Peritonitis prevention in CAPD: to mask or not?

To assess the efficacy of wearing a face mask to prevent peritonitis during continuous ambulatory peritoneal dialysis (CAPD) bag exchange.

Renal unit at a university hospital.

Two groups of patients on CAPD were compared: those performing bag exchange with (n = 24) and those without a face mask (n = 40).

Occurrence of first episode of peritonitis and total number of episodes.

No difference was found between groups with respect to probability of developing the first episode of peritonitis (p = 0.757). Patients holding university degrees had evidence of protection, with borderline significance [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; Cl 95%, 0.18 - 0.98; p = 0.04). Incidence of peritonitis was not significantly different between groups: with-mask group had 1.0 episode/year, and without-mask group had 0.94 episodes/year. Staphylococcus epidermidis was the most commonly identified agent. Staphylococcus aureus was found more frequently in the with-mask group (p = 0.003). Peritonitis due to Streptococcus viridans and Enterococci were detected only in the without-mask group.

The current study suggests that routine use of face masks during CAPD bag exchanges may be unnecessary and could be discontinued.