The impact of the correction of hyponatremia during hospital admission on the prognosis of SARS-CoV-2 infection.

Background: SARS-CoV-2 infection is frequently associated with hyponatremia (plasma sodium <135 mmol/L), being associated with a worse prognosis. The incidence of hyponatremia is estimated to be 20-37% according to the series, but there are no data on the prognosis after correction of hyponatremia. Therefore, our objectives were: to analyse the incidence and severity of hyponatremia at hospital admission, and to determine the association of this hyponatremia with the prognosis of COVID-19. Methods: Observational and retrospective cohort study. Patients who were admitted with a diagnosis of COVID-19 infection and hyponatremia, in the period March-May 2020, were included. We recorded epidemiological, demographic, clinical, biochemical, and radiological variables of SARS-CoV-2 infection and hyponatremia at the time of diagnosis and during hospitalization. The clinical follow-up ranged from admission to death or discharge. Results: 91 patients (21.8%) of the 414 admitted for SARS-CoV-2 infection presented hyponatremia (81.32% mild hyponatremia, 9.89% moderate and 8.79% severe). The absence of correction of hyponatremia 72-96 h after hospital admission was associated with higher mortality in patients with COVID-19 (Odds Ratio 0.165; 95% confidence interval: 0.018-0.686; p = 0.011). 19 patients (20.9%) died. An increase in mortality was observed in patients with severe hyponatremia compared with moderate and mild hyponatremia during hospital admission (37.5% versus 11.1% versus 8.1%, p = 0.041). Conclusion: We conclude that persistence of hyponatremia at 72-96 h of hospital admission was associated with higher mortality in patients with SARS-Cov-2.

Introduccion: La infección por SARS-CoV-2 se asocia con frecuencia con hiponatremia (sodio plasmático <135 mmol/l), relacionándose con peor pronóstico. La incidencia de la hiponatremia se estima en 20­37% según las series, pero no existen datos sobre el pronóstico tras la corrección de la hiponatremia. Por ello, nuestros objetivos fueron: analizar la incidencia y gravedad de la hiponatremia al ingreso hospitalario, y determinar la asociación de dicha hiponatremia con el pronóstico del COVID-19. Material y método: Estudio de cohorte observacional y retrospectivo. Se incluyeron pacientes que ingresaron con diagnóstico de infección por COVID-19 e hiponatremia, en el periodo marzo-mayo 2020. Registramos variables epidemiológicas, demográficas, clínicas, analíticas y radiológicas de la infección por SARS-CoV-2 e hiponatremia al momento del diagnóstico y durante la hospitalización. El seguimiento clínico comprendió desde el ingreso hasta el exitus o el alta. Resultados: 91 pacientes (21,8%) de los 414 ingresados por infección del SARS-CoV-2 presentaron hiponatremia (81,32% hiponatremia leve, 9,89% moderada y 8,79% grave). La ausencia de corrección de la hiponatremia a las 72­96 horas del ingreso hospitalario estuvo asociado a mayor mortalidad en los pacientes con COVID-19 (OR 0,165; 95% intervalo de confianza: 0,018­0,686; p = 0,011). Fallecieron 19 pacientes (20,9%). Se observó un aumento de la mortalidad en pacientes con hiponatremia grave en comparación con hiponatremia moderada y leve durante el ingreso (37,5% versus 11,1% versus 8,1%, respectivamente, p = 0,041). Conclusiones: La persistencia de la hiponatremia tras las primeras 72­96 horas del ingreso hospitalario fue asociada a mayor mortalidad+- en los pacientes con SARS-Cov-2.

The impact of the correction of hyponatremia during hospital admission on the prognosis of SARS-CoV-2 infection. / Impacto de la corrección temprana de la hiponatremia en el pronóstico de la infección del síndrome respiratorio agudo grave del coronavirus 2 (SARS-CoV-2).

INTRODUCTION: SARS-CoV-2 infection is frequently associated with hyponatremia (plasma sodium<135mmol/L), being associated with a worse prognosis. The incidence of hyponatremia is estimated to be 20-37% according to the series, but there are no data on the prognosis after correction of hyponatremia. Therefore, our objectives were: to analyze the incidence and severity of hyponatremia at hospital admission, and to determine the association of this hyponatremia with the prognosis of COVID-19. MATERIAL AND METHOD: Observational and retrospective cohort study. Patients who were admitted with a diagnosis of COVID-19 infection and hyponatremia, in the period March-May 2020, were included. We recorded epidemiological, demographic, clinical, biochemical, and radiological variables of SARS-CoV-2 infection and hyponatremia at the time of diagnosis and during hospitalization. The clinical follow-up ranged from admission to death or discharge. RESULTS: 91 patients (21.8%) of the 414 admitted for SARS-CoV-2 infection presented hyponatremia (81.32% mild hyponatremia, 9.89% moderate and 8.79% severe). The absence of correction of hyponatremia 72-96h after hospital admission was associated with higher mortality in patients with COVID-19 (Odds Ratio .165; 95% confidence interval: .018-.686; P=.011). 19 patients (20.9%) died. An increase in mortality was observed in patients with severe hyponatremia compared with moderate and mild hyponatremia during hospital admission (37.5% versus 11.1% versus 8.1%, P=.041). CONCLUSIONS: We conclude that persistence of hyponatremia at 72-96h of hospital admission was associated with higher mortality in patients with SARS-CoV-2.