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BRS YEAR 2 > Endo - Adrenal Disorders 2 > Flashcards

Endo - Adrenal Disorders 2 Flashcards

1
Q

Describe the rhythm of cortisol?

A

Diurnal rhythm

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2
Q

What is a the concentration of cortisol at its peak

A

428nM

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3
Q

What is the concentration of cortisol at its lowest

A

55nM

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4
Q

When should we check if cortisol is too low

A

We should check it in the morning when it is meant to be highest ie 9am

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5
Q

What may affect cortisol rhythm

A

Nightshift workers or people with altered body clock will have e different times as to when cortisol peaks

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6
Q

What are the symptoms of Cushing’s?

A 
Centripetal obesity
Moon face
Purple striae
Proximal myopathy 
Buffalo dumb between shoulders
Hypertension
Hypokalaemia 
Thin skin
Bruising 
Diabetes
Osteoporosis Pitting oedema
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7
Q

What are the causes of Cushings

A

Steroid use
Pituitary dependent Cushing’s disease
Ectopic ACTH from lung cancer
Adrenal adenoma

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8
Q

What are the steps to investigating Cushings

A

Establish a source for potential Cushings
24 hour urine collection for urinary free cortisol
Blood diurnal cortisol levels - measured at different times over the day/night

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9
Q

Outline a LDDST

A

Low dose dexamethasone suppression test - this is a glucocorticoid with fluoride therefore we give 0.5mg every 6 hours for 48 hours to see if cortisol production is suppressed due to negative feedback (ACTH should go down) - If cortisol doesn’t go to 0 then there is Cushings

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10
Q

What do we need to know before we start treating Cushings

A

We need to know where the source of Cushings is

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11
Q

What must be done before an operation for Cushings

A

We must reduce cortisol via pharmacological manipulation of steroids

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12
Q

What are examples of enzyme inhibitors?

A

Metyrapone

Ketoconcazole

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13
Q

What are examples of receptor blockers

A 
Spironolactone
Epleronone 
(Both block aldosterone receptors)
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14
Q

How does metyrapone work?

A

Blocks 11-Beta-Hydroxylase therefore blocks the conversion of 11-deoxycortisol to cortisol. There is no negative feedback therefore this works well.

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15
Q

How do we adjust dosage of metyrapone?

A

Aim for a serum cortisol of 150-300nmol/L

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16
Q

When is metyrapone used?

A

Used after radiotherapy for Cushings

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17
Q

What are the side effects of metyrapone?

A

We get increased adrenal androgen production therefore hirsutism in women.
We also get a build up of 11-dexoycorticosterone as it cannot be converted to aldosterone therefore we get hypertension (however, some 11-deoxycorticosterone is converted to aldosterone via aldosynthase)

18
Q

How does ketoconazole work?

A

Antifungal drug that blocks 17-alpha-hydroxyalse therefore inhibiting cortisol production

19
Q

What is a possible side effect of ketoconazole?

A

Risk of hepatotoxicity as it is an antifungal - at a higher concentration it inhibits steroidogenesis

20
Q

What surgery can be used for Cushings disease from the pituitary?

A

Transphenoidal hypophysectomy

21
Q

What Cushings surgery may we use if there is ectopic ACTH from lung cancer?

A

Bilateral adrenalectomy

22
Q

What surgery can be used for a one sided adrenal mass?

A

Unilateral adrenalectomy

23
Q

Is surgery preferred over drugs?

A

Yes

24
Q

What is Conn’s syndrome?

A

Benign tumour of the glomerulus therefore we get unregulated production of aldosterone

25
Q

What should we do if we ever find a high blood pressure?

A

Check if they have hypokalaemia - Conn’s syndrome increases aldosterone which in turn increases blood pressure but excretes potassium

26
Q

Describe the RAAS in Conn’s

A

Suppressed - aldosterone is high despite renin being low, this typically indicates Conn’s

27
Q

How do we treat a Conn’s adenoma?

A

Remove it

28
Q

What drugs should we use for Conn’s before a surgery

A

use a drug that blocks aldosterone recpetors

29
Q

How does Spironolactone work?

A

Mineralocorticoid receptor antagonist, after being converted into canrenone to stop Na reabsorption or K excretion in the tubules.
It is orally active and highly protein bound, and metabolised in the liver

30
Q

What are the side effects of spironolactone?

A 
Menstrual irregularities (as it can stimulated the progesterone receptor)
Gynaecomastia (as it blocks androgen receptor)
31
Q

How does epleronone work?

A

MR antagonist with a similar affinity to spironolactone

32
Q

Describe the side effects of epleronone

A

It binds less to other steroid receptors therefore has less side effects compared to spironolactone

33
Q

What is a phaeochromocytoma?

A

This is an adrenal medulla tumour therefore we get an increase in the production of catecholamines (noradrenaline and adrenalin)

34
Q

Why can phaeos cause a heart attack or stroke?

A

The tumour of the medulla acts as a neural syncytium therefore builds up adrenaline and doesn’t release it until a certain moment and at this point, it releases a great quantity of adrenalin to cause this heart attack or stroke via random cell degranulation

35
Q

What are the clinical features of a phaeo?

A

Hypertension in young people
Episodic severe hypetension (often triggered e.g. if you poke the abdomen)
Cna cause sudden MI or CVA therefore death

36
Q

What are the 2 stages if phaeo management?

A

Stabilise patient

Surgery

37
Q

What drugs do we first give to a phaeo patient?

A

Alpha blockade to block alpha adrenoreceptors - this causes a fall in blood pressure

38
Q

Why may we get low blood pressure in a phaeo patient and how do we stop this?

A

Because patients are used to high adrenaline therefore a fall in adrenaline means their blood pressure drops too low, as they are resistant to lower levels of adrenaline.
We. can treat this by giving IV fluids with blockade

39
Q

How do we prevent tachycardia in a phaeo patient?

A

Beta blockade (Beta blockers)

40
Q

What is the rule of 10 for phaeos?

A

10% are extra adrenal in the sympathetic chain
10% are malignant
10% are bilateral

41
Q

Can phaeos run in the family?

A

Yes - there are a few genes which put you at risk, and phaeos are more common in certain inherited conditions

BRS YEAR 2 (37 decks)

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