Adequacy of dialysis.

Despite improvements in the delivery of dialysis, morbidity and mortality remain excessively high in end-stage renal disease patients. Multiple lines of evidence suggest that inadequate dialysis is responsible these trends. The limits of our understanding of the influence of dialysis dose on mortality and morbidity are discussed. In that context, the relationship between dialysis dose and nutritional status of dialysis patients is also reviewed. The best marker for adequacy of dialysis is yet to be determined. However, urea as a surrogate for small molecular weight solute clearance, has been demonstrated by many studies to be a parameter of adequacy, both in hemodialysis and peritoneal dialysis populations. The application of kinetic modeling of urea is discussed for hemodialysis. The new insights that will be forthcoming at the conclusion of the National Institute of Health HEMO study should help to define an optimal dose of dialysis.