Adrenal Insuffiency Flashcards
What is adrenal insuffiency?
Where the adrenal glands do not produce enough of the steroid hormones cortisol and aldosterone
What is primary adrenal insuffiency?
Where damage to the adrenal glands results in a lack of cortisol and aldosterone
What is the most common cause of primary adrenal insuffiency?
Autoimmune conditions
What is secondary adrenal insuffiency?
A lack of ACTH leads to a lack of stimulation of the adrenal glands, and less cortisol.
It is usually as a result of damage to the pituitary gland
What is tertiary adrenal insufficiency?
Tertiary adrenal insufficiency is a result of a lack of CRH (corticotrophin releasing hormone) from the hypothalamus
What is the most common cause of tertiary adrenal insufficiency?
Long term steroid use causes suppression of the hypothalamus
Why does tertiary adrenal insufficiency occur with long term steroid use?
When steroids are withdrawn, the hypothalamus cannot make endogenous steroids quick enough
What is the presentation of adrenal insufficiency?
Fatigue
Muscle weakness
Muscle cramps
Thirst and salt craving
Dizziness
Weight loss
Abdominal pain
Depression
What are the physical signs of adrenal insufficiency?
Bronze pigmented skin
Hypotension (specifically postural hypotension
Why does adrenal insufficiency cause bronze pigmented skin?
Excessive ACTH stimulated melanocytes to produce melanin
What biochemical findings may be seen in adrenal insufficiency?
Hyponatraemia
Hyperkalaemia
Hypoglycaemia
Raised creatinine and urea (dehydration)
Hypercalcaemia
What is the investigation of choice for diagnosis of adrenal insufficiency?
Short synacthen test
What antibodies may be present in primary adrenal insufficiency?
Adrenal cortex antibodies
21-hydroxylase antibodies
How is the short synacthen test performed?
Synthetic ACTH (synacthen) is given - blood cortisol is tested after 30 and 60 minutes
Failure of cortisol levels to double indicates primary adrenal insufficiency (or secondary insufficiency that has caused significant adrenal atrophy)
What is the first line management of adrenal insufficiency?
Hydrocortisone to replace cortisol
Fludrocortisone to replace aldosterone
