete ductal obstruction or pseudocyst formation.
· Approx. 85% will have a raised amylase level.
· Levels may be normal if there is a delay before blood samples are taken, chronic pancreatits, or if hypertriglyceridemia is present.
· 20-40% false negatives and positives