Dose and efficiency of renal replacement therapy: continuous renal replacement therapy versus intermittent hemodialysis versus slow extended daily dialysis.

Acute kidney injury represents an independent risk of death in the intensive care unit and significantly contributes to in-hospital mortality. The only accepted treatment of severe acute kidney injury so far is renal replacement therapy, which is not a causative therapy but rather a life-support treatment. Renal replacement therapy can be performed by several different techniques: intermittent hemodialysis, slow extended daily dialysis, peritoneal dialysis, or continuous renal replacement therapy. There is controversy about which technique should be used, which dosage should be selected for each therapy, and whether the technique and/or the dose of renal replacement therapy may impact survival in critically ill patients. After a careful review of the recent literature, definitive conclusions cannot be drawn: Trials are in most cases underpowered and conducted over many years, in which significant changes in the practice of acute dialytic techniques have taken place. Other studies have described therapeutic modalities requiring a high level of specific expertise in the field and generally not easily reproducible in the routine practice. While practitioners are waiting for the ultimate trial to be published, we think it is worth reporting some broad concepts and few suggestions for renal replacement therapy prescription derived from current evidence and from the available experience.