Hyponatremia occurs in nearly one-third of patients hospitalized with COVID-19, and it independently predicts a higher risk of dying in the hospital, according to a recent study.
Of 4645 patients admitted to New York City hospitals with COVID-19 from March 1 to May 13, 2020, hyponatremia (sodium level below 135 mmol/L) occurred in 1373 (30%) cases, Jennifer A. Frontera, MD, of the NYU Grossman School of Medicine in Brooklyn, New York, and colleagues reported in Critical Care Medicine. Of the patients with hyponatremia, 374 (27%) required invasive mechanical ventilation.
Mild, moderate, and severe hyponatremia (defined as admission sodium levels of 130 to 134, 121 to 129, and 120 mmol/L or less, respectively) occurred in 1032 (22%), 305 (7%), and 36 (1%) of patients, respectively. Each level of worsening hyponatremia was significantly associated with 43% increased odds of in-hospital death after adjusting for age, gender, race, body mass index, past medical history, admission laboratory abnormalities, and other variables.
Patients with moderate or severe hyponatremia had significant 83% increased odds of requiring invasive mechanical ventilation and 36% decreased odds of being discharged home compared with patients who had higher sodium levels, according to the investigators. Patients with severe hyponatremia had significant 8-fold increased odds of encephalopathy.
Frontera JA, Valdes E, Huang J, et al. Prevalence and impact of hyponatremia in patients with coronavirus disease 2019 in New York City. Crit Care Med. Published online August 18, 2020. doi:10.1097/CCM.0000000000004605