Management of Adrenal Failure Flashcards
How can we use dexamethosone to diagnose Cushings?
Low dose dexamethasone suppression test, normal people will suppress cortisol to zero, Cushings will not
What is dexamethosone?
Highly potent artificial steroid
How is Cushing’s treated?
First work out if its pituitary, adrenal or ectopic
Metyrapone or ketoconazole (inhibit steroid biosynthesis)
How does metyrapone work?
Inhibits 11 hydroxylase, no cortisol or aldosterone produced
How does ketoconazole work?
Blocks 17 hydroxylase reducing cortisol levels
Does 11 deoxycortisone have negative feedback?
No
Who is metyrapone given to? When and why?
Control Cushings prior to surgery (they have poor wound healing so this helps with surgery recovery)
Control Cushings after radiotherapy
What are side effects of metyrapone?
Excess 11 deoxycortisone= high BP, low K
Excess testosterone= hirtuism
Who is ketoconazole given to? What must we also do?
Control Cushings prior to surgery
Make sure to check liver function as it can damage the liver
What are surgical options for Cushing’s?
Pituitary surgery
Bilateral adrenalectomy
Unilateral adrenalectomy for adrenal mass
What is Conn’s syndrome? What happens to aldosterone levels?
Benign adrenal tumor of zone glomerulosa
Excess aldosterone= hypertension and hypokalaemia
How is Conn’s diagnosed?
Renin - angiotensin system should be suppressed (exclude secondary hyperaldosteronism)
How is Conn’s treated?
Spironolactone or epleronone
How does spironolactone work?
Antagonist of mineralocorticoid receptor
Blocks na resorption and k secretion
What are side effects of spironolactone?
Menstrual irregularites
Gynaecomastia
How does epleronone work?
Mineralocorticoid antagonist
What are phaeochromocytomas? What hormone do they effect and how?
Tumors of adrenal medullas that secrete catecholamines
How does phaeochromocytoma present?
Hypertension (especially in young people is uncommon so think phaeo/cushings/cohns)
Episodic severe hypertension- can cause myocardial infarction or stroke
Panic attacks
How can we differentiate between phaeochromocytoma and Cohn’s?
Phaeo= episodic sever hypertension
What do you have to treat phaeos as?
A medical emergency
How is phaeo treated?
Surgery but cant do this straight away as tumor cannot be touched
First step= give alpha blocker after saline (to prevent severe BP fall)
IV fluid as alpha blockade commences
Beta blocker to prevent tachycardia
Once crisis is over then do surgery (weekend before massively block with alpha and beta blockade)
Do phaeos have to be in the adrenal?
No, they can be extra adrenal and make adrenaline anyways
