Etiology and Clinical Outcomes of Acute Kidney Injury in the Emergency Department: A 10-Year Retrospective Cohort Study

Aim: Acute kidney injury (AKI) is a common and clinically critical condition encountered in emergency departments (EDs), yet long-term data on its etiological distribution and outcomes in ED populations remain limited. This study aimed to evaluate the epidemiology, clinical characteristics, and short-term outcomes of AKI cases presenting to a tertiary ED over a 10-year period.Material and Methods: This retrospective cohort study included adult patients diagnosed with AKI in the ED between January 2015 and January 2025. AKI was defined and staged according to KDIGO criteria. Demographics, comorbidities, laboratory findings, etiological factors, KDIGO stage distribution, need for intensive care, and in-hospital mortality were recorded. Independent predictors of in-hospital mortality were identified using multivariate logistic regression analysis.Results: A total of 742 patients were included (mean age 68.4 ± 15.7 years; 58.0% male). The overall in-hospital mortality rate was 18.0%. Sepsis was the most common etiology (35.6%), followed by nephrotoxic drug exposure (27.6%) and dehydration or hypovolemia (21.8%). KDIGO Stage 3 accounted for 31.0% of cases and demonstrated significantly higher rates of ICU admission (37.8%) and mortality (39.5%). Non-survivors were significantly older and exhibited higher creatinine, urea, CRP, and potassium levels, as well as a higher prevalence of heart failure and chronic kidney disease (all p < 0.05). In multivariate analysis, age (OR 1.04), sepsis (OR 3.62), KDIGO Stage 3 (OR 4.88), CRP (OR 1.08 per 10 mg/L), admission creatinine (OR 1.21), and ICU admission (OR 3.31) were independent predictors of mortality (all p < 0.001).Conclusion: Over a 10-year period, AKI cases presenting to the ED demonstrated substantial clinical severity, with sepsis emerging as the predominant etiology. Higher KDIGO stage, sepsis, systemic inflammation, and elevated initial creatinine levels were strongly associated with in-hospital mortality. These findings highlight the importance of early risk stratification and timely multidisciplinary management, including early nephrology consultation, in ED patients with AKI.