Hyperaldosteronism + Adrenal insufficiency + Phaeo Flashcards
Primary Hyperaldosteronism
Excess aldosterone, independent of RAAS
Features of primary hyperaldosteronism
Hypokalaemia
Paraesthesia
↑BP
Hypokalaemia symptoms
Weakness
Hypotonia
Hyporeflexia,
Cramps
Causes of primary hyperaldosteronism
Bilateral adrenal hyperplasia
Adrenocortical adenoma -Conn’s syndrome
Ix of primary hyperaldosteronism
Bloods:
- U+E: ↑/normal Na
- ↓K
- alkalosis
Aldosterone: renin ratio: ↑ in primary
ECG
Adrenal CT/MRI
Mx of primary hyperaldosteronism
Care with diuretics, hypotensives, laxatives, steroids
Conn’s: laparoscopic adrenelectomy
Hyperplasia: Spironolactone, eplerenone or amiloride (K+ sparring diuretics)
Hypokalaemia ECG
- Inverted T waves
- U waves
- depressed ST segments
- prolonged PR and QT intervals
Secondary Hyperaldosteronism
Due to ↑ renin from ↓ renal perfusion
Causes of secondary hyperaldosteronism
Renal artery stenosis Diuretics Congestive HF Hepatic failure Nephrotic syndrome
Ix for secondary hyperaldosteronism
Aldosterone: renin ratio: normal
Bartter’s Syndrome
Autosomal recessive
Blockage of NaCl reabsorption in loop of Henle (as if taking furosemide)
Decreased resorption of Na and water - RAAS activation → hypokalaemia and metabolic alkalosis
- Normal BP
Primary Adrenal Insufficiency
Addison’s disease
Addison’s disease
Destruction of adrenal cortex → glucocorticoid and
mineralocorticoid deficiency
Causes of Addison’s disease
Autoimmune destruction
TB
Metastasis: lung, breast, kidneys
Symptoms of Addison’s disease
- Wt. loss + anorexia
- n/v, abdo pain, diarrhoea/constipation
- Lethargy, depression
- Hyperpigmentation: buccal mucosa, palmer creases
- Postural hypotension → dizziness, faints
- Hypoglycaemia
- Vitiligo
- Addisonian crisis
Addisonian Crisis
Shocked: ↑HR, postural drop, oliguria, confused
Hypoglycaemia
Precipitants of Addisonian Crisis
Infection
Trauma
Surgery
Immediately stopping long-term steroids
Ix for Addison’s disease
Bloods;
- ↓Na/↑K
- ↓glucose
- ↓Ca
- Anaemia
Stimulation test - Short synACTHen test
- Exclude Addison’s if ↑ cortisol
Other:
- Plasma renin and aldosterone
- CXR: evidence of TB
- AXR: adrenal calcification
Mx of primary adrenal insufficiency
Replace:
- Hydrocortisone
- Fludrocortisone
(Majority of hydrocortisone given in morning)
Advice
- Don’t stop steroids suddenly
- ↑ steroids during intercurrent illness, injury
- Wear a medic-alert bracelet
Follow up:
- Watch for autoimmune disease
Secondary Adrenal Insufficiency
hypothalamo or pituitary failure
Causes of secondary adrenal insufficiency
Chronic steroid use → suppression of HPA axis
- Pituitary apoplexy / Sheehan’s
- Pituitary microadenoma
Features of secondary adrenal insufficiency
Normal mineralocorticoid production No pigmentation (ACTH ↓)
Tx of addisonian crisis
Ix:
- Bloods: cortisol, ACTH, U+E, cultures
- Check CBG: glucose may be needed
Tx: Hydrocortisone IV 6hrly IV Fluids Septic screen Treat underlying cause
Sheehan syndrome
Post partum pituitary gland necrosis
- less ACTH released
Phaeochromocytoma pathology
Catecholamine-producing tumours arising from
sympathetic paraganglia
- found in adrenal medulla
Rule of 10s - Phaeochromocytoma
- 10% malignant
- 10% extra-adrenal
- 10% bilateral
- 10% part of hereditary syndromes
Presentation of phaeochromocytoma
Triad:
- episodic headache
- sweating
- tachycardia
Adrenergic features:
- ↑BP, palpitations
- Headache, tremor, dizziness
- Anxiety
- Diarrhoea and vomiting
- Abdo pain
- Heat intolerance, flushes
Ix of phaeochromocytoma
Plasma + urine metadrenaline
Abdo CT/MRI
MIBG scan (mete-iodobenzylguanidine) scan
Tx of phaeochromocytoma
Medical if malignant:
- Chemo or radiolabelled MIGB
Surgery: adrenelectomy
- α-blocker first, then β-
- Monitor BP post-op for ↓↓BP
Hypertensive Crisis
Features:
- Pallor
- Pulsating headache
- Feeling of impending doom
- ↑↑BP
Tx:
α-blocker or labetalol IV
Repeat to safe BP
α-blocker PO when BP controlled
Elective surgery after 4-6wks to allow full α-blockade
Sick rule for steroids
Glucocorticoid should be doubled
