Epidemiology of sepsis-associated acute kidney injury in the ICU with contemporary consensus definitions.

BACKGROUND

The definition of sepsis-associated acute kidney injury (SA-AKI) was updated in 2023. This study aims to describe the epidemiology of SA-AKI using updated consensus definition and to evaluate clinical outcomes.

METHODS

The study was a retrospective cohort analysis conducted at two academic medical centers. Adult patients admitted to intensive care units (ICU) between 2010 and 2022 were included and categorized as SA-AKI, sepsis alone, or AKI alone. SA-AKI was further classified by time of onset (early < 2 days from sepsis diagnosis vs. late 2-7 days following sepsis diagnosis) and presence of septic shock. Clinical outcomes included hospital mortality and major adverse kidney events (MAKE = death, kidney replacement therapy, or reduced kidney function from baseline) at discharge.

RESULTS

187,888 adult ICU patients were included, and SA-AKI was found in nearly half of sepsis patients and about 1 in 6 ICU admissions. 1 in 4 patients with SA-AKI died during hospitalization and 37.7% experienced at least one MAKE by hospital discharge. Compared to sepsis or AKI alone, SA-AKI was associated with higher mortality (adjusted HR 1.59; 95% CI 1.51-1.66) and higher odds of MAKE (adjusted OR 3.35; 95% CI 3.19-3.51). The early clinical phenotype of SA-AKI was most common, with incident AKI decreasing daily from sepsis onset. The presence of septic shock significantly worsened outcomes.

CONCLUSIONS

Applying updated consensus definitions highlights the high prevalence of SA-AKI in the ICU and its significant associated morbidity and mortality. Outcomes differ based on clinical phenotypes, including the timing of SA-AKI onset and the presence of shock.