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.