Sasan Sadrizadeh1, Jovan Pantelic2, Max Sherman3, Jordan Clark4, Omid Abouali5. 1. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA; University of California - Berkeley, Center for the Built Environment, CA 94720, USA. Electronic address: SSadrizadeh@lbl.gov. 2. University of California - Berkeley, Center for the Built Environment, CA 94720, USA. 3. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA. 4. The Ohio State University, College of Engineering, Columbus, OH 43210, USA. 5. Shiraz University, School of Mechanical Engineering, Shiraz, Iran.
Abstract
BACKGROUND: Operating rooms (ORs) are usually over-pressurized in order to prevent the penetration of contaminated air and the consequent risk of surgical site infection. However, a door-opening can result in the rapid disappearance of pressure and contaminants can then easily penetrate into the surgical zone. Therefore, a broad knowledge and understanding of OR ventilation systems and their protective potential is essential for optimizing the surgical environment. OBJECTIVES: This study investigated the air quality and level of airborne particles during a single and multiple door-opening cycles in an operating room supplied by a turbulent-mixing ventilation system. METHODS: The exploration was carried out numerically using computational fluid dynamics. Model validation was performed to ensure the validity of the achieved results. The OR was initially over-pressurized by approximately 15Pa, relative to the adjacent corridors. Both sliding and hinged doors were simulated and compared. RESULTS: Penetration of bacteria carrying particles from the corridors to the OR can be successfully restricted by using a positive-pressure system. However, the results clearly indicate that frequent door opening can interfere with airflow ventilation systems, alter the pressure gradient, and increase the infection risk for the patient undergoing surgical intervention. Door-opening disturbs the airflow field and could result in containment failure.
BACKGROUND: Operating rooms (ORs) are usually over-pressurized in order to prevent the penetration of contaminated air and the consequent risk of surgical site infection. However, a door-opening can result in the rapid disappearance of pressure and contaminants can then easily penetrate into the surgical zone. Therefore, a broad knowledge and understanding of OR ventilation systems and their protective potential is essential for optimizing the surgical environment. OBJECTIVES: This study investigated the air quality and level of airborne particles during a single and multiple door-opening cycles in an operating room supplied by a turbulent-mixing ventilation system. METHODS: The exploration was carried out numerically using computational fluid dynamics. Model validation was performed to ensure the validity of the achieved results. The OR was initially over-pressurized by approximately 15Pa, relative to the adjacent corridors. Both sliding and hinged doors were simulated and compared. RESULTS: Penetration of bacteria carrying particles from the corridors to the OR can be successfully restricted by using a positive-pressure system. However, the results clearly indicate that frequent door opening can interfere with airflow ventilation systems, alter the pressure gradient, and increase the infection risk for the patient undergoing surgical intervention. Door-opening disturbs the airflow field and could result in containment failure.