Around the world, health facilities are mobilizing to manage their assets to meet the anticipated increase of infectious patients associated with the spread of the COVID-19 virus.

One of the overwhelming issues faced by healthcare facilities is the potential volume of critical patients and the availability of treatment areas capable of being isolated from other patients. There’s a pressing need to increase patient bed space capacity as quickly as possible to treat infected patients.

Isolation rooms are defined by The Centers for Disease Control and Prevention as those that have negative or positive air pressure to contain (infectious isolation) or prevent (protective isolation) airborne pathogens.

These types of rooms are commonly known as AII (airborne infection isolation) rooms. Most hospitals employ negative pressure and anterooms to achieve protective isolation within these AII rooms. AII rooms are recommended to have least 12 air changes per hour and be negative pressure to adjacent spaces.

Preferably, COVID-19 patients are treated in AII Rooms because these enable care providers to contain the virus within a given space, which has become the fundamental containment strategy.

At present, every hospital addressing COVID-19 patients is stressed with an inadequate amount of ICU isolation rooms and general patient care spaces. As such, hospitals are scrambling to relocate or cohort COVID-19 patients into common areas or wings of a hospital. In fact, some healthcare organizations with more than one hospital are choosing to cohort all COVID-19 patients in one facility, thereby alleviating the other hospital(s) in their system to care for non-COVID patients.

As the numbers of cases increases, there is a greater demand on beds, requiring entire units to be occupied by coronavirus patients. It’s important to ensure these areas are held under negative pressure to contain the airborne spread of the virus to non-infected patients.

Key related engineering controls and strategic considerations include:

  • Creating negative pressure requires an air balance of more exhaust than fresh air. Patient wards are typically serviced from a single air handling unit, and therefore rebalancing of this unit could be a way of achieving net-negative pressure in the ward.
  • Another simple way to help create negatively pressured areas is to increase fresh air rates to adjoining space, increasing positive pressurization. This requires careful consideration of existing system capacities and pressure regimes.
  • Facilities can increase exhaust rates within the contained/infected area by increasing the performance of existing systems such as toilet exhausts.
  • Often patient floors or wings on a floor are built within smoke compartments, which inherently have good building sealing properties at their boundary. Smoke exhaust/spill systems are often available to create negative pressure within wards.
  • Locating anterooms at entries and exits to isolate negative-pressure spaces is critically important. Anterooms should include negative pressure, fan-assisted HEPA modules. Either manual or automatic controls are required to ensure that doors to and from the anterooms cannot open simultaneously.
  • HEPA-filtered portable negative air units, typically utilized in managing pressurization in construction sites, have also been employed to help create negative pressure spaces.
  • Stiffening and sealing of the ceilings may be required. Traditional grid-type ceilings will perform poorly with respect to negative pressure isolation. Any over-pressurization will cause ceiling tiles to lift.

Rooms that are converted to isolation should be reviewed carefully to ensure the required/desired quantity of emergency power and data outlets are provided. And finally, consider if there are adequate wireless and telemetry systems in the areas to allow for flexing of rooms, function, and acuity in care.

Additional strategies for pandemic response

Another opportunity being employed to reduce the strain on healthcare facilities are alternative care sites (ACS). These temporary structures could be constructed as tents or fabric structures, lightweight panelized constructed buildings, or even modular buildings, which can be located adjacent to the hospital buildings or offsite.

Conversion of “healthcare similar” facilities for “hospital” status, even field hospital designation, is also being considered. Ambulatory surgery centers with both ORs and PACU beds are set at the highest level of infrastructure so these would meet ICU level support and prep/recovery could be augmented with portable monitors, portable oxygen cylinders and ventilators bedside if available. Freestanding birthing and endoscopy centers may also be considered.

There’s also significant activity throughout the healthcare industry and among governmental agencies about the possibility of converting existing hotels, dormitories, classrooms/schools, community centers, convention centers, or other large unoccupied buildings into COVID-19 or general patient care spaces.

For many reasons, the conversion of these non-healthcare spaces into COVID-19 patient care centers with isolation room space capabilities is highly challenging. Isolation rooms have requirements for environmental separation for air, power, water, and support spaces. These facilities are not constructed with adequate infrastructure systems to support this, so conversion of these spaces for isolation will typically require additional time and expense.

However, there’s strong rationale behind these off-site spaces being earmarked for the least acute and non-COVID-19 patients, which could include those who are either already under observation or under quarantine. Another appropriate use is to house staff, caregivers, hospital administration, and first responders—essentially those who are on call 24/7 and can’t easily go home or need to be close to the patient population.

To best utilize these types of convertible spaces, there needs to be a strong understanding of the existing mechanical, electrical, plumbing, and information technology systems’ capacities and configurations to support those requirements mandated for effective healthcare operations as defined by the provider and regulatory agencies.

Awareness of the capacity of these buildings will determine whether they can be used in whole or only partially as settings for healthcare needs. Hotels, for example, have a finite amount of air distribution and exhaust in the space; the quantity of air that’s used in a hotel room is far less than the quantity of air that’s needed in a healthcare setting, even in the most minimal instances. Therefore, it may not be possible to use the entire hotel’s capacity for healthcare. For example, an available 500-room hotel may only be able to be used to serve up to 250 patient rooms.

Engineering requirements to implement a functioning ACS include:

  • The removal of potential infection sources such as carpet and the installation of flooring that is easy to decontaminate
  • Increased electrical supply, both in the number of outlets and levels of power generation.
  • Revision of existing HVAC ducting. This includes the introduction of HEPA filtration, dedicated exhausts, and modification of existing zoning.
  • Creating of medical air and vacuum gas systems and their distribution, especially when bottled gas supply will be insufficient.
  • Provision for the secure and safe storage of medical equipment and supplies. such as medical gas, ventilators, and pharmaceuticals.
  • Adding plumbing systems such as the installation of dedicated hand washing facilities.
  • Containment structures such as isolation pods, temporary walls, and fencing.
  • Critical site elements such as medical/general waste removal, materials drop-off and pickup, patient drop-off, and ambulance/EMS access.

As shown here, there are many concerns to be aware of in converting a space for healthcare use. Thankfully, there’s also a great deal of guidance available. The Centers for Disease Control (CDC) offers extensive information specifically about healthcare facilities. ASHE (the American Society of Healthcare Engineers), ASHRAE (The American Society of Heating, Refrigerating and Air-Conditioning Engineers) and CDC have prepared materials available on the internet.

Healthcare facilities need to keep pursuing the above strategies to ensure a safe environment for both infected and non-infected citizens.

Tariq Amlani is a principal and health sector engineering lead, Canada, at Stantec (Vancouver). He can be reached at Patrick Chambers is an associate and mechanical project engineer at Stantec (Brisbane). He can be reached at Jeff Hankin is a senior principal and health sector engineering lead, US, at Stantec (San Diego, Calif.). He can be reached at Douglas King is a healthcare principal at Stantec (Chicago). He can be reached at