Impact of Early Initiation of Continuous Renal Replacement Therapy in Critically Ill Patients with Acute Kidney Injury

Abstract

Background: Although continuous renal replacement therapy (CRRT) has become the most commonly used modality for critically ill patients with acute kidney injury (AKI), the optimal timing of initiation remains controversial. CRRT is usually initiated when conventional indications of AKI arise; however, preemptive therapy may be beneficial. We evaluated the prevalence of preemptive and conventional CRRT initiation in critically ill patients and compared the associated 90-day mortality and renal recovery. Methods: This retrospective study was performed in 2 tertiary centers between 2014 and 2017. Patients were divided into preemptive and conventional groups according to CRRT indications at the time of initiation. The primary clinical outcomes were 90-day mortality and renal recovery. Renal recovery was defined as a creatinine clearance of ≥15 mL/min and no need for renal replacement therapy for an additional 90 days. Results: Patients with preemptive initiation showed higher diastolic blood pressure, higher bicarbonate level, lower blood urea nitrogen, and lower initial 6-h urine output at the time of initiation. More required simultaneous extracorporeal membrane oxygenation. This group showed a significantly lower 90-day mortality and higher renal recovery rate. In multivariate analysis, late initiation of CRRT remained an independent risk factor for increased 90-day mortality and lack of renal recovery in survivors. Conclusion: Our study demonstrated that early preemptive CRRT initiation is associated with significantly lower 90-day mortality and higher renal recovery. Additional large-scale randomized controlled trials are needed to determine the optimal timing of therapy.