The role of point-of-care ultrasound in the evaluation and management of hyponatremia: a systematic review

Hyponatremia is the most common electrolyte disorder. Accurate assessment of extracellular fluid volume status (hypovolemic, euvolemic, or hypervolemic) is essential for determining the underlying etiology and guiding treatment. Point-of-care ultrasound (PoCUS) has emerged as a complementary bedside tool to objectively assess volume status in hyponatremia. We systematically reviewed the relevant literature up to June 2025. The aim of this systematic review was to evaluate the role of PoCUS in the assessment and management of hyponatremia. The evidence suggests that combined lung, cardiac, and abdominal PoCUS (including the venous excess ultrasound score, VExUS) helps overcome the limitations of physical examination. PoCUS leads to a more accurate etiologic diagnosis and optimized treatment. PoCUS also aids in monitoring treatment response, enabling real-time adjustment of diuretics or fluids based on serial examinations. Its role may be limited by operator dependency and inability to detect non-ultrasound-revealed pathologies such as hypothyroidism. Integrating bedside ultrasound into hyponatremia management improves volume assessment accuracy and supports a more individualized approach. Although current evidence is mainly derived from small studies and case series, findings consistently support using PoCUS as an adjunct to traditional evaluation.