Adrenal Issues Flashcards
What is Addison’s disease?
Autoimmune destruction of the adrenal glands
What is the commonest cause of hypoadrenalism in the UK
Addison’s disease
Autoimmune destruction of the adrenal glands is the commonest cause of primary hypoadrenalism in the UK, accounting for 80% of cases.
Addison’s disease and results in reduction of which hormones
reduced cortisol and aldosterone being produced.
Which electrolyte disturbances will occur as a result of Addison’s disease?
hyperkalaemia
hyponatraemia
hypoglycaemia
metabolic acidosis
Addison’s disease sx
lethargy, weakness, anorexia, nausea & vomiting, weight loss, ‘salt-craving’
hyperpigmentation (especially palmar creases)*, vitiligo, loss of pubic hair in women, hypotension
crisis: collapse, shock, pyrexia
Addisons disease causes hypo or hyperglycaemia
hypoglycaemia
What are the primary causes of hypoadrenalims?
primary addison's tuberculosis metastases (e.g. bronchial carcinoma) meningococcal septicaemia (Waterhouse-Friderichsen syndrome) HIV antiphospholipid syndrome
What are the secondary causes of hypoadrenalims?
pituitary disorders (e.g. tumours, irradiation, infiltration)
Exogenous glucocorticoid therapy
Hypoadrenalism always causes hyperpigmentation
false
Primary Addison’s is associated with hyperpigmentation whereas secondary adrenal insufficiency is not
In a patient with suspected Addison’s disease the definite investigation is
ACTH stimulation test (short Synacthen test)
Describe ACTH simulation test
Plasma cortisol is measured before and 30 minutes after giving Synacthen 250ug IM. Adrenal autoantibodies such as anti-21-hydroxylase may also be demonstrated.
If an ACTH stimulation test is not readily available (e.g. in primary care) then what test can be useful:
9 am serum cortisol
Describe results of 9am serum cortisol for addisons
> 500 nmol/l makes Addison’s very unlikely
< 100 nmol/l is definitely abnormal
100-500 nmol/l should prompt a ACTH stimulation test to be performed
Patients who have Addison’s disease are usually given what therapy.
both glucocorticoid and mineralocorticoid replacement
hydrocortisone: usually given in 2 or 3 divided doses. Patients typically require 20-30 mg per day, with the majority given in the first half of the day
fludrocortisone
Describe patient education in Addison’s disease?
emphasise the importance of not missing glucocorticoid doses
consider MedicAlert bracelets and steroid cards
patients should be provided with hydrocortisone for injection with needles and syringes to treat an adrenal crisis
discuss how to adjust the glucocorticoid dose during an intercurrent illness
Management of intercurrent illness in addisons?
in simple terms the glucocorticoid dose should be doubled
the Addison’s Clinical Advisory Panel have produced guidelines detailing particular scenarios - please see the CKS link for more deta
Causes of addisonian crisis?
sepsis or surgery
adrenal haemorrhage eg Waterhouse-Friderichsen syndrome (fulminant meningococcemia)
steroid withdrawal
Outline management of addisonian crisis?
hydrocortisone 100 mg im or iv - continue hydrocortisone 6 hourly until the patient is stable.
1 litre normal saline infused over 30-60 mins or with dextrose if hypoglycaemic
No fludrocortisone is required because high cortisol exerts weak mineralocorticoid action
oral replacement may begin after 24 hours and be reduced to maintenance over 3-4 days
Describe the which hormones are released from the parts of the cortex?
Zona glomerulosa – produces and secretes mineralocorticoids such as aldosterone.
Zona fasciculata – produces and secretes corticosteroids such as cortisol. It also secretes a small amount of androgens.
Zona reticularis – produces and secretes androgens such as dehydroepiandrosterone (DHES). It also secretes a small amount of corticosteroids.
What is Cushing’s Syndrome?
is used to refer to the signs and symptoms that develop after prolonged abnormal elevation of cortisol.
What is Cushing’s disease?
specific condition where a pituitary adenoma (tumour) secretes excessive ACTH. Cushing’s Disease causes a Cushing’s syndrome, but Cushing’s Syndrome is not always caused by Cushing’s Disease.
Endogenous are the commonest causes of cushings disease
FALSE
exogenous causes of Cushing’s syndrome (e.g. glucocorticoid therapy) are far more common than endogenous ones.
ACTH dependent causes of cushings?
Cushing’s disease (80%): pituitary tumour secreting ACTH producing adrenal hyperplasia
ectopic ACTH production (5-10%): e.g. small cell lung cancer is the most common causes
ACTH independent causes of cushings?
iatrogenic: steroids
adrenal adenoma (5-10%)
adrenal carcinoma (rare)
Carney complex: syndrome including cardiac myxoma
micronodular adrenal dysplasia (very rare)
