Continuous flow peritoneal dialysis: is there a need for it?

Continuous flow peritoneal dialysis: first experience in children with acute renal failure

BACKGROUND AND OBJECTIVES

Acute renal failure can be treated with different dialysis modalities, depending on patient characteristics and hospital resources. Peritoneal dialysis (PD) can be first choice in situations like hypotension, disturbed coagulation, or difficult venous access. The main disadvantage of PD is the relatively limited efficacy. The aim of this study was to investigate whether continuous flow peritoneal dialysis (CFPD) is a more effective treatment than conventional PD in acute renal failure.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A pilot study was performed at The Red Cross University Hospital in Cape Town in six patients. Patients were treated with both CFPD and conventional PD for 8 to 16 hours. CFPD was performed with two bedside-placed catheters. After initial filling, dialysate flow rate (100 ml/1.73 m2 per minute) was maintained with an adapted continuous venovenous hemofiltration machine. Ultrafiltration flow rate was set at 2.5 ml/1.73 m2 per minute.

RESULTS

Mean ultrafiltration was 0.20 ml/1.73 m2 per minute with conventional PD versus 1.8 ml/1.73 m2 per minute with CFPD. Mean clearances of urea and creatinine were 5.0 and 7.6 ml/1.73 m2 per minute with conventional PD versus 15.0 and 28.8 ml/1.73 m2 per minute with CFPD, respectively. No complications occurred.

CONCLUSIONS

In this first report of CFPD in six pediatric patients with acute renal failure, CFPD was on average three to five times more effective for urea and creatinine clearance and ultrafiltration than conventional PD, without any complications observed. CFPD has the ability to improve therapy for acute renal failure.

What's new in peritoneal dialysis: biocompatibility and continuous flow peritoneal dialysis

PURPOSE OF REVIEW

This review examines recent developments in the understanding of the effect of conventional, bioincompatible peritoneal dialysis fluids on structural and functional changes in the peritoneal membrane. Emphasis is placed on the clinically relevant outcome of failure of long-term peritoneal dialysis. Therapeutic strategies to prevent technique failure, including the use of new peritoneal dialysis fluids and continuous flow peritoneal dialysis, are explored.

RECENT FINDINGS

Long-term (greater than 6 months) exposure to new peritoneal dialysis fluids with physiologic pH, lower lactate concentrations, or lower concentrations of glucose degradation products results in improved leukocyte cytokine release, ultrafiltration, and mesothelial cell mass, respectively. Continuous flow peritoneal dialysis allows efficient small molecule removal using dialysate with lower glucose concentration and possibly less glucose degradation products. Recent technical advances include creation of a double-lumen peritoneal dialysis catheter, and methods of monitoring intra-abdominal pressure and ultrafiltration.

SUMMARY

Though initial reports with biocompatible peritoneal dialysis fluids are promising, the efficacy of these new solutions in preventing long-term peritoneal dialysis failure is unproven. Conditions in which new peritoneal dialysis fluids may be beneficial are suggested. Continuous flow peritoneal dialysis requires substantial technical improvements before this technique can be widely accepted.