Blood purification with continuous veno-venous hemofiltration in patients with sepsis or ARDS: a systematic review and meta-analysis

INTRODUCTION: Severe inflammatory conditions, as severe sepsis/septic shock and acute respiratory distress syndrome (ARDS), are related to high morbidity and mortality. We performed a meta-analysis of randomized trials to assess if blood purification with continuous veno-venous hemofiltration (CVVH) reduces mortality in these settings. EVIDENCE ACQUISITION: Online databases were searched for pertinent studies up to March 2017. We included randomized-controlled trials on the use of CVVH as blood purification technique in comparison to conventional therapy in adult patients with severe sepsis/septic shock or ARDS but no acute kidney injury needing renal replacement therapy. EVIDENCE SYNTHESIS: Eleven studies and 679 patients were included in the analysis. Patients who received CVVH had significantly lower mortality compared to conventional therapy (96 of 351 [27.35%] patients in the CVVH group vs. 129 of 328 [39.33%] in the conventional therapy group, OR=0.58 [95% CI: 0.42, 0.81], P=0.002, I-2=10%, number needed to treat: 8) at longest follow-up available. CONCLUSIONS: Overall, low-quality evidence indicates that blood purification with CVVH might be associated with a significant reduction in mortality when performed in patients with sepsis or ARDS. The evidence is still insufficient to support a definitive conclusion of benefit. Further high-quality randomized controlled trials, adequately powered for mortality, are needed to clarify the impact of CVVH on these conditions.