Impact of Early Continuous Kidney Replacement Therapy in Patients With Sepsis-Associated Acute Kidney Injury: An Analysis of the MIMIC-IV Database

Background: Renal replacement therapy (RRT) is an important treatment option for sepsis- associated acute kidney injury (AKI); however, the optimal timing for its initiation remains controversial. Herein, we investigated the clinical outcomes of early continuous kidney replacement therapy (CKRT), defined as CKRT initiation within 6 hours of sepsis-associated AKI onset, which was earlier than the initiation time defined in previous studies. Methods: We used clinical data sourced from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. This study included patients aged >= 18 years who met the sepsis diagnostic criteria and received CKRT because of stage 2 or 3 AKI. Early and late CKRTs were defined as CKRT initiation within 6 hours and after 6 hours of the development of sepsis- associated AKI, respectively. Results: Of the 33,236 patients diagnosed with sepsis, 553 underwent CKRT for sepsis- associated AKI. After excluding cases of early mortality and patients with a dialysis history, 45 and 334 patients were included in the early and late CKRT groups, respectively. After propensity score matching, the 28-day mortality rate was significantly lower in the early CKRT group than in the late CKRT group (26.7% vs. 43.9%, P = 0.035). The early CKRT group also had a significantly greater number of days free of mechanical ventilation (median, 19; interquartile range [IQR], 3-25) and vasopressor administration (median, 21; IQR, 5-26) than the late CKRT group did (median, 10.5; IQR, 0-23; P = 0.037 and median, 13.5; IQR, 0-25; P = 0.028, respectively). The Kaplan-Meier curve also showed that early CKRT initiation was associated with an improved 28-day mortality rate (log-rank test, P = 0.040). In contrast, there was no significant difference in the 28-day mortality between patients who started CKRT within 12 hours and those who did not (log-rank test, P = 0.237). Conclusion: Early CKRT initiation improved the survival of patients with sepsis-associated AKI. Initiation of CKRT should be considered as early as possible after sepsis-associated AKI onset, preferably within 6 hours.