Investigation of abnormal electrolyte values and post-discharge outcomes in geriatric patients admitted to the emergency department

With the increasing proportion of the geriatric population, the rate of elderly patients presenting to emergency departments has risen significantly. Age-related physiological changes, decreased renal reserve, polypharmacy, and comorbidities predispose older adults to electrolyte disturbances, which can have a substantial impact on clinical outcomes. Even in elderly individuals, the impact of electrolyte levels considered "borderline" and not routinely treated has not been fully elucidated regarding mortality, morbidity, and short-term readmissions. The aim of this study was to evaluate the frequency of abnormal and borderline sodium, potassium, calcium, magnesium, chloride, and phosphorus levels in geriatric patients presenting to the emergency department, and to investigate their relationship with re-admission, hospitalization, and mortality within 72 hours after discharge. This retrospective descriptive study was conducted in the Emergency Department of Düzce University Medical Faculty Hospital among patients aged 65 years and older. Patients were categorized based on laboratory reference intervals, and clinical outcomes were analyzed statistically. The findings demonstrated that even borderline electrolyte deviations were significantly associated with increased rates of 72-hour re-admission and hospitalization among geriatric patients. Particularly, slight alterations in sodium, potassium, and phosphorus levels were found to adversely affect short-term clinical outcomes. In conclusion, the assessment of electrolyte disturbances in elderly patients should not rely solely on clearly abnormal laboratory values. Borderline electrolyte changes may also carry clinical significance and should be carefully considered in risk stratification and discharge planning. These findings emphasize the importance of early recognition and individualized management of electrolyte abnormalities in geriatric emergency care. Keywords: Geriatrics, Electrolyte Disorders, Borderline Values, Emergency Department, Morbidity, Mortality Prediction