Changes in causative organisms and their antimicrobial susceptibilities in CAPD peritonitis: A single center's experience over one decade

Abstract

◆ Background: In recent years, the rate of peritonitis during continuous ambulatory peritoneal dialysis (CAPD) has been significantly reduced. However, peritonitis remains a major complication of CAPD, accounting for considerable mortality and hospitalization among CAPD patients. ◆ Objective: To generate a "center tailored" treatment protocol for CAPD peritonitis by examining the changes of causative organisms and their susceptibilities to antimicrobial agents over the past 10 years. ◆ Method: Retrospective review of the medical records of 1015 CAPD patients (1108 episodes of peritonitis) who were followed up from 1992 through 2001. ◆ Results: The overall incidence of peritonitis was 0.40 episodes/patient-year. The annual rate of peritonitis and the incidence of peritonitis caused by a single gram-positive organism were significantly higher in 1992 and 1993 compared with those in the rest of the years (p <0.05). The incidence of peritonitis due to coagulase-negative staphylococcus (CoNS) decreased significantly over time, whereas there was no significant change in the incidence of Staphylococcus aureus (SA)-induced peritonitis. Among CoNS, resistance to methicillin increased from 18.4% in 1992 - 1993 to 41.7% in 2000 - 2001 (p < 0.05). In contrast, the incidence of methicillin-resistant SA was not different according to the calendar year. Catheter removal rates were significantly higher in peritonitis due to a single gram-negative organism (16.6%) compared with gram-positive peritonitis (4.8%, p < 0.005). The mortality associated with peritonitis was also higher in gram-negative (3.7%) compared with gram-positive peritonitis (1.4%), but there was no statistical significance. Among single gram-positive organism-induced peritonitis, catheter removal rates were significantly higher in SA (9.3%) than those in CoNS (2.9%, p < 0.01) and other gram-positive organisms (2.9%, p < 0.05). In peritonitis caused by CoNS, the methicillin-resistant group showed significantly higher removal rates than the methicillin-susceptible group (8.2% vs 1.0%, p < 0.01). ◆ Conclusion: The incidence of peritonitis for 2001 decreased to less than half that for 1992, due mainly to a significant decrease in CoNS-induced peritonitis, whereas the proportions of peritonitis due to a single gram-negative organism and methicillin-resistant CoNS increased. These findings suggest that it is necessary to prepare new center-based guidelines for the initial empirical treatment of CAPD peritonitis. Copyright © 2004 International Society for Peritoneal Dialysis.