Adrenal Disease Flashcards
what does the adrenal medulla secrete?
catecholamines
name two catecholamines
noradrenaline
adrenaline
name two adrenal androgens
DHEA
androstenedione
what is the starting point for steroid hormones produced by the adrenal glands?
cholesterol
what regulates production of aldosterone?
RAAS
plasma potassium
what are the three main clinical uses for corticosteroids?
suppress inflammation
suppress the immune system
replacement treatment
what are the three routes of administration of corticosteroids?
oral
IM
IV
what is adrenal insufficiency?
when there is inadequate adrenocortical function
what are the two types of adrenal insufficiency?
primary
secondary
what causes primary adrenal insufficiency?
disorders of the adrenal gland
addison’s. CAH, adrenal TB/malignancy
what causes secondary adrenal insufficiency?
lack of ACTH production
steroids, pituitary disease, hypothalamic disease
what is addison’s disease?
autoimmune destruction of the adrenal cortex
how does addison’s present? (5)
anorexia fatigue dizziness abdominal pain skin pigmentation
what is the most common cause of primary adrenal insufficiency?
addison’s disease
what biochemistry should raise suspicion of adrenal insufficiency?
low sodium
high potassium
hypoglycaemia
what is the diagnostic test for adrenal insufficiency?
short synacthen test
what does a short synacthen test involve?
measure plasma cortisol before and then 30 mins after an ACTH injection
what is a normal result from a short synacthen test?
baseline >250
post ACTH >550
what are ACTH levels like in addison’s disease?
raised
what causes the skin pigmentation in addison’s disease?
raised ACTH
what are renin and aldosterone levels like in addison’s disease?
increased renin
reduced aldosterone
what is the management of primary adrenal insufficiency?
hydrocortisone
fludrocortisone
what is cushing’s syndrome?
excess cortisol secretion
what group is cushing’s syndrome more common in ?
women aged 20-40
name five clinical features of cushing’s syndrome
bruising striae obesity thin skin proximal myopathy
what are the three categories of causes of cushing’s syndrome?
ACTH dependent
ACTH independent
iatrogenic
name two ACTH dependent causes of cushing’s syndrome
cushing’s disease
ectopic ACTH/CRH
what is cushing’s disease?
a pituitary adenoma secreting excess ACTH
what is the gold standard test for cushing’s syndrome?
low dose dexamethasone suppression test
what happens in a low dose dexamethasone suppression test?
patient takes 0.5mg of dexamethasone every 6 hours for 48 hours
what is a normal result for a low dose dexamethasone suppression test?
cortisol suppressed to less than 50 at the end of the test
what is the most common cause of cushing’s syndrome?
iatrogenic - due to prolonged steroid therapy
what is primary aldosteronism?
autonomous production of aldosterone
what is the most common cause of secondary hypertension?
primary aldosteronism
what are the three main clinical features of primary aldosteronism?
hypertension
hypokalaemia
alkalosis
what are the two main causes of primary aldosteronism?
adrenal adenoma
bilateral adrenal hyperplasia
what is an adrenal adenoma causing primary aldosteronism called?
conn’s syndrome
how is primary aldosteronism diagnosed?
confirm aldosterone excess
confirm cause
how is aldosterone excess confirmed in primary aldosteronism?
measure the aldosterone:renin
saline suppression test = failure to suppress by >50% = PA
how is conn’s syndrome cured?
surgical removal
how is bilateral adrenal hyperplasia causing primary aldosteronism treated?
mineralocorticoid antagonists (spironolactone or eplerenone)
what causes congenital adrenal hyperplasia?
deficiency in an enzyme needed for cortisol synthesis
what is the most common cause of congenital adrenal hyperplasia?
21a-hydroxylase deficiency
how is congenital adrenal hyperplasia inherited?
autosomal recessive pattern
what does a 21a-hydroxylase deficiency result in?
blocks production of cortisol and aldosterone
increased androgens
what are the two types of congenital adrenal hyperplasia?
classic
non classic
when does classic congenital adrenal hyperplasia present?
infancy
how can classic congenital adrenal hyperplasia present?
adrenal crisis or adrenal insufficiency
virilization
what causes non classic congenital adrenal hyperplasia?
partial 21a-hydroxylase deficiency
when does non classic congenital adrenal hyperplasia present?
adolescence/adulthood
how does non classic congenital adrenal hyperplasia?
hirsutism
menstrual issues
infertility
how is congenital adrenal hyperplasia diagnosed?
measure 17-OH progesterone
how is congenital adrenal hyperplasia managed?
steroid replacement
what are catecholamines derived from?
tyrosine
where are catecholamines secreted?
adrenal medulla
how does pheochromocytoma present?
hypertension
postural hypotension
paroxysmal sweating, headache, pallor and tachycardia
can be asymptomatic
what is a pheochromocytoma called if it is extra adrenal?
paraganglionoma
these are found in the sympathetic chain
how can pheochromocytoma be fatal?
arrythmia
ischaemia
how is pheochromocytoma diagnosed?
urine or plasma catecholamine measurement
MRI
what is done prior to surgery for pheochromocytoma?
alpha blockade followed by beta blockade
what alpha blocker is given prior to pheochromocytoma surgery?
phenoxybenzamine
what beta blocker is given prior to pheochromocytoma surgery?
propranalol, atenolol or metoprolol
what is the treatment of choice for pheochromocytoma?
laparoscopic surgical excision