Endocrine Abstracts

Background: Dysnatremia is common in hospitalized patients, often worsening the prognosis in pneumopathies and critical illnesses, such as COVID-19. Here, hyponatremia is an indicator of pulmonary involvement, while hypernatremia is associated with worse assistance outcomes, particularly when resulting from an overcorrected hyponatremia. Longer hospitalizations, readmissions after discharge and higher short- and long-term mortality rates have been observed in acute patients experiencing sodium abnormalities.

Objective and methods: 117 patients hospitalized for COVID-19 between 1^st March and 30^th April 2020 and participating the “EPISODICO” study [1] were followed-up for 18±4 months. The proportion of emergency room or hospital readmissions (Ancona University Hospital) for all causes, the mortality rate after recovery from COVID-19 and their association with recurrent sodium alterations were assessed.

Results: Of the 97 discharged patients (70 males, 62±12 years), almost 30% were readmitted to the emergency room or any hospital department at least once. At readmission, 10% patients had hyponatremia, 14% had hypernatremia, whereas 7% patients experienced both disorders (“mixed dysnatremia”) by the end of follow-up. Gender, age, clinical and biochemical features of their previous hospitalization for COVID-19 were similar between readmitted and non-readmitted patients, the former having overlapping sodium levels in both hospitalizations. Considering the whole “EPISODICO” cohort, mortality rate at the end of follow-up was 25%, since twenty patients died in the “EPISODICO” study and further nine patients died during follow-up: of them, 4 died as outpatients in 1-11 months after discharge, and 5 as inpatients in 3-17 months after the first discharge. Last available sodium levels were significantly lower in dead patients as compared to survivors (137±11 vs 141±3 mmol/l, P=0.026). Death occurred in 2/3 patients having hyponatremia at readmission and in 100% patients encountering mixed dysnatremia. When only “EPISODICO” participants with sodium alterations during their COVID-19 hospitalization were selected, readmission rate was 26% and mortality rate at the end of follow-up was 28%.

Conclusions: Similarly to what happens in other acute medical conditions, COVID-19-related sodium alterations are frequently associated with hospital readmissions and long-term mortality. The worst outcomes involve patients whose sodium abnormalities recur after discharge, particularly hyponatremia at the time of hospital readmission and mixed dysnatremia occurring during hospital stay.

References: [1] Martino M et al. “Sodium alterations impair the prognosis of hospitalized patients with COVID-19 pneumonia” Endocr Connect. 2021 Oct 15;10(10):1344-1351. doi: 10.1530/EC-21-0411.