BACKGROUND: Proper air ventilation and filtration in Operating Rooms (OR) are two prevention measures to avoid Surgical Site Infections (SSI), which cause increase of hospital staying, cost and death. For identifying how system ventilation variations may impact on the quality of OR air, ad hoc researches need be conducted. The aim is to study how a mobile air particle filtering system may impact on the air quality of the OR when placed in two different positions.

METHODS: This descriptive study was conducted during April-May 2018 in an Italian University Hospital. We measured inflow and outflow air ventilations of both an OR and a mobile novel air decontamination-recirculation system unit having a patented crystalline ultraviolet C reactor and a high efficiency particulate air filter. OR was redesigned using the software Solidworks 2017 3D. Using experimental data, the interaction of airflows was graphically simulated by placing the device both next to the main OR entrance, with its airflow towards the surgical bed, and next to the latter, with the airflow towards the main entrance.

RESULTS: The device has been able to modify the main flow of a normal air diffusion from the ceiling vents and has created a low pressure effect that drags the air into contact with potentially contaminated surfaces. Air contamination can occur when OR door is opened. If the device is positioned with its air intake next to the door, entry of particulate is facilitated, reducing the effectiveness of the positive pressure inside the OR. To avoid possible contamination caused by the device airstream, we have oriented its air intake towards the operating table. if the door is opened, the airstream helps to prevent the entry of contaminants.

CONCLUSIONS: Different positioning of extra flows can significantly impact on air dynamic. Ad-hoc environmental measures are necessary for the most efficient positioning of the device.