Acute kidney injury at a tertiary nephrology referral center: predictors of renal recovery and in-hospital mortality

Acute kidney injury (AKI) is a global health problem associated with substantial morbidity, mortality, and healthcare costs. Despite advances in prevention and management, in-hospital mortality remains high, particularly among critically ill patients. To determine incidence, risk factors of AKI among patients admitted to Mansoura Nephrology and Dialysis Unit (MNDU), a tertiary nephrology referral center in Dakahlia governorate, Egypt, over one year, and to identify predictors of renal recovery at discharge and in-hospital mortality. This prospective observational study was conducted from June 2022 to May 2023 and included adult patients admitted with various kidney disorders. Patients were classified into AKI and non-AKI groups according to KDIGO 2012 criteria. Clinical, laboratory, and outcome data were analyzed, and multivariable regression analyses were used to identify independent predictors of in-hospital mortality and renal recovery after AKI. A total of 839 patients were enrolled, including 330 (39.3%) with AKI and 509 (60.7%) without AKI. The most common pathophysiological causes of AKI were pre-renal (54.2%) followed by intrinsic renal (38.5%) one. In-hospital mortality was significantly higher in AKI than non-AKI group (17.3% vs. 3.8%), with septic shock being the leading cause of death (84.2%). Among patients with AKI, 45.2% achieved complete renal recovery, 21.8% had partial recovery, and 33.0% had no recovery at discharge. On multivariable logistic regression analyses, KDIGO Stage 3 AKI (adjusted OR 0.277, P = 0.046), kidney replacement therapy (adjusted OR 0.409, P = 0.004), and requirement of vasopressor therapy (adjusted OR 0.041, P < 0.001) were independently associated with lower odds of renal recovery, whereas necessity of vasopressor therapy emerged as the only independent predictor of in-hospital mortality (adjusted OR 420.511, 95% CI 97.451–1814.543; P < 0.001). AKI was common among hospitalized patients and was associated with substantially increased in-hospital mortality. Vasopressor requirement was the strongest independent predictor of mortality, emphasizing the prognostic impact of hemodynamic instability and critical illness severity. Severe AKI (KDIGO Stage 3), kidney replacement therapy, and vasopressor necessity were independently associated with reduced renal recovery at discharge. These readily available clinical indicators may support early risk stratification and guide closer monitoring of high-risk patients.