Adrenal disease Flashcards
Recall the 3 zones of the adrenal gland and what is produced in each one
Zone glomerulosa = aldosterone
Zona fasiculata = cortisol
Zona reticularis = androgens
What are the peripheral and adrenal catecholamines?
Peripheral: Noradrenaline
Adrenal: Adrenaline
Give 2 likely causes of wasted adrenal glands
Addison’s disease
Long term steroid tx
Give 2 likely causes of hyper plastic adrenal glands
Cushing’s disease
Ectopic ACTH
How do the measurements of aldosterone and cortisol differ?
A: PICOmoles
C: NANOmoles (you make 1000x more C than A)
What diagnosis would you suspect in a patient with fatigue and high TSH and low T4?
Primary hypothyroidism
What is Schmidt’s syndrome?
Primary hypothyroisidm + Addisson’s disease
Antibodies against thyroid + adrenals
What’s the test for Addison’s, and how should it be performed?
SynACTHen test
1. Measure cortisol + ACTH
2. 250ug ACTH IM
3. Check cortisol at 30 + 60m
If fail to stimulate = failure of endocrine function
What is the expected electrolyte abnormality in untreated primary adrenal failure?
Hyponatraemia
Hyperkalaemia
(Mineralocorticoid deficiency)
What abnormalities may accompany hyponatraemia and hyperkalaemia in Addisons disease?
Hypoglycaemia (glucocorticoid deficiency)
Low BP (mineralocorticoid deficiency)
What is the treatment for a patient in an addisonian crisis?
IV Saline 0.9% 1L/hr
IV Hydrocortisone
What is the long term treatment for Addisons disease?
Hydrocortisone (Glucocorticoid)
Fludrocortisone (Mineralocorticoid)
What are the 3 differentials to consider when a patient with severe HTN also has an adrenal mass?
- Phaeochromocytoma (medullary tumour secreting adrenalinę)
- Conn’s syndrome (zona glomerulosa tumour: secreting aldosterone)
- Cushing’s (zona fasciculata tumour secreting cortisol)
What test is used to identify pheochromocytoma?
Urinary catecholamines: HIGH
How should phaeochromocytoma be treated?
- IMMEDIATE: Alpha blockers (phenoxybenzamine) causes reflex tachy
- Beta blockers (to deal with reflex tachycardia)
- Surgery
What are the expected aldosterone and renin levels in untreated Conn’s syndrome?
HIGH Aldosterone
LOW Renin
What electrolyte abnormalities would you see in Conn’s syndrome?
HIGH Na
LOW K+
Describe why Renin is suppressed in Conn’s
Adrenal gland autonomously secretes aldosterone
Causes increased Na + water retention + K+ excretion
HTN
Suppresses renin production at JGA
How does treatment differ if Conn’s syndrome is caused by unilateral adrenal adenoma or bilateral adrenocortical hyperplasia?
Unilateral: Surgery
Bilateral: Spironolactone (aldosterone antagonist)
What are the expected aldosterone and renin levels in untreated Cushing’s syndrome?
LOW Aldosterone
LOW Renin
What biochemical abnormalities would you see in Cushing’s syndrome?
HIGH Na
LOW K
HIGH Glucose
What 3 tests can be used to investigate for Cushing’s?
- 9am cortisol (HIGH in ALL)
- Sneaky midnight cortisol (HIGH in CUSHING’s)
- Dexamethosone suppression test (NO ACTH suppression)
What does the term ‘cushing’s disease’ refer to?
Cushing’s syndrome caused by a pituitary tumour secreting ACTH
DISEASE = pituitary DEPENDENT
What is the diagnosis in a patient with symptoms of Cushing’s but a normal result in the low-dose dexamethosone suppression test?
Normal obese person
