MAJOR REDUCTION OF CAPD PERITONITIS AFTER THE INTRODUCTION OF THE TWIN-BAG SYSTEM

In recent years an impressive decrease in the incidence of CAPD-relate d peritonitis was observed in our centre, from 1.4 in the mid-eighties to 0.4 per patient year in 1991. In order to analyse which factors we re most responsible for this decline, the present study was performed. From the start of our CAPD programme in 1982 until September 1991, 10 0 patients were enrolled. For each patient, time elapsed from catheter insertion until first peritonitis episode was recorded. Outcome was m easured as the peritonitis-free interval in days. The following variab les have been evaluated: age, gender, type of catheter, type of system , presence of diabetes mellitus, leakage, break-in period, presence of an exit-site infection, and performing surgeon. Data were analysed fi rst by Kaplan-Meier product-limit estimate of survival (peritonitis-fr ee inter-val). Thereafter Cox proportional hazard analysis was applied to the data, providing a conditional probability of peritonitis at ea ch moment during follow-up, given a certain combination of risk factor s. Our results show that the system, in conjunction with the type of c atheter, was a decisive factor in the decline of the peritonitis rate in our centre. Patients on the twin-bag system (twin-bag group) showed a significant increase in the peritonitis-free interval in comparison with patients using other systems (non-twin bag group). Among the oth er variables analysed, only diabetes mellitus appeared to be relativel y important. Episodes of culture negative peritonitis were more freque ntly observed in the twin-bag group, compared to the non-twin bag grou p. In absolute numbers Staph. non-aureus was the micro-organism most e ffectively reduced.