Hypertension and Renal Manifestations of Systemic Disease
Hypertension and Renal Manifestations of Systemic Disease
This domain tests secondary hypertension workup, resistant hypertension, and kidney involvement in systemic diseases such as lupus, vasculitis, scleroderma, and myeloma.
Core rules
- Secondary hypertension: consider in young patients, abrupt onset, refractory hypertension, hypokalemia, or flash pulmonary edema. Renal artery stenosis may cause rising creatinine after ACE inhibitor.
- Primary aldosteronism: elevated aldosterone-to-renin ratio; confirm with saline suppression or captopril challenge; adrenal CT and adrenal vein sampling before surgery.
- Resistant hypertension: uncontrolled on three drugs including a diuretic, or controlled on four. Check adherence, white-coat effect, and secondary causes.
- Lupus nephritis: biopsy to classify; class III/IV proliferative disease is treated with steroids plus mycophenolate or cyclophosphamide; class V is membranous.
- Scleroderma renal crisis: abrupt hypertension, rising creatinine, microangiopathic hemolysis; treat with ACE inhibitor.
- Myeloma cast nephropathy: high light chains, bland sediment, chronic kidney disease; treat with chemotherapy and hydration.
Worked example
A 35-year-old woman has hypertension, potassium 3.1 mmol/L, and metabolic alkalosis. Aldosterone is high and renin is suppressed. This suggests primary aldosteronism. Confirm with saline suppression, then image adrenals; adrenal vein sampling distinguishes unilateral adenoma from bilateral hyperplasia before surgery.
Traps
- Missing secondary hypertension in young or resistant cases.
- Using ACE inhibitors in bilateral renal artery stenosis.
- Treating lupus nephritis without biopsy classification.
- Missing ACE inhibitor benefit in scleroderma renal crisis.