Secretin Stimulation for Zollinger-Ellison Syndrome (Secretin Provocation Test)

Norm of Secretin Stimulation for Zollinger-Ellison Syndrome (Secretin Provocation Test)

Serum gastrin: ≤200 pg/mL with no increase in production.
Increased
Gastrinoma (gastrin levels increase <100 pg/mL) and Zollinger-Ellison (ZE) syndrome (gastrin levels increase ≥110 pg/mL within 10 minutes). Drugs include amino acids, calcium, catecholamines, and insulin. Herbal or natural remedies include coffee (Coffea).
Decreased
Duodenal ulcer, G-cell hyperplasia (astral), and pancreatic dysfunction. Drugs include atropine.

 

Description of Secretin Stimulation for Zollinger-Ellison Syndrome (Secretin Provocation Test)

A stimulation test to assess for gastrinomas that can be correlated with chemical findings for diagnostic purposes. Secretin is a polypeptide secreted by the duodenal mucosa and the upper jejunum in response to gastric acidity. It acts to stimulate gastric pepsinogen, hepatic duct bicarbonate and water, pancreatic juice, bile, and intestinal fluid secretion and to inhibit gastric acid and gastrin secretion and intestinal smooth muscle contraction. ZE syndrome is a gastrointestinal disease in which elevated gastrin is formed, and pancreatic gastrinomas are present. In clients with ZE syndrome, the intravenous administration of secretin produces a paradoxical increase in serum gastrin levels. This test aids diagnosis of ZE syndrome for clients with baseline gastrin levels of 100–500 pg/mL (equivocal levels).

 

Professional Considerations of Secretin Stimulation for Zollinger-Ellison Syndrome (Secretin Provocation Test)

Consent form NOT required.

Risks
Allergic reaction to secretin.
Contraindications
Positive reaction to secretin skin testing.

 

Preparation

1. See Client and Family Teaching.
2. Establish intravenous access.
3. Obtain secretin for intravenous administration, a tourniquet, and 7 each of alcohol wipes, needles, syringes, and red-topped tubes. Number the tubes sequentially.
4. Perform secretin skin testing to assess for allergy to the foreign protein. Inject 0.1 mL intradermally and observe 30 minutes for development of a wheal at the injection site.

 

Procedure

1. Draw a 5-mL blood sample for the gastrin level.
2. Inject intravenously 2–3 U/kg of body weight of secretin over 30 seconds. Repeat step 1 above every 5 minutes × 6 for a total of 30 minutes after injection, using the tubes in sequential order.
3. An alternative procedure is to infuse secretin 9 U/kg of body weight over 1 hour and draw blood specimens every 15 minutes. In ZE syndrome, gastrin levels peak after 45–90 minutes.

 

Postprocedure Care

1. Label all the tubes and laboratory requisitions with the time the specimens were collected.

 

Client and Family Teaching

1. This test helps diagnose ZE syndrome.
2. Fast from food and fluids from midnight before the test.

 

Factors That Affect Results

1. None.

 

Other Data

1. Gastrin secretion may increase by 100–200 pg/mL (ng/L) every 5 minutes after secretin injection when gastrinoma is present.
2. Calcium provocation tests are also sometimes performed to aid in the diagnosis of ZE syndrome.