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Buildings for Health Care Facilities

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The health maintenance and enhancement, the safety and the comfort of people in health care facilities are seriously affected if specific building requirements are not met. Health care facilities are rather unique buildings, in which heterogeneous environments coexist. Different people, several activities in each environment and many risk factors are involved in the pathogenesis of a broad spectrum of diseases. Functional organization criteria classify health care facility environments as follows: nursing units, operating theatres, diagnostic facilities (radiology unit, laboratory units and so on), outpatients’ departments, administration area (offices), dietary facilities, linen services, engineering services and equipment areas, corridors and passages. The group of people which attends a hospital is composed of health personnel, staff personnel, patients (long-stay inpatients, acute inpatients and outpatients) and visitors. The processes include health care specific activities—diagnostic activities, therapeutic activities, nursing activities—and activities common to many public buildings—office work, technological maintenance, food preparation and so on. The risk factors are physical agents (ionizing and non-ionizing radiation, noise, lighting and microclimatic factors), chemicals (e.g., organic solvents and disinfectants), biological agents (viruses, bacteria, fungi and so on), ergonomics (postures, lifting and so on) and psychological and organizational factors (e.g., environmental perceptions and work hours). The illnesses related to the above-mentioned factors range from environmental annoyance or discomfort (e.g., thermal discomfort or irritative symptoms) to severe diseases (e.g., hospital-acquired infections and traumatic accidents). In this perspective, the risk assessment and control require an interdisciplinary approach involving physicians, hygienists, engineers, architects, economists and so on and fulfilment of preventive measures in the building planning, design, construction and management tasks. Specific building requirements are extremely important among these preventive measures, and, according to the guidelines for healthy buildings introduced by Levin (1992), they should be classified as follows:

  • site planning requirements
  • architectural design requirements
  • requirements for building materials and furnishings
  • requirements for heating, ventilation and air-conditioning systems and for microclimatic conditions.

 

This article focuses on general hospital buildings. Obviously, adaptations would be required for specialty hospitals (e.g., orthopaedic centres, eye and ear hospitals, maternity centres, psychiatric institutions, long-term care facilities and rehabilitation institutes), for ambulatory care clinics, emergency/urgent care facilities and offices for individual and group practices. These will be determined by the numbers and types of patients (including their physical and mental status) and by the number of HCWs and the tasks they perform. Considerations promoting the safety and well-being of both patients and staff that are common to all health care facilities include:

  • ambience, including not only decoration, lighting and noise control but also partitioning and placement of furniture and equipment that avoid entrapment of workers with potentially violent patients and visitors
  • ventilation systems that minimize exposure to infectious agents and potentially toxic chemicals and gases
  • storage facilities for clothing and effects of patients and their visitors that minimize potential contamination
  • lockers, changing rooms, wash-up facilities and rest rooms for staff
  • conveniently-located hand-washing facilities in each room and treatment area
  • doorways, elevators and toilets that accommodate wheel chairs and stretchers
  • storage and filing areas designed to minimize workers’ stooping, bending, reaching and heavy lifting
  • automatic and worker-controlled communication and alarm systems
  • mechanisms for collection, storage and disposition of toxic wastes, contaminated linens and clothing and so on.

 

Site Planning Requirements

The health care facility site must be chosen following four main criteria (Catananti and Cambieri 1990; Klein and Platt 1989; Decree of the President of Ministers Council 1986; Commission of the European Communities 1990; NHS 1991a, 1991b):

  1. Environmental factors. The terrain should be as level as possible. Ramps, escalators and elevators can offset sides of hills, but they hinder the access of elderly and handicapped people, adding both a higher cost to the project and an extra burden to fire departments and evacuation teams. Heavy wind sites should be avoided, and the area should be far from sources which create pollution and noise (especially factories and landfills). Radon and radon daughters levels should be assessed, and measures to reduce exposure should be taken. In colder climates, consideration should be given to embedding snow-melting coils in sidewalks, entrance ways and parking areas to minimize falls and other accidents. 
  2. Geological configuration. Earthquake-prone areas should be avoided, or at least anti-seismic construction criteria must be followed. The site must be chosen following an hydrogeological assessment, to avoid water infiltrations into the foundations. 
  3. Urbanistic factors. The site should be easily accessible to potential users, ambulances and service vehicles for goods supply and waste disposal. Public transportation and utilities (water, gas, electricity and sewers) should be available. Fire departments should be nearby, and fire-fighters and their apparatus should find ready access to all parts of the facility. 
  4. Space availability. The site should allow some scope for expansion and provision of adequate car parking.

 

Architectural Design

Health care facilities architectural design usually follows several criteria:

  • class of the health care facility: hospital (acute-care hospital, community hospital, rural hospital), large or small health care centre, nursing homes (extended care facilities, skilled nursing homes, residential care homes), general medical practice premise (NHS 1991a; NHS 1991b; Kleczkowski, Montoya-Aguilar and Nilsson 1985; ASHRAE 1987)
  • catchment area dimensions
  • management issues: costs, flexibility (susceptibility to adaptation)
  • ventilation provided: an air-conditioned building is compact and deep with as small an amount of external walls as possible, to reduce the heat transfer between outside and inside; a naturally ventilated building is long and thin, to maximize exposure to breezes and to minimize internal distances from windows (Llewelyn-Davies and Wecks 1979)
  • building/area ratio
  • environmental quality: safety and comfort are extremely relevant targets.

 

The listed criteria lead health care facilities planners to choose the best building shape for each situation, ranging essentially from an extended horizontal hospital with scattered buildings to a monolithic vertical or horizontal building (Llewelyn-Davies and Wecks 1979). The first case (a preferable format for low-density buildings) is normally used for hospitals up to 300 beds, because of its low costs in construction and management. It is particularly considered for small rural hospitals and community hospitals (Llewelyn-Davies and Wecks 1979). The second case (usually preferred for high-density buildings) becomes cost-effective for hospitals with more than 300 beds, and it is advisable for acute-care hospitals (Llewelyn-Davies and Wecks 1979). The internal space dimensions and distribution have to cope with many variables, among which one can consider: functions, processes, circulation and connections to other areas, equipment, predicted workload, costs, and flexibility, convertibility and susceptibility of shared use. Compartments, exits, fire alarms, automatic extinction systems and other fire prevention and protection measures should follow local regulations. Furthermore, several specific requirements have been defined for each area in health care facilities:

1.       Nursing units. Internal layout of nursing units usually follows one of the following three basic models (Llewelyn-Davies and Wecks 1979): an open ward (or “Nightingale” ward)—a broad room with 20 to 30 beds, heads to the windows, ranged along both walls; the “Rigs” layout—in this model beds were placed parallel to the windows, and, at first, they were in open bays on either side of a central corridor (as at Rigs Hospital in Copenhagen), and in later hospitals the bays were often enclosed, so that they became rooms with 6 to 10 beds; small rooms, with 1 to 4 beds. Four variables should lead the planner to choose the best layout: bed need (if high, an open ward is advisable), budget (if low, an open ward is the cheapest one), privacy needs (if considered high, small rooms are unavoidable) and intensive care level (if high, the open ward or Rigs layout with 6 to 10 beds are advisable). The space requirements should be at least: 6 to 8 square metres (sqm) per bed for open wards, inclusive of circulation and ancillary rooms (Llewelyn-Davies and Wecks 1979); 5 to 7 sqm/bed for multiple bedrooms and 9 sqm for single bedrooms (Decree of the President of Ministers Council 1986; American Institute of Architects Committee on Architecture for Health 1987). In open wards, toilet facilities should be close to patients’ beds (Llewelyn-Davies and Wecks 1979). For single and multiple bedrooms, handwashing facilities should be provided in each room; lavatories may be omitted where a toilet room is provided to serve one single-bed room or one two-bed room (American Institute of Architects Committee on Architecture for Health 1987). Nursing stations should be large enough to accommodate desks and chairs for record keeping, tables and cabinets for preparation of drugs, instruments and supplies, chairs for sit-down conferences with physicians and other staff members, a wash-up sink and access to a staff toilet.

2.       Operating theatres. Two main classes of elements should be considered: operating rooms and service areas (American Institute of Architects Committee on Architecture for Health 1987). Operating rooms should be classified as follows:

  • general operating room, needing a minimum clear area of 33.5 sqm.
  • room for orthopaedic surgery (optional), needing enclosed storage space for splints and traction equipment
  • room for cardiovascular surgery (optional), needing a minimum clear area of 44 sqm. In the clear area of the surgical suite, nearby the operating room, an additional pump room should be designed, where extracorporeal pump supplies and accessories are stored and serviced.
  • room for endoscope procedures, needing a minimum clear area of 23 sqm
  • rooms for waiting patients, induction of anaesthesia and recovery from anaesthesia.

 

Service areas should include: sterilizing facility with high-speed autoclave, scrub facilities, medical gas storage facilities and staff clothing change areas.

3.       Diagnostic facilities: Each radiology unit should include (Llewelyn-Davies and Wecks 1979; American Institute of Architects Committee on Architecture for Health 1987):

  • appointment desk and waiting areas
  • diagnostic radiographic rooms, needing 23 sqm for fluoroscopic procedures and about 16 sqm for radiographic ones, plus a shielded control area, and rigid support structures for ceiling-mounted equipment (where necessary)
  • dark room (where necessary), needing almost 5 sqm and appropriate ventilation for the developer
  • contrast media preparation area, clean-up facilities, film quality control area, computer area and film storage area
  • viewing area where films can be read and reports dictated.

 

The wall thickness in a radiology unit should be 8 to 12 cm (poured concrete) or 12 to 15 cm (cinder block or bricks). The diagnostic activities in health care facilities may require tests in haematology, clinical chemistry, microbiology, pathology and cytology. Each laboratory area should be provided with work areas, sample and material storage facilities (refrigerated or not), specimen collection facilities, facilities and equipment for terminal sterilization and waste disposal, and a special facility for radioactive material storage (where necessary) (American Institute of Architects Committee on Architecture for Health 1987).

4.       Outpatient departments. Clinical facilities should include (American Institute of Architects Committee on Architecture for Health 1987): general-purpose examination rooms (7.4 sqm), special-purpose examination rooms (varying with the specific equipment needed) and treatment rooms (11 sqm). In addition, administrative facilities are needed for the admittance of outpatients.

5.       Administration area (offices). Facilities such as common office building areas are needed. These include a loading dock and storage areas for receiving supplies and equipment and dispatching materials not disposed of by the separate waste removal system.

6.       Dietary facilities (optional). Where present, these should provide the following elements (American Institute of Architects Committee on Architecture for Health 1987): a control station for receiving and controlling food supplies, storage spaces (including cold storage), food preparation facilities, handwashing facilities, facility for assembling and distributing patients’ meals, dining space, dishwashing space (located in a room or an alcove separated from the food preparation and serving area), waste storage facilities and toilets for dietary staff.

7.       Linen services (optional). Where present, these should provide the following elements: a room for receiving and holding soiled linen, a clean-linen storage area, a clean-linen inspection and mending area and handwashing facilities (American Institute of Architects Committee on Architecture for Health 1987).

8.       Engineering services and equipment areas. Adequate areas, varying in size and characteristics for each health care facility, have to be provided for: boiler plant (and fuel storage, if necessary), electrical supply, emergency generator, maintenance workshops and stores, cold-water storage, plant rooms (for centralized or local ventilation) and medical gases (NHS 1991a).

9.       Corridors and passages. These have to be organized to avoid confusion for visitors and disruptions in the work of hospital personnel; circulation of clean and dirty goods should be strictly separated. Minimum corridor width should be 2 m (Decree of the President of Ministers Council 1986). Doorways and elevators must be large enough to allow easy passage of stretchers and wheelchairs.

Requirements for Building Materials and Furnishings

The choice of materials in modern health care facilities is often aimed to reduce the risk in accidents and fire occurrence: materials must be non-inflammable and must not produce noxious gases or smokes when burnt (American Institute of Architects Committee on Architecture for Health 1987). Trends in hospital floor-covering materials have shown a shift from stone materials and linoleum to polyvinyl chloride (PVC). In operating rooms, in particular, PVC is considered the best choice to avoid electrostatic effects that may cause explosion of anaesthetic flammable gases. Up to some years ago, walls were painted; today, PVC coverings and fibreglass wallpaper are the most used wall finishes. False ceilings are today built mainly from mineral fibres instead of gypsum board; a new trend appears to be that of using stainless steel ceilings (Catananti et al. 1993). However, a more complete approach should consider that each material and furnishing may cause effects in the outdoor and indoor environmental systems. Accurately chosen building materials may reduce environmental pollution and high social costs and improve the safety and comfort of building occupants. At the same time, internal materials and finishes may influence the functional performance of the building and its management. Besides, the choice of materials in hospitals should also consider specific criteria, such as ease of cleaning, washing and disinfecting procedures and susceptibility to becoming a habitat for living beings. A more detailed classification of criteria to be considered in this task, derived from the European Community Council Directive No. 89/106 (Council of the European Communities 1988), is shown in table 1 .

Table 1. Criteria and variables to be considered in the choice of materials

Criteria

Variables

Functional performance

Static load, transit load, impact load, durability, construction requirements

Safety

Collapse risk, fire risk (reaction to fire, fire resistance, flammability), static electric charge (explosion risk), disperse electric power (electric shock risk), sharp surface (wound risk), poisoning risk (hazardous chemical emission), slip risk, radioactivity

Comfort and pleasantness

Acoustic comfort (features related to noise), optical and visual comfort (features related to light), tactile comfort (consistence, surface), hygrothermal comfort (features related to heat), aesthetics, odour emissions, indoor air quality perception

Hygienicity

Living beings habitat (insects, moulds, bacteria), susceptibility to stains, susceptibility to dust, easiness in cleaning, washing and disinfecting, maintenance procedures

Flexibility

Susceptibility to modifications, conformational factors (tile or panel dimensions and morphology)

Environmental impact

Raw material, industrial manufacturing, waste management

Cost

Material cost, installation cost, maintenance cost

Source: Catananti et al. 1994.

On the matter of odour emissions, it should be observed that a correct ventilation after floor or wall-coverings installation or renovation work reduces exposure of personnel and patients to indoor pollutants (especially volatile organic compounds (VOCs)) emitted by building materials and furnishings.

Requirements for Heating, Ventilation and Air-Conditioning Systems and for Microclimatic Conditions

The control of microclimatic conditions in health care facilities areas may be carried out by heating, ventilation and/or air-conditioning systems (Catananti and Cambieri 1990). Heating systems (e.g., radiators) permit only temperature regulation and may be sufficient for common nursing units. Ventilation, which induces changes of air speed, may be natural (e.g., by porous building materials), supplementary (by windows) or artificial (by mechanical systems). The artificial ventilation is especially recommended for kitchens, laundries and engineering services. Air-conditioning systems, particularly recommended for some health care facility areas such as operating rooms and intensive-care units, should guarantee:

  • the control of all microclimatic factors (temperature, relative humidity and air speed)
  • the control of air purity and concentration of micro-organisms and chemicals (e.g., anaesthetic gases, volatile solvents, odours and so on). This target may be achieved by adequate air filtration and air changes, right pressure relationships among adjacent areas and laminar airflow.

 

General requirements of air-conditioning systems include outdoor intake locations, air filter features and air supply outlets (ASHRAE 1987). Outdoor intake locations should be far enough, at least 9.1 m, from pollution sources such as exhaust outlets of combustion equipment stacks, medical-surgical vacuum systems, ventilation exhaust outlets from the hospital or adjoining buildings, areas that may collect vehicular exhaust and other noxious fumes, or plumbing vent stacks. Besides, their distance from ground level should be at least 1.8 m. Where these components are installed above the roof, their distance from roof level should be at least 0.9 m.

Number and efficiency of filters should be adequate for the specific areas supplied by air conditioning systems. For example, two filter beds of 25 and 90% efficiency should be used in operating rooms, intensive-care units and transplant organ rooms. Installation and maintenance of filters follow several criteria: lack of leakage between filter segments and between the filter bed and its supporting frame, installation of a manometer in the filter system in order to provide a reading of the pressure so that filters can be identified as expired and provision of adequate facilities for maintenance without introducing contamination into the air flow. Air supply outlets should be located on the ceiling with perimeter or several exhaust inlets near the floor (ASHRAE 1987).

Ventilation rates for health care facility areas permitting air purity and comfort of occupants are listed in table 2 .

Table 2. Ventilation requirements in health care facilities areas

Areas

Pressure relationships to adjacent areas

Minimum air changes of outdoor air per hour supplied to room

Minimum total air changes per hour supplied to room

All air exhausted directly to outdoors

Recirculated within room units

Nursing units

         

Patient room

+/–

2

2

Optional

Optional

Intensive care

P

2

6

Optional

No

Patient corridor

+/–

2

4

Optional

Optional

Operating theatres

         

Operating room (all outdoor system)

P

15

15

Yes1

No

Operating room (recirculating system)

P

5

25

Optional

No2

Diagnostic facilities

         

X ray

+/–

2

6

Optional

Optional

Laboratories

         

Bacteriology

N

2

6

Yes

No

Clinical chemistry

P

2

6

Optional

No

Pathology

N

2

6

Yes

No

Serology

P

2

6

Optional

No

Sterilizing

N

Optional

10

Yes

No

Glasswashing

N

2

10

Yes

Optional

Dietary facilities

         

Food preparation centres3

+/–

2

10

Yes

No

Dishwashing

N

Optional

10

Yes

No

Linen service

         

Laundry (general)

+/–

2

10

Yes

No

Soiled linen sorting and storage

N

Optional

10

Yes

No

Clean linen storage

P

2 (Optional)

2

Optional

Optional

P = Positive. N = Negative. +/– = Continuous directional control not required.

1 For operating rooms, use of 100% outside air should be limited to these cases where local codes require it, only if heat recovery devices are used; 2 recirculating room units meeting the filtering requirement for the space may be used; 3 food preparation centres shall have ventilation systems that have an excess of air supply for positive pressure when hoods are not in operation. The number of air changes may be varied to any extent required for odour control when the space is not in use.

Source: ASHRAE 1987.

Specific requirements of air-conditioning systems and microclimatic conditions regarding several hospital areas are reported as follows (ASHRAE 1987):

Nursing units. In common patient rooms a temperature (T) of 24 °C and a 30% relative humidity (RH) for winter and a T of 24 °C with 50% RH for summer are recommended. In intensive-care units a variable range temperature capability of 24 to 27 °C and a RH of 30% minimum and 60% maximum with a positive air pressure are recommended. In immunosuppressed patient units a positive pressure should be maintained between patient room and adjacent area and HEPA filters should be used.

In full-term nursery a T of 24 °C with RH from 30% minimum to 60% maximum is recommended. The same microclimatic conditions of intensive-care units are required in special-care nursery.

Operating theatres. Variable temperature range capability of 20 to 24 °C with RH of 50% minimum and 60% maximum and positive air pressure are recommended in operating rooms. A separate air-exhaust system or special vacuum system should be provided in order to remove anaesthetic gas traces (see “Waste anaesthetic gases” in this chapter).

Diagnostic facilities. In the radiology unit, fluoroscopic and radiographic rooms require T of 24 to 27 °C and RH of 40 to 50%. Laboratory units should be supplied with adequate hood exhaust systems to remove dangerous fumes, vapours and bioaerosols. The exhaust air from the hoods of the units of clinical chemistry, bacteriology and pathology should be discharged to the outdoors with no recirculation. Also, the exhaust air from infectious disease and virology laboratories requires sterilization before being exhausted to the outdoors.

Dietary facilities. These should be provided with hoods over the cooking equipment for removal of heat, odours and vapours.

Linen services. The sorting room should be maintained at a negative pressure in relation to adjoining areas. In the laundry processing area, washers, flatwork ironers, tumblers, and so on should have direct overhead exhaust to reduce humidity.

Engineering services and equipment areas. At work stations, the ventilation system should limit temperature to 32 °C.

Conclusion

The essence of specific building requirements for health care facilities is the accommodation of external standard-based regulations to subjective index-based guidelines. In fact, subjective indices, such as Predicted Mean Vote (PMV) (Fanger 1973) and olf, a measure of odour (Fanger 1992), are able to make predictions of the comfort levels of patients and personnel without neglecting the differences related to their clothing, metabolism and physical status. Finally, the planners and architects of hospitals should follow the theory of “building ecology” (Levin 1992) which describes dwellings as a complex series of interactions among buildings, their occupants and the environment. Health facilities, accordingly, should be planned and built focusing on the whole “system” rather than any particular partial frames of reference.

 

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