Addison's Disease (& Primary Adrenal Insufficiency) Flashcards
Addison’s disease
- Main cause of primary adrenal insufficiency
- autoimmune adrenalitis
Main causes of primary adrenal insufficiency
- autoimmune (addisons)
- trauma
- infections (TB)
- invasions (neoplastic, sarcoid)
Main causes secondary adrenal insufficiency
- pituitary disorders (tumours, sheehan)
- chronic opiate use
- isolated ACTH deficiency
Main cause (99%) of adrenal insufficiency
long-term glucocorticoid use
Main causes of tertiary adrenal insufficiency
- long term glucocorticoid use
- directly after treating Cushings disease
Pathophysiology of Addison’s (& adrenal insufficiency)
- destruction or inactivation of adrenal layers
- cortisol deficiency
- aldosterone deficiency
- adrenal androgen deficiency
Functions of cortisol
- maintain gluose homeostasis
- immune function
- regulate stress response
Signs of cortisol deficiency
- hypoglycaemia
- increased infections
- impaired stress response
Functions of aldosterone
- regulates Na+ and K+ balance via kidneys
Signs of aldosterone deficiency
- hyponatraemia
- hyperkalaemia
- volume depletion
- orthostatic hypotension
Functions of adrenal androgens
- Maintenance of secondary sexual characteristics
Signs of adrenal androgen deficiency
(more prominent in women, as males have testes producing testosterone)
- reduced body hair
- reduced libido
Main consequence of lost negative feedback from adrenal glands in Addison’s (& primary adrenal insufficiency)
- increased ACTH levels from pituitary
- increased melanocyte-stimulating hormone
- ** hyperpigmentation of the skin**
Clinical features of Addisonian crisis
- hypotension
- hypovolaemic shock
- acute abdominal pain
- fever
- vomiting
- collapse
- hyperkalaemia
Symptoms of chronic adrenal insufficiency
- fatigue and weakness
- anorexia and weight loss
- nausea and vomiting
- ‘salt craving’
- diarrhoea and constipation
- syncope and dizziness
- irritable, confused
Signs of chronic adrenal insufficiency
- hyperpigmentation
- hypotension
- hypoglycaemia
- hyponatraemia
- loss of body hair
Investigating Addison’s disease
Bloods:
- decreased Na+, increased K+
- decreased glucose
- increased ACTH
- adrenal antibodies (anti-21 hydroxylase)
ABG:
- normal gap metabolic acidosis
short synacthen test:
- no increase in cortisol (after giving ACTH)
- indicates primary insufficiency
Short synacthen test
- used to differentiate primary & secondary adrenal insufficiency
- measure cortisol levels then give ACTH
- remeasure cortisol after 30mins
- normal = rise in cortisol
Managing acute adrenal/addisonian crisis
- ABCDE
- aggressive IV fluids
- IM or IV hydrocortisone
Long-term management of primary adrenal insufficiency
combination of hydrocortisone & fludracortisone
patient education crucial
