Point of care ultrasound (PoCUS) and the approach to hyponatremia: a case series

Hyponatremia is a common condition in clinical practice characterized by low blood sodium levels (<135 mmol/L), which can have severe neurological consequences and increase the risk of mortality. Its management requires identifying the underlying cause, for which the use of various tools has been described. In this case, the use of Point-of-Care Ultrasound (PoCUS) to estimate extracellular volume and determine the etiology of the condition is highlighted. Five clinical cases documenting the presence of hyponatremia are presented, with ultrasound findings guiding the etiology in each case. Currently, non-invasive methods are proposed, such as PoCUS, which, along with clinical findings and paraclinical tests, allow for characterizing patients’ volume status and determining the type of hyponatremia. Estimating extracellular volume can lead to estimating the cause. Despite limitations in its use and scant literature in this area, its implementation emerges as an innovative strategy to enhance early identification and management of hyponatremia.