Adrenals Flashcards
What parts of the adrenal gland secrete what?
Zona glomerulosa = mineralocorticoids e.g. aldosterone
Zone fasciculata = glucocorticoids e.g. cortisol
Zona reticularis = androgens e.g. DHEA
Medulla = adrenaline and noradrenaline
WHat is and causes of cushings syndrome?
Pathological manifestation of hypercortisolism
Exogenous steroids (most common) Pituitary adneoma (disease = 85%) Ectopic ACTH (Small cell lung cancer) Adrenal tumour
What are the symptoms of cushings syndrome?
Centripetal obesity, facial rounding, proximal myopathy, thinning of skin = purple striae and metabolic compications e.g. DM, dyslipidaemia, metabolic bone disease and HTN
WHat are the Ix for cushings syndrome?
Low dose dexamethosone test (morning >50nanomol/L)
Midnight cortisol (to exclude cushings)
24hr urinary free cortisol
Plasma ACTH
Dexa shows if its present and then plasma ACTH low = adrenal tumour. If normal or high = pituitary or ectopic tumour
What is the Mx for cushings?
Stop the steroids
Remove the tumour
What are further investigations for cushings?
Pituitary vs ectopic ACTH?
= Inferior petrosal sinus sampling (IPSS)
Increased ACTH = pituitary adenoma. Normal = adenoma
WHat is and causes of adrenal insufficiency?
Clinical manifestation of hypocorticolism?
Primary = Addisons Secondary = pituitary/hypothalamic involvement
Causes = TB (worldwide most common)
Autoiimune (in UK)
Hypopituitarism (tumour, surgery, radiotherapy, apoplexy, sheehans)
SS of adrenal insufficiency?
Fatigue adn weakness anorexia weight loss postural hypotenson salt craving mucocutaneous hyperpigmentation
RFs = coexisting autoimmune condition, confirmed TB
Ix for adrenal insuffiency?
Bloods = U&Es, FBC
Decreased Na and increased K+ due to decreased aldosterone production
Morning serum cortisol
GOLD STANDARD = short synACTHen test
Mx for adrenal insufficiency?
Life long glucocorticoids and minerolcorticoids
What is primary hyperaldosteronism and causes?
Conns syndrome from an adenoma
What are symptoms of conns?
HTN in young person (usually refractory to treatment)
hypokalaemia (polyuria/polydipsia, muscle weakness and arrhythmia
Ix for Conns?
Potassium levels
Increased Plasma aldosterone:renin ration
Mx for conns?
Unilateral laparoscopic adrenalectomy
Spironolactone - aldosterone antagonist
WHat is a phaeochromocytoma?
Tumour arising from catecholamine-producing chromafing cells in the adrenal medulla
Associated with MEN-2 and von Hippel-Lindau disease
Presentations of phaeos?
Increased adrenaline
Increased HR = palpitations
Pallor - vasoconstriction of skin vasculature
Increased BP in young Episodic increased BP HEadaches Tremor Sweating Anxiety (fight/flight)
Medical emergency as can cause MI and stroke or v.fib + death
WHat tuours are related to von hippel-lindau syndrome?
Phaeos Hamengioblastomas Retinal angiomas Clear cell renal cell carcinoma ccRCC pancreatic neuroenocrine tumour
Ix for phaeos?
1st = 24hour urine collection of catecholamines (= metanephrones, normetanephrones)
If clinical suspicion high = serum free metanephrines/normetanephrines
Mx for phaeos?
Alpha blocker -> beta blocker -> surgical excision
Alpha = phenoxybenzamine/doxasozin
beta = atenolol
Phaeos 10 rules?
10% extra adrenal
10% malignant
10% bilateral
RARE
Causes of hyperkalaemia?
Reduced excretion = renal (CKD e.g. diabetic nephropathy/CKD), endocrine (RAAS), drugs (ACEi/ARBs)
Release from cells = rhabdomyolysis, acidosis
ECG for hyperkalaemia?
Loss of p waves
Tall tented T waves
Widened QRS complex
Mx for hyperkalaemia?
10mls 10% calcium gluconate
50mls 50% dextrose + 10 units short acting insulin (actrapid)
Salbutamol as adjunct
treat cause
Causes of hypokalaemia?
Renal e.g. renal tubular acidosis, diuretics, elevated mineralocorticoids (CONNS), elevated cortisol
GI = vomiting, villous adenoma, VIPoma
Skin = burns, eczema, psoriasis
Insulin, salbutamol and metabolic alkalosis
