Enhancement of peritoneal dialysis: the PD Plus concept

The need for a peritoneal dialysis modality capable of providing higher clearances of small solutes at a competitive cost with continuous ambulatory peritoneal dialysis (CAPD) has been identified. A new modality of therapy (PD Plus; Fresenius USA, Walnut Creek, CA), which is based on the principles of optimal dwell time and large exchange volumes while the patient is supine, is described. This technique combines automated cycles with a manual diurnal exchange. Seven patients were studied during CAPD and while on PD Plus. Peritoneal Kt/Vurea increased from 0.22 +/- 0.04 to 0.29 +/- 0.07 (P < 0.002), creatinine clearance from 37.69 +/- 2.45 to 51.14 +/- 8.34 L/wk/1.73 m2 (P < 0.005), and normalized protein catabolic rate from 0.74 +/- 0.14 to 0.80 +/- 0.15 g/kg/d during CAPD and PD Plus, respectively, with a mean increase in dialysis solution volume of only 2.76 L. A comparative cost-efficiency analysis demonstrated a highly significant increase in dialysis dose (delta Kt/Vurea 57%) for a small increase in cost (6%) between CAPD and PD Plus. The data suggest that a significant increase in dialysis dose is possible with a minimal increase in the cost of therapy.