A 12-month review of peritoneal dialysis-related peritonitis in Western Australia: is empiric vancomycin still indicated for some patients?

BACKGROUND

The International Society for Peritoneal Dialysis (ISPD) guidelines recommend empiric therapy with cefazolin and ceftazidime for peritoneal dialysis (PD)-related peritonitis. Empiric cefazolin therapy may have diminishing efficacy because of emerging methicillin resistance in gram-positive bacteria (GPB). Western Australia also has large numbers of Aboriginal and isolated regional patients, where giving these antimicrobials can be impractical.

OBJECTIVES

To evaluate, based on local antimicrobial resistance patterns, the feasibility of following ISPD guidelines in Western Australia and to identify any subgroups of PD peritonitis patients that may benefit from alternative empiric intraperitoneal antibiotics (e.g., vancomycin).

STUDY DESIGN

Retrospective study of all PD peritonitis episodes in Western Australia from 1 February 2000 to 31 January 2001.

SETTING

Three adult tertiary referral university hospitals and their PD patients in metropolitan Perth and regional Western Australia.

PATIENTS

All adults on PD in Western Australia.

MAIN OUTCOME MEASURE

Isolates and antibiograms were analyzed versus patient characteristics, including race and patient demographics.

RESULTS

293 patients (28% Aborigines, 32% regional patients) received PD. 145 episodes of PD peritonitis occurred during the study. The overall PD peritonitis rate was 1 episode/16 patient months, with Aborigines having 1 episode/10.5 patient months versus non-Aborigines having 1 episode/17 patient months (p < 0.001). 36% of isolates from PD peritonitis episodes were resistant to cefazolin or ceftazidime. 22% were methicillin-resistant GPB (MR-GPB) [18% coagulase-negative staphylococci (CoNS), 1.6% MR Staphylococcus aureus]; 2.5% were multidrug-resistant gram-negative bacteria (MDR-GNB); 5.7% were polymicrobial (MR-GPB and/or MDR-GNB); and 5.7% were fungal. 63% of CoNS were methicillin resistant. Non-Aboriginal patients yielded MR-GPB in 22% of isolates versus 23% in Aborigines (p = 0.9). Six of seven cases of fungal peritonitis occurred in Aboriginal patients (p < 0.001).

CONCLUSIONS

In our study population the ISPD guidelines were appropriate for 64% of patients with PD peritonitis. We could not identify specific patient subgroups where empiric cefazolin use could be more effective. High proportions of MR-GPB PD peritonitis episodes, along with local factors, make empiric cefazolin unsuitable for many regional PD patients in Western Australia.