Hyponatremia - Treatment standard 2024.

Hyponatremia is the most common electrolyte disorder in hospital patients associated with increased morbidity, mortality, hospital stay and financial burden. The speed of a correction with 3% sodium chloride as 100 mL IV bolus or continuous infusion depends on the severity and persistence of the symptoms, and needs frequent biochemical monitoring. The rapid intermittent administration of hypertonic saline is preferred for treatment of symptomatic hyponatremia. In asymptomatic mild hyponatremia, an adequate solute intake with an initial fluid restriction (FR) of 500 mL/d adjusted according to the serum sodium levels is preferred. Almost half of the syndrome of inappropriate diuresis hormone (SIADH) patients do not respond to FR as first-line therapy. At present, urea and tolvaptan are considered as most effective second-line therapies in SIADH. However, the evidence for guidance on the choice of second-line therapy of hypotonic hyponatremia is lacking. Oral urea is considered as very effective and safe treatment. Mild and asymptomatic hyponatremia is treated with adequate solute intake (salt and protein) and an initial FR with adjustments based on serum sodium levels. Specific treatment with vaptans may be considered in either euvolemic or hypervolemic patients with high ADH activity. In order to ensure optimal patient outcome, a close monitoring and readiness for administration of either hypotonic fluids or desmopressin may be crucial in decision making process for specific treatment and eventual overcorrection consequences. According to the guidelines, a gradual correction and clinical evaluation is preferable over the rapid normalization of serum sodium towards the laboratory reference ranges.