Early versus late initiation of renal replacement therapy in critically ill patients with acute kidney injury after cardiac surgery: A systematic review and meta-analysis

Objective To investigate the impact of early versus late renal replacement therapy (RRT) on mortality in patients with acute kidney injury (AKI) after cardiac surgery. Design Meta-analysis of 9 retrospective cohort studies and 2 randomized clinical trials extracted from the Medline engine from 1950 to 2013. Setting University medical school. Participants 841 Patients. Interventions None. Measurements and Main Results A total of 841 patients were studied. Pooled estimates of the odds ratio with 95% confidence interval using a random-effect model were conducted as well as the heterogeneity, publication bias, and sensitivity analysis. Primary outcome was 28-day mortality, and secondary outcome was the intensive care unit (ICU) length of stay. The 28-days mortality rate was lower in the early RRT group (OR = 0.29, 95% CI, 0.16-0.52, p<0.0001, NNT = 5). Heterogeneity was high (I2 = 56%), and publication bias was low. Secondary outcome suggested 3.9 (1.5-6.3) days shorter ICU stay in the early RRT group, p<0.0001, with extremely high heterogeneity (I² = 99%), and low publication bias. Specifically, studies before 2000 and studies with mortality less than 50% in the late RRT group reported significantly higher odds ratio and mean difference than overall value favoring early RRT. Conclusion Early initiation of RRT for patients with AKI after cardiac surgery revealed lower 28-days mortality and shorter ICU length of stay. However, this was based on 11 studies of various qualities with very high heterogeneity of results. Defining treatment guidelines needs further research with a larger and better database.