Epidemiology of acute kidney injury (AKI) and sepsis-associated AKI in critically ill patients: A retrospective cohort study

Background and Aims: Acute kidney injury (AKI) is a common complication in critically ill patients and is associated with poor outcomes. However, data on the epidemiology of AKI and sepsis-associated AKI (SA-AKI) from Indian intensive care units (ICUs) remain limited. This study aimed to develop a risk prediction model for SA-AKI and evaluate the incidence and outcomes of AKI in a tertiary care ICU. Material and Methods: This retrospective, single-center observational study included adult patients admitted to a multidisciplinary ICU between January and December 2020. AKI was defined according to the Kidney Disease: Improving Global Outcomes criteria, and SA-AKI according to the Acute Disease Quality Initiative 28 consensus statement. Multivariable logistic regression was used to identify predictors of SA-AKI, and Kaplan–Meier analysis was performed to assess survival. Results: Of 379 patients, 253 (66.7%) developed AKI, with 208 (82.0%) having AKI at ICU admission. SA-AKI accounted for 81.2% of AKI cases. In the SA-AKI prediction model, lower serum bicarbonate levels and higher APACHE II scores were independently associated with the development of SA-AKI, and the model demonstrated good discriminatory performance (AUC 0.839). Compared with patients without AKI, those with AKI had higher ICU mortality (47.8% vs. 12.6%; P < 0.001). AKI was also associated with significantly reduced survival (hazard ratio 2.74, 95%CI: 1.62–4.64; P < 0.001). Conclusions: AKI, predominantly SA-AKI, was highly prevalent among critically ill patients and was associated with worse outcomes. The proposed SA-AKI prediction model showed promising performance but requires external validation before clinical application.