Challenging the Current Treatment Paradigm for Methicillin-Resistant Staphylococcus Epidermidis Peritonitis in Peritoneal Dialysis Patients

Abstract

Objectives To analyze clinical outcomes of Staphylococcus epidermidis peritoneal dialysis peritonitis before and after an interventional switch from a vancomycin/tobramycin to a cefazolin/tobramycin regimen for empiric treatment. To examine risk factors associated with clinical failure. Design A retrospective study. Setting A peritoneal dialysis program within a university-affiliated tertiary-care hospital. Patients 93 episodes of S. epidermidis peritonitis over a 6-year period. Interventions Clinical responses were compared between treatments using chi-square or Fisher's exact test. Univariate and multivariate analyses were used to identify significant risk factors for clinical failure. Measurements and Main Results There was no difference in the overall response rates observed with vancomycin (40/49; 81.6%) and cefazolin (23/29; 79.3%) regimens for episodes of S. epidermidis peritonitis. Furthermore, the presence of methicillin resistance in 63 of 93 cases (67.7%) had no influence on clinical outcome, with response rates of 83.9% (26/31) and 82.4% (14/17) for empiric vancomycin and cefazolin regimens, respectively. Tobramycin therapy of less than 2 days was an independent risk factor for clinical failure in multivariate logistic regression analysis (odds ratio 4.44, 95% confidence interval 1.28 – 15.48; p = 0.02). Conclusions Empiric treatment with intraperitoneal cefazolin was as effective as vancomycin for S. epidermidis peritonitis despite a high prevalence of methicillin resistance. Tobramycin therapy of less than 2 days was strongly associated with treatment failure.