Pancreatic Enzymes Flashcards
What is Amylase used to detect? What are the normal and critical ranges?
Used to detect and monitor clinical course of pancreatitis and is frequently ordered with acute abdominal pain
Normal range 30-220 units/L
Critical values > 3 times upper limit of normal
What is the function of Amylase in the body and where is it found?
It is secreted from pancreatic acinar cells into the pancreatic duct and into the duodenum
Aids in catabolism of carbohydrates to simple sugars
Describe the rise and fall of Amylase injuries with an injury to the pancreas.
Rise occurs within 12 hours of onset of disease
Levels return to normal 48-72 hours after initial insult as amylase is rapidly cleared by kidneys.
Persistent problems will cause persistent amylase elevation
Describe how amylase enters the bloodstream with an injury or obstruction in the pancreas.
Damage to the pancreatic cells (pancreatitis) or obstruction of duct flow (carcinoma or common bile duct gallstones) cause enzyme to enter intrapancreatic lymph system and peritoneum and then be absorbed into bloodstream
Is amylase specific for pancreatic disorders?
No
How do chronic poancreatic diseases affect Amylase?
Chronic pancreatic disorders may cause pancreatic cell destruction in patients with massive hemorrhagic pancreatic necrosis.
These patients may not have high amylase levels as there are so few pancreatic cells left to make amylase
Interfering factors of Amylase?
Lipemia factitiously decreases amylase
IV dextrose can lower amylase levels and cause a false negative result
Drugs that increase amylase include aspirin, corticosteroids, alcohol, loop diuretics, narcotics, oral contraceptives, prednisone
Drugs that decrease amylase include citrates, glucose, and oxalates
Causes of increased Amylase?
Acute pancreatitis, chronic relapsing pancreatitis – amylase gets released
Penetrating peptic ulcer into the pancreas – penetrates the posterior wall of the duodenum into the pancreas – localized pancreatitis
Other GI diseases – necrotic bowel, perforated bowel, or duodenal obstruction cause amylase to leak out of the gut
Acute cholecystitis, parotiditis, ruptured ectopic pregnancy
Renal failure – reduced excretion of amylase by kidneys
DKA, pulmonary infarction, after endoscopic procedures involving pancreas
What is Lipase used to evaluate? What are the normal ranges?
Used in evaluation of pancreatic disease
Normal 0-160 units/L
What is the function of Lipase in the body?
Lipase is an enzyme secreted by the pancreas into the duodenum to break down triglycerides into fatty acids. It appears in the bloodstream following damage to or disease affecting the pancreatic acinar cells
How can Lipase be used to differentiate between pancreatitis and nonpnacreatic diseases?
Lipase elevations in nonpancreatic diseases are less than 3 times the upper limit of normal as compared to pancreatitis, which can cause a 5-10 fold increase
Describe the time line of the rise and fall of lipase levels in acute pancreatitis.
In acute pancreatitis, elevated lipase levels parallel amylase but rise a little later (24-48 hours after onset) and remain elevated for 5-7 days, so it is more useful in late diagnosis of acute pancreatitis
Less useful in more chronic pancreatic diseases
Interfering factors of Lipase?
Drugs that increase levels include codeine, indomethacin, morphine, meperedine
Drugs that decrease levels include calcium ions
Causes of increased levels of Lipase?
Pancreatic diseases (acute pancreatitis, chronic relapsing pancreatitis, pancreatic cancer, pancreatic pseudocyst) – lipase released from diseased or injured cells
Biliary diseases (acute cholecystitis, cholangitis, extrahepatic duct obstruction)
**Renal failure** – lipase normally excreted by kidney Intestinal diseases (bowel obstruction, infarction) – lipase is in mucosal cells lining the bowel (mainly duodenum)
Salivary gland inflammation or tumor – salivary glands contain small amount of lipase
Peptic ulcer disease
