Linking clinical manifestations and causative organisms may provide clues for the treatment of peritoneal dialysis-associated peritonitis

Abstract

Introduction: Different initial manifestations of peritoneal dialysis-associated peritonitis (PDAP) may depend on the type of pathogenic organism. We investigated the association between the clinical characteristics of PDAP and susceptibility to vancomycin and investigated the possibility of using vancomycin monotherapy alone as an initial treatment regimen for some PDAP patients to avoid unnecessary antibiotic exposure and secondary infection. Methods Patients with culture-positive PDAP were retrospectively analyzed and divided into two groups: those who presented with only cloudy effluent (PDAP-cloudy) or those who presented with cloudy effluent, abdominal pain and/or fever (PDAP-multi). The bacterial culture of PD effluent and antibiotic sensitivity test results were compared between groups. Logistic regression was used to investigate factors predicting susceptibility to vancomycin. Results Of the 162 patients who had a positive bacterial culture of PD fluid, 30 patients were in the PDAP-cloudy group, and 132 patients were in the PDAP-multifroup group. Thirty (100%) patients in the PDAP-cloudy group had gram-positive bacterial infections, which was significantly greater than that in the PDAP-multifroup group (51.5%) (P < 0.001). Twenty-nine (96.7%) peritonitis patients in the PDAP-cloudy group were susceptible to vancomycin, compared to 67 (50.8%) in the PDAP-multi group (P < 0.001). The specificity of PDAP-cloudy for vancomycin-sensitive peritonitis was 98.48%. Only one patient (3.3%) in the PDAP-cloudy group experienced vancomycin-resistant peritonitis caused by Enterococcus gallinarum, which could neither be covered by vancomycin nor by the initial antibiotic regimen recommended by the current ISPD guidelines. The presence of only cloudy effluent was an independent predictor of susceptibility to vancomycin according to multivariate analysis (OR = 21.893, 95% CI 2.803-171.004, p = 0.003), in addition to PD effluent WBC counts (OR = 0.988, 95% CI 0.980–0.996, p = 0.004) and concomitant diabetes mellitus (OR = 2.878, 95% CI 1.347–6.129, p = 0.006). The specificity of presenting with only cloudy effluen for vancomycin-sensitive peritonitis was 98.48%. Conclusions Cloudy dialysate, as the only symptom at PDAP onset, was an independent predictor of vancomycin-sensitive PDAP, which is an important new insight that may guide the choice of initial antibiotic treatment.