Serum sodium and serum potassium levels as a marker of severity in COVID-19 patients

This study aims to determine the predictive value of serum sodium and potassium levels at the time of admission in assessing the severity of COVID-19. This is a cross-sectional record-based descriptive study conducted at a tertiary care center in the State of Kerala, for six months. 227 COVID cases with electrolyte abnormalities were taken for the study. Serum sodium and serum potassium levels at the time of admission were noted. Details regarding the treatment received and the course of patients in the hospital were recorded. Any progress to severity, such as ICU admission, need for mechanical ventilation, and mortality was duly noted. Mean serum electrolyte levels were calculated. Patients were classified as hyponatremia, hypernatremia, hypokalemia, and hyperkalemia and evaluated for any association with markers of severity. The mean sodium level was 132.47 ± 6.1 mEq/L and the mean potassium level was 3.74 ± 0.73 mEq/L. Of the 227 cases, 179 had hyponatremia (78.9%) and three had hypernatremia (1.3%). Hypokalemia was present in 106 cases (46.7%), and hyperkalemia in 15 cases. Only sodium abnormality was present in 106 (46.7%) patients, only potassium abnormality in 45 (19.8%) patients, and both sodium and potassium were abnormal in 76 (33.5%) patients. Out of 227 hospitalized COVID-19 patients, 56 (24.7%) were transferred to the ICU and 39 (17.2%) needed ventilation. During the course of treatment, 24 (10.6%) out of 227 patients died. A significant association was found between hyponatremia and mortality (p = 0.03). Hyponatremia is the primary electrolyte abnormality in COVID-19 patients and is significantly associated with mortality. Thus, hyponatremia can be used as a marker of severity in COVID-19 cases.