- Chronic adrenal failure with myriad of vague symptoms = fatigue, weight loss, anorexia, abdo pain, diarrhoea, postural hypotension, hyperpigmentation (in scars, buccal mucosa, palms/soles)
- Can lead to acute adrenal failure (‘Addisonian/adrenal crisis’) = hypovolaemic shock, profound hypoglycaemia, coma and death.
- o Always suspect adrenal failure in shock with hyponatriemia (+/- hyperkalaemia).
- o Hyponatriemia only occurs in later stages of primary adrenal failure (not in secondary adrenal failure as the RAA system remains intact and functional).
- o Cortisol will be low or normal
- o ACTH is high in primary failure but low in secondary failure
- o Short synACTHen test: adrenal stimulation test using synthetic ACTH – fails to produce cortisol when given only once in adrenal failure from any cause.
- o Long synACTHen test: is given repetitively over 3 days, if adrenal glands are intact, will produce cortisol.
- o Adrenal antibodies are found in autoimmune Addison’s disease
- o Imaging/CT/biopsy can be used.
- o Acute adrenal failure: IV physiological fluids, IV hydrocortisone, monitor electrolytes, glucose and treat precipitating cause.
- o Chronic adrenal failure: glucocorticoid replacement with hydrocortisone 20mg/d in divided doses. If infection, surgery, intercurrent illness = use 40mg/d
- o In primary adrenal failure: mineralocorticoid replacement (fludrocortisone)