4 - adrenal

Question 1

what hormones are secreted where in adrenal glands?

Answer 1

adrenal medulla = secretes adrenaline & noradrenaline

adrenal cortex:
zona glomerulosa = mineralocorticoids (aldosterone)
zona fasciculata = glucocorticoids (cortisol + corticosterone)
zona reticularis = androgens (testosterone)

Question 2

what are the hormones of adrenal cortex all made from?

Answer 2

cholesterol as a basic 1st step for all of them - they go through different pathways

Question 3

what is different about aldosterone regulation?

Answer 3

not regulated by hypothalamus or anterior pituitary stuff - by RAAS pathway

*reminder RAAS increases BP, increases Na and lowers K+

Question 4

what is RAAS pathway?

Answer 4

renin released from kidneys which converts angiotensinogen to angiotensin I
angiotensin I converted to angiotensin II by ACE
angiotensin II tells adrenal gland to make aldosterone which increases BP, increases Na, lower K+

Question 5

what is addison’s disease?

Answer 5

primary adrenal insufficiency = autoimmune destruction of adrenal cortex meaning low cortisol + low aldosterone

Question 6

what is presentation of addison’s disease? biochem results?

Answer 6

• anorexia & weight loss
• fatigue & lethargy
• dizziness & low BP
• abdominal pain, vomiting, diarrhoea
• skin pigmentation (from high ACTH)

biochem results = low Na, high K, hypoglycaemia (in kids)

Question 7

what is diagnostic test for addison’s?

Answer 7

short synacthen test (when give synthetic ACTH which should make cortisol above 250 but in addison’s above 550 = super high)

Question 8

what would renin & aldosterone levels be like in addison’s? symptoms of this?

Answer 8

high renin, low aldosterone

*patients really crave salt

Question 9

what is treatment of adrenal insufficiency? (like addison’s etc)

*if acute and also for chronic ongoing management

Answer 9

if acute = urgent hydrocortisone!!, 15-30mg

for chronic aldosterone replacement = fludrocortisone

Question 10

what are important SICK day rules for adrenal insufficiency?

Answer 10

*in adrenal insufficiency they take fludrocortisone (to replace aldosterone)

• when ill, we use loads more cortisol so need to double the fludrocortisone
• if severely ill then need IV hydrocortisone throughout illness

*basically just need to remember to properly replace cortisol and aldosterone when ill and if pregnant etc. they should always carry medical alert badge

Question 11

what is treatment if adrenal crisis?

Answer 11

adrenal crisis = life threatening emergency!!

give immediate IV hydrocortisone 100mg and 0.9% saline (then replace electrolyte)

*if in doubt = TREAT!!

Question 12

what is secondary adrenal insufficiency? most common cause? treatment?

Answer 12

adrenal glands not making enough hormones because of problem further up line in pituitary or hypothalamus

steroids = most common cause

treat = hydrocortisone (cortisol replacement)
*don’t need aldosterone replacement as regulated through RAAS, nothing to do with pituitary & hypothalamus

Question 13

what does fludrocortisone and hydrocortisone replace?

Answer 13

fludrocortisone = replaces aldosterone
hydrocortisone = replaces cortisol

Question 14

what is primary hyperaldosteronism?

Answer 14

= autonomous production of aldosterone independent of regulation by RAAS e.g. makes too much aldosterone (which means increased BP, increased Na, decreased K)

Question 15

what are the causes of primary hyperaldosteronism?

Answer 15

1. Conn’s syndrome (adrenal adenoma) - genetic, 30%
2. bilateral adrenal hyperplasia - idiopathic (most common cause - 60%)

Question 16

what are clinical features of primary hyperaldosteronism? bad side effects of too much aldosterone?

Answer 16

• significant hypertension
• hypokalaemia
• compensatory metabolic alkalosis

*too much aldosterone = LV hypertrophy, increased risk of atheroma

Question 17

what is steps to diagnosis of primary hyperaldosteronism?

Answer 17

1. measure renin and aldosterone ratio (positive diagnosis would be too much aldosterone to renin)
2. saline infusion test (positive test would be remained high aldosterone)
3. confirm subtype of primary hyperaldosteronism by adrenal CT to check for adenoma

Question 18

what is management of primary hyperaldosteronism?

Answer 18

if conn’s syndrome - unilateral adrenal adenoma = surgery

if bilateral adenoma or bilateral adrenal hyperplasia then mineralocorticoid antagonists like spironolactone or eplerenone

Question 19

what is congenital adrenal hyperplasia?

Answer 19

inherited group of disorders, characterised by deficiency in different enzymes necessary for cortisol synthesis

*each different type is deficient in different enzymes. because of the pathways and way hormone production works, lack of cortisol + aldosterone can mean excess androgen

most common deficiency = 90% from autosomal recessive 21 ⍺-hydroxylase deficiency

Question 20

how does classical congenital adrenal hyperplasia present?

Answer 20

presents at birth, genital ambiguity, adrenal failure, poor weight gain, hypoglycaemia, hypokalaemia

Question 21

how does non classical congenital adrenal hyperplasia present?

Answer 21

presents later, precocious puberty, hirsutism, acne, oligomenorrhea, infertility

Question 22

how to investigate & diagnose congenital adrenal hyperplasia?

Answer 22

• basal or stimulated 17-OH progesterone (21 hydroxylase usually helps make cortisol, 17-OH progesterone is further up in steps and when 21 hydroxylase not there then cortisol can’t be made so 17-OH progesterone builds up. high levels = positive diagnosis)
• genetic analysis

Question 23

what is management of congenital adrenal hyperplasia?
a) in paediatric
b) in adults

Answer 23

a) glucocorticoid replacement, surgical correction, try achieve max growth

b) glucocorticoid replacement, control androgen excess (to help fertility)

Question 24

what is phaeochromoctyoma?

Answer 24

rare tumour of adrenal medulla, difficult to diagnose as lots of general symptoms and rare diagnosis (means high catecholamines since in medulla)

*can also get extra tumour - paraganglioma (anywhere in ganglion)

Question 25

what is presentation of phaeochromocytoma?

Answer 25

• labile hypertension (random spikes of high BP)
• postural hypotension (normal BP when sitting but sometimes go super high, sometimes super low)
• paroxysmal sweating
• headache

*also pallor, tachycardia, inner anxiety, constipation, weight loss

Question 26

why is diagnosis of phaeochromocytoma important?

Answer 26

high morbidity associated and lots of complications:
- LV hypertrophy
- myocardial necrosis
- stroke
- shock
- paralytic ileus of bowel

Question 27

what are biochemical abnormalities seen in phaeochromocytoma?

Answer 27

• high adrenaline (which causes hyperglycaemia)
• low K+
• high Hb concentration
• mild hypercalcaemia
• lactic acidosis

Question 28

what is steps to diagnosis of phaeochromocytoma?

Answer 28

1. confirm catecholamine excess
2. 24hr urinary metanephrines = 24hr urine collection (loads of drugs, diet etc can give false positive)
3. plasma metanephrine = if urine not worked, increased specificity
4. can then do CT scan - chest, abdomen, pelvis (to look for paraganglioma’s)
5. MIBG scan

Question 29

what is management of phaeochromocytoma?

Answer 29

definitive management = surgery (laparoscopic - need total excision & chemo if malignant or metastases)

pharmacological treatment until surgery:
a before b!!

1. alpha blocker e.g. phenoxybenzamine or doxazosin (to prevent cardiac instability)
2. beta blocker, after alpha, if still needed e.g. propranolol, atenolol, metoprolol

*if 2 at same time can get severe side effects

• high salt diet
• high fluid

→often feel unwell in this but good as need to be high fluid before surgery to prevent hypotension/hypovolaemia