Adrenal glands disorders Flashcards
Describe the gross anatomy and blood supply of the adrenal glands
retroperitoneal
sit on kidneys
right = pyramidal
left = semilunar
right = has own artery from aorta and has own vein that drains into renal vein
left = has a division of the renal artery and own vein that drains into renal vein
Describe the microscopic appearance of the adrenal glands
layers from outer to inner
capsule
zona glomerulosa
zona fasciculata
zona reticularis
medulla
What does the zona glomerulosa layer of the adrenal gland produce?
mineralocorticoid (aldosterone)
What does the zona fasciculata layer of the adrenal gland produce?
glucocorticoid (cortisol)
What does the zona reticularis layer of the adrenal gland produce?
sex hormones (adrenal androgens)
What does the medulla of the adrenal gland produce?
catecholamine (adrenaline, noradrenaline, dopamine)
What causes high catecholamines?
pheochromocytoma
What causes low cortisol?
adrenal failure
primary:
- Addison’s
- adrenalectomy
- infections
- congenital adrenal hyperplasia
pituitary
exogenous steroid
What causes high cortisol?
Cushing’s syndrome
- adrenal (benign + ca)
- pituitary
- ectopic ACTH
What causes low aldosterone?
adrenal failure
- Addison’s
- adrenalectomy
- infections
- congenital adrenal hyperplasia
What causes high aldosterone?
Conn’s syndrome
Rules of endocrine tests
check hormone level in question if possible
provocation tests:
- suppression test for hormone excess
- stimulation test for hormone deficiency
minimise other interferences:
- diurnal variation
- postural changes
- SNS Stimulation
- medications
What is an addisonian crisis in simple terms?
can’t produce cortisol in response to stress as they taker steroids so when a stressful event happens they are then cortisol deficient and their body cannot deal with the stress
needs steroids urgently
Symptoms of an Addisonian crisis
sudden penetrating pain in lower back, abdomen or legs
severe vomiting + diarrhoea, followed by dehydration
low blood pressure + shock
loss of consciousness
Addisonian crisis management
is suspected:
- take blood and send for later: cortisol, ACTH and adrenal antibody measurement
- 2-3L 0.9% saline and/or colloid to restore BP
- 10% glucose if hypoglycaemic
- hydrocortisone 100 mcg IV
- antibiotics if signs of infection
make diagnosis with 250 micrograms synacthen test
Addison’s disease symptoms/signs
cortisol deficiency
progressive weakness, fatigability
GI disturbance
hyperpigmentation (as ACTH also stimulates melanocytes)
decreased mineralocorticoid activity - hyperkalaemia, hyponatraemia, volume depletion, hypotension
Hypoadrenalism causes
primary chronic hypofunction (rare)
autoimmune adrenalitis (Addison’s)
autoimmune polyendocrine syndrome (APS 1 + 2)
TB
AIDS
metastatic cancer
What can cause massive adrenal haemorrhage?
neonates
anticoagulant therapy
DIC post-surgery
Waterhouse-Friderichsen syndrome
Hyperaldosteronism treatment (Conn’s)
spironolactone (lowers aldosterone, lowers BP, potassium-sparing)
Blood results in Conn’s
hypokalaemia
hypernatraemia
low renin
high aldosterone
aldosterone-renin ratio high
What investigation can be used to work out which adrenal gland is causing hyperaldosteronism?
selective adrenal vein sampling
measures cortisol and aldosterone in adrenal veins
Another name for Conn’s syndrome
primary hyperaldosteronism
What is a phaeochromocytoma?
tumour of the chromaffin cells that secrete unregulated and excessive amounts of catecholamines
What will most patients with phaeochromocytoma also have?
hypertension (often above 180 systolic)
