Innovative peritoneal dialysis: flow-thru and dialysate regeneration

As the peritoneal dialysis (PD) patient's residual renal function declines, the dialysis dose must be increased. However, the options for increasing the dose are limited to increasing the number of exchanges and/or the volume of each exchange. A review of the literature indicates that the dialysis dose can be significantly increased by flow-through PD, wherein the dialysate flows continuously into the peritoneal cavity through one catheter and out another and/or by regenerating the spent dialysate, thereby, significantly increasing the dialysate flow rate. Flow-thru PD has been used with and without dialysate regeneration. Regeneration has been used with standard inflow/outflow PD. In nearly all cases, substantially increased clearances over standard PD were obtained with reported urea and creatinine clearances as high as 58 and 48 ml/min, respectively. Applying flow-thru to the PD patient would require two catheters or a dual lumen catheter, and to obtain optimum clearances, the dialysate should be pumped through the peritoneal cavity at a high flow rate. Regenerating the dialysate allows high dialysate flow rates while reducing the total amount of dialysate required. For the continuous ambulatory peritoneal dialysis (CAPD) patient, the unit would have to be wearable; whereas for the patient on automated PD, flow-thru and/or regeneration PD could be incorporated into the equipment. With sorbent regeneration, the protein in the spent PD could be purified and returned to the patient thereby minimizing protein loss, increasing ultrafiltration, and enhancing the removal of protein-bound metabolic toxins.