Hospital medical industry is a very large and special industry, especially the hospital operating room for air cleanliness requirements are also very high. Usually, the minimum requirement for hospital air in qualified hospital operating room purification project or medical cleaning room is to use a 30% efficiency filter and a 90% efficiency sub-high efficiency filter to filter. Usually no high-efficiency filter is needed, but in special cases such as isolation room, specific test and nursing area, high-efficiency filter is needed.
Reference for Class and Grade of Clean Operating Room:
Cleanliness of Hospital Operating Room Name Category
Special Sterile Purification Operating Room Class I 100 (Local Laminar Flow)
Sterile Operating Room Class II 1000-10000
Class III 100000 General Operating Room
Bacterial operating room IV generally not required or > 100000 grade
Toxic Operating Room V No Requirements
Class III 100000 Surgical Auxiliary Area
The clean rooms of other 100000-1000000 class hospital systems were first used in the operating room, which is what we now call the hospital operating room purification project. At first, it was only widely used in orthopaedic surgery, because orthopaedic surgery takes a long time and is easy to cause infection. The ideal control level is to use the air cleanliness near the operating table to reach 100 levels. It is generally recommended to use a top efficient air filtration system, which covers an area of at least 3m x 3m, thus including the operating table and people. Other areas in which medical cleanrooms have been used include delivery rooms, nurseries, burn rooms, and care units for heart patients. One of the latest developments is the use of dental surgery clean rooms, which reduces the risk of infection among medical staff during long-term surgery.
As one of the important functional zones of a hospital, the engineering quality of a clean room directly affects the use of the hospital and the treatment of patients. In order to improve the engineering quality of hospital cleanrooms, attention must be paid to design, construction and maintenance at the same time.
The most widely used clean operating room in hospitals is the modern operating room which uses air cleaning technology to replace the traditional ultraviolet ray and other means to control the pollution in the whole process. In a clean operating room, the infection rate of patients can be reduced by more than 10 times, so that antibiotics that can harm the immune system of patients can be used less or not. Dust-free and sterile are the characteristics of clean operating room.

Hospital clean rooms include operating rooms, obstetrics, infant ward (NICU), ICU (intensive care unit), burn ward and anatomy room, purification laboratory, artificial dialysis room, specimen room and so on. The engineering quality has a direct and important relationship with medical quality.

I. Design
The Code for Construction and Acceptance of Clean Room in China (hereinafter referred to as the "Code") emphasizes that fresh air must follow the principle of three-stage filtration. This is because compared with air conditioning system, the dust concentration ratio of fresh air in purification system is more than 90%. Therefore, in order to run quality, three-stage filtration of fresh air must be emphasized. Nowadays, it has been stipulated in the standards and norms of the clean operation Department of the hospital. In addition, the return air must have a filter, which can give the best effect. Only by accurately understanding the requirements of "norms" can the designer make the clean room meet the functional requirements of the hospital to the greatest extent.
In order to ensure the quality of the clean room project, the designer must also carefully investigate and inspect the construction site of the hospital clean room. Otherwise, the quality of the designed clean room project will be greatly reduced. For example, when testing the dust concentration in a clean room of a hospital, it is suddenly found that the dust concentration generally rises sharply and exceeds the standard seriously. Engineers first think of the filter vent leakage, after inspection, although it is found that there is leakage, but not the amount of dust detected. According to experience, the design of new air outlet is improper. Because of the new air outlet located downward on the top of the fifth floor, there is a garbage station just below it. The garbage station has the habit of burning garbage regularly. A lot of heavy dust comes from the smoke coming from the new air outlet. Such a new air outlet location will inevitably result in endangering indoor cleanliness. Regardless of the construction quality in the later stage, the engineering quality of the clean room is difficult to meet the requirements. In fact, this is contrary to the general requirement that the new clean operating room should be far away from the pollution sources required in the "code".
Design is the basis of cleanroom engineering quality. The design of hospital operating room cleaning project is not a closed door vehicle. It needs to constantly solve problems to meet the requirements of cleanroom engineering quality. Therefore, design is the first guarantee of cleanroom engineering quality.
II. Construction
The construction quality control of clean room can be divided into three stages: preparation stage, construction stage and acceptance stage.
(1) Key points of quality control in preparation stage
1. Carefully do a good job in drawing examination and technical submission
Fully comprehend the design intention, do a good job of drawing examination and technical submission is an important technical link to ensure the construction quality of clean room, find and solve difficult technical problems in construction, and lay a solid foundation for ensuring the construction quality of clean room.
There will be various contradictions in the construction, which requires the cooperation of the construction party and the design and construction party to make reasonable changes on the premise of ensuring the construction quality of the clean room.
For example, in the inspection of a clean room renovation and expansion project, it is found that the original design of air duct size can not be constructed at all in the ceiling floor of the main building whose floor height is limited. After coordination between the constructor and the designer and the constructor, the size of air duct is changed from square to flat without affecting the quality of the project, which meets the requirement of wind. Quantity requirement ensures the requirement of construction ceiling height. 2. Strict control of material and equipment quality
The materials and equipment of clean room mainly include all kinds of decorative materials and air conditioning equipment materials. Decoration materials should be inspected and verified strictly in accordance with the relevant national engineering technical standards, construction quality acceptance specifications and design documents. Clean rooms should be made of dust-free, dust-free, corrosion-resistant, moisture-proof, mildew-proof and fire-proof materials. Wood and gypsum boards should not be used as surface decorative materials.
Air-conditioning insulation materials must also meet the relevant provisions of the state to meet the requirements of corrosion resistance, dust-free, dust-free and fire-proof.
(2) Key Points of Engineering Quality Control
1. Select the construction team trained specially
Clean room construction involves decoration, HVAC, electrical and medical gas specialties. Construction personnel should have a comprehensive understanding of the construction specifications, construction technology and construction quality of clean room. Otherwise, construction quality is difficult to be guaranteed.
2. Key Control Points of Clean Room Sealing
The key content of sealing control in clean room is the quality of sealing construction of enclosure structure, such as uniform coating of sealant between board and board to achieve tight air leakage; sockets, switches, smoke detectors, lighting boxes, medical lamp belts and viewing lamps installed on wall panels, etc. in clean room are needed. Sealant is used for sealing, and reliable and effective sealing measures must be adopted between various pipes and boxes in the instrument cabinet.
3. Quality Control of Air Supply and Return Pipeline
The sealing of the air supply and return system pipeline is to prevent the unclean air from entering the air duct and prevent the polluted air from penetrating out of the air duct, so as to meet the cleanliness of the clean room and prolong the use time of the high efficiency filter. Pipeline processing, pipeline construction and installation quality of equipment should be mainly controlled in construction.
The cleaning of air duct equipment and sealing measures in pipeline processing should be emphasized. High-quality galvanized steel sheets should be used in pipeline processing to meet the requirements of smoothness, smoothness, firmness and corrosion resistance. The noise-absorbing materials filled in mufflers should be dust-free, slag-free (fiber), moisture-absorbing and pollution-free, and should not use loose materials. Fiber materials should be felted materials, and the outer covering materials can prevent fibers from penetrating. Foam plastics and centrifugal glass wool should not be used. Use neutral detergent to remove grease before air control operation, prevent scratches during production, and wipe the inner surface with white silk cloth at the end of production should be free of any grease stain and ashes to qualify for cleaning. After the air duct section is processed and cleaned, both ends of the air duct are protected by plastic film and then shipped to the site for installation. All air duct fittings and equipment must be wiped clean before installation, otherwise they can not be installed.
In the process of pipeline connection and equipment installation, attention should be paid to sealing measures to avoid secondary pollution. Because of the dust retention problem of hoses and soft joints, soft joints can be used in connection of cleaning pipelines and motor equipment, but they are not suitable for use in pipelines.
Secondly, controlling secondary microbial contamination is more meaningful than secondary contamination, and it is easier to be ignored. Secondary microbial contamination is contained in secondary dust pollution, mainly in air conditioning treatment equipment. Bacteria and dust accumulated during operation of air-conditioning equipment. During shutdown period, high temperature and humidity environment and nutrients provided by dust particles provide the most favorable conditions for microbial reproduction. New microorganisms and the harmful odorous gases they emit and a large number of harmful metabolites, corpses and debris - a large part of which can not be blocked by efficient filters, thus constituting secondary microbial pollution.
The fact tells us that soft joint is also an important source of secondary microbial contamination. This is because soft joints are usually not insulated and condensation occurs here. For medical cleanrooms, even a small number of soft joints must be double-decked or insulation soft joints.
Finally, all joints of combined air-conditioning units should be sealed. Water seals should be installed on the condensate drain pipe of surface condenser to ensure air-conditioner is airtight.
(3) Quality Control Points in Acceptance Stage
Debugging of purified air-conditioning system is an indispensable and important work in the stage of project acceptance. Through debugging, some defects in construction can be found in time and corrected and repaired in time. Debugging is also an important verification process for design drawings.
Clean rooms and air-conditioning supply and return air ducts should meet the cleaning requirements before installing high-efficiency filters. Purification and air-conditioning systems must be continuously air-blown for more than 12 hours. After air-blown, the supply and return air ducts and air-conditioning units should be cleaned and scrubbed.
After the completion of the project, the construction unit shall organize the medical department, the corresponding departments using the clean room, the design and construction units to comply with the engineering design documents and the Technical Code for Construction of the Hospital Clean Operating Department (GB50233-2002), the Code for Construction Acceptance of Ventilation and Air Conditioning Engineering (GB50243-2002) and the Code for Construction and Acceptance of the Clean Room (JGJ). 71-90) and other relevant construction quality acceptance criteria should strictly check and accept the quality of clean rooms, and qualified third-party testing units should be entrusted to check the cleanliness of clean rooms against design documents and relevant standards and norms.
III. Maintenance and Maintenance
It also plays an important role in the process of ensuring the quality of hospital operating room purification project. Some data show that the staff in a hospital's clean room suddenly fainted. On the one hand, there was no effective filtration before the fresh air heater. The relevant parts of the pipeline were seriously blocked. Because of the lack of maintenance, there was no fresh air inhalation. In addition, some of the fans in the air conditioning box dropped out, and the total air volume was small, which led to the relative clean room. Closed, weaker people in long-term hypoxia indoors will appear fainting.
Again, a clean operating room in a hospital suddenly found a point of bacterial growth, can only stop the operation to be checked. Results A loophole was found in the filter above a certain point. Technicians believe this vulnerability has existed before. The problem is that there is no leak detection system for filters in peacetime. If the orifice plate is often opened for inspection, this problem is not difficult to find.
Through the above discussion, we can see that design, construction and maintenance are the trinity of ensuring the quality of hospital clean room engineering, and they are indispensable. Only by ensuring the rationality of the function of the clean room drawings in the design, ensuring the quality process control of the clean room strictly according to the drawings in the construction, and paying attention to regular inspection and maintenance of the clean room engineering in peacetime, can we guarantee the engineering quality of the clean room from the perspective of overall quality control.
Negative Pressure Operating Room Solution
Negative pressure clean operating room should be established for patients with infectious diseases. Methods: Effective measures such as adding exhaust fans should be taken to adjust the exhaust volume so as to change the positive pressure into negative pressure in the clean operating room. Result: The negative pressure difference of air was used to control the airflow, absorb harmful gases and clean the indoor air in the clean area. Conclusion: Using negative pressure operating room can fundamentally control and solve the problem of air pollution in operating room.
A negative pressure operating room usually includes a ventilation system to allow air to flow from corridors or any adjacent area into the negative pressure operating room, while ensuring that polluted air cannot escape from the negative pressure operating room and into other areas of hospitals and health institutions.
Under natural conditions, air flows from the high pressure zone to the low pressure zone. If the operating room is in a negative pressure state, the outside air will continue to flow into the room from under the door, while preventing the gas pollution particles from escaping from the room and entering the corridor outside. Take a common example of a negative pressure chamber. A bathroom with an exhaust fan is a negative pressure chamber. When the negative pressure condition is formed, close the bathroom door and the fan will stop the bad smell and moisture from escaping from the bathroom.
To create a negative pressure state, it can be achieved by balancing the ventilation system of the room so that the air automatically emitted is more than the air automatically provided. This results in unbalanced ventilation, and the room ventilation system constantly sucks in air from the outside of the room to supplement. In a carefully designed vacuum chamber, air flows completely through a gap (usually about half an inch high) under the door. In addition to the gap, the negative pressure chamber should be as sealed as possible to prevent air from entering through various other cracks and slots, such as all kinds of cracks around windows, wall lighting equipment and sockets. Even if the room has achieved negative pressure conditions, the air leakage from these places may offset or eliminate the negative pressure state of the room.
The minimum pressure difference required to achieve and maintain room negative pressure so that air can flow into the room is very small (0.001 inches of the water gauge). The actual negative pressure depends on the difference between air consumption and supply in the ventilation system and the structure and size of the room, including air flow path and flow opening. If the room is well sealed, it is easy to achieve a negative pressure value higher than 0.001 inch water gauge. However, if the room is not well sealed, as is the case in many health institutions (especially older ones), a larger negative pressure may require a greater difference in emissions/supply than the capacity of the ventilation system.
In order to achieve a negative pressure environment under the normal operation of a ventilation system, first of all, adjust the air flow supply and emissions of the room to achieve emissions 10% or 50 cubic feet/minute higher than the supply (depending on the higher value). In most cases, this standard can achieve a negative pressure of at least 0.001 inch water gauge. If the negative pressure of the 0.001-inch water level gauge cannot be achieved, or by increasing the flow difference (within the allowable range of the ventilation system), it is necessary to carefully check whether there are gaps in the room (such as door gaps, window gaps, water pipe devices and various devices embedded in the wall), and then take remedial measures to seal these gaps.
The negative pressure in the room can be changed by changing the operation of the ventilation system or opening and closing the door, corridor door or window of the room. If an operational structure has been established, ensure that all doors and windows of the negative pressure chamber and other areas (e.g. corridor doors affecting air pressure) are properly closed, except where personnel are required to enter or leave the room or area.
Smoke test
Smoke test is a very simple procedure to determine whether the room is in a negative pressure state. Place a fire tube under the door of the negative pressure chamber and keep it about 2 inches away from the door. Gently squeeze the bulb of the fire pipe to produce a small amount of smoke. Hand-held fire pipe, parallel to the door, the smoke is slowly discharged from the pipeline to ensure that the smoke discharging speed is lower than the air speed. If the room is under negative pressure, smoke will flow into the room from below the door. If the room is under non-negative pressure, the smoke will blow out of the door or remain stationary.
The test must be carried out with the door closed, and all windows in the room must be closed. If the room's air purifier is already in operation (including ventilation cabinets or biosafety cabinets), it must be maintained in operation. If there is a reception room in the room, the pressure difference from the corridor to the reception room and from the reception room to the room should be tested.
Established in August 2010, Shandong Aide Purification Engineering Co., Ltd. has devoted ten years to the construction of special departments in hospitals. It is a laminar operation room purification, clean operation room decoration, ICU ward construction, neonatal NICU construction, CCU ward, hospital laboratory, central supply room decoration, laminar flow ward construction, venous configuration center design. Construction of professional enterprises. The main target of service is large, medium and small hospitals with professional contracting qualifications related to purification projects. There are many cases in the industry. Welcome new and old customers to consult.
To learn more about the medical purification industry, please pay attention to the Wechat Public No. Aide-188 (Ed Purification and Oxygen Supply)