Indications

Follow up of Nelson's syndrome, post-adrenalectomy for Cushing's disease

Contraindications

None

Procedure

Non-fasting, but if taking hydrocortisone, omit morning dose.

Take blood for cortisol (red vial) and ACTH at time 0 sample

Give morning hydrocortisone

Take blood for cortisol and ACTH at 60 and 120 minutes.

Blood for ACTH should be taken into 3 x 4.5ml EDTA cooled in iced water, send to the laboratory immediately.

Interpretation guidelines

Plasma ACTH should peak before the mornings dose of hydrocortisone and then fall promptly.
Patients with nonsuppressible ACTH's or ACTH levels that are rising annually, exclude pituitary macroadenoma by MRI.