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
- Is additional Chemotherapy or radiotherapy required
- How can we follow the course of the disease
What can cause hyposecretion/ 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%)
- T1DM (15%)
- Premature ovarian failure (15%)
What pathophysiology is found in Addison’s disease?
- +ve adrenal autoantibodies (to 21-OHase) in 70% cases
- 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 / hypotension / dehydration
- Unexplained hypoglycaemia
- Other endocrine features (hypothyroidism, body hair loss, amenorrhoea)
- Previous depression or weight loss
What investigations should be carried out for adrenal insufficiency?
- Routine blood tests: U+Es, glucose and FBCs
- Random cortisol
- > 700nmol/l (not Addison’s)
- <700nmol/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
- Hydrocortisone (20-30mg )
- Prednisolone (7.5mg)
- Dexamethasone (0.75mg)
-Given in divided doses to ‘mimic normal diurnal variation’
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 (>7.5mg prednisolone daily, or equivalent)
- Patients who have received such treatment during the previous 18/12 (HPA axis may still be suppressed)
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 in event of intercurrent illness (eg flu, UTI)
- If severe vomiting or diarrhoea, call for help without delay (likely to need IM hydrocortisone - some patients or their partners are taught to inject)
