adrenal disorders Flashcards
(30 cards)
autoimmune destruction of adrenal glands
70% of cases have another autoimmune disorder
primary and secondary adrenal insufficiencies requires lifelong treatment with
steroid replacement
what does tertiary adrenal insufficiency develop from
long term use of exogenous steroids
This required careful management to prevent patients from developing signs of hypoadrenalism
what is adrenal over activity called?
cushings
predominantly treated surgically
Adrenal glands are situated where
above kidneys
the inner medulla is part of
sympathomimetic nervous system and is responsible for synthesising and secreting catecholamines
the outer cortex
is involved in producing steroids hormones and is divided into
- the zona glomerulosa - secretes aldosterone n response to hyperkalaemia, hyponatraemia and RAAS
- the zona fasciculate - secretes cortisol
- the zona retucularis
Primary adrenal insufficiency
Addison’s disease
caused by damage to the adrenal gland itself
deficient of all three hormonesL aldosterone, cortisol and to a lesser extent androgens
Caused by autoimmune or infections for example TB
Diagnosis - low morning cortisol ( we want >300) followed by a short synacthen test. (test 30 mins after we wants >450)
what do we use to treat primary adrenal insufficiency?
Hydrocortisone TDS usually
lowest dose possible e.g. 10, 5, 5
largest dose AM mimics body natural release of hormone
when is fludrocortisone used
to treat mineralcotricoid deficiency only in primary adrenal insufficiency at doses of 50-200mcg/day
not used in secondary as only cortisol is impaired
general recommendations:
- glucocorticosteroid dose should be doubled if a patient has a fever or prescribed ABX
- hydrocortisone 20mg should be taken by mouth with oral fluids if they feel nauseated
- parenteral hydrocortisone should be self administered and get advice if vomit
- hydrocortisone 20mg given in event of major injury
- diarrhoea - get help
- strenuous exercise - increase dose up to double
- less strenuous 50-10mg HCS before activity
Secondary adrenal insufficiency
inadequate secretion of ACTH (adrenocorticotrophic hormone) regulated the levels of cortisol. So results in deficient cortisol.
Caused by tumours, irradiation, infection, genetic
They do not get salt craving or low sodium or low potassium in this one.hyperpigmentation is also absent.
How do we test for this compared to primary
long synacthen test
measure cortisol for 24 hours
Same treatment as primary however fludrocortisone is not required as aldosterone is not affects here
Tertiary adrenal insufficiency
suppression of CRH secretion from the hypothalamus
main cause is long term use of high dose exogenous glucorticosteroids.
Occurs in patients wish bushings and is sometimes drug induced
manage by gradual withdrawal of steroid
adrenal crisis management
- hydrocortisone 100mg IV or IM - aggressive fluids
follow by IV hydrocortisone 50-100mg every 6 hours or by continuous IV infusion 200mg over 24 hours.
fludrocortisone is not required here as high doses of hydrocortisone have an appropriate mineralocorticoid effects
hydrocortisone IV
hydrocortisone sodium succinate is preferred due to the pain and parasthesia associated with the sodium phosphate injection.
clinical features of cushings
- moonfaced, weight gain
- violaceous striae
- muscle weakness
- bone fracture/osteoporosis
- impaired glucose tolerance/ DM
- susceptibiltiy to infections
- mood disturbances
- acne/hirtuism
- low libido/impotence/menstrual disturbance
how to test for cushings
dexamethasone suppression tes
oestrogen can interfere with this.
1mg of deb administered at 11pm with cortisol measured at 9am. If cortisol <50 then the patient has shown adequate suppression and does not have bushings
long dexamethasone suppression test
500microgram at strict 6 hour intervals for 2 days starting at 9am
cortisol is measured at the beginning and at 48 hours.
This test is more accurate
how do we treat bushings
surgery
metyrapone 250mg TDS (inhibits cortisol and aldosterone synthesis) - can increase testosterone
ketoconazole 400-600mg (divided) titrated to a max 1200mg daily dose. - hepatotoxicity
if LFT’s are > 3 times upper limit what do we do
STOP
if it is less we can monitor closer
Signs and symptoms of adrenal insufficiency - PRIMARY
- weak / fatigue
- anorexia/weight loss
- N and V
- constipation, diarrhoea, abdo pain
- dizziness, syncope
- hyperpigmintation
- salt craving
- hyponatraema
- hyperkalaemia
Thinking of the skin is due to
Adrenal overactivity
Hypotension is caused by
adrenal insufficiency