Primary adrenal cortical insufficiency - not enough steroid hormones
- Autoimmune is most common form
- Treat with long term steroid replacement
Triad of hyperpigmentation, postural hypotension and hyponatraemia
Plus Hyperkalaemia, metabolic acidosis
Secondary and tertiary causes of adrenal insufficiency:
More common than Addison’s
Secondary:
- pituitary adenoma
- pituitary surgery
- radiotherapt
- Sheehans’ syndrome
- Trauma
Tertiary: exogenous steroids, inadequate release of CRH
Difference
- No hyperpigmentation from low ACTH
- ACTH injection still stimulates cortisol
- No lack of aldosterone effects
- Usually some other evidence of pituitary failure eg hypotheyroidism after steroid withdrawal
Causes/Factors
- Autoimmune - other auroimmune conditions, T1DM, vitiligo, pernicious Anaemia, Hashimoto’s thyroiditis, RA
- Infections - Tuberculosis, fungal infections
- Genetic factors - rarely genetic mutations
Symptoms
- Fatigue
- Weight loss
- Muscle weakness/twitching
- Low BP when standing
- Hyperpigmentation
Diagnostic Tests
- Blood test - measure cortisol and aldosterone levels
- ACTH stimulation test (short synacthen test) - to assess if adrenal glands release in response to hormone
- Imaging - CT to see glands
Management
Patients need to carry round an emergency card or bracelet to let people know what to do if they cannot.
- Glucocorticoid replacement - hydrocortisone/prednisone to replace cortisol
- Mineralcorticoid replacement - fludrocortisone to replace aldosterone
- Salt supplementation?
Need to double their dose during times of stress - illness, injury, surgery to prevent Addisonian crisis
Management of a Crisis
Most commonly caused by: GI illness, infections, peri operative, physiological stress or pain
- A-E approach
- Calcium gluconate for cardioprotection
- IM/IV hydrocortisone
- IV fluids
- Correct Hypoglycaemia with IV dextrose
- Monitor electrolytes and fluid balance
Complications/red Flags
- Adrenal crisis - life threatening situation, extreme weakness and low BP - requires hydrocortisone injection immediately
- Electrolyte imbalance - hyponatraemia, Hyperkalaemia
- Avoid treatment with dexamethasone as it increases risk of Cushing’s Syndrome