Effectiveness of the systematic use of antimicrobial filters in the water taps of critical care units for the prevention of healthcare-associated infections with Pseudomonas aeruginosa

Background: Pseudomonas aeruginosa (PA) is the third leading aetiological agent in healthcare-associated infections (HAIs) and the one most frequently found in patients with pneumonia associated with mechanical ventilation. In intensive care units (ICU), its appearance is associated with higher mortality, an increase in the days spent on ventilation, and hospital stay length and costs. Thus, evaluating strategies for preventing these infections is essential for their control. Therefore, our objective was to evaluate the effectiveness of the systematic use of antimicrobial filters in preventing PA infections in critical care units. Methods: This was an open experimental crossover study. A total of 2,156 patients admitted for more than 24 hours in critical care units were included, 1,129 of them in units with filters, and 1,027 in units without filters. The study groups were followed-up for 24 months and HAIs were checked for the presence of PA. Chi-squared test were used to compare the rate of HAIs between groups and we calculated 95% confidence intervals adjusted by Poisson regression for the rate ratio (RR) of the association magnitude. Results: Both groups were homogeneous in terms of intrinsic and extrinsic patient factors. The incidence of PA infections in the units with filters was 5.5 cases/1,000 hospitalized days and 5.4/1,000 hospitalized days for the units without water filters (RR = 1.09 [0.67-1.79]). Conclusions: Routine placing antimicrobial filters in the water taps in critical care units was not an effective means of preventing the emergence of HAIs caused by PA.This study has been funded by: Instituto de Salud Carlos III (Carlos III Health Institute) through Fund for Health Research (FIS), Ministry of Health, Spanish Government. Project # PI15/01344; Generalitat Valenciana (Valencian Regional Government) Grants for Support to a Research or Technology Transfer Project. Project # APOTIP/2016/A/011; Alicante Institute for Health and Biomedical Research through Grants to supplement the development of active research projects under the State Plan for Scientific and Technical Research and Innovation. Project # 180192 and Project # 190181