Background: Unilateral renal artery stenosis can lead to severe complications, such as hyponatremic hypertensive syndrome (HHS). This case is noteworthy due to the patient’s early age and the presentation of an unusual condition in children. It highlights the diagnostic and therapeutic challenges associated with this condition. Case Description: A 16-month-old boy presented with a 1-week history of vomiting, diarrhea, and abdominal pain. On admission, his blood pressure was 145/75 mmHg, indicating severe hypertension. During clinical observation, laboratory tests revealed metabolic alkalosis, hyponatremia, hypokalemia, proteinuria, natriuresis, hypercalciuria, and signs of renal tubular damage. Elevated serum renin (30 ng/mL/h) and aldosterone levels (>100 ng/dL) suggested renal hypoperfusion, and imaging confirmed right renal artery stenosis. Initial treatment with amlodipine at 1.25 mg/day (0.125 mg/kg/day) was ineffective, as hypertension persisted (>150/90 mmHg) and polyuria worsened. Management included volume repletion and titrated electrolyte correction. Due to ongoing hypertension, ramipril was added at 1.25 mg/day (2.5 mg/m2). The patient subsequently underwent percutaneous transluminal renal angioplasty (PTRA). A few days after PTRA, technetium-99m mercaptoacetyltriglycine (Tc99m-MAG3) scintigraphy showed reduced split renal function in the right kidney (26%). Due to inadequate blood pressure control, losartan (0.77 mg/kg/day) was added one week later to achieve dual blockade of the renin-angiotensin-aldosterone system. Over a 3-year follow-up, the patient showed significant clinical improvement, normalization of blood pressure, and increased right kidney split renal function (40.9%). Antihypertensive medications were gradually discontinued: amlodipine at 2 months, ramipril at 4 months, and losartan at 2 years post-PTRA. The child remained normotensive and asymptomatic at the latest follow-up. Conclusions: This case underscores the importance of early recognition and management of HHS in pediatric patients with renal artery stenosis. Prompt diagnosis and timely intervention, including PTRA, can result in favorable outcomes, such as recovery of renal function and withdrawal of antihypertensive therapy. It highlights the need for clinical awareness of HHS in young children presenting with severe hypertension and electrolyte imbalances.
A 16-month-old boy with severe hypertension, metabolic alkalosis, hyponatremia and hypokalemia: a case report and literature review
Capasso G.;Marzuillo P.;Guarino S.;Tirelli P.;Malgieri G.
2025
Abstract
Background: Unilateral renal artery stenosis can lead to severe complications, such as hyponatremic hypertensive syndrome (HHS). This case is noteworthy due to the patient’s early age and the presentation of an unusual condition in children. It highlights the diagnostic and therapeutic challenges associated with this condition. Case Description: A 16-month-old boy presented with a 1-week history of vomiting, diarrhea, and abdominal pain. On admission, his blood pressure was 145/75 mmHg, indicating severe hypertension. During clinical observation, laboratory tests revealed metabolic alkalosis, hyponatremia, hypokalemia, proteinuria, natriuresis, hypercalciuria, and signs of renal tubular damage. Elevated serum renin (30 ng/mL/h) and aldosterone levels (>100 ng/dL) suggested renal hypoperfusion, and imaging confirmed right renal artery stenosis. Initial treatment with amlodipine at 1.25 mg/day (0.125 mg/kg/day) was ineffective, as hypertension persisted (>150/90 mmHg) and polyuria worsened. Management included volume repletion and titrated electrolyte correction. Due to ongoing hypertension, ramipril was added at 1.25 mg/day (2.5 mg/m2). The patient subsequently underwent percutaneous transluminal renal angioplasty (PTRA). A few days after PTRA, technetium-99m mercaptoacetyltriglycine (Tc99m-MAG3) scintigraphy showed reduced split renal function in the right kidney (26%). Due to inadequate blood pressure control, losartan (0.77 mg/kg/day) was added one week later to achieve dual blockade of the renin-angiotensin-aldosterone system. Over a 3-year follow-up, the patient showed significant clinical improvement, normalization of blood pressure, and increased right kidney split renal function (40.9%). Antihypertensive medications were gradually discontinued: amlodipine at 2 months, ramipril at 4 months, and losartan at 2 years post-PTRA. The child remained normotensive and asymptomatic at the latest follow-up. Conclusions: This case underscores the importance of early recognition and management of HHS in pediatric patients with renal artery stenosis. Prompt diagnosis and timely intervention, including PTRA, can result in favorable outcomes, such as recovery of renal function and withdrawal of antihypertensive therapy. It highlights the need for clinical awareness of HHS in young children presenting with severe hypertension and electrolyte imbalances.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
