S2009 Impact of Hyponatremia on Mortality and Other In-Hospital Outcomes in Patients With Ulcerative Colitis (UC): A Retrospective Cohort Analysis Using the National Inpatient Sample

Introduction: Hyponatremia can be an associated electrolyte abnormality in patients with ulcerative colitis (UC) owing to the inflammatory processes, increased fluid loss through diarrhea, and medications used to treat UC. The aim of this study is to assess the impact of hyponatremia on outcomes of patients hospitalized with ulcerative colitis using a large national database. Methods: The US National Inpatient Sample (2018-2020) was analyzed to identify patients hospitalized with UC, with and without hyponatremia using International Classification of Diseases-10 codes. Confounders were adjusted by using multivariable regression analysis. The primary outcome was in-hospital mortality, and the secondary outcomes were mean length of stay (LOS), mean total hospital charges (THC), anemia, blood transfusions, toxic megacolon, intestinal perforation, hypovolemic shock, hypoalbuminemia acute kidney injury, sepsis, colectomy and mechanical ventilation required. Results: Among 60,660 hospitalized patients with UC, 7425 (12.24%) also had hyponatremia, and 53,235 (87.75%) were without hyponatremia. Patients with hyponatremia exhibited a statistically significant 21-fold increase in inpatient mortality (adjusted odds ratio [aOR] 21.33; 95% confidence interval [CI], 4.90-92.89; P < 0.001), along with an adjusted 2-fold increase in mean length of stay (mean difference 2.02; 95% CI, 1.39-2.65; P < 0.001) and a rise in mean total hospital charges (THC). Moreover, the hyponatremia group had significantly higher rates of anemia, blood transfusions, intestinal perforation, hypoalbuminemia, acute kidney injury, sepsis, and mechanical ventilation (all P < 0.05). However, no statistically significant differences were found in the rates of toxic megacolon, hypovolemic shock, colectomy, or renal replacement therapy between the 2 groups. Conclusion: Hyponatremia, a common electrolyte disturbance in patients with UC, is associated with increased mortality, prolonged hospitalizations, elevated healthcare costs, and a higher incidence of complications relative to patients without hyponatremia. Early detection and prompt, effective management of this condition are critical for optimizing clinical outcomes in hospitalized individuals.