Our customers in hospitals in northern Europe have asked us if they are better protected from Corona-related infections in their operating rooms equipped with Opragon than in other operating rooms. We have reasons to think that this might be the case based on previous research on bacteria.
While no research has been done on Coronavirus transmission in operating rooms during surgery, we have made a scientific assessment based on the fundamental working principles of the different technical ventilation principles that are found in operating rooms.
Experts say in late March 2020 that corona virus particles are carried on droplets. These droplets fall towards the floor due to gravity and/or ride the general airflow in the room. A key aspect to look at is thus how the air moves inside the OR.
Contrary to most ventilation systems, Temperature-controlled Airflow (TcAF, Opragon) controls the air in the whole operating room with strong directionality downwards. This means that any bacteria or virus particles emitted from the staff or patient are pushed down towards the floor and then evacuated. All air that enters the OR via an Opragon system, and often also in other systems, undergoes continuous HEPA filtration which is the current state-of-the-art for capture of harmful organisms effective against 99.97% of airborne contaminants. The pure number of air changes in the room additionally provides a diluting effect. Taken together, this indicates a low risk for airborne virus transmission from person to person inside ORs equipped with Opragon.
The most common and basic ventilation principle is called turbulent mixing ventilation. Its cleaning effect is solely based on dilution, i.e. the number of air changes per hour, and the higher the number the better the positive effect. There is no strong direction of the flow and molecules are randomly scattered around the room. It is thus hard to see how there would be a benefit to such a solution from a virus transmission point of view, apart from the dilution effect.
Laminar Airflow (LAF/UDF) systems on the other hand do have a directional airflow under the LAF ceiling itself. In this central area of the room both viruses and bacteria will move down and away. The concern here would be in the periphery of the room where there is no control of the airflow and where air from the central part of the room freely will whirl around. Studies of LAF systems also show that the protective effect is limited to the area immediately around the operating field.
− “It is important to use a ventilation system that is both energy efficient and reduces the risk for infections – two aspects that temperature-controlled airflow (TcAF/Opragon) does very well compared to the two other types of ventilation. Furthermore, the TcAF system did not create any disturbing noise or chilling draught according to our research and interviews with staff”, says Professor Löndahl at Lund University.
It should be noted that staff may wear fully ventilated bio-hazard suits to limit infection risk, but this is very uncomfortable and not available in most hospitals. In a perfect world, no one would enter the OR with an infection. Until then, our best course of action is to manage airborne contamination as effectively as the technology will allow.
If you have additional questions or thoughts, please ask us and we will support.