Indmedica Home | About Indmedica | Medical Jobs | Advertise On Indmedica
Search Indmedica Web
Indmedica - India's premier medical portal

Journal of the Academy of Hospital Administration

Operating Unit - Planning Essentials and Design Considerations

Author(s): S.K. Gupta*, S. Kant**, R. Chandrashekhar***

Vol. 17, No. 2 (2005-01 - 2005-12)


There has been spectacular progress in the development of diagnostic facilities, improved aseptic procedures sophisticated equipment and skills in the recent past. These coupled with safer anesthetic techniques have made surgical intervention feasible for a number of medical entities. It is imperative that operation theatre (OT) is designed scientifically to ensure sterility, easy maintenance and effective utilization.


OT is that specialized facility of the hospital where life saving or life improving procedures are carried out on the human body by invasive methods under strict aseptic conditions in a controlled environment by specially trained personnel to promote healing and cure with maximum safety, comfort and economy. Views of inside of an OT are shown in Plates 1,2, 23 and 24.

Missing Image

Plate 1: An inside view of the Operating Room


The main objectives of planning should be:

  • Promote high standard of asepsis.
  • Ensure maximum standard of safety.
  • Optimise utilization of OT and staff time.
  • Optimise working conditions.
  • Patient & staff comfort in terms of thermal, acoustic and lighting requirements.
  • Allow flexibility.
  • Facilitate coordinated services.
  • Minimises maintenance.
  • Ensure functional separation of spaces
  • Provide soothing environment.
  • Regulates flow of traffic.


The essential principles that should be followed in planning the physical layout of operating room suite are exclusion of contamination from outside the suite with proper traffic patterns within the suite and separation of clean areas from contaminated areas within the suite.

OTs require specialized planning because surgical facilities represent a central life saving activity, they make or break the reputation of the hospital, depending on their functional efficiency, it is a major cost center in the establishment of the hospital, are responsible for an appreciable quantum of revenue in private sector and no one plan suits all hospitals. A scientific and detailed planning is required while designing an OT in order to ensure its smooth functioning, efficiency and effective utilization. A schematic diagram of OT service is shown in Fig. 1.

Missing Image

Fig.1: A Schematic Diagram of OT Services

Missing Image

Plate 2: Inside of an OT

Missing Image

Plate 3: Corridors of OT

Missing Image

Plate 4: Hermetically Sealed Door

Missing Image

Plate 5: Sliding Doors


OT should be planned so as to ensure:

  • Avoidance of unrelated hospital traffic flow in the area.
  • Convenient functional relationship and communication with surgical ward, ICU, CSSD, blood bank,medical imaging and laboratory services.
  • Avoidance of outdoor source of noise.
  • Provision for future expansion/alterations.
  • If planning for Modular Theatre, the walls should be galvanised iron I/ Stainless steel panels, joints filled with epoxy and grinded. The final prepared surface is treated with anti bacterial paint.
  • Doors should be of sliding type of minimum 1.2 m width in areas where patient movement is anticipated like operation theatre, pre and post operative rooms. The sliding doors are preferred (Plate 5) to the double action leaf type since they are more user friendly, saves space and prevents air turbulences. Ideally doors should be electrically operated hermetically sealed sliding doors to ensure sterilization and correct air pressure. The main advantages of a hermetically sealed sliding door (Plate 4) are: that disinfections is quicker and safer, contamination risks are under control, acoustic and noise control is easier and In case of failure of air handling unit temperature and humidity levels are brought within range more quickly.
  • Corridors should not be less than 2.85 m. in width to facilitate movement of trolleys and stretchers. (Plate 3)
  • Walls and ceiling should be aesthetically pleasing nonporous, fire resistant, water and stain proof, seamless, non-reflective and easy to clean. They should not cause build up of a static electrical charge. They should be jointless or have joints capable of being sealed.

Missing Image

Plate 6: Modular Theater Walls

Missing Image

Plate 8: Coved Corners

Missing Image

Plate 7: Surgical sinks with electronical sensoras

Missing Image

Plate 9: Flash Autoclave

  • Floors should be smooth, non slip, impervous material conductive enough to dissipate static electricity but not conductive enough to endanger personnel from shock. The flooring should either be inset mosaic with least possible joints and copper strips to carry away any static electricity produced or of jointless conductive tiles. Conductive copper mesh and self levelling epoxy flooring may be done.
  • Ceiling should be painted with washable paint and corners of the rooms should be rounded off to prevent collection of dirt and dust. (Plates 8)
  • Taps in the scrub room should be knee/elbow operated or preferably electronically controlled taps activated by infrared sensor. (Plates 7 & 14)
  • Power back up with provision of stand-by generating sets.
  • Certain facilities may be shared with the obstetric/birthing unit. However it must be ensured that when service areas are shared with delivery rooms they should be designed to avoid movement of patients/staff between the operating room and delivery room areas.
  • In operating rooms anaesthetic room(s) recovery room, holding area, colour of walls and ceilings should be such that they do not alter the observers perception of skin colour this will facilitate patient monitoring and management.
  • OT should have facilities for high speed autoclaves/ sterilizers for immediate/emergency requirements of sterilizing equipment. (Plate 9)
  • Essential pharmaceutical storage including refrigeration facilities should be available.
  • There should be a waiting room with toilet facilities for patient attendants.
  • Pass-through cabinets that circulate clean air through them while maintaining positive air room pressure allow transfer of supplies from outside the OR to inside it. They help ensure the rotation of supplies in storage or can be used only for passing supplies as needed from a clean center core. (plate 12)
  • There should be X-ray film illuminators preferably recessed into the wall. (plate 10)
  • There should be emergency communication system that can be activated without the use of hands. Preoperative Patient Holding Area: This should be able to facilitate stretcher as well as ambulatory patients not requiring stretchers. Each stretcher station should be of 80 sq. feet (7.43 sqm) and should have a clearance of 4 feet (1.22m) on the sides of the stretcher and foot of the stretcher. Post Anaesthetic Care Units : These should contain a medication station, hand washing station, nurse station, (plate 16) storage space for stretchers, supplies and equipment. Additionally 80 sq feet (7.43 sqm) for each patient bed clearance of 5 feet (1.5 m) between bed and 4 feet should be (1.22m) between patient bed sides and adjacent walls. (Plate 13)

Missing Image

Plate 10: X-Ray View Box

Missing Image

Plate 12: Pass Through Door

Missing Image

Plate 11: Control Panel

Missing Image

Plate 13: Post Anaesthetic Care Unit

Service Area: These should include control station located to permit patient observation of all units in to the suite.

  • A sub sterile area between two or more operating areas for flash sterilizer, sterile supply storage area and hand washing station.
  • Scrub facilities near the entrance of each operating room. (Plate 14)
  • Dirty utility for collection and disposal of soiled material. (Plate 15)
  • Clean supply room (Plate 19)
  • Operation room
  • Medical gas storage facilities.
  • Anaesthesia workroom for cleaning, testing and storing anaesthesia equipment.

Staff Amenities: Separate areas should be provided for male and female personnel containing lockers showers (Plate 17), toilets, lavatories and space for donning surgical attire should allow one way traffic i.e. personnel entering from outside the surgical suite to change and move inside.

Medical gases: The main storage of medical gases should be outside the facility and there should be provision for additional separate storage of reserve gas cylinders for a minimum of one day requirement.

Anaesthetic Work room: It should provide space for anaesthetic trolleys and equipment and should be located with direct access to circulation corridors and ready access to the operating room. It is to provide cleaning, testing and storing of anaesthesia equipment. It should contain work benches, Sink(s) and racks for cylinder It should have sufficient power outlets and medical gas panels for testing of equipment.

Missing Image

Plate 14: Scrub Facility

Missing Image

Plate 16: Nurses Duty Room

Missing Image

Plate 15: Sluice ( Dirty Utility)

Missing Image

Plate 17: Change Room

Blood Store: There should be provision for refrigerated blood storage. The storage refrigerator may be in a dedicated or shared space.

Set up Room: It is the clean workroom where clean/sterile materials are held and arranged prior to use in the operating room. Its functions include storage of instruments and materials, holding of sterile supplies and packs, preparation of dressing and instrument trolley, storage of drugs and where theatre sterile supply unit service is not available flash sterilization of dropped or specialized instruments. It should be so located that it has direct access to operating rooms and Central Supply/Theatre Sterile Supply Unit. Positive pressured to be maintained relative to adjoining rooms.

Laboratory: An area for preparation and examination of frozen section may be provided. Depending on the operational policy this may be part of the main laboratory.

Storage: For equipment and supplies utilized in the operating unit adequate store rooms should be provided. The design should allow ease of access to the storage areas for delivery of consumables. Controlled access from an external corridor is recommended. Store rooms are best designed in an elongated rectangular shape to allow easy access to all items. Part of the room may be utilized as an area for testing operating equipment. For this purpose a separate room called as Bio medical Engineering room may also be planned. Storage bays preferably recessed into the corridor walls should be provided for equipment such as stretchers and portable x-ray.


Zones are area of varying degrees of cleanliness in which the bacteriological count progressively diminishes from the outer to the inner zones (operating area) and is maintained by a differential decreasing positive pressure ventilation gradient from the inner zone to the outer zone. They are of following types.

  • Protective Zone: Areas included in this zone are:
    • Reception
    • Waiting area
    • Trolley bay
    • Changing room (Plate 17)
  • Clean Zone: Areas included in this zone are:
    • Pre-op room
    • Recovery room (Plate 18)
    • Plaster room
    • Staff room
    • Store
  • Sterile Zone: Areas included in this zone are:
    • Operating Suite
    • Scrub Room
    • Anesthesia Induction Room (Plate 20)
    • Set up Room
  • Disposal Zone: Areas included in this zone are:
    • Dirty Utility (Plate 15)
    • Disposal corridor
    • The recommended schedule of accommodation is shown in Table 1.

Missing Image

Plate 18: Recovery Room

Missing Image

Plate 19: Sterile Supply

Missing Image

Plate 20: Induction Room

Ventilation: Central air conditioning should ensure temperature range of 18-24o centigrade with 50-60 humidity levels. A minimum of 20 air changes/hour should be ensured. It is preferred to have 100% fresh air. Theatre to maintain positive pressure, and controlling of pressure is adhered to by providing pressure Release Dampers (Plate 21) at the time of opening & closing of the door. The minimum bacteriological requirements are that the air should not contain detectable clostridium spores of coagulase positive staphylococcus. Aerobic cultures on non-selective medium should indicate not more than 35 bacteria-carrying particles in 1 m3 of ventilating air. During surgical operations the concentration of bacterially - contaminated airborne particles in the operating theatre averaged over any 5 minute period should not exceed 180 per m3 (5 per ft 3), and special types of surgical operation, e.g., orthopaedic and transplantation procedures, higher standards of air cleanliness must be ensured.

Lighting: General illumination is furnished by ceiling lights. Lighting should be evenly distributed throughout the room. around 300 lux the anesthesiologist must have sufficient light, to adequately evaluate the patient's skin colour. Electrical wiring should be in concealed conduit lighting both natural and artificial should be of appropriate illumination.

Isolated power systems help prevent sparks from igniting flammables anesthetics and also help to protect patients and personnel from shock. Ground fault circuit interrupters (GFCIS) may be utilized which are designed to shut off the electric power within a few milliseconds of the occurrence of a ground fault, thereby preventing serious electric shock.

To minimize eye fatigue, the ratio of intensity of general room lighting to that at the surgical site should not exceed 1:5, preferably 1:3. This contrast should be maintained in corridors and scrub areas, as well as in the room itself, so that the surgon becomes accustomed to the light before entering the sterile field. Color and hue of the lights also should be consistent. The overhead operating light must. (Plate 22)

  • Make an intense light, within a range of 27,000 to 127,000 lux, into the incision without glare on the surface. The light may be equipped with an intensity control.
  • Provide a diameter light pattern and focus appropriate for size of the incision. Fixture should provide focused depth by refracting light to illuminate both the body cavity and the general operating field.

Missing Image

Plate 21: Pressure Release Damper

Missing Image

Plate 22: OT Light

Missing Image

Plate 23: Inside of an Operation Theatre

  • Be shadowless. Multiple light sources and/or reflectors decrease shadows.
  • Produce the blue-white color of daylight.
  • Be freely adjustable to any position or angle by either a vertical or horizontal range of motion.
  • Should enable easy cleaning.
  • Should be aerodynamically designed to facilitate airflow.
  • Produce a minimum of heat. Halogen bulbs generate less heat than other types.

Auditory Effects: Sound level in OT should be limited to 25-35 db. The reverberation time in OR should be reduced to below one second.

Fire Safety: Both ionization and optical fire detectors should be provided in the operation theatres as against heat detectors, since equipment - oriented operation theatres are likely to create more smoke than heat in the eventuality of fire. Hydrants and fire extinguishers should be provided. Fire exist route should be clearly identified, earmarked and well illuminated.

Water Supply: Besides normal supply of available water at the rate of 400 litres per bed per day separate reserve emergency over head tank should be provided for operation theatre.

Modular Systems: Modular systems are available which consist of prefabricated units for operating suites complete with integrated mechanical and electrical services including air-conditioning.

Missing Image

Plate 24: Inside of an Modular Operation Theatre

Integrated Operating Room: In a integrated OR technology, it is possible to control everything from medical devices, lighting cameras and teleconferencing from a central station, which may be inside or outside the sterile area. A schematic linkage diagram of a integrated operation room is shown in Fig. 2.

Conclusion: The operative unit provides a controlled climatic environment for the operative and peri operative care of patients undergoing diagnostic and surgical procedures under anaesthesia. Surgical practices in the past were not as sophisticated as in the present. The introduction of safer practices in anesthesia, surgical advances, integration of computerization system including robotic surgery has necessitated the modernization of operation theatres. The design of an operating theatre offers a challenge to the planning team to optimize efficiency by creating conclusive environment conditions, realistic functional traffic flow, and flexibility for future expansion.

Missing Image

Table 1: Recommended Schedule of Accomodation

Room/Space Area (sq m) Remarks
Reception 10 many may be required depending on size of hospital
Anaesthetic Induction Room 15 -do-
Operating Room (major) 42-50 -do-
Scrub up/gowning 6 may be co-located between operating rooms
Support Areas
Anaesthetic room 10-15 many may be required depending on size of hospital
Mobile Equipment bay 4 many may be required depending on size of hospital
Bay Linen 3 -do-
Cleaners room 4 -do-
Clean up room 10 -do-
Disposal room 8 -do-
Flash sterilizing 5-6 -do-
Laboratory/Frozen section 4-12 -do-(Optional)
Set up Room 20 -do-
Store Anaesthetic 20 -do-
Store Equipment 20-40 depending on size of hospital
Store Sterile 20-80  
Store Non sterile 20-30  
Blood Store 4  
Recovery Area
Bay Patient 9 many may be required depending on size of hospital
Bay Linen 3 generally 2 bays for patient per operating room
Bay Resustation trolley 2  
Bay Hand washing 1 -do-
Clean utility 12  
Dirty utility 10  
Staff station 6-14 depending on size of hospital
Administrative Staff and Shared Areas
Area/Space Area in sq.m Remarks
Change room 10-30 Many may be required depending on type and size of hospital
Office single person 9 -do-
Store 10 -do-
Toilet staff 2 -do-
Shower staff 2 -do-
Staff lounge 10-30 Depending on size of hospital and staffing establishment
Shared Areas Meeting Room 20-30  
Store general 9  
Waiting 4  
Circulation areas of 40% should be catered.

* Medical Superintendent Dr RP Centre of Ophthalmic Sciences, AIIMS New Delhi
** JDMS (P) Office of DGMS (Army)
*** Senior Architect, DteGHS Min. of Health and Family Welfare Govt. of India Nirman Bhawan New Delhi

Access free medical resources from Wiley-Blackwell now!

About Indmedica - Conditions of Usage - Advertise On Indmedica - Contact Us

Copyright © 2005 Indmedica