Treatment of severe chronic hypotonic hyponatremia: a new treatment model

Abstract

Recommended treatment of severe hypotonic hyponatremia is based on the infusion of 3% sodium chloride solution, with a daily correction rate below 10 mEq/L of sodium concentration, according to the Adrogué and Madias formula that includes the current desired change in sodium concentrations. However, such treatment needs close monitoring of the rate of infusion and does not take into account the body weight or age of the patient. This may result in hypercorrection and neurological damage. We made an inverse calculation using the same algorithms of the Adrogué and Madias formula to estimate the number of vials of sodium chloride needed to reach a correction rate of the serum sodium concentration below 0.4 mEq/h, taking into account the body weight and age of the patient. Three tables have been produced, each containing the number of vials to be infused, according to the patient’s age and body weight, the serum sodium concentration, and the rate of correction over 24 h to avoid the risk of brain damage. We propose a new practical model to calculate the need of sodium chloride infusate to safely correct the hyponatremia. The tables make treatment easier to manage in daily clinical practice in a wide range of patient ages and body weights.