Single‐Pass Continuous Flow Peritoneal Dialysis Using Two Catheters

Abstract

With a renewed interest in continuous flow peritoneal dialysis (CFPD), our standard practice of implanting a second catheter in those patients facing access failure provided us the opportunity to perform acute studies on CFPD in these patients, since it temporarily provided us with two catheters. Four patients were studied, with a total of five studies performed. A standard protocol was followed utilizing 1.5% dextrose solution, a 2 L fill, an inflow rate of 200 ml/min with a proportionate outflow for a 4-hour session. A full drain was performed at the end of the study. Our results provided us with a mean effective peritoneal clearance for urea (KpeU) and creatinine (KpeCr) of 40 ml/min and 28 ml/min, respectively, and a mean ultrafiltration rate (Qf) of 13.4 ml/min. Our average mass transfer coefficient (MTC) for urea was 40 ml/min, consistent with kinetic modeling and historical data. The Kpe, MTC, and Qf achieved are significantly higher than other investigators, which could possibly be explained by those obtained by two separate catheters resulting in adequate mixing of the dialysate. These clinical results provide a solid foundation for the future development of this PD modality.

Peritoneal Dialysis for Acute Kidney Injury

“…Continuous flow peritoneal dialysis has been shown in chronic adult PD patients to increase the clearance of small solutes 3-to 8-fold and to significantly increase ultrafiltration compared to conventional PD (100)(101)(102). In one of the few studies of this dialysis technique in patients with AKI, Ponce et al used CFPD in two adult AKI patients and achieved a clearance similar to that reported with extracorporeal blood purification methods and an ultrafiltration rate of 200 -500 mL/h (45).…”

“…5 PDI rate of between 100 -300 mL/min and a glucose concentration of 1.5%. With this prescription, greatly improved ultrafiltration and clearances were obtained (100)(101)(102)(103). However, these studies were conducted with stable chronic PD patients.…”

“…Tubing from the outflow catheter should also run through a pump which is set at a slightly faster rate (2.5 mL/1.73m 2 /min) than the inflow pump. A transducer should preferably be connected to this circuit which is set to alarm if the outflow pressure becomes excessive (101,102).…”

“…Single-pass CFPD circuits have been described in adult patients using only an inflow pump and partially occluding outflow to maintain satisfactory flow (102,103). Purely gravity-assisted CFPD has also been described in children, but without a fixed intraperitoneal volume (104).…”

What Is the Role of Automated Peritoneal Dialysis and Continuous Flow Peritoneal Dialysis?

“…Conventional modalities of APD using the intermittent technique can almost double the clearances obtained with CAPD. However, CFPD can achieve clearances close to the mass transfer area coefficient for urea or approximately 40 ml/min [11].…”