Planning and Designing An Isolation Facility in Hospitals Need of The Hour PDF
Planning and Designing An Isolation Facility in Hospitals Need of The Hour PDF
Planning and Designing An Isolation Facility in Hospitals Need of The Hour PDF
K Shweta et al 10.5005/jp-journals-10035-1036
REVIEW ARTICLE
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• To prevent escape of airborne particles from such • Gasketing should be provided at the sides and top of
rooms into the corridor and other areas of the facility the door, and at ceiling and wall penetrations, such
using directional airflow. as those around medical and electrical outlets.
• To protect patients who are immunocompromised
from potential harmful pathogens. Bed Management System3
International Journal of Research Foundation of Hospital & Healthcare Administration, January-June 2015;3(1):48-56 49
K Shweta et al
• Communication system.
• A nurse call system with the capacity for direct
communication between the nurse and patient should Fig. 1: Negative pressure isolation room (adapted from HVAC
be available in each room. design for healthcare facilities by CED engineering)12
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first passed over the staff/other occupants and then to the that air flow must be from the ‘cleaner’ area toward the
patient. Air distribution should reduce the staff’s expo- adjoining space (through doors or other openings). This
sure to potential airborne droplet nuclei from infectious is achieved by the HVAC system providing more air into
patients, accounting for the positions of the staff and the the ‘cleaner’ space than is mechanically removed from
patient, and the procedures undertaken in the isolation that same space.6
room. Insider patient room, the supply air should be from In the Figure 2, an airlock or anteroom is provided
the ceiling diffuser located at the perimeter near to the adjacent to the patient room. For a positive pressure room,
entry and the exhaust air should be drawn at lower levels air would flow from the isolation room to the anteroom
approximately 6" above the floor in the room. Exhaust air and then to the corridor. Pressure control is maintained
ducts should be independent of the building’s common by modulating the main supply and exhaust dampers
exhaust air system to reduce the risk of contamination based on a signal from a pressure transducer located
from back draught. The exhaust fan should be located inside the isolation room.
at a point in the duct system that will ensure the duct is
under negative pressure throughout its run within the Ventilation
building. The makeup air intakes should be located so
Class P rooms can be either 100% fresh air or can use
that no contaminated air from nearby exhaust stacks or
recirculated air usually a 60/40 mix of outdoor air/
any sources of air contaminants is drawn into the makeup
recirculated air. The supply air should be located such
air system. Ensure supply air ducts are independent of
that clean air is first flows across the patient bed and
the building’s common supply air system. If sharing of
exits from the opposite side of the room. Air distribution
supply ducts with other isolation rooms is unavoidable,
should reduce the patient’s exposure to potential airborne
provide the ducts with terminal HEPA filters (or other
droplet nuclei from occupants. Positive pressure rooms
failsafe back draught prevention system). A high effi-
may share common supply air systems (Table 1).
ciency bag filter may be installed as a pre-filter to protect
the HEPA filter. ANTEROOMS4
Emergency Rooms and Reception Areas If space and budget permit, an anteroom should be pro-
vided between the negative/positive pressure isolation
The likelihood of airborne contaminants leaving these
room and the corridor (Fig. 3). It is always recommended
rooms is reduced by keeping these rooms under negative
for both positive and negative isolation rooms for three
pressure, relative to surrounding areas. Air is exhausted
main reasons:
from these rooms either directly to the outside or through
1. To provide a barrier against loss of pressurization,
high efficiency particulate air (HEPA) filters.
and against entry/exit of contaminated air into/out
CLASS P — POSITIVE PRESSURE of the isolation room when the door to the airlock is
ISOLATION ROOMS opened.
Fig. 2: Positive pressure isolation rooms (adapted from HVAC Fig. 3: Anteroom: outside and inside view (isolation room design
design for healthcare facilities by CED engineering)12 by Thailand engineering company)13
International Journal of Research Foundation of Hospital & Healthcare Administration, January-June 2015;3(1):48-56 51
K Shweta et al
2. To provide a controlled environment in which protec- also eventually reduce load on the air handling plant.
tive garments can be donned without contamination Ensure air tightness by
before entry into the isolation room. • Properly constructing windows, doors, and intake
3. To provide a controlled environment in which equip- and exhaust ports
ment and supplies can be transferred from the isola- • Maintain plasterboard ceilings that are smooth
tion room without contaminating the surrounding and free of fissures, open joints and crevices
areas. • Sealing all penetrations on the walls above and
below the ceiling
Other Requirements of Anteroom • Monitoring for leakage and making any necessary
• Provision of a sink, cabinets and work counter repairs.
• Provision of a view window in the door to the isola- 3. Proper room pressurization can be checked using a
tion room smoke stick or smoldering match at doors held open
• Alignment of door to corridor with door to isolation approximately 1/4 inch to visually see which direction
room air is moving. Care must be taken when checking this
• Maximum of two isolation rooms per anteroom. to make sure that the door is not moving during the
test since a door swinging can move more air than the
SPECIFIC DESIGN CONSIDERATIONS6,7 design ventilation differential in the room. An alarm
system (visual/audible) should be installed to warn
Environment control is very important in isolation faci-
of pressurisation failure.
lity. This is achieved by:
4. Thermal comfort: Isolation rooms have relatively high
Maintaining air changes: A monitoring system should
air exchange rates in relation to other patient rooms.
be provided to signal any malfunction of the supply/
This implies high ventilation air supply and exhaust
exhaust air system. A separation of 25 feet is recom-
rates as well. Potentially uncomfortable air velocities
mended between exhaust from isolation rooms and other
(draughts) within the patient room can result, and
ventilation system intakes or occupied areas.11
therefore special attention must be given to thermal
1. Pressure gradient
comfort, particularly for the patient, as a design issue.
Room type Room Ensuite Anteroom
Class N –ve 30 Pa –ve 30 Pa –ve 15 Pa 5. Air distribution (Fig. 4)12
Class P +ve 30 Pa +ve 30 Pa +ve 15 Pa • Air distribution systems should be designed
Class P room with negative +ve 15 Pa +ve 30 Pa +ve 15 Pa to provide a high effective ventilation rate. The
pressure anteroom design and balance of the ventilation system
2. Planned and unplanned leaks—rooms are well-sealed should ensure that air flows from less contami-
for better maintenance of pressure gradients that will nated to more contaminated areas. Air in an open
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Fig. 4: Air distribution pattern (adapted from HVAC design for healthcare facilities by CED engineering)12
class N room, for example, should flow from • Investigate the use of a pressure stabilizer above the
corridors into the isolation room to prevent the bedroom door
spread of airborne contaminants from the isola- • Compliant exhaust system
tion room to other areas. Within the room, the air • Compliant air supply (see below)
should follow similar principles: • Sliding transfer grille in room door
– In a class N room, the air should pass over first • Sealed, monolithic ceiling with sealed access panels
the staff then the patient • Windows to the exterior to be locked shut and sealed
– In a class P room, the air should pass over first • Provision of two-way intercommunication system
the patient then the staff between the patient’s room and the nurses’ station.
– Air distribution should reduce the staff’s
exposure to potential airborne droplet nuclei Fire Strategy
from infectious patients, accounting for the
• The isolation suite is intended to be built as a single
positions of the staff and the patient, and the
fire compartment (Fig. 5).9 The positive pressure in the
procedures undertaken in the isolation room.
lobby will detect smoke originating in the corridor
Renovating or Converting a Room (Appendix-2) from entering the room. Smoke from a fire in the room
will be contained within the suite and extracted via
When an isolation room is being incorporated into an the en-suite extract. Because of this the ventilation
existing facility, it is rarely possible to create the ideal system serving the isolation facility should be kept
room. Physical and financial factors often constrain the
running in the event of a fire.
construction. It is critical to create a room that is fit for its
• Ductwork thickness should be such that ducts can
purpose; therefore, the design intent should be adhered
be considered an extension of the isolation suite. Fire
to as closely as possible.
dampers, where the ducts penetrate walls and floors
When converting existing accommodation into class N
will not then be required.
rooms, the easiest and least expensive option is to adapt
• A motorized smoke/fire damper should be fitted at the
existing single rooms with ensuite facilities. The follow-
discharge of the supply air handling unit (AHU). The
ing requirements should be met in any conversion:
damper should close in the event of an AHU or intake
• Furnishing and fittings:
fire under the control of a smoke detector mounted in
• Clinical hand wash basin with non-touch, fixed tem-
the AHU.
perature mixer tap
• Wall-mounted soap dispensers
CONCLUSION
• Disinfectant hand rub dispensers
• Disposable towel holders The physical design of a hospital is an essential compo-
• Glove dispensers nent of its infection control measures to minimize the
• Storage for clean personal protective equipment risk of transmission of any infectious disease. Today,
• Clean waste bins with a more progressive outlook, it is the fundamental
• Observation window in corridor wall with integral requirement to adopt a holistic view of the design and
privacy blinds management of hospitals.
International Journal of Research Foundation of Hospital & Healthcare Administration, January-June 2015;3(1):48-56 53
K Shweta et al
With the challenges of new and emerging infectious 2. Provide suitable extract fan.
diseases as well as higher public expectations and aware- 3. Install transfer grille to en-suite door.
ness of healthcare related issues, much consideration has 4. Supply air.
to be given to these in the planning phase of building 5. Pressure stabiliser.
hospitals. For existing institutions and hospital buil- 6. Observation window in corridor wall with integral
dings, renovation and upgrading plans must incorporate privacy blinds to allow for staff observation and
the necessary changes. Among the various methods for patient views out.
infection control two important environment factors 7. Double door for personnel and bed access.
are isolation and ventilation. Infected patients or those 8. Disposable apron dispenser.
highly susceptible to infection need to be isolated in 9. En-suite WC to be non-touch flush and wash basin to
private rooms with proper ventilation systems in order have single tap with flow and temperature control.
to stop spread and reduce the possibility of developing 10. Ceiling to be sealed solid construction, external win-
a new infection. The more stringent guidelines stress the dow to be sealed.
importance of utilizing an engineering team that has
experience in designing the mechanical systems for AII Appendix II
rooms. Collaboration between the mechanical engineer
and architect early in the design process is essential in Upgrading three existing single rooms to provide two
avoiding issues that may arise relating to the placement single rooms with anteroom in common (NHS estates
of supply and exhaust locations and maintaining the health building note) (Fig. 7).9
standard pressure differential. Minimum requirements to upgrade existing facilities.
1. Add clinical hand-wash basin with non-touch fixed
Appendix I temperature mixer tap.
2. Provide suitable extract fan.
Newly built single isolation room with anteroom (NHS 3. Install transfer grille to ensuite door.
estates health building note) (Fig. 6).9 4. Observation window in corridor wall with integral
privacy blinds to allow for staff observation and
Minimum Requirements
patient views out.
1. Clinical hand washbasin with non-touch, fixed tem- 5. Ensuite WC to be non-touch flush and wash basin to
perature mixer tap. have single tap with flow and temperature control.
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Fig. 6: Newly built single isolation room with anteroom (adapted from NHS estates health building note)9
International Journal of Research Foundation of Hospital & Healthcare Administration, January-June 2015;3(1):48-56 55
K Shweta et al
6. Rydock JP, Lindqvist C. Best practice in design and testing of 10. Guidelines for the classification and design of isolation rooms
isolation rooms in nordic hospitals, Nordic innovation centre, in health care facilities Victorian Advisory Committee on
September, 2004. Infection Control, 2007.
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Best Practice Standards for Capital Planning. Belfast; Depart- ture for Health. Guidelines for design and construction
ment of Health, Social Services and Public Safety, Regional of hospital and healthcare facilities. 1996-97. Ameri-
Advisory Committee on Communicable Disease Control; 2003. can Institute of Architects, Press Washington 1996;
8. Chowdhury PK, Bajaj S. HVAC Design Criteria for Isolation 102-105.
Rooms. HVAC J 2002 Jul-Sep. 12. Bhatia A. HVAC design for healthcare facilities course no:
9. Scottish Health Planning Note 04. In-patient Accommoda- M06-011 credit; 6 PDH. CED engineering.
tion: Options for Choice Supplement 1: Isolation Facilities in 13. Supote T. Isolation room design. Air conditioning engineer-
Acute Settings. ing association of Thialand, Article 17 sets:56-66.
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