Synacthen stimulation test

Diagnostic Use

Please note - this is NOT the same as the saline suppression test (SST). Please check with Endolab if unsure of test request.

To assist in the investigation of suspected adrenal insufficiency.
Synacthen stimulation tests may also be useful in the characterisation of 21-hydroxylase deficiency (Congenital Adrenal Hyperplasia).

After a basal cortisol blood test is taken, Synacthen is administered to stimulate the secretion of cortisol from the adrenal glands. Cortisol is then taken again at one or two time points (30 or 60 mins) post administration. Inadequate response to Synacthen indicates adrenal insufficiency and warrants further investigation.

Department

Endocrine Test Centre

Delphic Registration Code

SCO1 (pre) SCO2 (post)

Laboratory Handling

Phlebotomy

Please label tubes with collection time so it is clear which sample is PRE and which sample is POST.

Registration

Not the same as a saline suppression test - please check! Also check collection time and form carefully. PRE sample is first time point and POST sample is second timepoint.

Constituent Tests

• Cortisol – serum/plasma

Synonyms

ACTH stimulation test
Serial Cortisol

Turnaround Time

1 day

Test Code

SCO1, SCO2

Specimen Type

• Serum
• Plasma

Specimen Requirements

Tube/Container Type:

Preferred

• EDTA (Lavender Cap)

Preferred if West Coast

• Lithium Heparin - Gel (Light Green Cap)

Acceptable

• Serum (Red Cap)
• SST II (Gold Cap)
• Lithium Heparin - Non-gel (Green Cap)
• Lithium Heparin - Gel (Light Green Cap)

Preferred Sample Volume (ml)

1

Minimum Sample Volume (ml)

0.5

No of Samples Required

2

Pre-testing Requirements

Withhold any treatment with steroids for 24 hours prior to test.

Aliquot Instructions

Sample Type

• Serum
• Plasma

Minimum Volume (ml)

0.4

Transport to Lab

Ambient (8 - 24 degrees Celsius)
If overnight - Frozen

Interpretation

A cortisol result of >400nmol/L post Synacthen administration indicates adequate response to Synacthen and suggests normal adrenal reserve.

A post synacthen cortisol of <400nmol/L suggests adrenal insufficiency (primary or secondary) and warrants further evaluation by an endocrinologist.

 

 

Test Method

Competitive ECLIA Roche Cobas E402.

Contact Canterbury Health Laboratories on +64 3 364 0484 or email LabInfo@cdhb.health.nz

Please contact the Endocrine Test Centre for Synacthen protocol (80934).

Contact Information

Enquiry Form