Repeated peritoneal dialysis-associated peritonitis: a multicenter registry study.

ABSTRACT

BACKGROUND: Determinants and outcomes of peritoneal dialysis (PD)-associated peritonitis occurring within 4 weeks of completion of therapy of a prior episode caused by the same (relapse) or different organism (recurrence) recently have been characterized. However, determinants and outcomes of peritonitis occurring more than 4 weeks after treatment of a prior episode caused by the same (repeated) or different organism (nonrepeated) are poorly understood. STUDY DESIGN: Observational cohort study using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data. SETTING & PARTICIPANTS: All Australian PD patients between October 1, 2003, and December 31, 2007, with first episodes of repeated or nonrepeated peritonitis. PREDICTORS Repeated versus nonrepeated peritonitis, according to International Society of PD (ISPD) criteria. OUTCOMES & MEASUREMENTS Relapse, hospitalization, catheter removal, hemodialysis transfer, and death. RESULTS: After a peritonitis episode, the probability that a subsequent episode represented repeated rather than nonrepeated peritonitis was highest in the second month (41%), then progressively decreased to a stable level of 14% from 6 months onward. When first episodes of repeated (n = 245) or nonrepeated peritonitis (n = 824) were analyzed, repeated peritonitis was predicted independently by a shorter elapsed time from the prior episode (adjusted OR per day elapsed, 0.91; 95% CI, 0.88-0.94). Staphylococcus aureus and coagulase-negative staphylococcus were isolated more frequently in repeated peritonitis, whereas Gram-negative, streptococcal, and fungal organisms were recovered more frequently in nonrepeated peritonitis. Using multivariate logistic regression, repeated peritonitis was associated independently with higher relapse (OR, 5.41; 95% CI, 3.72-7.89) and lower hospitalization rates (OR, 0.63; 95% CI, 0.46-0.85), but catheter removal, hemodialysis transfer, and death rates similar to nonrepeated peritonitis. LIMITATIONS: Limited covariate adjustment. Residual confounding and coding bias could not be excluded. CONCLUSIONS: Repeated and nonrepeated peritonitis episodes are caused by different spectra of micro-organisms and have different outcomes. Study findings suggest that the ISPD definition for repeated peritonitis should be limited to 6 months.