The evolution of hypovolemic and euvolemic hyponatremia coincides with an inflammatory status in patients with COVID-19

Abstract

BACKGROUNDHyponatremia is a frequent electrolytic disorder in hospitalized patients with Coronavirus Disease 2019 (COVID-19). Inflammatory status could be associated with hyponatremia in patients with COVID-19. We evaluate the hospital evolution of hyponatremia and inflammation markers in COVID-19 patients.METHODSA case-series of adult patients with COVID-19 pneumonia and hyponatremia at admission were included and retrospectively followed during hospitalization. Data of the volemic status, general characteristics, inflammation, and clinical outcomes, were collected and analyzed. Comparative and multivariate analyzes were developed, and Hazzard ratio (HR) with 95%-confidence intervals (95% CI) were calculated.RESULTS49 patients with hyponatremia followed, 32 (65.3) were male, and 22 (44.9%) euvolemic. Mean age: 69.9 ± 14.7 years. From the 100% of patients with hyponatremia at admission, only 26.2% remained hyponatremic at the 7th -10th hospitalization day. Improvement in serum sodium (SNa) coincided with improvement in inflammatory markers during hospitalization, as well as a decrease in the rate of hyponatremia. A lower SNa at admission was independently associated with mortality (HR: 12.23, 95%CI: 2 to 25.6).CONCLUSIONBoth admission hypovolemic and euvolemic hyponatremia in COVID-19 patients occurred in a inflammation status, and improved as inflammation markers decreased.