Advances in Peritoneal Dialysis, Vol. 22, 2006 Peritonitis During the First Year After Commencement of Peritoneal Dialysis Has an Impact on Technique Survival and Patient Morbidity The timing of the first episode of peritonitis in perito- neal dialysis (PD) might have some special charac- teristics and may depend on many factors such as a patient’s attitudes, age, comorbidity, or training ca- pacity. It may also have a significant impact on fur- ther peritonitis episodes and technique failure. We retrospectively analyzed data for 168 PD pa- tients who were undergoing continuous ambulatory PD by a twin-bag system, automated PD, or in-center in- termittent PD over 12 years. There were 121 cases of peritonitis recorded in 60 patients, with an overall peri- tonitis rate of 1 episode per 45.75 patient–months. The mean time to the first episode of peritonitis after commencement of PD was 26.4 ± 22 months (range: 1 – 110 months). In 20 patients, a first perito- nitis episode presented rather early—during the first 12 months on PD (group A)—and in 27 patients, a first episode presented rather late—after at least 24 months on PD (group B). Group A had lower technique survival (30.4 ± 26.5 months), were more prone to further episodes of peritonitis during follow-up, and had a total perito- nitis rate of 1 episode per 14.85 patient–months. In group B, technique survival was longer (69.3 ± 33.8 months), and the total peritonitis rate was 1 episode per 45.68 patient–months. We ob- served no differences between the two groups in comorbidity, age, or PD modality. These results indicate that patients with early- onset peritonitis are prone to making mistakes during connection, resulting usually in infection with gram- positive pathogens. These patients may present repeated peritonitis episodes and experience de- creased technique survival. Key words Infection, peritonitis, automated peritoneal dialysis Introduction Peritonitis is the most common serious complication of peritoneal dialysis (PD) and the leading cause of technique failure requiring a switch to hemodialysis. Improvements in technology such as the Y-set and the double-bag system (1,2) and a better understanding of the risk factors that predispose to the development of peritonitis have been responsible for a decline in the rate of peritonitis since the mid-1990s. Peritonitis rates vary from center to center and are largely determined by patient selection, quality of patient training, and social factors (3). However, the changing spectra of causative organisms and their in- creasing resistance to antibiotics, combined with the increased use of automated machines that provide greater dialysate volumes and increased solute clear- ances create new dilemmas for the appropriate man- agement of PD-related peritonitis (3,4). Severe or repeated episodes of peritonitis are par- ticularly damaging to the peritoneal membrane. Davies et al. (5) demonstrated that single episodes of peritonitis had no significant effect on membrane characteristics and ultrafiltration in the short term. However recurrences or clusters of peritonitis epi- sodes might increase peritoneal membrane perme- ability and reduce ultrafiltration independently of the infecting organisms (3–5). No extensive studies have examined whether the timing of the first PD-related peritonitis episode might Costas Fourtounas, Eirini Savidaki, Periklis Dousdabanis, Andreas Hardalias, Pantelitsa Kalliakmani, Evangelos Papachristou, Anastasios Drakopoulos, Dimitrios S. Goumenos, Jannis G. Vlachojannis From: Department of Internal Medicine–Nephrology, Uni- versity of Patras, Patras, Greece.