Sodium evolution in hyponatremia: A retrospective analysis in a tertiary care center.

Abstract

Introduction: Hyponatremia is the most common electrolyte disorder in hospitals. This study analyses the evolution of serum sodium levels during hospitalization.

Materials and methods: This is an observational, retrospective, and analytical study. Patients hospitalized for hyponatremia in a tertiary care hospital were included. Demographic and laboratory variables were collected, and hyponatremia was classified according to severity and etiology. Criteria and risk factors for serum sodium overcorrection were defined, and the effectiveness of treatments used for hyponatremia was described. The Chi-square test was used for qualitative variables, while Student's t-test and Mann-Whitney U test were applied for quantitative variables. Predictive models were also used to determine the risk of an event.

Results: A total of 216 patients hospitalized for hyponatremia were included, with a higher prevalence in patients over 75 years of age and females. Longer hospital stays were associated with older age and male gender. Severe hyponatremia and hypokalemia were linked to a higher risk of overcorrection. The therapies for hyponatremia correction across the three groups were effective either alone or in combination. Additionally, severe hyponatremia was associated with increased 5-year mortality.

Conclusions: Hyponatremia in hospitalized patients is more prevalent in those over 75 years old and in females. Severe hyponatremia increases 5-year mortality. There are factors that increase the risk of overcorrection, so treatment should be carefully managed to avoid osmotic demyelination syndrome (ODS).