Abstract
BACKGROUND: Renal replacement therapy (RRT) is essential in the presence of life-threatening complications associated with acute kidney injury (AKI). In the absence of urgent indications, the optimal timing for RRT initiation is still under debate. This meta-analysis aims to compare the benefits between early and late RRT initiation strategies in critically ill patients with AKI. METHODS: Studies were obtained from three databases [Medical Literature Analysis and Retrieval System Online (MEDLINE), Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus], searched from inception to May 2021. The selected primary outcome was 28-day mortality. Secondary outcomes included overall mortality, recovery of renal function (RRF) and RRT-associated adverse events. A random-effects model was used for summary measures. Heterogeneity was assessed through Cochrane I (2) test statistics. Potential sources of heterogeneity for the primary outcome were sought using sensitivity analyses. Further subgroup analyses were conducted based on RRT modality and study population. RESULTS: A total of 13 randomized controlled trials including 5193 participants were analysed. No significant differences were found between early and late RRT initiation regarding 28-day mortality [risk ratio (RR) 1.00; 95% confidence interval (CI) 0.89-1.12, I² = 30%], overall mortality (RR 1.00; 95% CI 0.90-1.12, I² = 42%) and RRF (RR 1.02; 95% CI 0.92-1.13, I² = 53%). However, early RRT initiation was associated with a significantly higher incidence of hypotensive (RR 1.34; 95% CI 1.17-1.53, I² = 6%) and infectious events (RR 1.83; 95% CI 1.11-3.02, I² = 0%). CONCLUSIONS: Early RRT initiation does not improve the 28-day and overall mortality, nor the likelihood of RRF, and increases the risk for RRT-associated adverse events, namely hypotension and infection.