Citation
  • Daneshazarian, R., Siegel, J. (2025). Pressurization and HVAC Configuration of Operating Rooms for Patients with Airborne Infectious Diseases. Canadian Standards Association, Toronto, ON.

Executive Summary

This report summarizes the key findings and insights derived from a comprehensive study on managing airflow dynamics and particulate matter concentration within health-care operating rooms (ORs) to mitigate the transmission of airborne infectious diseases. Extensive experimental testing in a real OR was conducted to investigate the influence of pressure differentials, anteroom presence, and health-care worker activity on particulate dispersion within OR environments. Results highlighted the critical role of these factors in shaping airflow patterns and particle distribution. Numerical simulations, validated against experimental data, provided further insights into airflow dynamics and particulate dispersion within ORs. The simulations confirmed the reliability of computational models in capturing real-world phenomena, thus enhancing our understanding of ventilation system performance. A survey was conducted to gather insights from health-care professionals with experience in OR operations. The survey revealed significant challenges in implementing negative pressure ORs, including financial constraints, aging infrastructure, and the need for specialized expertise.

Based on the study findings, several recommendations are proposed:

  • Emphasize the importance of an anteroom, particularly in scenarios where the OR can not be operated under negative pressure.
  • Optimize positive pressure systems for uniform airflow, minimizing elevated aerosol concentrations near an infected patient while considering the potential risk to the patient from losing the positive protective environment.
  • Consider negative pressure ORs to reduce the infectious disease transmission risk to health-care workers in the OR and all individuals in the semi-restricted clean corridor.
  • Invest in research to further explore contaminant transmission from the semi-restricted clean corridor to the sterile field (surgical site) under negative pressure.
  • Continue research and collaboration to address evolving challenges and refine OR ventilation practices.
  • Any inclusion of these findings in future standards should balance the importance of reducing infectious disease transmission with other outcomes (e.g., surgical site infections) as there is a need for clear guidance during periods of elevated airborne risk.

This research report highlights the importance of effective ventilation strategies in ORs for mitigating the transmission of airborne pathogens. By leveraging insights from stakeholder input, experimental testing, and numerical simulations, health-care facilities can enhance their infection control measures and safeguard both patients and health-care workers. Continued research and collaboration are essential to address the complex challenges associated with OR ventilation and ensure the ongoing improvement of health-care facility environments.