Pancreatic Function Test

Pancreatic Function Test

Mrs. Noreen Yap, RMT

Pancreas

– a compound acinotubular gland situated behind the stomach / lies beneath the stomach and is connected to the small intestine at the duodenum

- is a yellowish organ about 7 inches (17.8 cm) long and 1.5 inches. (3.8 cm) wide.

- important gastrointestinal accessory organ

- involve in the disease from both exocrine and endocrine aspects

Function:

- produces both an external and an internal secretion

external= pancreatic juice;

internal= hormone insulin and glucagons

- also helps neutralize chyme and helps break down proteins, fats and starch.

pancreatic juice

- for digestion of all classes of food

hormone insulin

- lowers the blood sugar level

- regulate carbohydrate metabolism

Glucagons

- increase concentration of glucose in the blood

Pancreatic enzymes consists mainly of:

1. Starch Digesting Amylase

2. Fat-Digesting Lipase

3. Protein-Digesting Trypsin

4. Bicarbonate

5. Certain other substances

Most important Pancreatic Parenchymal Diseases are:

1. Acute Pancreatitis – inflammed condition of pancreas

2. Chronic Pancreatitis

3. Carcinoma of the Pancreas

Acute Pancreatitis

- Form of pancreatitis characterized by necrosis, suppuration, gangrene and hemorrhage

Manifestations:

- Sudden onset of severe epigastric pain that may radiate elsewhere, often to the back

- Vomiting, belching of gas

Commonly used laboratory tests:

1. Alpha Amylase (Serum Amylase)

- Derived from pancreas and salivary glands

- Serum levels become abnormal 2-12 hours after onset of acute pancreatitis in many patients and within 24 hours in 90% of cases.

Serum amylase level reaches a peak by 24 hours and returns to normal in 48-72 hours

2. Urine Amylase

- Helpful especially when serum amylase level is normal or equivocally elevated

- Urine amylase usually rises within 24 after serum amylase

- As a rule remains abnormal for 7-10 after the serum concentration returns normal

Drawback: Renal function relationship of serum and urine amylase

When renal function is sufficiently diminished to produce serum blood urea nitrogen elevation, amylase excretion also diminishes, leading to mild or moderate elevation in serum amylase levels and a decrease in urine amylase levels.

3. Amylase/ Creatinine Clearance Ratio

- more specific for pancreatitis than changes

in the serum amylase level.

- increased amylase clearance compared creatinine

- A/CCR becomes abnormal 1-2 days after of serum amylase levels

- A/CCR ratio increases

- Serum and urine amylase would be helpful if the A/CCR result is reference limits.

FORMULA:

A/CCR (in %) = { urine amylase x Serum creatinine x 100

Serum amylase Urine creatinine}

4. Macroamylase

- macromolecular complex that contains amylase bound to other molecules

- macro amylase does not pass the filter but accumulates in serum, if a amylase test is performed, the will be included in the amylase and may produce an elevated test result. Could simulate pancreatic disease

- Elevated serum amylase level and A/CCR has been used to diagnose macroamylasemia

5. Amylase isoenzyme fractionation

- Pancreatic and salivary separation serum amylase into its isoenzymes is possible by selective enzymatic or chemical inhibition or by electrophoresis

acute pancreatitis – increase in pancreatic type of isoenzyme

Diabetic ketoacidosis – increase in salivary type isoenzyme

6. Serum Lipase

- more specific for pancreatic damage than the amylase level

- rise slightly later than the serum amylase levels, beginning 3-6 hours, with a peak most often at 24 hours

- tend to remain abnormal longer, in most instances returning to reference range in 7-10 days

7. Serum Immunoreactive trypsin

- RIA

- Trypsin is exclusively produced by pancreas

- Trypsin presursor is Trypsinogen which is N trypsin activity in serum

- In acute pancreatitis, trypsinogen is to form trypsin

- Serum immunoreactive trypsin level elevated in acute and chronic pancreatitis

8. Carboxypeptidase A and Phospolipase A

- Advocated to diagnose acute pancreatitis

- Elevated longer than serum amylase and lipase levels. Thus, more specific for pancreatic disease

9. Endoscopic Retrograde Cholangiopancreatography

- Alterations in pancreatic duct x-ray morphology can suggest acute, chronic pancreatitis, pancreatic carcinoma and pancreatic cyst

- reliable single procedure to detect degrees of dysfunction

- insensitive to mild or minimal pancreatic disease

10. Computerized tomography and ultrasound

- Ultrasound for very thin persons

- Computerized tomography for obese patients

- Both can visualize the pancreas

Therapy:

- supportives

IV dextrose

Analgesics

Bowel rest

Chronic Pancreatitis

- Form of pancreatitis marked by formation of scar tissue associated with malfunction

The classic case of chronic pancreatitis manifests as:

1. Diabetes

2. Pancreatic calcification on x-ray study

3. Steatorrhea

Other Manifestations:

Test Useful in diagnosis of chronic pancreatitis:

1. Serum Amylase

- Half of the patients are within normal range (repeated determinations are necessary at intervals of 3 days some are in the borderline or slightly elevated

- A/CCR is most helpful

- Urine amylase is also helpful

2. Serum Immunoreactive trypsin

- Variation in chronic pancreatitis

- Most of the patients are reported to have decreased SIT or within reference limits

3. Bentiromide test

- Synthetic peptide linked to a p-aminobenzoic acid(PABA) molecule

- Arylamines are assayed in a 6 hour urine collection beginning with the oral dose

- Decreased excretion suggests decreased absorption from the duodenum, suggests

deficient activity of pancreatic chymotrysin due to decreased pancreatic function

- Sensitivity of the test depends on the severity of the disease (greater sensitivity correlating with greater severity)

4. Endoscopic retrograde cholangiopancreatography

5. Pancreatic Stimulation tests

- Best diagnostic test for chronic pancreatitis

- The stimulation test does not become abnormal until 75% of pancreatic exocrine function is lost

6. D-xylose test

- Useful if the px has demonstrable steatorrhea

- N D xylose is found in pancreatic insufficiency or in cystic fibrosis

7. Other test

- Presence of undigested meat fibers suggests abnormal pancreatic fnx

Therapy

Narcotic Analgesics

Insulin therapy

Pancreatic enzyme replacement

Surgery

3. Pancreatic cancer

=Pancreatic carcinoma is a malignancy of pancreas

=slightly more common in men than in women, and risk increases with age

=cause is unknown, but more common smokers and in obese individuals

=there is controversy as to whether type 2 is a risk factor for pancreatic cancer

=related to hereditary syndromes

Symptoms:

- Thick pancreatic secretions

- Secondary atrophy of the pancreatic cells

- Thick secretions of the lungs

- Recurrent bronchopneumonia

- thickened bile in the liver

- plugging of the small ducts

- Secondary cirrhosis

Diagnosis:

-excrete N sweat volumes

-elevated Sodium and concentration than the normal persons

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