Inferior vena cava point of care ultrasound: new perspectives in management of hyponatraemia

Background Hyponatraemia is the most common electrolyte disorder in clinical practice, affecting 4% of patients presenting to the Emergency Department and up to 30% of patients in general medicine wards. It is associated with increased morbidity and mortality, therefore requiring prompt management. Current approach in defining aetiology of hypotonic hyponatraemia is based on extracellular fluid volume evaluation, which is potentially difficult, because of lack of highly sensible and specific clinical or laboratory tools. Evaluation of caval index through inferior vena cava point of care ultrasound could be helpful in defining intravascular volume status, as assessed in several conditions.