Timely renal replacement therapy linked to better outcome in patients with sepsis-associated acute kidney injury

BACKGROUND: Recent studies suggest that acute kidney injury (AKI) can be treated with renal replacement therapy (RRT). However, its benefits to patients with sepsis-associated AKI (SA-AKI), which is linked to high mortality and morbidity rates, remain under debate. The aim of this study was to compare the outcomes of different RRT strategies for patients with SA-AKI. METHODS: This retrospective study evaluated patients who were admitted to the hospital with sepsis and developed SA-AKI during hospitalization from 1st January 2014 to 31st January 2019. Mortality, renal recovery, and systemic organ function at 90 days following admission were compared between the RRT group (RG) and non-RRT group (NRG), as well as the early-RRT group (EG) and delayed-RRT group (DG). The groups were defined according to the time from admission to RRT initiation (criterion 1, EG1 and DG1) and Kidney Disease Improving Global Outcomes (KDIGO) classification (criterion 2, EG2 and DG2). Categorical and continuous variables were compared using the chi-squared test or Fisher's exact test and Student's t-test or Wilcoxon test. Kaplan–Meier curves were constructed to determine the unadjusted survival rates for the different subgroups. RESULTS: A total of 116 patients were included in this study; of those, 38 received RRT and 46 expired within 90 days. Among different strategies of RRT, there were no significant differences found in 90-day mortality (RG vs. NRG: χ(2)=0.610, P=0.435; EG1 vs. DG1: χ(2) =0.835, P=0.360; EG2 vs. DG2: χ(2)=0.022, P=0.899) and renal recovery. However, the values of change in sequential organ failure assessment (ΔSOFA)(max–min) of patients in the EG and RG were significantly higher than those recorded in the NRG (ΔSOFA(RG)=7.0, ΔSOFA(NRG)=3.60, ΔSOFA(EG1)=9.00, ΔSOFA(EG2)=6.30; P<0.050). Also, the 90-day renal recovery in the EG was better than that noted in the DG with criterion 1 (87.5% vs. 38.5%, respectively, χ(2)=10.425, P=0.032), suggesting that RRT (especially timely RRT) may be beneficial to the restoration of systemic organ function in patients with SA-AKI. CONCLUSION: RRT did not reduce the 90-day mortality among patients with SA-AKI. However, timely RRT may benefit the restoration of systemic organ function, thereby improving the quality of life of patients.