CONTINUOUS FLOW-THROUGH PERITONEAL-DIALYSIS (CFPD) - COMPARISION OF EFFICIENCY TO IPD, TPD, AND CAPD IN AN ANIMAL-MODEL

Objective: To determine whether continuous flow-through peritoneal dia lysis (CFPD), a treatment schedule in which peritoneal dialysate is in fused continuously into one part of the abdomen (over the liver) and i s drained from a distant part of the abdomen (the pelvis), can provide greater clearance than continuous ambulatory peritoneal dialysis (CAP D), tidal peritoneal dialysis (TPD), or intermittent peritoneal dialys is (IPD). Design: A prospective study comparing four schedules of peri toneal dialysis in the awake, normal dog, using glucose clearance as a substitute for urea clearance. Methods: We placed two chronic dialysi s catheters into the abdomen of anesthetized dogs (with intraperitonea l portions of fluted or miniature column-disc design). On successive d ays, with the dogs awake and prone, we performed peritoneal dialysis f or 4 hours with 1.5% dialysate according to one of four schedules, eac h with 2 L maximum intraperitoneal volume: CFPD (unidirectional flow a t an average of 3.6 L/hr), IPD (2 L/hr), TPD (average of 3.6 L/hr, 1 L residual volume), and CAPD (2 L/4 hr). Glucose and urea clearances we re calculated from brood and peritoneal concentrations and dialysate f low rates. Results: Stabilized glucose clearances (from 60 to 240 minu tes) averaged 11 +/- 5 mL/min for IPD, TPD, and CFPD, and 5 +/- 2 mL/m in for CAPD. However, glucose clearances of CFPD were 13 +/- 6 mL/min when the intraperitoneal volume was maintained at 800 - 1000 mL, and 1 6.5 +/- 6 mL/min when flow rate was 6 L/hr. Urea clearances were twice the measured glucose clearances. Conclusion: When CFPD is performed w ith an appropriate intraperitoneal volume and flow, it is the most che mically effective method of peritoneal dialysis in removing small mole cules like urea.