Associations, microbiology and outcomes of pre-training peritoneal dialysis-related peritonitis

Background: Pre-training peritonitis (PTP), defined as peritonitis that occurred after catheter insertion and before peritoneal dialysis (PD) training, is increasingly recognized as a risk factor for adverse patient outcomes, yet poorly understood with limited studies conducted to date. This study was conducted to identify the associations, microbiologic profiles and outcomes of PTP compared to post-training peritonitis. Methods: This single-centre, case-control study involved patients with kidney failure who had PD as their first kidney replacement therapy and had experienced an episode of PD peritonitis between 1 January 2005 and 31 December 2015. Individuals experiencing their first episode of peritonitis were included in the study and categorized according to whether it occurred pre- or post-training. The primary outcome was peritonitis cure rates and composite outcome of hemodialysis (HD) transfer for >= 30 days or death. The secondary outcomes included catheter removal and refractory peritonitis rates. Results: Among 683 patients who received PD for the first time, 121 (17.7%) had PTP while 265 (38.8%) had post-training peritonitis. PTP patients were more likely to have had exit-site infection (ESI) prior to peritonitis (24.8% compared to 17% in the post-training peritonitis group, p = 0.2). Culture-negative peritonitis was significantly more common in the PTP patients (53.7%) than in the post-training group (27.3%, p < 0.001). The cure was achieved in 68.9% of cases and was not significantly different between the PTP and post-training peritonitis groups (66.1% vs. 70.2%; OR 0.83, 95% CI 0.51-1.35). Lower odds of cure were associated with peritonitis caused by moderate and high severity organisms (OR 0.49, 95% CI 0.29-0.85; OR 0.18, 95% CI 0.08-0.43, respectively). Composite outcome of HD transfer or death was more commonly observed among patients with PTP (87.5% vs. 75.8%; OR 2.2, 95% CI 1.20-4.48) in whom significantly shorter median time to HD transfer was observed (PTP 10.7 months vs. post-training peritonitis 21.9 months, p < 0.0001). Conclusions: PTP is a common condition that is highly associated with preceding ESI, is frequently culture-negative and is associated with worse composite outcome of HD transfer or death. PTP rates should be routinely monitored and reported by PD units for continuous quality improvement.