What is the clinical significance of abnormal serum amylase?

The normal value of serum amylase varies with different experimental methods, so we should refer to the normal value set by the hospital when analyzing it. Su's unit is generally used, and its normal value is 50 ~ 180 Su's unit (50 ~ 180 Su's unit /dl) per 100 ml of blood.

The obvious increase of serum amylase is more common in acute pancreatitis, which is the simplest and most sensitive method to diagnose acute pancreatitis, but attention should be paid to its increase range and detection time.

At the onset of acute pancreatitis, serum amylase generally starts to increase at 4-8 hours after onset, and reaches a peak at18-24 hours, lasting for 3-5 days, often 3-4 times higher than the normal level, reaching 500 su units, and 300-500 su units are suspicious. It should be pointed out that the increase of serum amylase is not necessarily parallel to the condition of acute pancreatitis. Some necrotizing pancreatitis may not be very high, and normal serum amylase cannot completely rule out pancreatitis. If the serum amylase suddenly drops from very high to very low, and the clinical symptoms are obviously aggravated, we should consider whether there is hemorrhagic necrotizing pancreatitis. If serum amylase continues to rise for more than 10 days, it means that amylase continues to ooze from the pancreas, suggesting that there is still inflammation in the pancreas, or pancreatic duct obstruction, pancreatic pseudocyst formation or pancreatic abscess. Besides acute pancreatitis, elevated serum amylase can also be seen in other diseases, such as pancreatic cancer, cholecystitis, cholangitis, pancreatic duct or bile duct obstruction, intestinal obstruction, ulcer perforation, tubal ectopic pregnancy rupture and so on. However, when these diseases occur, the increase of serum amylase is generally small, so we should pay attention to distinguish them.