Point-of-care ultrasound to evaluate volume status in severe hyponatremia

A 51-year-old man was hospitalised for severe hyponatremia. Initial history and physical examination suggested hypovolemia, and he was treated with normal saline at 100 mL/hour. After several days, his hyponatremia failed to improve, and then worsened without resolution of presenting ataxia and fatigue. He had no new complaints including no cough or orthopnea. He had no jugular venous distention or oedema, and his lungs were clear to auscultation. Point-of-care ultrasound was used, revealing a distended inferior vena cava, pulmonary oedema and pleural effusion, suggesting hypervolemia. Based on ultrasound findings, we treated with 60 mg oral torsemide two times per day. Hyponatremia resolved without complication within 48 hours. In this case, physical examination failed to recognise volume status change from hypovolemic to hypervolemic, increasing hospitalisation and morbidity. The point-of-care ultrasound proved to be an accurate tool for proper volume evaluation, and may be used as an adjunct to physical examination for hyponatremic patients.