Continuous flow peritoneal dialysis: current state-of-the-art and obstacles to further development

Peritoneal dialysis (PD) is still underutilized as home based renal replacement therapy and in-patient treatment of acute renal failure. Hindering the expansion of PD is poor solute clearance, which is a result of the intermittent dwell technique. Continuous flow PD is an old concept that has demonstrated urea clearances from 2-5 times higher than standard PD. It relies on a 2-3 l dwell volume and continuous dialysate flow at 100-300 ml/min. This high flow rate dictates the need for an efficient dual lumen catheter, or two separate catheters with ports separated maximally, as well as a means to generate or regenerate large volumes of fluid. A modified hemodialysis system can easily be adapted to regenerate sterile peritoneal dialysate, and a dual lumen catheter with excellent flow characteristics has been designed. Ultrafiltration control and a means to accurately balance transperitoneal with external ultrafiltration persist as technical challenges. Continuous flow PD remains an attractive modality for daily home dialysis and treatment of acute renal failure.