Abstract

Background

We aimed to study the role of aetiology, pre-existing chronic kidney disease (CKD) and infections in acute kidney injury (AKI) on renal outcome and mortality.

Methods

This retrospective study analysed patients with AKI admitted to a university nephrology department from January 1st, 2020 through December 31st, 2020. Aetiology of AKI, underlying renal disease in case of pre-existing CKD and presence of infections were assessed. Development of renal function and risk of death were studied with follow-up until January 31st, 2023.

Results

Of 1402 patients screened, 432 patients (30.8%, 67.9 ± 15.4 years) fulfilled the inclusion criteria, half of the population presented with advanced CKD. Even though CKD patients were more often in need of chronic dialysis at time of discharge (6.9% vs 4.5%, p < .001), duration of hospital stay was shorter and in-hospital mortality tended to be lower when compared to AKI without prior renal disease. Neither aetiology of AKI nor pre-existing CKD had an impact on the combined endpoint of end-stage kidney disease and mortality (log rank 0.433 and 0.909). Overall, septic patients showed the highest in-hospital mortality (23.5%) and longest hospital stay (30.0 ± 22.8 days, p < .001), while patients with urosepsis had the shortest hospitalisation time (9.7 days) with lowest risk for dialysis (4.4%). Of note, outcome did not differ in patients with AKI when considering the infectious status.

Conclusions

Overall renal outcome and mortality in AKI patients were not affected by the cause of AKI, pre-existent CKD or infectious status. Only severity of AKI had a negative impact on outcome.

Graphical abstract