Continuous cyclic peritoneal dialysis led to lower rates of peritonitis and dialysis-related hospital admission than continuous ambulatory peritoneal dialysis for patients with renal failure
ACP J Club. 1994 July-Aug;121:12. doi:10.7326/ACPJC-1994-121-1-012
de Fijter CW, Oe LP, Nauta JJ, et al. Clinical efficacy and morbidity associated with continuous cyclic compared with continuous ambulatory peritoneal dialysis. Ann Intern Med. 1994 Feb 15;120:264-71.
To compare continuous ambulatory peritoneal dialysis with a Y-connector (CAPD-Y) with continuous cyclic peritoneal dialysis (CCPD) in patients with end-stage renal failure.
Randomized controlled trial of 4.5 years' duration.
University hospital in the Netherlands.
97 patients (mean age 55 y, 46% women) with end-stage renal failure entering the dialysis program. Exclusion criteria were previous serious abdominal inflammations with adhesions and ostomies. 13 patients dropped out before starting dialysis, and 2 patients regained kidney function after starting dialysis. 82 patients were followed. The median duration of treatment was 17.5 months for CAPD-Y patients (range 4 to 32 mo) and 19.5 months for CCPD patients (range 1.5 to 43 mo).
Patients were randomly assigned to receive CAPD-Y (n = 50) or CCPD (n = 47) after stratification by age and sex. All patients received standardized training for home peritoneal dialysis (PD). Patients assigned to CAPD-Y used Y-set connectors without disinfectant and did 3 to 5 daily 2-L exchanges. Patients assigned to CCPD used an automated cycler providing 4 to 5 nocturnal cycles and 1 diurnal cycle.
Main outcome measures
Survival; hospitalization rates; infectious morbidity; and adequacy of dialysis assessed by clinical measures of blood pressure control, laboratory values, nerve conduction velocities, and Karnofsky score (measure of patients' performance status on a scale of 0 [death] to 100 [no evidence of disease]).
During the 4.5-year follow-up, 2 patients using CAPD-Y died compared with 4 patients using CCPD. Adequacy of dialysis did not differ between patients using CAPD-Y and CCPD. The mean number of hospitalizations per patient-year was higher for CAPD-Y than for those using CCPD (1.0 vs 0.6, P = 0.02). Patients receiving CAPD-Y had more episodes per year of peritonitis compared with patients receiving CCPD (0.94 vs 0.51 episodes per patient-year, 95% CI for the 0.43 difference 0.1 to 0.8, P = 0.03).
Continuous cyclic peritoneal dialysis was as effective as continuous ambulatory peritoneal dialysis for patient and technique survival and dialysis adequacy and had lower rates of peritonitis and dialysis-related hospital admission.
Source of funding: Dutch Ministry of Education and Sciences.
For article reprint: Dr. C.W.H. de Fijter, Department of Internal Medicine, Division of Nephrology, Free University Hospital, P.O. Box 7057, 1007 MB Amsterdam, the Netherlands. FAX 31-20-647-5733.
Approximately 17% of patients on dialysis in the United States and 37% in Canada receive chronic PD; 85% to 90% of these patients receive CAPD. A typical CAPD prescription requires 4 daily exchanges with 2 litres of dialysate instilled by gravity into the peritoneal cavity after used dialysate is drained. A bag of peritoneal dialysate is manually connected and disconnected for each exchange. For CCPD, a cycler automatically provides 4 to 5 nighttime exchanges, with a single diurnal cycle. Peritonitis, the most important complication of PD, is usually caused by bacterial contamination of the dialysis system during connection and disconnection, or extension of bacteria from the peritoneal catheter tunnel. Y-set connectors, which allow the PD system to be flushed (with or without a disinfectant rinse) before fresh dialysate is placed into the abdomen, have dramatically reduced CAPD peritonitis rates (1).
The most important findings in this well-done study were reduced rates of peritonitis and dialysis-related hospital admissions in CCPD patients compared with CAPD-Y patients. The most likely explanation for this is that fewer manual connections and disconnections are required with CCPD than with CAPD. Peritoneal dialysis also impairs peritoneal host defense mechanisms involving peritoneal macrophages, IgG, and complement. The long daytime dwell of CCPD may allow recovery of these defense mechanisms, which are continually diluted out with CAPD regimens and rapid nocturnal CCPD cycles (2).
CCPD is more expensive than CAPD, primarily because of the cost of the cycler and extra dialysate. Reduced hospital admissions and peritonitis treatments could decrease this difference. Indications for CCPD, rather than CAPD, may include very young or advanced age; ultrafiltration failure, inadequate dialytic clearance with CAPD, or both; recurrent hernias; and patient preference.
Jeffrey S. Berns, MD
The Graduate HospitalPhiladelphia, Pennsylvania, USA