[Dysnatremias and their association with morbidity and mortality in patients with COVID- 19].

Background: Coronavirus disease 2019 (COVID-19) has provoked one of the greatest health crises of our time, which is why risk stratification at the time of hospitalization is essential to identify in good time patients with high morbidity and mortality risk. Dysnatremia as an independent predictor of mortality in patients with COVID-19 has recently become relevant. Objective: To find out if there is an association of dysnatremia with 28-day mortality, and as secondary objectives, its association with hospital stay, invasive mechanical ventilation (IMV) requirement and presence of acute kidney injury (AKI) during hospital stay. Material and methods: Retrospective, descriptive and analytical cohort study. All consecutive patients of 16 years or older of any gender, admitted to a third level hospital from March 1, 2020 to March 2021, who have a diagnosis of COVID-19 with positive PCR were included. Results: The study included a total of 722 patients. The prevalence of dysnatremia was as follows: 18 patients presented hypernatremia (2.49%) and 153 hyponatremia (21.19%). The presence of hypernatremia once sodium was corrected for glucose was associated with higher mortality (p < 0.05, OR 3.446; 95% CI 1.776-6.688), an increased probability of presenting AKI (p <0.05, OR 2.985; 95% CI 1.718-5.184) and a greater requirement for IMV (p < 0.05, OR 1.945; 95% CI 1.701-5.098). Conclusions: Hypernatremia was associated with higher mortality, higher risk of presenting AKI and the requirement for IMV during hospitalization.