Fractional direct dialysis quantification: A new approach for prescription and monitoring hemodialysis therapy

We describe a new methodology, fractional direct dialysis quantification (FDDQ) utilizing the Fresinius(R) Dialysate Sampling Module (DSM), for quantitating total solute removal during hemodialysis (no). Our data demonstrate that this technique and Direct Dialysis Quantification (DDQ) yield virtually identical results. FDDQ, however, obviates the practical obstacles that have limited the applicability of DDQ. We discuss the theoretical and practical advantages of this methodology, as compared to urea kinetic modeling (UKM) with Kt/V, for prescribing and monitoring dialysis therapy. FDDQ provides reliable and accurate quantitative data of dialysis function and protein catabolic rate (PCR) independent of questionable theoretical assumptions and parameters required for UKM with Kt/V. It is simple to comprehend and apply. It permits easy comparison of standard and rapid high efficiency dialyses. It also facilitates the quantitative comparison of HD and continuous therapies (peritoneal dialysis and various types of continuous hemofiltration). FDDQ permits the use of other solutes, in place of or in addition to urea, for the quantitation of HD. Because of its simplicity and probable low cost, it can be used with each HD session. It will thus provide accurate data on delivered versus prescribed therapy. These features should permit more accurate monitoring and lead to a clearer understanding of the relationship of outcomes versus delivered dialysis dose, and consequently more effective adjustment of dialysis therapy.