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Abstract: PO1141

Hyponatremia, Inflammation, and Hospital Mortality in Hospitalized COVID-19 Patients

Session Information

Category: Fluid, Electrolyte, and Acid-Base Disorders

  • 902 Fluid, Electrolyte, and Acid-Base Disorders: Clinical

Authors

  • Ayus, Juan Carlos, University of California Irvine School of Medicine, Irvine, California, United States
  • Moritz, Michael L., UPMC Children's Hospital of Pittsburgh Child Development Unit, Pittsburgh, Pennsylvania, United States
  • Lee, Kyung Min, Hospital Posados, Buenos Aires, Argentina
  • Caputo, Daniel, Hospital Posados, Buenos Aires, Argentina
  • Borda, Maria Elena, Hospital Posados, Buenos Aires, Argentina
  • Go, Alan S., Kaiser Permanente, Oakland, California, United States
  • Eghi, Carlos, Hospital Posados, Buenos Aires, Argentina
Background

Systemic inflammation has been associated with severe COVID-19 disease. Hyponatremia can result from inflammation due to non-osmotic stimuli for vasopressin production. Hyponatremia is an independent risk factor for hospital mortality.

Methods

Hospitalized patients with COVID-19 were prospectively evaluated between March and November 2020 at Hospital Posadas in Buenos Aires, Argentina, in order to evaluate the association between hyponatremia and inflammation and its impact on clinical outcomes. Admission biochemistries, high-sensitivity C-reactive protein (hsCRP), ferretin, patient demographics, and outcome data were recorded. Outcomes (within 30 days after symptom) that were evaluated included admission tothe ICU during hospitalization, mechanical ventilation, dialysis-requiring AKI, and in-hospital deaths. In-hospital mortality, length of hospital stay (in days), and hospital readmission for any cause within 30 days after discharge were evaluated using comprehensive data from the EHR.

Results

Among 799 hospitalized COVID-19 patients, hyponatremia was present on admission in 366 (45.8%). Hyponatremic patients had higher hsCRP levels than normonatremic patients (median 10.3 [IR 4.8-18.4] mg/dl vs 6.6 [IR 1.6 – 14.0] mg/dl, respectively, p< 0.01), and hsCRP level was inversely correlated with plasma sodium level (Spearman's correlation coefficient = – 0.23; p = < 0.01). Hyponatremic patients had higher serum ferritin levels than normonatremic patients (median 649 [IQR 492-1168] ng/dl vs 393 [IQR 156-1440] ng/dl, respectively, p = 0.02), and serum ferritin level was inversely correlated with plasma sodium level (Spearman's correlation coefficient= – 0.26; p = < 0.01).
Hyponatremic patients had increased mortality on unadjusted (odds ratio 1.87, 95%CI:1.28-2.73) and adjusted (odds ratio 1.61, 95%CI:1.05-2,49) Cox proportional hazard models. Crude 30-day survival was lower for patients with hyponatremia at admission (mean [SD] survival 22.1 [0.70] days) compared with patients who were normonatremic (mean [SD] survival 27.1 [0.40] days, p < 0.01).

Conclusion

This study demonstrates that hyponatremia on admission is common in patients with COVID-19 and is associated with inflammation and in-hospital mortality. Thus, hyponatremia could be a novel marker for identifying patients with COVID-19 at risk for hospital mortality.