Separating the Effects of Hemodialysis Dose and Nutrition: In Search of the Optimal Dialysis Dose

The renal community owes Dr. Frank Gotch a great debt for the contributions that he has made to clarify the relationship between urea clearance and the dose of dialysis. With John Sargent he developed the mathematical approach to hemodialysis (1). In his seminal publication he re-analyzed data of the National Cooperative Dialysis Study to establish the association between the theoretically derived Kt/V for urea and clinical outcomes (2). Although diffusion equations are well understood and are used in many fields of science, Dr. Gotch’s persistent and tireless efforts to identify and quantitate the specific aspects of this process in dialysis through formal kinetic modeling, yielding additionally the protein catabolic rate (PCR) (3), have been extremely valuable to both patients and clinicians alike. The continuing measurement of Kt/ Vurea in every dialysis unit is a lasting tribute to Dr. Gotch’s contributions. Accurate measurement of the dose of dialysis is important in part because of its relationship to patient outcomes and to the cost of dialysis. Further, the concepts underlying the dose of episodic hemodialysis, pioneered by Dr. Gotch, are of practical importance in understanding the role of residual renal function and in quantitateing the dose of continuous dialytic procedures. Kt/V has been found to be one of the key modifiable components of the practice of hemodialysis.