A Proposed Peritoneal-Based Wearable Artificial Kidney

Ideally, an artificial kidney should simulate the normal kidney in providing continuous metabolic control, removal of toxins, and unrestricted patient freedom. Of the dialysis procedures available, continuous ambulatory peritoneal dialysis (CAPD) comes the closest to this ideal but provides inadequate dialysis and fails to remove protein-bound toxins. A continuous, wearable, peritoneal-based artificial kidney is proposed in which the spent peritoneal dialysate is regenerated using a REDY sorbent cartridge one-tenth the size of the present cartridge, with the urease chemically bound to an inert support to eliminate the possibility of its displacement by protein in the spent dialysate. To simplify the flow path and to increase clearance, the dialysate flow will be through the peritoneal cavity using a dual lumen catheter instead of the traditional in/outflow through a single catheter. At a flow rate of 4 L/hour through the peritoneal cavity, of which 2 L/hour will pass through the sorbent cartridge, it is estimated that the weekly Kt/V will be 6.5 and the creatinine clearance will be 250 L. In addition, any protein in the spent peritoneal dialysate will be stripped of toxins by the sorbents and returned to the patient, thereby minimizing protein loss. The only disposables will be the sorbent cartridge and infusate, which will be changed every 8 hours.