Adrenal Disorders Flashcards
What does the adrenal cortex produce?
- Glucocorticoids (cortisol) - affect carbohydrate, lipid and protein metabolism
- Mineralocorticoids (aldosterone) - control sodium and potassium levels
- Androgens - sex hormones
What is Cushing’s syndrome?
The clinical state produced by chronic exposure to high cortisol levels
What are the clinical features of cushing’s syndrome?
Round plethoric face, acne, skin thinning, bruising, hirsutism, central obesity, buffalo hump, proximal muscle weakness, mood disturbances, hypokalemia
What causes cushings syndrome?
Endogenous:
- ACTH dependent) - increased ACTH due to cushings disease (pituitary adenoma) or other cancer
- ACTH independent - adrenal adenoma, nodular hyperplasia
Exogenous:
- Steroid use
What is the first line investigation of Cushing’s?
24 hour urinary free cortisol excretion AND
Overnight dexamethasone suppression test
If tumour is suspected, do CT/MRI to investigate
What causes hypoadrenalism?
Primary - autoimmune (addisons), TB, HIV
Secondary - Prolonged exogenous steroids, pituitary lesions
What is Addison’s disease?
Adrenal insufficiency due to autoimmune destruction of the adrenal gland
What are the symptoms and signs of Addison’s disease?
Lean, TANNED, tired, tearful, dizzy, faints, mood disorders - very non-specific
How can hypoaldrenalism be investigated?
Short synacthen test:
- Do baseline bloods for cortisol and acth
- Give 250 mcgrams synacthen IM (corticotrophic agent)
- Measure cortisol at 0, 30, 60 minutes
Those with hypoadrenalism will have only small rises in cortisol
How can hypoaldrenalism be treated?
Glucocorticoid replacement (hydrocortisone, prednisolone, dexamethasone)
Mineralocorticoid replacement (fludrocortisone) - NB this isn’t necessary in secondary hypoadrenalism as the adrenal cortex is still intact)
When should steroids be given?
Earlier in the day as they can cause insomnia
What is an Addisonian crisis?
Shock, drowsiness, N&V, low BP, severe headache, hyperkalemia, hyponatremia, hypoglycaemia etc - precipitated by severe physical shock, infection, infarction or dehydration
How should an Addisonian crisis be managed?
IV fluid bolus
IV hydrocortisone STAT
What is metyrapone?
Treatment given in cushion’s syndrome that suppresses steroid biosynthesis
Describe the system that leads to androgen and glucocorticoid production
- Hypothalamus secretes corticotrophin-releasing factor
- Pituitary secretes ACTH
- Adrenal cortex produces androgens/glucocorticoids
This is a negative feedback system