Recent developments in the management of acute and chronic hyponatremia

The aim of the study is to review recent studies on the management of acute and chronic hyponatremia.

In acute symptomatic hyponatremia, bolus infusion of hypertonic saline improves hyponatremia and neurological status more quickly than continuous infusion. In chronic hyponatremia, newly identified predictors of nonresponse to fluid restriction include a high urine osmolality (>500 mOsm/kg) and high urine sodium (>133 mmol/l). Vasopressin-receptor antagonists effectively raise the serum sodium concentration in patients with euvolemic or hypervolemic hyponatremia but have a risk of overcorrection, even at low doses. Several observational studies now support the use of urea for a more gradual correction of hyponatremia without a risk of overcorrection. Recently identified risk factors for overcorrection include lower serum sodium at presentation, polydipsia, hypovolemia, and early urine output during treatment. Specific treatments with potential efficacy are the use of intravenous albumin for hyponatremia because of liver cirrhosis, and fludrocortisone for hyponatremia in tuberculous meningitis.

The recent data will help to further optimize and personalize the management of patients with acute and chronic hyponatremia. However, most data are still observational and retrospective. Therefore, the field is in need of prospective studies comparing interventions for chronic hyponatremia and focusing on patient-relevant outcomes.