Microsoft word - sop - short synacthen stimulation test.doc

Clinical Biochemistry Department
Endocrinology Department
SHORT SYNACTHEN TEST
INTRODUCTION
Tetracosactrin (Synacthen, Cortrosyn) is a synthetic preparation comprising the first 24 amino acids of
ACTH. It stimulates the adrenal cortex to produce cortisol, failure to respond indicating impaired
adrenocortical function. This test is of value in patients with suspected adrenocortical insufficiency eg.
Addison’s disease and also during the later stages of withdrawal and following total cessation of
previous long-term high dose glucocorticoid drug therapy, including topical preparations.
CONTRAINDICATIONS AND SIDE EFFECTS
Allergic reactions to tetracosactrin are a possibility, but rarely occur.
PATIENT PREPARATION
This test should be used as an out-patient screening procedure, although it can be done for in-patients
presenting acutely with suspected adrenal failure.
This test is should be carried out between 9am and 10am, where practical, as responses will decline
later in the day. The patient should rest for 30 minutes prior to the test. Smoking is not permitted.
Patients on theurapeutic steroids
The cortisol assay is interfered with by therapeutic glucocorticoids (prednisolone / methyl-prednisolone /
hydrocortisone). Therapy with such steroids should be discontinued and substituted with an alternative
steroid (e.g. dexamethasone, betamethasone) at an equivalent dose (see BNF section 6.3.2) at least 3
days before the test. Alternatively, glucocorticoids should be stopped for 18 hours prior to the test.
Caution: withdrawal of glucocorticoids may be dangerous.

PROTOCOL
1. Take basal venous blood sample (5ml SST tube – yellow top) An additional sample for ACTH may also be collected for storage, pending results of the Synacthen
test (5ml EDTA tube - purple top) but must be sent to Biochemistry immediately.
2. 250ug of Tetracosactrin dissolved in about 1ml of sterile water or isotonic saline is administered intramuscularly (adults only, for children refer to paediatric protocol). (Tetracosactrin is marketed as Synacthen (Ciba) for Cortrosyn (Organon)). 3. After 30 minutes a further blood sample is taken (6ml SST tube – yellow top). 4. A sample taken at 60 minutes post Synacthen is not recommended, unless test is being performed Label the samples with patient details and actual time taken. When test is complete, send request form and samples to the Clinical Biochemistry Department as soon as possible. INTERPRETATION
>550 nmol/L: Suggests intact HPA axis and unlikely to be associated with adrenocortical insufficiency.
500 - 550 nmol/L: May be adequate response, but may be associated with a degree of adrenocortical
insufficiency (e.g. may need hydrocortisone cover during stress). A repeat test (especially if not
performed in the morning) after at least 5 days may be helpful; adrenal antibodies may be useful if
autoimmune adrenal disease suspected.
<500 nmol/L: Adrenocortical insufficiency likely, requires endocrinologist assessment.
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Source: http://www.baspath.co.uk/clinical_chemistry/handbook/SOP_SST.pdf