Adrenal gland clinical Flashcards
Name 2 hypofunction disorders of the adrenal gland
Addison’s disease (primary adrenal insufficiency)
Congenital adrenal hyperplasia (a deficiency in 21-hydroxylase)
Most common cause of Addison’s disease (primary adrenal insufficiency)
Autoimmune destruction of adrenal cortex
-adrenal autoantibodies to 21-hydroxylase
Biochemical investigations of Addison’s disease (5)
Rapid ACTH stimulation test (synacthen test) – synacthen is synthetic form of ACTH so would expect it to stimulate adrenal glands and cause rise in cortisol, however in Addison’s cortisol and aldosterone levels would still be low after synacthen injected
Plasma ACTH - elevated
Adrenal antibodies (to 21-hydroxylase)
Morning serum cortisol - in normal person is high but if low, raises suspicion of addison’s
U and Es - elevated blood urea, low Na+, high K+
Addison’s may be associated with what other autoimmune conditions
Thyroid disease (hypo/hyperfunction) Type 1 DM
Symptoms (5) /signs (3) of Addison’s disease
Symptoms
- fatigue/lethargy
- anorexia
- muscle weakness
- unexplained nausea/vomiting
- low mood/irritable
Signs
- hyperpigmentation (of buccal mucosa, eyes, skin)
- weight loss
- hypotension
- salt craving
What can Addison’s disease do to BG levels + why
Hypoglycaemia
-because of deficient counter-regulatory release of cortisol to insulin
If suspicion of Addison’s diagnosis is high and patient acutely unwell, what should you do
just treat with steroids straight away
If rapid ACTH stimulation test gives a result of low aldosterone and cortisol levels, raises suspicion of adrenal insufficiency further so what test should be done next
Plasma ACTH
- if elevated –> primary adrenal insufficiency (Addison’s disease)
-if suppressed –> secondary adrenal insufficiency
Treatment of Addison’s disease (2)
Corticosteroid replacement for life
- oral hydrocortisone (to replace cortisol)
- oral fludrocortisone acetate (to replace aldosterone)
+/-extra salt in diet
Why is the hydrocortisone treatment given for Addison’s disease given in divided doses (2 tablets a day; morning dose higher)
To mimic normal diurnal variation
-as cortisol levels are higher in morning
Being on high dose steroids can do what to the adrenal gland
Suppress the hypothalamic pituitary adrenal axis, so stopping adrenal gland from producing hormones so body just relies on synthetic steroids
What patients are most vulnerable in times of physiological stress (2)
Adrenal hypofunction patients (i.e. Addison’s disease or secondary adrenal insufficiency) on replacement steroids
Patients on steroid dose sufficient to suppress hypothalamic pituitary adrenal axis
Guidelines for management of patients on replacement (synthetic) steroids due to adrenal hypofunction
- during acute illness/acute physiological stress
- during major illness/operation
Acute illness/ acute physiological stress
-double glucocorticoid dose (i.e. double hydrocortisone)
Major illness or operation
- IV hydrocortisone 100mg
- as stress decreases, reduce hydrocortisone dose by 50% per day until back on usual replacement dose
3 self care rules for patients on steroids
Never miss medication
Double hydrocortisone dose in event of acute illness (flu, uTI etc)
If severe vomiting or diarrhoea, go to hospital as likely going in adrenal crisis)
Name the 2 hyperfunction syndromes of the adrenal cortex
Cushing’s syndrome,
Conn’s syndrome
Endocrine causes of hypertension (7)
Conn's syndrome Cushing's syndrome Pheochromocytoma Acromegaly Hyperparathyroidism Hypothyroidism Congenital adrenal hyperplasia
Name a cause of hyperfunction of the adrenal medulla
Pheochromocytoma
Causes of Cushing’s syndrome (4)
Benign pituitary adenoma secreting ACTH (cushing’s disease)
Adrenal adenoma/carcinoma/bilateral hyerplasia causing excess cortisol production
Ectopic ACTH secreting tumour
Long term iatrogenic corticosteroid therapy
Clinical features of Cushing’s syndrome (13)
Symptoms
-mood swings - irritable, depressed
Signs
- weight gain - CENTRAL obesity
- facial plethora (round + red - ‘MOON FACE’)
- buffalo hump - fat in back of neck and shoulders)
- proximal muscle weakness
- thin arms/legs compared to trunk
- decreased sex drive
- skin thinning/atrophy
- hirsutism
- osteoporosis
- purpura (red/purple patches on skin)
- purple striae
- easy bruisability
What does a cushingoid appearance refer to
when therapeutic corticosteroids have caused a cushing’s syndrome-like symptoms/signs