Ventilation Considerations for COVID-19 Surge Conditions

Mike Gerhardt, Intalere Sr. Director, Facility Management Advisory Solutions

 At Intalere, we are receiving many requests for temporary furniture and equipment, such as medical cots, in order to plan for and outfit surge areas to deal with the possible surge in patients due to COVID-19. Utilization of these temporary spaces is less than ideal and hopefully our country’s quick action to shelter in place will minimize the need in most parts of the country for “makeshift” triage and treatment areas.  

The CDC has published a great reference, Interim Infection Prevention and Control Recommendations for Patients with Suspected or Confirmed Coronavirus Disease 2019 (COVID-19) in Healthcare Settings. This document gives full spectrum guidance on infection control. For the purposes of this article, we are focusing on room airflow ventilation consideration for patients. The CDC is recommending placing patients with known or suspected COVID-19 in a single-person private room with a dedicated bathroom. The recommendations go on to say that COVID-19 patients undergoing Aerosol Generating Procedures (AGPs) ideally should be in an AIIR (Airborne Infection Isolation Room) that is negatively pressured – meaning air flows into the room and out the exhaust. Most ICUs only have a few isolation rooms. The typical ICU room is positively pressured, meaning the air flows outward from the room, in order to not draw germs towards the very fragile patient.   

The issue is that many COVID-19 patients will be undergoing AGPs like ventilation, intubation, lavage and induced sputum, and thus ideally should be in an isolation room. As censuses surge, there will be more patients undergoing AGPs than there are available isolation rooms. As hospitals quickly run out of isolation rooms, they will have to do their best to change ICU and other patient room airflows from positive to negative to mimic conditions in AIIRs. If airflows are not adjustable by adjustment of exhausts and pressurizing corridors, then facilities will need to do their best to group patients in specified wings or areas. A risk assessment should be performed to identify the best plan.

In preparation for the above and more dire situations where existing patient room and treatment area capacity has been exceeded and planning or implementing some type of temporary surge areas is necessary, be sure to consult your facility engineering team or HVAC supplier to best consider ventilation options for triage and treatment spaces. As a resource to assist with ventilation options for these spaces, consult this outstanding guide from the Minnesota Department of Health Office of Emergency Preparedness on Airborne Infectious Disease Management – Methods for Temporary Negative Pressure Isolation.

Below are a few summarized highpoints of the document:

  • Ensure that any surge isolation intervention not create adverse changes to the existing HVAC system or its inherently-designed protective airflow and pressurization functions.
  • Surge plans that will cohort non-confirmed cases are not appropriate, since you could potentially end up exposing someone with a common cold to another person with actual COVID-19 virus infection.
  • In the absence of an effective vaccine, surge strategies that cohort confirmed cases into a collective treatment area are discouraged, as this scenario increases the occupational exposure potential to healthcare workers who must enter the containment area to provide treatment.
  • Now is not the time for energy conservation measures – especially in temporary spaces. Increase your ACH (Air changes per hour) by opening outside air intake dampers and speeding up exhaust fans. This may remove airborne contaminates more quickly from the spaces. Do not make it too windy, that you are blowing droplets around the space. Increased humidity should help aerosolized droplets fall out of the air faster which should reduce the distance they move.
  • Consider utilizing your smoke compartments (per your life safety drawings) as containment areas to keep the air segregated for that part of the building. You will need to close the fire doors and evaluate and activate the smoke dampers to isolate the space. HVAC capacity and airflow assessment must be understood for these compartments operating in a closed state.
  • Portable HEPA machines and anterooms are in short supply. Secure whatever is available. In the absence of any available portable equipment, creative engineering with HEPA filers and exhaust fans may be better than nothing.
  • If you are venting unfiltered contaminated air outdoors, ensure it is 25 feet away from public access and air intakes
  • Ask for help if you need it. Your Group Purchasing and HVAC vendor partners are available to help find sources for filters or offer engineering recommendations.

Some good news to close with: COVID-19 is spread by droplets – it is not an airborne disease. Yes, the droplets can become aerosolized through sneezing, coughing, toilet flushing or medical procedures. Aerosolized means it can travel short distances in the air, hence the 6-foot social distancing best practice. In surge times you do your best with whatever is available. The CDC understands this by stating “ideally” you should house COVID-19 patients undergoing AGPs in isolation. In reality, the chances of the disease traveling in the air room to room, long distance down corridors, or thru HVAC systems is very small. Still, you must do what you can to manage ventilation to minimize transmission risks for staff and patients. Consult the details in the refenced documents, do your risk assessments, make plans and beat this pandemic.

We Can Help

Intalere provides a number of resources that can assist in the areas of facility management and surge capacity solutions as well as many other areas of your operations. Please reach out to us to see how we can help. Contact Customer Service at  877-711-5600 or customerservice@intalere.com or your Intalere representative.

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