Case 16 - Adrenal Disorders Flashcards
What is Cushing’s syndrome?
High glucocorticoid (cortisol) levels
What are the symptoms of Cushing’s syndrome?
Rapid weight gain
Mood change
Proximal weakness
Acne
What are the signs of Cushing’s syndrome?
Central obesity Moon face Buffalo neck hump Skin and muscle atrophy Bruises Abdominal striae Osteoporosis Increased BP Increased Glucose
What are the different causes of Cushing’s syndrome?
Cushings disease (ACTH secreting pituitary tumour)
Ectopic ACTH releasing tumour, e.g, small cell lung cancer, carcinoid
Adrenal tumour secreting excess cortisol
Long term glucocorticoid (steroid) use e.g, prednisolone
Why do patients with cushings get high glucose levels?
High levels of cortisol can cause insulin resistance
What is Dexamethasone?
How is it used in the suppression test?
Exogenous steroid similar to cortisol
Suppress the production of ACTH from the pituitary gland using negative feedback, therefore reducing cortisol production
What will the Dexamethasone suppression test results be in patients with cushings disease (pituitary gland tumour)
Low dose Dexamethasone - no reduction in cortisol
High dose Dexamethasone - some reduction in cortisol
What will the Dexamethasone test results be in patients with an ectopic ACTH secreting tumour or an adrenal tumour?
Low dose Dexamethasone - no reduction in cortisol
High dose Dexamethasone - no reduction in cortisol
When should you refer obese patients to tertiary care?
If the cause of being obese needs to be assessed
If conventional treatment has been unsuccessful
Specialist interventions
Surgery is being considered
Which patients should be considered for bariatric surgery
BMI >40, or between 35-40 with diabetes/hypertension
All non surgical measures have been tried
The person has been receiving intensive management in tier 3 service
They are fit for anaesthesia and surgery
What is the treatment for cushings disease (ACTH secreting pituitary Tumour)?
Pituitary surgery - to remove tumour
What is conns?
Hyperaldosteronism - over production of aldosterone mainly caused by a solitary aldosterone producing adeoma in the adrenal cortex
What are the symptoms of hyperaldosteronism?
Hypertension
Hypokalaemia
What hormones does the pituitary gland release?
Growth hormone FSH, LH Prolactin TSH ACTH
What important structure anterior to the pituitary gland can become compressed?
What might this result in?
Optic chiasm
Bilateral temporal hemianopia
What is Addison’s disease?
Autoimmune disease resulting in an underproduction of glucocorticoids and mineralcorticoids from the adrenal gland
How is Addison’s disease diagnosed?
Short synacthten test (uses synthetic ACTH to try and stimulate cortisol release from adrenal gland)
If you have Addison’s then you won’t release a lot of cortisol
What are the important things to note for patients on long term hydrocortisone (Steroid)?
Steroid card (and wristband) incase they are in an accident so can get early steroid treatment Cortisol levels must be measured regularly When ill (flu, take a double dose)
What is the presentation of an adrenal (Addison’s) crisis?
Hypotension
Hyponatraemia
How do you treat an Addison’s crisis?
High dose IV hydrocortisone
What is metyrapone?
Which enzyme does it inhibit?
Cortisol synthesis inhibitor
11 beta-hydroxylase
What tests can be used in screening for cushings?
Urinary free cortisol
Late night salivary cortisol
Low dose overnight dexamethasone - won’t reduce cortisol
48 hour low dose dexamethasone suppression test
Which test can differentiate between pituitary and adrenal cushings?
Plasma ACTH levels
Pituitary - will be high
Adrenal - will be low
What investigation would you do if ectopic ACTH excess was suspected and why?
Chest X-ray (to rule out small cell lung cancer)
