Healthcare Design - May 2020 - 24

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COVID-19

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SOLUTIONS

ACHIEVING
NEGATIVE
PRESSURE

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 others. 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 with 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 from that task.
As the number 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.

MAY 2020

Following are some key related engineering
controls and strategic considerations:
* 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 netnegative 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
patient units.
* Siting anterooms at entries and exits to isolated 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.-Tariq Amlani, principal and
health sector engineering lead, Canada; Patrick
Chambers, associate and mechanical project engineer; Jeff Hankin, senior principal and health
sector engineering lead, U.S.; and Douglas King
healthcare principal, Stantec

hard to deliver the latest news, resources, and
industry insights to help navigate the design
response to the COVID-19 crisis. A COVID-19
Coverage and Resources page is updated daily
and can be accessed directly at HCDmagazine.
com/covid-19. There, you'll also find details on
initiatives being rolled out by numerous industry
organizations. Here are a few to check out.
ASHRAE

An ASHRAE COVID-19 Preparedness Resources
webpage was developed to provide proactive
guidance on addressing COVID-19 concerns
with respect to the operation and maintenance
of heating, ventilating, and air-conditioning
systems.
THE CENTER FOR HEALTH DESIGN

The Center is providing its Infection Control Toolbox free of charge, allowing access to a selection
of evidence-based strategies and best practices
with an emphasis on hand hygiene, contact
transmission, surface cleaning, infection control
for new hospital buildings, and the role of facility
design on healthcare-associated infections.
I N T E R N AT I O N A L W E L L B U I L D I N G
INSTITUTE

The IWBI has assembled a task force aimed to
reduce the health burden from COVID-19 and
other respiratory infections by mining scientific literature to identify enhanced opportunities for the
built environment to improve population health
and address hazards.
AMERICAN INSTITUTE OF
ARCHITECTS

The AIA is compiling an online database of
ongoing COVID-19-related projects to capture
efforts nationally regarding the pandemic.
Indusry members are invited to share information
on their design actions, and then the searchable
database will include interactive graphics that
allow users to search for information.
CENTERS FOR MEDICARE &
MEDICAID SERVICES

CMS launched an enhanced, focused inspection process for all inspectors and facilities. This
includes a self-assessment tool developed in coordination with the Centers for Disease Control and
Prevention for providers to ensure facilities are
prepared to prevent the spread of coronavirus.

Healthcare Design - May 2020

Table of Contents for the Digital Edition of Healthcare Design - May 2020