Adrenal disorders Flashcards
name a condition that affects the production of each of the adrenal hormones.
aldosterone - Conn's cortisol - cushings (hyperfunction) cortisol - addisons (hypofunction) sex hormones - congenital adrenal hyperplasia epinephrine - phaeochromocytoma
what is the cause of Conn’s syndrome?
over production of aldosterone caused by a tumour of the pituitary gland
what is the presentation of a paeochromocytoma?
episodic / paroxysmal attacks;
- palpitations
- sweating
- pallor
- headache
- tremor
- anxiety / fear
what is the most common cause of addison’s disease?
autoimmune destruction of the adrenal glands
what is the presentation of Addison’s disease?
fatigue weakness anorexia / weight loss salt craving unexplained vomiting or diarrhoea postural symptoms hypotension skin pigmentation / vitiligo
what is commonly associated with Addisons disease?
other autoimmune conditions because if you have one your are likely to have another such as;
- type 1 diabetes
- thyroid disease (hashimotos)
- premature ovarian failure
when carrying out a random cortisol if there is suspicion of addisons disease, what values would suggest addisons or not?
> 700 nmol/L = not addisons
< 700 nmol/L (adrenal status still uncertain but may be addisons)
what is the name of the confirmatory test for diagnosing addisons?
Synacthen test
what is the treatment for addisons?
hydrocortisone therapy 20-30mg
- given in divided dose i.e. 20mg in the morning and 10mg at dinner time
prednisolone 7.5mg
dexamethasone 0.75mg
mineralocorticoid therapy - flurocortisone 50-300mg (resolve the hypotension & hyponatraemia)
why can addison’s cause hypotension and salt cravings?
with cortisol insufficiency from the hypofunctioning adrenal gland , it can also cause hypo secretion of mineralocorticoids - aldosterone
what are the causes of cushings syndrome?
pituitary tumour
actopic ACTH secretion from lung carcinoma
adrenal tumour
corticosteroid therapy
what is the presentation of cushings syndrome?
central obesity muscle atrophy proximal weakness pink striae moon face hypertension hyperglycaemia - diabetes mellitus poor wound healing osteoporosis hirsutism amenorrhoea / galactorrhoea acne personality changes / depression
how would you screen for curhsings syndrome?
24 hour urine free cortisol
1mg overnight dexamethasone test
what results in the tests of low dose and high dose dexamthasone would be suggestive of cushings disease (tumour in the pituitary)?
with a low dose dexamthasone the cortisol levels are still high - doesnt respond
but it responds to high levels as the cortisol levels will derease
what is the plasma renin activity (PRA) and plasma aldosterone concentration (PAC) like in someone with conn’s syndrome?
plasma renin decreased
plasma aldosterone raised
if there is increased plasma renin activity and increased plasma aldosterone concentration, what would you investigate next to come to a diagnosis?
increased PRA & PAC = secondary hyperaldosteronism
investigate for causes such as renovascular hypertension, coarctation of aorta, diuretic use, malignant hypertension etc
(causes of secondary hypertension that isnt caused by an endocrine condition)
what could be the cause of a decreased plasma renin activity and a decreased plasma aldosterone concentraion?
congenital adrenal hyperplasia
what tests would you carry out to establish the source of the over production of aldosterone ? (after PRA and PAC has been carried out)
CT scan of adrenal glands
upright posture test
adrenal venous sampling
24 hour urine aldosterone and sodium
why is a phaeochromocytoma termed as the 10% tumour?
10% malignancy 10% extra adrenal 10% multiple 10% hyperpglycaemia but 30% has an inherited origin
what are the first 2 tests you carry out if your suspect adrenal insufficiency?
plasma cortisol ( < 700nmol/L) synACTHen test ( < 500 mmol/L)
how do you differentiate whether the low cortisol is due to primary adrenal insufficiency or secondary?
plasma ACTH levels
low ACTH = secondary
high ACTH = primary
what tests would you carry out to investigate the cause of primary adrenal insufficiency?
MRI adrenal glands - tumour, infarction, haemorrhage, infection
serum antibodies- Addison’s, anti 21 hydroxylase, other autoimmune conditions
screen for rarer causes such as HIV, TB, secondary malignancy
how long is a patient on steroid therapy for it to suppress their pituitary adrenal axis?
> 7.5mg prednisolone daily for 3 weeks
what adjustments do people on steroid therapy (due to adrenal insufficiency) have to make if they have vomiting/diarrhoea?
IM injection of hydrocortisone
not allowed to do it themselves
