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Flashcards in Management of adrenal failure Deck (29)
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1
Q

What are the clinical features of cortisol?

A
Too much cortisol (always high)
Centripetal obesity
Moon face and buffalo hump
Proximal myopathy
Hypertension and hypokalaemia
Red striae, thin skin and bruising
osteoporosis, diabetes
2
Q

What are the causes of Cushing’s?

A

Taking too many steroids
Pituitary dependent Cushing’s disease
Ectopic ACTH from lung cancer
adrenal adenoma secreting cortisol

3
Q

How is Cushing’s diagnosed?

A

24 h urine collection for urinary free cortisol
Blood diurnal cortisol levels
(cortisol’s usually highest at 9am and lowest at midnight, if asleep)
Low dose dexamethasone suppression test

4
Q

How does the Low dose dexamethasone suppression test work?

A

Potent glucocorticoid should suppress cortisol

Give 1/2 mg 6 hourly for 48 hours

Cortisol would be zero the next day if normal

Does not tell you what type of Cushing’s they have

5
Q

What drugs can be given to treat Cushing’s?

A

Enzyme inhibitors

Receptor blocking drugs

6
Q

Which drugs inhibit steroid biosynthesis?

A

Metyrapone

Ketoconazole

7
Q

What is the action of Metyrapone?

A

Inhibition of 11b-hydroxylase

steroid synthesis in the zona fasciculata [and reticularis] is arrested at the 11-deoxycortisol stage

11-deoxycortisol has no negative feedback effect on the hypothalamus and pituitary gland.

8
Q

How do we control cortisol prior to surgery?

A

adjust dose (oral) according to cortisol (aim for mean serum cortisol 150-300 nmol/L)

improves patient’s symptoms and promotes better post-op recovery (better wound healing, less infection etc)

9
Q

What are the side effects of metyrapone?

A

high blood pressure

high testosterone

10
Q

What was the main use of Ketoconazole?

A

main use as an antifungal agent – although withdrawn in 2013 due to risk of hepatotoxicity

at higher concentrations, inhibits steroidogenesis – off-label use in Cushing’s syndrome

11
Q

What is the mechanism of action for Ketoconazole?

A

Inhibition of 17-hydroxylase

12
Q

Summarise the invasive treatments for Cushing’s?

A

Depends on cause
Pituitary surgery (transsphenoidal hypophysectomy)
Bilateral adrenalectomy
Unilateral adrenalectomy for adrenal mass

13
Q

Summarise the medical treatments for Cushing’s?

A

Metyrapone

Ketoconazole

14
Q

What are the side effects of Ketoconazole?

A

Liver damage - possibly fatal - monitor liver function weekly, clinically and biochemically

15
Q

What causes Conn’s syndrome?

A

Benign adrenal cortical tumour (zona glomerulosa)
Aldosterone in excess
Hypertension and hypokalaemia

16
Q

How do you diagnose Conn’s syndrome?

A

Primary hyperaldosteronism

Renin - angiotensin system should be suppressed (exclude secondary hyperaldosteronism)

17
Q

What are the treatment’s for Conn’s syndrome?

A

spironolactone, epleronone

18
Q

What is the mechanism of action for spironolactone?

A

Converted to several active metabolites, including canrenone, a competitive antagonist of the mineralocorticoid receptor (MR).

Blocks Na+ resorption and K+ excretion in the kidney tubules (potassium sparing diuretic).
Therefore also used by cardiologists as a hypertensive

19
Q

What are the side effects of spironolactone?

A
Menstrual irregularities (+ progesterone receptor)
Gynaecomastia (- androgen receptor)
20
Q

What are the main features of epleronone?

A

Also a mineralocorticoid receptor (MR) antagonist
Similar affinity to the MR compared to spironolactone
Less binding to androgen and progesterone receptors compared to spironolactone, so better tolerated

21
Q

What are phaeochromaocytomas?

A

These are tumours of the adrenal MEDULLA which secrete catecholamines
(adrenaline and nor-adrenaline)

22
Q

What are the effects of phaeochromaocytomas?

A
Blood pressure elevation
Increased cardiac output
BMR elevation
Bronchodilation
Glycogenolysis 
Hyperglycaemia
CNS excitability
23
Q

What are the clinical features of phaeochromaocytomas?

A

Intermittent episodes of high BP (after abdominal palpitation)

As the tutor gets bigger they will have more attacks

Hypertension in young people

More common in certain inherited conditions

24
Q

When do patients with phaeochromaocytomas present?

A

They just think they are having unexplained panic attacks

It is only when they collapse that the tumour is discovered

25
Q

What can phaeo’s cause?

A

Hypertension in young people
Episodic severe hypertension (after abdominal palpation)
More common in certain inherited conditions

26
Q

How do you manage a phaeo?

A

Eventually need surgery, but patient needs careful preparation as anaesthetic can precipitate a hypertensive crisis

Needs to prepped for surgery

27
Q

How to prep a patient for a phaeo surgery?

A

Alpha blockade is first therapeutic step

Patients may need intravenous fluid (to maintain BP) as alpha blockade commences

Beta blockade added to prevent tachycardia

28
Q

What happens the weekend before a surgery for phaeo?

A

High does alpha blockade in hospital

By the surgery they have absolutely no adrenal function

29
Q

What are some key facts about phaeochromocytoma’s?

A

10 % extra-adrenal (sympathetic chain)
10 % malignant
10 % bilateral
Phaeo’s are extremely rare