Cortisol problems

Question 1

What is Addison’s disease?

Answer 1

Autoimmune destruction of the adrenal glands giving low cortisol and low aldosterone.

Question 2

Symptoms of Addison’s?

Answer 2

Lethargy, weakness, anorexia, nausea and vomiting, weight loss, hyperpigmentation in the palmar creases (only seen in primary adrenal insufficiency), hypotension, hypoglycaemia, loss of pubic hair.

Question 3

Addison’s metabolic disturbances?

Answer 3

Hyperkalaemia and hyponatraemia, leading to a hyperkaliaemic metabolic acidosis.

Question 4

Causes of adrenal insufficiency?

Answer 4

Addison’s disease
TB
Metastases
Pituitary disorders

Question 5

Addison’s investigations?

Answer 5

ACTH stimulation test/Synacthen test.
Plasma cortisol measured 30 mins before and after giving synacthen 250mg.
9am serum cortisol can also be used.
Also might see: high K+, low Na+, low glucose

Question 6

Addison’s treatment

Answer 6

Hydrocortisone 20-30mg/day
Fludrocortisone
Intercurrent illness- dose should be doubled.

Question 7

Addisonian crisis- treatment

Answer 7

Often 1st presentation, or after sepsis/surgery, can be due to an adrenal haemorrhage, steroid withdrawal.

Give hydrocortisone 100mg IM/IV.
1L saline over 30-60 minutes.
+/- dextrose if hypoglycaemic.

Continue hydrocortisone 6 hourly, oral replacement at 24 hours, reduce to maintenance levels by 3-4 days.

Question 8

Cushing’s syndrome- cause

Answer 8

Prolonged exposure to glucocorticosteroids.
Causes:
Exogenous steroids- ACTH independent
Cushing’s disease- caused by a pituitary adenoma, ACTH dependent
Ectopic ACTH production- seen in SCLC, ACTH dependent
Adrenal adenoma/carcinoma- ACTH independent

False Cushing’s- mimics Cushing’s syndrome, due to depression or alcohol excess

Question 9

Cushing’s syndrome- investigations

Answer 9

Overnight dexamethasone suppression test
Give 1mg dexamethasone at 11pm and measure cortisol at 8am. Should suppress natural morning rise.

Free urinary cortisol

Question 10

Cushing’s syndrome- symptoms and metabolic disturbances?

Answer 10

Tiredness, depression, weight gain
Amenorrhoea, reduced libido
Striae, acne, hirsutism, moon face, buffalo hump
HTN

See hypokalaemia and hypernatremia. Risk of hypokalaemic metabolic alkalosis.

Question 11

Cushing’s management?

Answer 11

Exogenous cause- gentle withdrawal. Beware Addisonian crisis.
Endogenous cause e.g. pituitary adenoma- Transphenoidal surgery