Outcomes of Acinetobacter Peritonitis in Peritoneal Dialysis Patients: A Multicenter Registry Analysis

Background: Acinetobacter is a rare but important cause of peritonitis in peritoneal dialysis (PD) patients. As the complication has not been comprehensively evaluated previously, the present study examined the outcomes of Acinetobacter peritonitis in a large, national cohort of PD patients.

Methods: The study included all episodes of peritonitis in Australia from January 2004 to December 2014 using Australia and New Zealand Dialysis and Transplant Registry (ANZDATA) data. The primary outcome was peritonitis cure and secondary outcomes were catheter removal, hemodialysis transfer, recurrent/relapsing peritonitis, peritonitis-related hospitalization, and death. Outcomes were compared using multivariable logistic regression.

Results: Overall, 5,367 patients experienced 11,122 episodes of peritonitis across 51 centers in Australia. Of these, 228 (4.2%) patients experienced 253 (2.3%) episodes of Acinetobacter peritonitis (176 episodes were due to Acinetobacter alone and 77 involved co-infection with other organisms). Of the 176 solitary Acinetobacter episodes, 131(74%) achieved cure with antibiotics alone. Compared with Acinetobacter, significantly lower odds of peritonitis cure were observed for Pseudomonas (adjusted odds ratio [AOR] 0.24, 95% confidence interval [CI]: 0.16 - 0.36), other gram-negative organisms (AOR 0.54, 95% CI 0.37 - 0.77), fungi (AOR 0.02, 95% CI 0.01 - 0.03), and polymicrobial organisms (AOR 0.36, 95% CI 0.25 - 0.51), whilst similar odds of cure were observed for Staphylococcus (AOR 0.73, 95% CI 0.50 - 1.06), other gram-positive organisms (AOR 1.32,95% CI 0.93 - 1.89), culture-negative (AOR 1.19, 95% CI 0.82 -1.71), and other organisms (AOR 0.72, 95% CI 0.49 - 1.07). The odds of catheter removal and hemodialysis transfer were higher with Pseudomonas, other gram-negative, fungal, and polymicrobial peritonitis than with Acinetobacter peritonitis. The odds of death were also higher with Pseudomonas and fungal peritonitis than with Acinetobacter peritonitis. Treatment of Acinetobacter peritonitis with gentamicin, ciprofloxacin, or ceftazidime achieved comparable outcomes.

Conclusions: Outcomes of Acinetobacter peritonitis were favorable compared with most other forms of organism-specific peritonitis. Commonly used antibiotics covering gram-negative bacteria achieved comparable outcomes in Acinetobacter peritonitis.