Severe sepsis-associated acute kidney injury and outcomes: a longitudinal cohort study

Background: Sepsis-associated acute kidney injury (SA-AKI) is common among patients admitted to the intensive care unit (ICU) with sepsis. Aims: This study aimed to demonstrate an association between an episode of SA-AKI and progression to dialysis dependence, with a view to identifying a cohort who may be suitable for intensive nephrology follow-up. Methods: Design: Retrospective data-linkage cohort study. Setting: Alice Springs Hospital ICU, 10-bed regional facility, housed in a 200-bed regional hospital, located in Central Australia. Participants: All patients admitted with a diagnosis code associated with sepsis between 2015 and 2017. Main outcome measures: Primary outcome was a composite measure comprising death or initiation of maintenance dialysis within 5 years of the index case of sepsis leading to ICU admission. Results: The unadjusted risk of the composite outcome was significantly higher in the SA-AKI group (odds ratio (OR) 3.22, 95% confidence interval (CI) 1.81–5.74, P < 0.01). This effect remains after adjustment for age, illness severity and co-morbidities (adjusted OR (aOR) 2.64, 95% CI 1.22–5.68, P = 0.01). Progression to maintenance dialysis was the primary driver of this effect (OR 7.56, 95% CI 2.23–25.65, P = 0.02), although it was modified by the effect of confounders (aOR 7.3, 95% CI 0.7–75.94, P = 0.10). Conclusions: These results demonstrate an association between an index episode involving SA-AKI and the composite outcome in a defined population. Identification of this group may allow intensive nephrology follow-up and secondary prevention with the goal of mitigating the risk of progression of disease with significant economic and personal benefits.