Renal replacement therapy quantification in acute renal failure.

Recent results suggest that RRT delivery affects outcome in critically ill ARF patients. These data have generated interest in the use of RRT quantification methods, originally developed for ESRD patients, in ARF. However, the fundamental differences between ARF and ESRD, with respect to both patient and therapy characteristics, must be fully appreciated before making this extrapolation. These differences may render many of the simplified ESRD quantification formulae of little use in ARF. As is the case in ESRD, the use of clearance-based methods to compare disparate therapies is problematic in ARF. Although the optimal technique for RRT quantification in ARF remains to be defined, dialysate-side quantification may be the most rational approach for the future, as has been suggested for ESRD patients [43].