Adrenal Disease Flashcards
(33 cards)
Adrenal Microanatomy
- Capsule
- Glomerulosa – produces mineralocorticoids
- Fasciculata – produces glucocorticoids
- Reticularis- produces sex steroids
- Medulla
“The deeper you go, the sweeter it gets”
Adrenal anatomy
has only 1 central vein and 57 adrenal arteries
- The left adrenal drains into the left renal vein
- The right adrenal drains directly into the IVC
To measure adrenal output, a cannula is placed through the IVC and into the adrenal vein
- 31-year-old presents with profound tiredness
- Acutely unwell a few days
- Vomiting
Data
- Na: 125, K: 6.5, U: 10, Glucose: 2.9mM
- FT4 < 5nM, TSH >50mU/L
low Na, high potassium, low glucose
hyponatraemia + hyperkalaemia = deficiency of mineralocorticoid - aldosterone
hypoglycaemia: deficiency of glucocorticoid- cortisol
ADDISON’S DISEASE
define Addison’s disease
Addison’s disease = adrenal insufficiency
Deficiency of mineralocorticoid and glucocorticoid
common causes of Addison’s disease (developed and developing countries)
autoimmune disease (developed countries
Tuberculosis of adrenal glands (developing countries)
primary hypothyroidism + addison’s disease =
SHMIDT’S SYNDROME
PGAI (Polyglandular autoimmune syndrome) Type 2.
Tests for Addison’s disease
Synacthen test:
- Measure cortisol + ACTH at the start of the test
- Administer 250microgram synthetic ACTH by IM injection
- Check cortisol at 30 and 60 minutes:
*If cortisol RISES A LOT = INTACT adrenals
*If cortisol does NOT rise= do NOT have intact adrenals
NOTE: Healthy people should produce > 550 nM of cortisol within 30 minutes
- Results of short synacthen test:
o ACTH > 100ng/dl – HIGH
o Cortisol < 10nM at 30 mins – LOW
o Cortisol < 10nM at 60 mins – LOW
What urgent treatment is needed?
results indicate adrenal insufficiency
Normal 0.9% Saline infusion over 1 hour and IV hydrocortisone
- Need to rehydrate the dehydrated hypotensive patient + Give IV hydrocortisone at the same time as giving saline infusion
- Saline should go first as it will work immediately
complications of addison’s disease
People die of hyperkalaemia – can lead to arrythmias AND/ OR hypotension and shock
- 32 year old present with hypertension
- He is noted to have an adrenal mass
What are the possible adrenal masses and describe there significance
- Adrenal medullary tumour: Phaeochromocytoma: adrenaline secreting tumour = SUDDEN episodic rises in BP
- Conn’s syndrome : secretes aldosterone: retention of sodium and loss of potassium
- Cushing’s syndrome: secretes cortisol : Moon face, buffalo hump, thin shiny skin
These 3 ALL cause hypertension + hypokalaemia
(less so for phaeochromocytomas)
HIGH levels of urinary catecholamines indicates what
pheochromocytoma
management of pheochromocytoma
- Fluids first as alpha blockade can decrease BP
- Give alpha-blockade NEXT (e.g. phenoxybenzamine or doxazosin)
- then beta blockade to prevent reflex tachycardia
-then later: Cure = surgical removal of tumour
So:
FABC
complications of pheochromocytoma
secretes huge amounts of adrenaline:
sudden severe hypertension, arrhythmias (VF) and sudden cardiac death
- Genetic syndromes associated with Phaeochromocytoma
MEN 2, NF I, VHL syndrome
- Hypertensive 33-year-old
- Na: 147, K: 2.8, U: 4,0, Glucose: 4mM
- Plasma aldosterone- RAISED
- Plasma renin SUPPRESSED
what is the diagnosis:
Conn’s syndrome/ Primary hyperaldosteronism
what is Conn’s syndrome/ Primary hyperaldosteronism
adrenal gland secretes high levels of aldosterone autonomously =
hypernatraemia + hypokalaemia+ hypertension and this will in turn suppress the renin at the JGA
- 34-year-old obese woman with T2DM, presents with hypertension and bruising
- Na: 146, K: 2.9, U: 4.0, Glucose 14.0
- Aldosterone < 75 (LOW)
- Renin LOW
What is the diagnosis
- Cushing’s syndrome
causes of Cushing’s syndrome
- oral steroids (this is the most common)
- Adrenal tumour producing cortisol without ACTH
- Pituitary tumour producing ACTH: Pituitary dependent Cushing’s disease
- Ectopic tumour producing ACTH: lung cancer
Test for Cushing’s syndrome
Which dynamic test is needed to confirm Cushing’s?
- 9am cortisol- elevated normally so will not help to distinguish
- 12 midnight cortisol- suppressed normally but high in Cushing’s
definitive diagnosis = - Dexamethasone suppression test
explain Dexamethasone suppression test
Dexamethasone is a VERY potent steroid
so will switch off ACTH normally + suppress cortisol to UNDETECTABLE LEVELS
In Cushing’s, there will NOT be suppression and it will keep on making the hormone
- MOST COMMON cause for Cushing’s syndrome
Being on oral steroids: becolmethasone inhalers etc
- An obese 35-year-old patient has the following results:
- 9am cortisol (Monday): 650nM
- Given 0.5mg dexamethasone every 6 hours for 48 hours- low dose dexamethasone suppression test
- 9am cortisol (Wednesday) < 50nM
what is the diagnosis
- Normal obese person: pseudo-Cushing’s syndrome
Obesity is a growing common reason now
Tell her she does not have any serious adrenal problem; she needs help for weigh loss
- 9am cortisol (Monday): 650nM
- Given 0.5mg dexamethasone every 6 hours for 48 hours- low dose dexamethasone suppression test
- 9am cortisol (Wednesday): 500nM NOT <50nM
what is the diagnosis
- Cushing’s syndrome
What is the next step once you have found cushing’s syndrome following low dose dexamethasone suppression test?
-Sampling from the pituitary (IPSS)
inferior petrosal sinus sampling
*measures ACTH levels in the veins near pituitary and compares them with the periphery- look at the gradient*
