Clinical Aspects of the Adrenal Glands Flashcards
What types of adrenal disorders are there?
- Hyperfunction
- Hypofunction
- Tumours
- Functional symptoms
What is the common approach taken towards adrenal disorders?
clinical suspicion
test for assessing functional status
- is it functioning
- is it primary or secondary
what is the aetiology
- is it a tumour
What questions should you be thinking of if you suspect someone has an adrenal tumour?
- can it be removed
- additional chemotherapy/radiotherapy required
- how can we follow the course of the disease
what can cause adrenal hypofunction
primary adrenal insufficiency
- addison’s disease
adrenal enzyme defects
Give an example of an adrenal enzyme defect which can result in primary adrenal insufficiency.
Congenital adrenal hyperplasia (most commonly 21-hydroxylase deficiency)
What can cause Addison’s disease?
- Immune destruction (auto)
- Invasion
- Infiltration
- Infection
- Infarction
- Iatrogenic
What is the greatest cause of adrenal failure in the UK?
> 85% caused by autoimmune Addison’s
What associated autoimmune diseases are common with Addison’s disease?
- thyroid disease (20%)
- type 1 DM (15%)
- premature ovarian failure (15%)
What pathophysiology is found in Addison’s disease?
- +ve adrenal autoantibodies to 21-OHase
- lymphocytic infiltrate of adrenal cortex
What are the common symptoms associated with Addison’s disease?
- weakness, fatigue, anorexia, weight loss (100%)
- skin pigmentation or vitiligo (92%)
- hypotension (88%)
- unexplained vomiting or diarrhoea (56%)
- salt craving (19 %)
- postural symptoms (12%)
What are the possible clues to the diagnosis of adrenal failure?
- disproportion between severity of illness & circulatory collapse
- unexplained hypoglycaemia
- previous depression or weight loss
- other endocrine features: hypothyroidism, body hair loss, amenorrhoea
What investigations should be carried out for adrenal insufficiency?
routine blood tests
- U+Es
- glucose
- FBCs
random cortisol
- > 450 nmol/l (not Addison’s)
- <450nmol/l (adrenal status uncertain)
syacthen test (and basal ACTH) -If suspicion high & patient unwell, treat with steroids and do Synacthen test later
How should adrenal insufficiency be treated?
glucocorticoid replacement
- given in divided doses to ‘mimic normal diurnal variation’
- hydrocortisone (20-30mg )
- prednisolone (7.5mg)
- dexamethasone (0.75mg)
mineralocorticoid replacement
- fludrocortisone (synthetic steroid)
What is fludrocortisone?
Synthetic steroid
What does fludrocortisone bind to?
Mineralocorticoid (aldosterone) receptors
How should fludrocortisone be administered?
50-300 micrograms daily
adjust dose according to:
- clinical status (postural BP, oedema)
- U&E
- plasma renin level
Who needs special care when it comes to steroids and stress?
- hypoadrenal patients on replacement steroids
- patients on steroids in doses sufficient to suppress the pituitary adrenal axis
- patients who have received such treatment during the previous 18/12
How should patients who require special care be managed with a short lived illness or stress?
Double glucocorticoid dose
How should patients who require special care be managed with a major illness or operation?
- Especially if nil by mouth or GI upset
- 100mg hydrocortisone iv stat
- 50-100mg HC iv 8-hourly
- As stress abates, reduce HC by 50% per day until back on usual replacement dose
What are the 3 important self-care rules for patients on steroids?
- never miss steroid doses
- double the hydrocortisone dose
- if severe vomiting or diarrhoea, call for help without delay
Abnormalities of aldosterone can lead to?
Hypertension
What are the endocrine causes of hypertension?
primary hyperaldosteronism
- unilateral adenoma
- bilateral hyperplasia
rarer causes
- phaeochromcytoma
- cushing’s syndrome
- acromegaly
- hyperparathyroidism
- hypothyroidism
- congenital adrenal hyperplasia
What disorders are associated with hypersecretion of the adrenal cortex
- Cushing’s syndrome
- Conn’s syndrome
What condition is associated with hypersecretion of the adrenal medulla?
Pheochromocytoma
