Continuous renal replacement therapy in the treatment of acute renal failure: critical assessment is required.

A continuous approach to renal replacement therapy (CRRT) for critically ill patients was introduced in 1977 and was hailed almost immediately as an improved alternative to intermittent hemodialysis (IHD). Now that CRRT has been in clinical practice for three decades, it is fair to ask whether research-based evidence (rather than expert opinion) supports the use of this complex technology in comparison to IHD. Several randomized clinical trials have compared the outcomes of CRRT and IHD. In one trial, patients assigned to CRRT had a significantly higher intensive-care mortality rate. In other recent trials, there has been no significant difference in outcome. A meta-analysis of observational studies similarly shows no benefit of CRRT versus IHD, with recent trends actually favoring IHD. While considerable attention has been focused on perceived benefits of CRRT compared to IHD, comparatively less attention has been focused on the potential for increased risks. When examining the totality of evidence from recent observational studies and clinical trials, there is no convincing evidence to support superiority of CRRT over IHD in the treatment of critically ill patients with ARF.