Current standards for dialysis adequacy

Multiple lines of evidence suggest that inadequately prescribed or delivered dosage of hemodialysis is associated with increased morbidity and mortality. Conversely, retrospective studies indicate that increased levels of hemodialysis reverse this trend of poor outcome. The results of the National Cooperative Dialysis Study (NCDS), a prospective and randomized trial, suggested that urea kinetic modeling was a valid method of quantifying the dose of hemodialysis delivered and also identified a level of treatment below which a number of adverse events occurred. In the ensuing years, urea kinetic modeling has been increasingly applied to quantitate dialysis. The application of the NCDS results as well as the limitations of the study are reviewed, and the modifications in applying urea kinetic modeling due to urea rebound are discussed. To assess the impact of newer membranes and higher levels of dialysis on an older hemodialysis population with more comorbid conditions than the subjects studied in the NCDS, a 5-year, multicenter, prospective and randomized trial, the HEMO Study, has recently been initiated.