Peritonitis prevention in CAPD: to mask or not?

Objective: To assess the efficacy of wearing a face mask to prevent periton itis during continuous ambulatory peritoneal dialysis (CAPD) bag exchange. Setting: Renal unit at a university hospital. Patients: Two groups of patients on CAPD were compared: those performing ba g exchange with (n = 24) and those without a face mask (n = 40). Outcomes: Occurrence of first episode of peritonitis and total number of ep isodes. Results: No difference was found between groups with respect to probability of developing the first episode of peritonitis (p = 0.757). Patients holdi ng university degrees had evidence of protection, with borderline significa nce [relative risk (RR) 0.52; confidence interval (CI) 95%, 0.23 - 1.18; p = 0.109]. Cox's proportional hazard regression analysis also demonstrated a significant protective factor for patients with university level education (RR 0.42; CI 95%, 0.18 - 0.98; p = 0.04). Incidence of peritonitis was not significantly different between groups: with-mask group had 1.0 episode/ye ar, and without-mask group had 0.94 episodes/year. Staphylococcus epidermid is was the most commonly identified agent, staphylococcus aureus was found more frequently in the with-mask group (p = 0.003). Peritonitis due to stre ptococcus viridans and Enterococci were detected only in the without-mask g roup. Conclusion: The current study suggests that routine use of face masks durin g CAPD bag exchanges may be unnecessary and could be discontinued.