adrenal disorder 2

Question 1

What rhythm does cortisol have. When should they take a sample to test for high cortisol?

Answer 1

Diurnal. Midnight - it should normally be low, but if its high cushings.

Question 2

When are big adrenal glands present?

Answer 2

any cause of cushings

Question 3

What are clinical features of cushings?

Answer 3

Centripetal obesity, fat pads, moon face, buffalo hump, proximal myopathy, hyperglycaemia, hypertension & hypokalaemia, osteoporosis, easy bruising, diabetes

Question 4

What are causes of cushings?

Answer 4

1. pituitary dependent cushings disease 2. ectopic ACTH (lung cancer), adrenal adenoma secreting cortisol, taking too many glucacorticoids by mouth

Question 5

What are investigations used for cushings?

Answer 5

1. 24h urinary free cortisol, 2. blood diurnal cortisol levels (wont go down in cushings) 3. low dose dexamethosone suppression test (LDDST): give low dose dexamethosone (glucocorticoid) 0.5mg 6 hourly 48 h - normally the pituitaty will feed back to decrease cortisol production to zero, but in cushings it will not go to zero.

Question 6

What is needed for a daiganosis of cushings?

Answer 6

Basal (9am) cortisol of 800nM, end of LDDST - 690 nM (normally should be zero)

Question 7

What types of drugs can be used to manipulate steroids

Answer 7

Enzyme inhibitors, receptor blockers

Question 8

What kind of surgery can be used for cushings?

Answer 8

Transphenoidal pituitary surgery, adrenalectomy (bilateral or unilateral)

Question 9

What is in excess in cushings syndrome? What drugs could be used?

Answer 9

Cortisol in excess. Metyrapone, ketoconazole (steroid synthesis inhibitors)

Question 10

What is in excess in conns syndrome? What drugs could be used?

Answer 10

Aldosterone in excess. Spironolactone or epleronone (Mineralocorticoid receptor antagonists)

Question 11

What does metyrapone do? When is it used? What dose? What are its effects? Unwanted actions?

Answer 11

Metyrapone inhibits 11-hydroxylase (which converts 11-deoxycortisol to cortisol) so excess 11-deoxycortisol which has no negative feedback onto pituitary. Used to control patients symptoms before surgery or radiotherapy. Adust dose to reach serum level cortisol 150-300. unwanted actions include hypertension and hirsutism in the long-term

Question 12

What is difference between cushings syndrome and disease?

Answer 12

Cushings syndrome is any cause of high cortisol but cushings disease is pituitary dependent cushings syndrome.

Question 13

What does ketoconazole do? Unwanted actions? What must be done when on this drug?

Answer 13

Ketoconazole is an antifungal that at higher levels inhibits steroidogenesis. But it causes hepatotoxicity. Used for treatment and preparation before surgery. Hepatotoxic so liver function must be monitored.

Question 14

What is treatment of cushings? What does it depend on?

Answer 14

Treatment for cushings depends on the cause. Surgical –> transphenoidal hypophysectomy, unilateral/bilateral adrenectomy. Medical –> drugs (metyrapone, ketoconazole)

Question 15

What is conns syndrome? What are the effects?

Answer 15

Conns syndrome is a benign adrenal cortical tumour in the zona glomerulosa of the adrenal gland making too much aldosterone. The effects include hypertension, low K (hypokalaemia)

Question 16

What should be excluded in conn’s diagnosis?

Answer 16

Conn’s is primary hyperaldosteronism. Must exclude secondary hyperaldosteronism (problems in the renin-angiotensin system)

Question 17

What does spironolactone do in the body? What are unwanted actions?

Answer 17

Spironolactone is a mineralocorticoid receptor antagonsit that binds to the kidney in order to prevent the actions of aldosterone, therefore inhibiting sodium reabosprtion. The unwanted actions arise because it also binds androgen receptors and progesterone receptors causing menstural irregularities and gynaecomastia.

Question 18

What does epleronone do? How is it different to spironolactone?

Answer 18

Epleronone is also a mineralocorticoid receptor antagonist but it is different to spironolactone because is more weakly binds the androgen/progesterone receptors so is better tolerated.

Question 19

What are phaeochromocytomas? What do they cause?

Answer 19

Phaechromocytomas are tumours of the adrenal medulla that secrete catecholamines (adrenaline, noradrenaline) every time they degranulate. They degranulate when poked or electrically stimulated during fight or flight. Then they release large amounts of catecholamines and can lead to sudden death/heart attack.

Question 20

What are clinical features of phaeochromocytomas?

Answer 20

The clinical features are hypertension in young people, severe episodic hypertension (after abdominal palpation). Severe hypertension can cause MI or stroke. High adrenaline can cause ventricular fibrillation and death. Medical emergency

Question 21

How is phaeochromocytoma managed?

Answer 21

Ultimately they will need surgery but need careful preparation as the anaesthetic can cause a hypertensive crisis. First need alpha blockage in order to block the effects of adrenaline. To prevent hypotension may need IV fluids. Then given beta blockade to prevent tachycardia.

Question 22

Where are phaeochromocytomas found? Are they benign? Are they bilateral?

Answer 22

Most are adrenal but some are extra-adrenal found in sympathetic chains. Some are malignant and some are bilateral.