(Modify Negative Pressure Operating Room) for Patients with Coronavirus Disease 2019 (COVID-19) in Emergency Situations**
The selection of an operating room to be used for patients infected with Coronavirus Disease 2019 (COVID-19) should be carefully considered by a medical and engineering team to determine the most appropriate approach. This includes performing air balance to control the pressure of each room, the direction of air flow both within the operating room and adjacent spaces, and the routes for physicians, staff, clean materials, contaminated materials, and patients, as well as the overall configuration of the entire surgical department in accordance with medical and engineering principles.
Characteristics of the modified ventilation and air conditioning system for the operating room:
- The operating room must be modified to maintain negative pressure relative to all surrounding areas to prevent the spread of infectious agents. (Note: There is currently no formal standard specifying a negative pressure operating room; therefore, it is at the discretion of medical personnel and engineers to assess the risks and determine whether to establish negative pressure.)
Design requirements for the HVAC (Heating, Ventilation, and Air Conditioning) system include at least the following:
- Temperature: 23 ± 2 °C
- Humidity: 50 ± 10% RH
- Negative pressure differential: At least -2.5 Pa relative to surrounding areas
- Air changes per hour (ACH): Not less than 20 ACH
- Fresh air supply rate: Not less than 4 ACH
An anteroom must be installed before and/or after the operating room. The anteroom should be maintained at positive pressure in order to ensure that air flowing into the operating room is of similar quality to the operating room air. The air supplied should pass through a HEPA filter (e.g., a Fan Filter Unit with a HEPA filter) in the anteroom. Additionally, consideration must be given to the effects of temperature and humidity in the anteroom so that they do not negatively impact the control of temperature and humidity in the operating room. Further adjustments or upgrades to the ventilation system should ensure that the exhaust airflow rate is greater than the supply airflow rate from outside, thereby maintaining a negative pressure of at least -2.5 Pa in the operating room.
