Effectiveness of bacterial disinfectants on surfaces of mechanical ventilator systems

Pathogens in healthcare settings can be transmitted via skin contact and environmental media. This study investigates bacterial contamination rate on surfaces of mechanical ventilator systems and bedside equipment. An experimental study evaluates the effectiveness of 75% alcohol in killing bacteria on surfaces.

Surface swab sampling was conducted on ventilator systems and patient bedside equipment for detection of bacterial contamination. Surfaces of ventilator systems, such as faceplates, Y-pieces, and water traps, were swab sampled at 0.5, 8, and 24 hours after initial disinfection using a solution containing 0.5% sodium hypochlorite and pasteurization. The 75% alcohol aerosol was sprayed on the surfaces of faceplates, Y-pieces, and water traps on ventilator systems at 24 hours after initial disinfection, and then bacterial levels on the surfaces were evaluated.

Detection rates of Staphylococcus aureus were measured on the handrails of mechanical ventilators (64.7%), Y-pieces of breathing circuits (86.7%), and resuscitators (60.0%). Pseudomonas aeruginosa was identified on the surfaces of Y-pieces (6.7%) and water traps (13.3%) of breathing circuits, and also on suction systems (6.7%) and resuscitators (13.3%). The positive rate for total bacterial count was clearly increased on the surfaces of faceplates, Y-pieces, and water traps at 8 hour following disinfection by 0.5% sodium hypochlorite solution and pasteurization. Concentrations of S. aureus on surfaces decreased following treatment with 75% alcohol. However, considerable P. aeruginosa growth on water trap surfaces was observed after treatment with 75% alcohol.

The surfaces of ventilator systems, including faceplates, Y-pieces, and water traps, must be disinfected frequently (at least every 8 h) to control bacterial growth. Disinfection using 75% alcohol spray with air drying effectively decreased S. aureus on ventilator system surfaces.