Hyper/hypoadrenalism Flashcards
What is the difference btw primary and secondary adrenal deficiency in terms of steroids lost?
-primary is deficiency of both
secondary is due to suppression usually and only results in glucocorticoid deficiency
Causes of primary adrenal failure?
Automimmune adrenalitis TB HIV Haemorrhage (waterhouse freidrichson, SLE) Tumour replacement (mets from lung, breast, renal) Adrenoleukodystrophy CAH Drugs (ketoconazole, rifampicin
Causes of secondary adrenal failure?
Iatrogenic Pituitary tumour, mets, cranipharyngoma TB surgery/radio trauma
At what point is insufficiency noticable clinically?
90%of the gland is destroyed
Symptoms of hypoadrenalism?
weakness/fatigue annorexia and wt loss N+V, non specific abdo pain salt craving postural dizziness pyrexia
Signs of hypoadrenalism?
Weight loss HYPERPIGMENTATION? hyponatreimia hyperkalaemia hypercalcaemia hypoglycaemia anameia females ay have axilliary hair loss and reduced libido
Ix in hypoadrenalism?
FBC, U+Es (hypoNA hyperK Incr urea)
Cortisol and ACTH levels at 9am
Cortisol <150nm is suggestive
Increased level of ACTH for level of cortisol is also suggestive
Diagnostic tests in hypoadrenalism?
SHort synacthen test- give 250ug acth and sample cortisol levels at baseline, 30 mins, 60 min
Failure to respond suggests adrenal failure
Long synacthen test- give 1000 and see if respnonse over a day. in secondary will be some recovery and response, diseased adrenals will still not respond
Further Ix in hypoadrenalism?
Adrenal autoantibodies- directed against 21 hydroxylase in 80%
exclude associated polyendocrine syndrome
Renin to assess mineralocorticoid deficiency
TFTs
Management of hypoadrenalism?
Glucocorticoid replacement hydro TDS (eg 10, 5, 5)
Mineralocorticoid- fludro 100mcg
DHEA may improve wellbeing but isnt on prescription
Monitoring needed in hypoadrenalism?
signs of glucocorticoid excess
BP
hypertension and oedema
Postural hypotension and salt craving
U+Es, renin, acth levels following replacement if getting pigmentation
Sick day rules in hypoadrenalism?
double the dose for any illness, trauma, stress, surgery
have a 100 hydro at home to IM if vomming, get to hosp
Clinical features of addisonian crisis?
shock hypotension pain unexplained fever major stress
causes of addisonian crisis?
often known addisons and too ill to take steroids
long term steroid user not taking tablets
bilateral adrenal haemorrhage (less common)
Management of addisonian crisis
Bloods for cortisol and acth straight to lab
U+Es- k+ can be high so ecg and calcium gluconate if needed
hydro 100mg IV
Iv fluid bolus to support BP
Monitor BG (hypo a risk)
Culture and abx if risk of infection
ongoing treatment in addisonian crisis?
glucose may be needed, give fluids as required, change hydro to oral after 3 days if improvement. GET HELP
Types of hyperadrenalism?
Cushings syndrome
Hyperaldosteronism
Phaeochromocytoma
Layers of the adrenals and fx?
Glomerulosa- aldosterone
fasciculata- cortisol
reticularis- DHEA
Medulla- adrenaline
When i cortisol usually highest?
Morning
What is cushings syndrome?
A clinical state produced by chronic glucocorticoid excess + loss of normal feedback
Two main categories of Cushings syndrome?
ACTH dependent: Pituitary oversecretion, ectopic ACTH secretion, Ectopic CRH secretion (some medullary thyroid and prostate ca)
ACTH independent: Ioatrogenic, adrenocortical carcinoma/ademona
adrenal micronodular dysplasia
What is cushings disease?
Bilateral adrenal hyperplasia from ACTH secreting pit adenoma (usually micro). No response to low dose DMST but will drop for High dose
Where can ectopic secretion of ACTH come from?
Small cell lung cancer, carcinoid tumours
What are the features of ectopic ACTH secretion?
Pigmentation due to increased ACTH, hypokalaemic metabilic acidosis, hyperglycaemia, high dose DMT fails, classical cushing features not present
What can cause pseudocushings?
depression and alcohol
Clinical features of cushings?
Appearance: facial rounding, acne, hirsuitism, supraclavicular/intrascapular fat pad, striae, centripetal obesity, easy bruising, thin skin
Catabolic: proximal myopathy, striae, bruising, osteoporosis
Glucocorticoid: obesity, incr glu or DM, increased infection and poor healing
Mineralocorticoid: HTN, hypocalcaemia
Also: gonadal dysfunction, mood change, recurrent achilles tendon rupture,
Ix route in cushings?
Confirm hypercortisolaemia -> localise -> image to confirm
Initial tests in cushings
24hr urinary free cortisol
1mg overnight DMST
Midnight and morning salivary cortisol
Low dose DMST (longer and lower)
Perform 2- if both abnormal, confirmed, 1 do more tests, both normal then excluded
When are false positives seen in DST?
obese inpatients, inducers of liver enzymes
Localising tests in cushings?
ACTH- if this is low, likely adrenal cause so CT them
if detectable ACTH keep looking
High dose DST: response makes cushings disease more likely
CRH test, cortisol will raise, not really with ectopic
what is bilateral inferior petrosal sinus sampling?
Basal:central 2:1 or 3:1 if crh given indicative of cushings disease
Treatment for cushings syndrome
Transphenoidal surgery: cushings disesase, long lasting remission in 50-60%
adrenal surgery: can get rid of one if isolated adenoma
bilateral adrenalectomy: control it in refractory cushings but can -> nelsons
ectopic ACTH- cut it out
Medical treatment for cushings syndrome?
If not suitable for surgery/c/i
inhibitors of steroidogenesis: ketoconazole, metyrapone, mitotane (adrenolytic)
ACTH lowering therapy: dopamine 2 r antagonists- cabergoline
when is radiotherapy used in cushings?
following transpehoidal surgery/persisting hypercortisolaemia
can cause progressive ant. pituitary failure
80% in remission after 4 years
what is nelsons syndrome?
occurs follwing adrenalectomy, high acth levels and hyperpigmentation from enlarging pit. tumour. loss of negative feedback means at least 50% incidence in 10 years so monitor for 6 starting 6mo post op
What is hyperaldosteronism?
Excess production of aldosterone independant of RAAS, incr na and water retention and reduced renin release
CLinical features of hyperaldosteronism?
hypertension, hypokalaemia in someone not on diuretics
na mildly raised or normal
can be asymptomatic
or signs of hypoK+ eg cramps parasthesiae, poluria polydipsia
Causes of hyperaldosteronism?
2/3 are an aldosterone secreting adenoma (Conns)
1/3 are bilateral adrenocortical hyperplasia
Rarely: adrenal carcinoma, GRA (acth regulatory element fixes to aldosterone synthase gene so aldosteron production goes up and under control of acth, suspect if FH)
Treatment of hyperaldosteronism?
COnns: adrenalectomy- spironolactone 4 weeks before controls BP and K+
Hyperplasia: spironolactone or eplerenone (doesnt cause gynaecomastia)
GRA: dex 1mg for 4 weeks
Carcinoma, poor prognosis, mitotane
Secondary hyperaldosteronism?
high renin from reduce renal perfusion: renal artery stenosis, CCF, diuretics
Bartters Syndrome?
Major cause of congenital salt wasting, NA and CL both lost through a defective channel
FTT
polyuria
polydipsia
BP normal
low na and increased renin and aldosterone
Hypokalaemia and metabolic alkalosis
k+ replacement is treatment
What is a phaeochromocytoma?
catecholamine producing tumour of the adrenal medula
What is the 10% rule in phaeochromocytoma?
10 % familial, extraadrenal, bilateral, familial
when shoudl you suspect phaeochromocytoma?
if severe or resistant HTN, in young or with: sweating, pallor or flush, apprehension, palpitations and throbbing headaches
What is the classic triad in phaeochromocytoma?
episodic headache, sweating and tachycardic
COmplications of phaeochromocytoma?
Stroke, HR, Cardiomyopathy
Ix in phaeochromocytoma?
24 hr urinary catecholamines
plasma catecholamines if crisis
abdo CT
what do you need to do before surgery in phaeo?
alpha blockade
Syndromes associated with phaeo?
MEN II
VHL
NF2
