Controlled trial of a Y-set dialysis delivery system to prevent peritonitis in patients receiving continuous ambulatory peritoneal dialysis

Peritonitis rates were compared in patients receiving continuous ambulatory peritoneal dialysis (CAPD) via either a Y-set dialysate delivery system or a standard system. Forty patients in each arm of the trial were matched for age (range 20–67 years, mean 49 years), and remained in the study for similar periods (range 3–36 months, mean 14·1 months). The observation time was 564 patient-months for each arm of the trial. There were 22 episodes of peritonitis in nine out of 40 patients using the Y-set and 57 episodes in 21 out of 40 patients using the standard system ( P = 0 ·005 Wilcoxon signed rank test for episodes, P = 0·02 McNemar's χ 2 test for patients). Peritonitis rates were one episode per 25 patient-months in the Y-set group, and one episode per 9·7 patient-months in the standard group. In the Y-set group there were significantly fewer episodes caused by coagulase-negative staphylococci and Acinetobacter spp. There was no difference in the rate of episodes caused by Staphylococcus aureus, streptococci, enterococci, corynebacteria, enterobacteria or pseudomonads. There was no difference in the incidence of catheter exit wound infections. The Y-set dialysis delivery system is effective in reducing peritonitis rates in CAPD patients caused by organisms derived from the commensal skin flora, principally coagulase-negative staphylococci, but does not reduce peritonitis caused by other organisms.