Comparative evaluation of air distribution systems for controlling airflow and bacteria-carrying particles in operating rooms

Air distribution systems are essential for controlling the concentration of bacteria-carrying particles (BCPs) and protecting patients from the risk of surgical site infections (SSIs) in operating rooms (ORs). Nevertheless, a comparative analysis of the collective performance of the various systems has yet to be conducted. This study compares the airflow characteristics and the dispersion of BCPs with common air distribution systems, including vertical laminar airflow (VLAF), horizontal laminar airflow (HLAF), differential vertical airflow (DVAF) and temperature-controlled airflow (TAF). A quantitative analysis was conducted to evaluate the airflow uniformity, ventilation performance and BCPs removal capability of each system. The results show that the airflow uniformity and air change efficiency (ACE) in the operating area of the HLAF ventilation system are worse than the other three vertical ventilation systems and have the highest BCPs suspension in the room. VLAF and DVAF ventilation systems result in more BCPs deposited on the surface of patients and instrument tables, which increases the risk of patient infection and therefore requires attention in practice. The TAF ventilation system can achieve better ventilation performance and BCPs control effect, the most effective ventilation strategy amongst the four ventilation systems to ensure the air environment in the operating area.