adrenal disease Flashcards
what does the zona glomerulosa produce
mineralocorticoids (e.g. aldosterone)
what does the zona fasiculata produce
glucocorticoids (cortisol)
what does the zona reticularis produce
androgen precursors (e.g. DHEA)
what does the medulla produce
catecholamines (e.g. adrenaline, noradrenaline)
what is the zona glomerulosa controlled by
renin angiotensin system
what is the zona fasciculata controlled by
CRH (hypothalamus) and ACTH (anterior pituitary)
what is the zona reticularis controlled by
CRH (hypothalamus) and ACTH (anterior pituitary)
what is the medulla controlled by
sympathetic nervous system
what is the effect of the zona glomerulosa
- increased sodium and water reabsorption
- increased potassium secretion
what is the effect of the zona fasciculata
- increased metabolism
- increased blood pressure
- anti-inflammatory effects
what is the effect of the zona reticularis
precursors used to produce sex steroids (testosterone)
what is the effect of the medulla
- increased heart rate/contractility
- increased vasoconstriction
- bronchodilation
what is primary adrenal insufficiency
- any condition associated with a reduction of steroids (mainly cortisol and aldosterone) due to failure within adrenal glands
- due to the negative feedback control of cortisol production, reduced levels will be associated with an increase in ACTH (causes increased skin pigmentation)
primary adrenal insufficiency causes
- infection: TB
- adrenal metastasis: lung, breast, renal, lymphoma
- autoimmune: Addison’s (most common cause)
- Waterhouse Friderichsen’s Syndrome (bilateral adrenal haemorrhage due to sepsis)
primary adrenal insufficiency presentation
- myalgia, arthralgia
- dizziness, weakness
- depression, psychosis
- abdominal pain, diarrhoea, vomiting
- lethargy, weight loss, hypoglycaemia, hypotension
- hyperpigmentation of skin (esp. palmar creases)
- vitiligo
- postural hypotension
primary adrenal insufficiency diagnosis
- bloods: low sodium, high potassium, low glucose
- diagnostic: short synacthen test
- give synthetic ACTH: cortisol should increase (normal)
- measure cortisol before and then 30-60mins after
- normal results: baseline >170, 30-mins >550
- Addison’s disease: no significant rise in cortisol
- chest x-ray
- CT CA
primary adrenal insufficiency management
steroid replacement
- aldosterone deficiency: 50-200mg fludrocortisone
- cortisol deficiency: 15-25mg hydrocortisone (given as divided dose and avoided at night to prevent insomnia)
sick days
- unwell/trauma/surgery: double steroid dose for at least a week
- vomiting: replace oral with IM
Addisonian crisis causes
bilateral adrenal haemorrhage, suddenly stopping long-term steroids, illness/trauma/surgery in those with primary adrenal failure
Addisonian crisis presentation
shock, weakness, reduced GCS (confusion/coma), hypoglycaemia