Intensity of continuous renal replacement therapies in patients with severe sepsis and septic shock: a systematic review and meta-analysis.

The purpose of this study was to assess the efficacy of continuous renal replacement therapies in patients with severe sepsis or septic shock, with or without acute kidney injury. We performed a systematic search in Medline, Embase, Web of Knowledge, Cochrane Library and Clinicaltrials.gov and a hand search of the retrieved studies. We included both randomised controlled clinical trials and subgroups of randomised trials that assessed the effect of continuous renal replacement therapies (at traditional or high doses) and reported clinical outcomes in adult patients with severe sepsis or septic shock. The study selection and data extraction were performed by duplicate. Analysis of heterogeneity and meta-analysis was performed according to the Cochrane Collaboration guidelines for conducting systematic reviews of interventions. Twelve studies (1895 patients) met the inclusion criteria. Pooling of all studies resulted in a mortality risk ratio of 0.96 (95% confidence interval 0.83 to 1.12). The studies showed moderate statistical heterogeneity (I2 statistic 52%, P = 0.02). The effect on mortality was not modified (interaction P values non significant) by the dose of continuous renal replacement therapies, the severity of illness or the risk of bias. The available evidence suggests that these therapies in patients with severe sepsis or septic shock are not associated with an improvement in other outcomes such as haemodynamics, pulmonary gas exchange, multiple organ dysfunction syndrome or length of stay. The best available evidence does not support the routine use of continuous renal replacement therapies (at traditional or high doses) in patients with severe sepsis or septic shock.