Deepak Venkatesh Agarkhed, General Manager – Engineering, Facilities & Quality, Sakra World Hospital, gives an insight about certain parameters which should be followed while designing an ICU
The intensive care unit (ICU), designated as high risk area from infection prevention point of view, has a concentration of lifesaving medical aid and nursing care for patients who are critically ill. The engineering controls both during design, commissioning and operation play a major role. The designer of an ICU should not only have insight of clinical work flow and protocol but have a sound knowledge of engineering controls. The design consultant should capture requirement of patients, intensivists, surgeon, nurses, technicians and infection control officer and in-house engineers (both general and clinical) for efficient design of ICU. The fine balancing act of quality, cost and time factors during design planning and execution will yield better results to hospitals on a long-term basis. Any flaws in ICU engineering control may result in serious compromise in patient care as evident from above mentioned examples.
The following facility related points are required to be considered as part of facility planning and further engineering controls during operation.
Space programme
The guidelines for ICU design should be based on criteria set by ISCCM, India given below.
Level I, six to eight beds —small district hospital, small private nursing homes, rural centres.
Level II, six to eight beds — larger general hospital
Level III, 10 to 16 beds-tertiary level hospitals
The new level III ICU are further planned based on type/ usage of ICU i.e. general or speciality-based like medical, cardiac, neurosurgical, transplant, paediatric. The location of ICU should be close to the operation theatre, imaging diagnostic services and laboratory.
The floor space area size of each patient bed space for ICU can be decided based on classification of open space ICU or cubicle/ separate room. The floor spaced per ICU bed can be planned 3 m X 4 m (12 sq. m) to maximum of 5 m X 5 m (25 sq. m) based on consideration of application of ICU including services and equipment positioning. The outside environment viewing window for each patient bed is strongly suggested as part of the design. A minimum of one to two metre distance should be kept between two beds as per NABH standard.
The height between floor and false ceiling should be three metres to facilitate to bring in engineering services from the ceiling. The ideal single leaf door size for each ICU cubicle or separate room having clear space of 2.1 m X 1.2 m height and width with wide view panel for visual access to patient is suggestive. It is indicative to have 12-16 beds per ICU area for optimal design considering all essential support functions. The total area of ICU should be 2.5 to three times the total space of ICU beds which includes supply and service corridor/ passageway of 2.4 metre width. At least one patient cubicle as isolation with anteroom facility having negative pressure is recommended within the ICU.
The overall design of the ICU should consider patients, staff and visitor movement, storage space of equipment and medicine, location of essential areas like nurse station, clean and dirty utility etc. The other essential areas in floor plan of ICU may contain nourishment room, stat lab, linen storage, staff lounge and utility services.
The civil structure
The structural cost of ICU is mainly decided by type of patient area planned i.e. open space or cubicle/ separate room.
The walls for separate room should be finished plaster wall of six inch block/ brick wall .The wall finish should be durable, tough wearing and should withstand water and routine cleaning by chemicals. Many hospital acquired infections, such as MRSA, are spread by direct contact with contaminated wounds or hands, typically those of healthcare workers. Two coats of anti-bacterial paint with approved shade on primer applied wall and ceiling will help to kill harmful bacteria that can cause hospital superbugs, including MRSA and E. coli. The fabricate protective wall strips at bed level height should be provided to protect the wall from damages.
The cubicle-based patient room should have partition wall which should be seamless, can be easily washed like ACP panel/ HPL board with toughed glass at height of 0.9 metre for visual access of patient. It should be easily cleaned and must withstand temperature from 10 to 250 decelsius and humidity range from 25 per cent to 65 per cent Rh. Curtain tracks for each patient area should be provided for the privacy of patients.
There should be enough space between ceiling and false ceiling to route entire electrical, plumbing, data and medical gases across patient area, as well as in-support service area based on functional requirement.
Imperforated false ceiling with good acoustics and monolithic finish need to be installed in ICU area. The flooring of ICU should be smooth, seamless and durable as there will be heavy movement of patient beds and medical equipment like portable X-Ray like vinyl 2.5 to 4.5 mm thickness. The flooring should be able to sustain wet things like water, chemical solutions without losing its characteristics. As per International Noise Council, the noise level in an ICU should be under 45 dB in the daytime, 40 dB in the evening and 20 dB at night. The material selection and planning should consider the above noise level limit aspect.
Electrical services
The main electrical circuit breaker panel should branch out to individual feeder line for each ICU. The emergency power source like DG power should quickly take over in case of city power failure. Each patient cubicle should have at least seven duplex grounded receptacles 5/15 amp as per AIA guidelines. The location of these receptacle can be either on wall, bedhead panel, ceiling suspended pendant units or vertical column based on choice from hospital team. It is strongly suggested to have at least 50 per cent of electrical receptacles connected to uninterrupted power supply (UPS) with proper label . Each receptacles or cluster within an ICU should be serviced by its own circuit breaker in the electrical panel preferably located in utility room of ICU.
The lighting distribution illumination control should be planned based on routine physical examination (around 350 lux), during procedure of patient (around 1000 lux), during night time (around 5 lux). The lighting distribution board should be separate from power distribution board. The emergency lighting should be connected to few light fixtures to avoid a complete black out scenario. The energy conservation aspect like LED lights and more natural daylight should also be considered.
Air-conditioning heating, ventilation services
Sterile air having low velocity with 21-240 centigrade with 30-60 per cent Rh in ICU should be planned. The central air conditioning system or ICU specific air conditioning system has to be planned based on guidelines of ASHRE standards i.e. for ICU cubicle the requirement of six minimum air changes per hour with two minimum outside air changes per hour having positive pressurisation. It is better to have dedicated air handling unit (AHU) having 99 per cent efficiency down to five microns for each ICU unit. The fresh air for AHU unit must not be located near potential contaminated air like DG/ Kitchen exhaust hood, vehicle parking area or laboratory hood. The design guidelines for immunosuppressed patients like organ transplant is further stringent. The energy conservation aspect like individual control of temperature, humidity using VAV controls with BMS integration needs to be considered.
Water supply
Water supply inside the ICU with sufficient pressure can be broadly classified into three types i.e. domestic soft water (hot and cold) for sinks and scrubs, RO water for dialysis port and for drinking purpose and treated sewage water for flushing in commodes. The domestic water should adhere to IS 10500 standard and RO water for haemodialysis should comply with AAMI standard. Zone stop valves must be installed on pipes entering ICU to allow service to be shut off, in case there is a break in pipeline. The provision of hand free sinks having hot and cold water facility at major functional area like nurse station, clean and dirty utility and ICU with cubicles has to be planned. The dirty utility should have provision for bed pan washer. The supply and drainage line for haemodialysis RO supply should not mix with other plumbing lines. Drainage pipelines should be avoided in the ICU ceiling. Regular domestic water sample test for bacterial contamination, pH, hardness, TDS etc. and endotoxin level for RO water need to be carried out as per NABH FMS standard. The technique of hyper chlorination, increased hot water temperature and regular storage tank cleaning will help to reduce the waterborne pathogens.
Piped medical gas system
Continuous supply of oxygen, compressed air and vacuum is essential for any ICU. HTM 02/01 and NFPA 99 are the standards which deal with piped medical gas system. Each patient should have provision for two number each for oxygen, vacuum outlet and compressed air outlet. Audible and visible low and high pressure alarms must be installed both in the ICU along with manual shut-off valve provision for each medical gas system. Each type of gas outlets should have specific diameter indexed safety system to prevent inadvertent connection to incorrect gas.
Firefighting and detection system
The National Building Code (NBC) has given norms on fire-related infrastructure like installation of extinguisher, sprinkler and alarm, water storage tank and pump capacity based on building height and plot area. In high rise building where ICU is located, the fire escape routes should be clearly indicated. Location of various types of fire extinguishers should be placed at prominent place. Smoke, heat sensors, sprinklers, manual call points and hydrant systems should be tested on a regular basis.
Extra low voltages
Speakers of public address system can be installed in the ICU for safety code like code blue announcement. IP surveillance camera as part of security surveillance system can be installed in the ICU area without affecting patient privacy. Access controlled ICU door having proximity cards and exit switches integrated to building management system can be installed to avoid unauthorised access for people inside the ICU. The nurse call system with call button facility for patient at bedside can be planned to observe audio-video signal at central nurse station nurse. Each patient area should have at least two data point i.e. one for patient physiological monitor and other for hospital information system. The nurse station should have at least five data points and three voice points. TV provision can be planned in each patient room/ cubicle based on requirement. The infrastructure for e-ICU, telemedicine and pneumatic chute can be considered as part of futuristic design.
Interior design and civil finish
A bedside utility column (freestanding, ceiling mounted, or floor mounted) or horizontal bedhead panel having provision of electrical power, oxygen, compressed air and vacuum, and data points besides accessories like IV poll, procedure lamp facility should be decided post mock-up stage itself. The interior work including fixed furniture should be planned based on other services like medical gas, plumbing etc. The storage space in each specific area like clean, dirty utility should be sufficient to keep items without closed shelves. Care should be taken to ensure that services like medical gases, electrical should be concealed rather than exposed on walls. Reflected ceiling plan, coordinated drawing and interior drawing should be signed off before execution of actual work on ground.
The ICU being high risk clinical area , careful engineering services planning, execution and periodic maintenance will help patient care and facilitate to improve clinical outcome.