The construction of simple negative pressure isolation ward (hereinafter referred to as simple negative pressure isolation ward) must be as follows:
First, the technical personnel implementing the transformation shall fully understand the specifications of the negative pressure isolation ward and the current conditions of the area to be transformed.
Second, reasonable location and layout, simple negative pressure isolation ward to achieve relative negative pressure, effective isolation, relative negative pressure simple understanding is that the room's intake air volume (fresh air) is less than the exhaust air volume. The location of the ward is isolated from other rooms. The "three areas" (potential pollution area and pollution area) in the ward are clearly divided. If conditions permit, it is better to set up double channels to achieve effective isolation.
Third, formulate safe and accessible technical measures based on the actual situation.
Fourth, ensure the safe operation of the system.
1、 Full understanding of specifications
Novel coronavirus is the main standard in the current hospital environment. The current requirements include: GB / T 35428-2017, the basic requirements for the construction and configuration of the negative pressure isolation ward in Beijing, DB11-663-2009 and the standard of the industry group, "the design standard for acute infectious diseases of acute infectious coronavirus", T/CECS. 661-2020 for reference, the technical personnel implementing the transformation should combine the characteristics of their own hospital and site conditions to develop a feasible technical plan.
2、 Correct location and reasonable layout
The simple negative pressure isolation ward should be located in an independent building as far as possible, preferably in the downwind side of the hospital. It should be close to the fever clinic to shorten the transfer distance. If the fever clinic is an independent building, a simple negative pressure isolation ward should be set up in the fever clinic. In addition, because the patients in the simple negative pressure isolation ward are not confirmed patients, it is better to use single room to avoid mixing with other patients, so as to prevent cross touching. The ward should be arranged at one end of the building to facilitate isolation. Try to choose a room with good airtightness. Try not to set up simple negative pressure isolation ward in the air conditioning system area with return air.
The simple negative pressure isolation ward area should be strictly divided into clean area, potential pollution area and pollution area according to the health and safety level, and the corresponding buffer room should be set between the adjacent areas. The clean area refers to the working area of medical care, including the rooms for office, consultation, treatment, nurse station, etc.; the potential pollution area refers to the inner corridor and buffer room, etc.; the pollution area refers to the ward room, including the toilet in the ward. Buffer room shall be set from clean area to potential pollution area and from potential pollution area to pollution area, and the area of buffer room shall not be less than 3 m2.
After selecting the appropriate area as the simple negative pressure isolation ward according to the requirements, the room layout should meet the requirements of Figure 1 as much as possible. If it can not meet the requirements, the corresponding area needs to be modified to achieve effective isolation and reduce the risk of infection. The simple negative pressure isolation ward shall be equipped with toilet. If it is too late to be reconstructed, toilet facilities such as bedpan shall be provided for patients to use, so as to ensure that patients will not leave the ward due to toilet.
Figure 1 layout and zoning of negative pressure isolation ward
3、 Fully assess the current situation
1. Check the existing room fresh air system. The main air conditioning system in the hospital includes fan coil plus fresh air system, all air conditioning system and multi split air conditioning system, as well as split air conditioning system. The general area of hospital is fan coil plus fresh air system, including general ward, diagnosis area and so on.
2. Check the existing room exhaust system. If the room is originally equipped with an exhaust system, the exhaust air volume shall be measured, and the pressure difference of the room shall be measured. The normal area is generally positive pressure or micro negative pressure, so it is difficult to meet the requirement that the pressure difference (negative pressure) between adjacent rooms of different pollution levels in the negative pressure isolation ward is not less than 5pa. In addition, check whether the exhaust system is an independent system. If it is an independent system, check whether its exhaust position is far away from the air inlet and personnel activity area, whether it is set at a place more than 3m above the building height within 15m of the radius, and the minimum distance from the nearest building door, window, ventilation acquisition port, etc. is more than 20m. If the above requirements are not met, the exhaust system of the room shall be stopped and technical measures such as setting blind plate shall be taken to close the exhaust outlet.
3. Check the tightness of the room envelope, doors and windows, and take effective measures to seal the places that are not tight. Check the reliability of power supply lines in the room to ensure the safety of regional power supply. Check whether there are drainage facilities in the room, and whether there are drainage pipes to the sewage treatment station.
4、 Optional, fast and accessible technical measures
1. Accurately understand the fresh air volume of the room according to the air conditioning system form of the area, and the per capita fresh air volume shall not be less than 40m? / h according to the requirements. It is better to accurately calculate the fresh air volume of the room and make records through the field measurement of anemometer, air volume hood and other equipment.
2. Reset the exhaust system for the unqualified exhaust system. If enough time or materials are available, metal or non-metal ventilation pipes can be made for ventilation and air conditioning system. If the time is urgent, and there is no suitable material and equipment, the portable fan or other emergency fan (see Figure 2) which is usually available in general hospitals can be used for emergency ventilation. The hose with few joints or PVC hard pipe can be selected for the pipeline, which is relatively easy to purchase in the market, but the conventional PVC pipes are mostly drainage pipes with small pipe diameter, so there is a certain limit on the exhaust air volume.
3. The ventilation times of pollution area and potential pollution area in simple negative pressure isolation ward should be 10 times / H ~ 15 times / h, and the ventilation times of clean area should be 6 times / H ~ 10 times / h. If it can not meet the requirements, the exhaust fan shall be selected in combination with the measured fresh air volume of the room to ensure that the exhaust air volume is more than 20% higher than the fresh air volume, and the exhaust air volume can be increased according to the sealing condition of the room. To ensure that the pressure difference between the clean area, potential pollution area, pollution area and buffer room is kept at 5pa, the air flow shall be ensured from the clean area to potential pollution area and then to the pollution area, and the negative pressure degree shall be from high to low in the order of ward toilet, ward, corridor and cleaning area between buffer room and potential pollution area. The air pressure in the clean area shall be kept at a positive pressure relative to the outdoor atmospheric pressure.
3. The air outlet shall be located at the lower part of the room to form the air distribution form of upper supply and lower exhaust. In addition, the exhaust fan in the pollution area shall be set outdoors, the tightness of the exhaust pipe must be ensured, the exhaust pipe shall be arranged indoors as far as possible, and the negative pressure must be maintained in the exhaust pipe in the building. The air outlet shall be set at a place with a height of more than 3 m higher than the radius of 15 m, and the minimum distance from the nearest building door, window, ventilation collection port, etc. shall not be less than 20 m, and the part less than 20 m shall be provided with enclosure. The air outlet of the pollution area shall be filtered by high-efficiency filter before discharging. If the air outlet cannot be equipped with high-efficiency filter exhaust system, effective disinfection measures shall be taken to ensure that the exhaust air is treated innocuously, and in principle, the risk of infection to other areas shall be reduced as much as possible.
5、 Ensure the safe operation of the system
The technical parameters of the simple negative pressure isolation ward, such as pressure difference, pressure gradient, air flow direction, etc., shall be tested according to the requirements of the specifications. The simple negative pressure isolation ward can only be used after it meets the requirements of the relevant standards. When put into use, the fresh air system and exhaust system in the simple negative pressure isolation ward area shall be normally open, and only fresh air can be supplied in the room in the medical area to maintain the relative positive pressure in the medical room; in the negative pressure area, the exhaust air volume shall be larger than the fresh air volume to maintain the necessary pressure gradient, so as to prevent the air overflow in the simple negative pressure isolation ward.
The fresh air system of the hospital is usually designed as an independent fresh air system with component layers and areas. The fresh air pipes connect many rooms at the same time. When the fresh air system is in normal use and the balance of each branch pipe is good, it can be ensured that there will be no backflow and cross wind. However, when a set of fresh air system bears more than two simple negative pressure isolation wards, when the fresh air fan is shut down and the exhaust fan is working, the air can be circulated through the fresh air duct due to the difference of exhaust air volume in each room, resulting in cross infection. In addition, when two simple negative pressure isolation wards share the same fresh air system, if the fresh air volume of the two rooms is the same, and there is too large difference in the exhaust air volume of the newly increased exhaust fan, it may cause cross infection through the fresh air duct. Therefore, the real-time monitoring of the system should be done well to avoid the above two situations. If the fresh air unit is out of service, the exhaust system shall be kept in normal operation, and the necessary pressure gradient can be maintained by opening windows and other means.
After the diagnosis, the patients were transferred rapidly according to the relevant requirements, and the final disinfection was carried out according to the requirements of the relevant sensory control standards. If it is determined that the simple negative pressure isolation ward is no longer used, the air conditioning system and the temporary exhaust system shall be thoroughly cleaned and disinfected. During cleaning and disinfection of ventilation and air conditioning, operators shall pay attention to protection and wear goggles, masks and protective gloves to avoid injury. Air filters that may be contaminated by pathogenic microorganisms must be disinfected before cleaning and scrapping, and treated according to the relevant requirements of medical waste.
Conclusion
Although there are some short boards in hardware, there is a certain gap between the general area of the hospital and the standard requirements. But considering the current special period, the time is urgent and the resources are scarce, combining with the hospital's own conditions, making use of the existing resources, adopting safe and accessible technical means to create certain security for the hospital staff and suspected patients as far as possible, and minimizing the risk of cross infection, it is a suitable strategy.
Shandong ed purification Engineering Co., Ltd., founded in August 2010, has been committed to the construction of special departments in the hospital for ten years. It is a professional enterprise engaged in purification of clean operating department, decoration of clean operating room, construction of ICU ward, construction of neonatal NICU, CCU ward, hospital laboratory, decoration of central supply room, construction of laminar flow ward and design and construction of vein configuration center. The main service object is a large, medium and small hospital, which has the qualification of professional contracting related to purification engineering. There are many industry cases. Welcome new and old customers to come for consultation. For more knowledge of cleanroom cleanroom industry, please pay attention to WeChat official account: Aide-188 (Ed purified oxygen supply).