Continuous blood purification as an adjunctive treatment in severe inflammatory diseases including sepsis

Sepsis and SIRS are characterized by a massive and uncontrolled release of inflammatory mediators into the circulation. The inflammatory turmoil causes biological alterations, hemodynamic instability, and tissue damage. Continuous renal replacement therapy (CRRT) may offer an interesting way to restore disturbed homeostasis by significantly reducing the inflammatory load.The most intensely debated item regarding continuous hemofiltration was the filtration dose needed to obtain the best outcome at the least untoward effects. Therefore, we prepared the path for a large randomized trial [the IVOIRE (hIgh VOlume in Intensive caRE) trial] that compared standard dose (35 ml/kg/h) with high dose (70 ml/kg/h) continuous hemofiltration as adjunctive treatment of septic shock complicated by acute kidney injury (AKI). Ultimately, the IVOIRE trial showed that mortality at 90 days was not different between both dose groups but appeared to be much lower as compared to similar studies that included less severely ill patients. This unexpectedly low mortality (approximately 50 %) may be explained by a more early start of hemofiltration at a lower level of kidney damage (i.e. "Injury" instead of "Failure", according to the standardized RIFLE classification for AKI). In summary, the results of the IVOIRE trial strongly argue against using a hemofiltration dose exceeding 35 ml/kg/h for adjunctive treatment of septic shock with AKI but suggest that hemofiltration is best and safely initiated at RIFLE "Injury" stage.To date, CRRT remains the only valid and performing technique for hemodynamic unstable, in particular septic, patients with AKI. Future studies should focus on the use of new filtration membranes and sorbents.