Culture-negative peritonitis in peritoneal dialysis patients in Australia: predictors, treatment, and outcomes in 435 cases.

BACKGROUND

Reports of culture-negative peritoneal dialysis (PD)-associated peritonitis have been sparse, conflicting, and limited to small single-center studies. The aim of this investigation is to examine the frequency, predictors, treatment, and outcomes of culture-negative PD-associated peritonitis.

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, 2006.

PREDICTORS

Demographic, clinical, and facility variables.

OUTCOMES & MEASUREMENTS: Culture-negative PD-associated peritonitis occurrence, relapse, hospitalization, catheter removal, hemodialysis transfer, and death.

RESULTS

Of 4,675 patients who received PD in Australia during the study period, 435 episodes of culture-negative peritonitis occurred in 361 individuals. Culture-negative peritonitis was not associated with demographic or clinical variables. A history of previous antibiotic treatment for peritonitis was more common with culture-negative than culture-positive peritonitis (42% vs 35%; P = 0.01). Compared with culture-positive peritonitis, culture-negative peritonitis was significantly more likely to be cured using antibiotics alone (77% vs 66%; P < 0.001) and less likely to be complicated by hospitalization (60% vs 71%; P < 0.001), catheter removal (12% vs 23%; P < 0.001), permanent hemodialysis therapy transfer (10% vs 19%; P < 0.001), or death (1% vs 2.5%; P = 0.04). Relapse rates were similar between the 2 groups. Patients with relapsed culture-negative peritonitis were more likely to have their catheters removed (29% vs 10% [P < 0.001]; OR, 3.83; 95% CI, 2.00-7.32). Administration of vancomycin or cephalosporin in the initial empiric antibiotic regimen and the timing of catheter removal were not significantly associated with clinical outcomes.

LIMITATIONS

Limited covariate adjustment. Residual confounding and coding bias could not be excluded.

CONCLUSIONS

Culture-negative peritonitis is a common complication with a relatively benign outcome. A history of previous antibiotic treatment is a significant risk factor for this condition.