Endo

Question 1

what are the 3 types of adrenal disease?

Answer 1

addisons (primary adrenal insufficiency)

conns syndrome (primary hyperaldosteronism)

phaeochromocytoma

Question 2

what is conns syndrome?

Answer 2

primary hyperaldosteronism - excess aldosterone production by the zone glomerulosa of adrenal gland (produces mineralocorticoids)

Question 3

what causes conns syndrome?

Answer 3

adrenal adenoma

bilateral idiopathic adrenal hyperplasia

Question 4

how would someone with conns syndrome present?

Answer 4

• hypertension - headaches, flushing
• hypokalaemia - fatigue, muscle weakness, headaches, parasthesia, constipation, HR rhythm changes
• alkalosis (metabolic)

Question 5

describe the RAAS system

Answer 5

• Normally, if there is a drop in BP, reduced blood flow in renal artery stimulates the release of renin from the kidney which aids the conversion of angiotensinogen → angiotensin I which travels to lungs where ACE aids in conversion of ang I → ang II
• ang II stimulates the release of aldosterone from adrenal cortex
  
  • also causes vasoconstriction (increase BP), stimulates ADH release (water reabsorption)
• normal BP and normal flow through renal artery reduces renin secretion and down-regulates RAAS (negative feedback)

Question 6

what is the role of aldosterone?

Answer 6

• aldosterone effects:
  
  • binds to Na/K pumps
    
    • drives K+ out, drives Na+ in and water follows into blood = increases BP
  • stimulates ATPase pumps
    
    • drives H+ (protons) out, bicarb in = increases in pH

Question 7

what happens to the RAAS system in conns syndrome?

Answer 7

• breakdown in normal negative feedback
• inappropriately high aldosterone in blood
• leads to excess Na+ and water reabsorption and vasoconstriction → high BP

Question 8

how do we investigate someone with suspected conns?

Answer 8

• plasma aldosterone/renin ratio - high ald, low renin
• high-res CT abdo - differentiate between unilateral and bilateral
• adrenal venous sampling - to find which gland secreting excess

Question 9

how do we manage someone with conns syndrome?

Answer 9

drugs - K sparing diuretics (ald antagonist) = spironolactone

surgery - laparoscopic adrenalectomy

Question 10

what is phaeochromocytoma?

Answer 10

neuroendocrine tumour of the adrenal medulla

It secretes excessive amounts of catecholamines (adrenaline) and causes high BP

It is a treatable hypertension!

Question 11

what causes phaeochromocytoma?

Answer 11

familial germline mutations - RET, NF1, VHL, SDH genes

Question 12

how might someone with phaeochromocytoma present?

Answer 12

usually asymptomatic

throbbing headache

sweating

palpitations

Question 13

what happens to the cardiovascular system of someone with phaeochromocytoma?

Answer 13

individual’s adrenal gland (medulla) produces excess catecholamines

these act on smooth muscle causing vasoconstriction

this increases total peripheral resistance

HR and CO also increase leading to hypertension

Question 14

what is a hypertensive emergency in a patient with phaeochromocytoma?

Answer 14

when BP is >180/120

small vessels start to break in the:

heart -> CHF
brain -> ischaemic or haemorrhagic stroke
eye -> retinal haemorrhage
kidney -> failure

Question 15

what investigations would you organise for someone with suspected pheochromocytoma?

Answer 15

24 hour urine collection (catecholamines and metanephrine)

US and CT scan

Question 16

how do we manage someone with pheochromocytoma?

Answer 16

surgical excision of neuroendocrine tumour