What problems should be paid attention to in the reconstruction of hospital negative pressure operating room?
The positive pressure clean operating room is an operating room with clean level (I, II, III, IV). Its air system consists of treated clean fresh air + circulating clean air with different air change times + exhaust air. In short, there are fresh air, circulating air and exhaust air. The starting sequence of fan should be fresh air, circulation and exhaust air. The fresh air delivered to the operating room is greater than the exhaust air volume. The relative pressure in the operating room is greater than that in the adjacent room.
01
Positive pressure clean operating room
The protection objects of positive pressure clean operating
room are mainly surgical patients. Because the exhaust outlet of clean
operating room is mostly designed at the top of operating room, the exhaust fan
is a single fan system, and the exhaust air can be provided with only medium
and low efficiency filters instead of high-efficiency filter.
02
Negative pressure operating room
Negative pressure operating room is generally operating
room without cleanliness level. The composition of its air system is treated
clean fresh air + exhaust air, that is, direct supply and direct exhaust. The
starting sequence of the fan should be exhaust air and fresh air, and the fresh
air volume sent to the room is less than the exhaust air volume. The relative
pressure in the operating room is less than that in the adjacent room.
The main
protection objects of negative pressure operating room are medical staff and
surrounding environment. The exhaust outlet of negative pressure operating room
should be set at the lower end of the side wall in the operating room, close to
the patient's head and the side of the top anesthesia working area. The exhaust
fan system is double fan. Exhaust air must be equipped with high efficiency
filter.
03
Positive and negative pressure switching operating room
The positive and negative pressure switching operating room
is a clean air-conditioning system with positive pressure clean operating room.
If necessary, it can also be used in negative pressure operating room. It also
has air organization system and building structure with negative pressure-controlled
environment.
When the positive and negative pressure switching operating
room is used as a positive pressure clean operating room, it mainly depends on
the treated fresh air and the circulating air and exhaust air which undertake
the main task of purification to realize its setting parameters. When it is
used as a negative pressure operating room, it mainly depends on the treated
fresh air and exhaust air to realize its setting parameters. It only has fresh
air and exhaust air, which is full supply and full exhaust, without circulating
air.
The exhaust of negative pressure chamber should be set
under the wall near the head of the patient, and that of positive pressure room
can be set on the top of the room. When the air return pipe of the unit is
switched to the return air pipe of the hospital, the air return pipe should be
used to switch the positive and negative exhaust pipe to the operation room.
Some use the top exhaust outlet of the operating room as the exhaust channel,
and the indoor exhaust flow direction is to the top.
Therefore, novel
coronavirus pneumonia is a dangerous risk to operation room. We suggest that
the operating room as a clean operating department, positive pressure is
positive pressure, negative pressure is negative pressure, do not engage in
so-called "positive and negative pressure switching operating room".
04
Problems in the construction of negative pressure operating
room
1.To protect the medical staff and the surrounding
environment as the primary goal.
In the process of fighting against the virus, medical
personnel are soldiers. Without safe soldiers and safe environment, what to
rely on to fight against the virus. Therefore, we must distinguish what is the
primary and secondary need to focus on Protection in the construction of
negative pressure operating room. It should be noted that the focus of
protection refers to the medical personnel (including all the staff working in
the negative pressure operating room and auxiliary related personnel as well as
the cleaning and maintenance personnel in the area).
2. The negative pressure operating room must form an
independent and complete surgical treatment functional area
The functional
area of surgical treatment should have independent fast and convenient access;
double buffer room should be set, mainly considering the dressing and
disinfection area with contaminated clothes; there should be corresponding
equipment room and instrument room; there should be independent dirt treatment
room, disinfection room and dirt transportation channel; the negative pressure
machine room area should also be relatively separate. Different pressure
gradients need to be set in different chambers in this area. Different
controlled environment areas should be warned with different bright colors. If
possible, the technical interlayer and ceiling layer should be separated from
other areas.
3. It is necessary to establish the concept that cleaning
and sterilization of all surfaces must be strengthened simultaneously
For example, people have two hands. Our air treatment is
one hand, and the surface disinfection and sterilization are the other hand. If
one hand is missing, a person is disabled.
Air treatment is to reduce the concentration of microbial
aerosol in the controlled environment and reduce the probability of infection.
Killing viruses and bacteria can effectively protect people and the
environment. Therefore, it is necessary to do a good job of cleaning and
sterilization in strict accordance with the requirements of the hospital infection
department. The disinfection and sterilization work can be carried out by
wiping, spraying wine, fumigation, ultraviolet radiation, high-energy ion
sterilization, etc., and the whole negative pressure operation area should be
cleaned and disinfected without dead corners.
Clean and
disinfect all walls,roofs, floors, doors, windows, air ducts and all indoor equipment,
facilities and independent articles in the building. The machine room and unit
are also strictly cleaned and disinfected. We can use spray and fumigation
high-energy ion sterilizing technology for the dead space such as crevice.
There should be inspection and evaluation system and measures for surface
sterilization.
4. Gas flow adopts directional flow from relatively clean
area to non-clean area (polluted area)
The negative pressure operating room is designed as full
air supply and full exhaust without circulating air and heat recovery system.
Therefore, air purification is not required, only fresh air is treated, but
primary efficiency, medium efficiency and sub efficiency filtration are
required for fresh air.
The ventilation frequency of negative pressure operating
room is required to be 12 times per hour, which does not mean that 12 fresh air
is sent in and 12 fresh air is discharged within 1 hour; it refers to that
fresh air can be sent in 6-8 times, and the exhaust air can be guaranteed to be
12. The operating room door and the surrounding buffer section door cannot use
the airtight door,
so that the internal air leakage in the surrounding area of some buildings can
supplement the fresh air volume to meet the air volume of 12 times.
The air flow
design of the other auxiliary areas of the negative pressure operating room
should also ensure that the flow direction of the air supply and exhaust air
should be from relatively clean to non-clean, and the air change frequency
should refer to the negative pressure operating room mode.
5. It needs to be equipped with complete and large capacity
UPS system.
The UPS system
should not only meet the needs of surgical treatment, but also ensure the
normal operation of negative pressure unit system in case of sudden power
failure. The UPS system should be inspected and maintained at short intervals.
6. The polluted wastewater in the negative pressure area
must have an independent discharge system and be disinfected.
The polluted
wastewater in the negative pressure area must be equipped with an independent
discharge pipeline system, and it is not allowed to share the discharge
pipeline with other areas. Check valves and deep u-traps are required at the
opening of each sewage discharge pipe. Drainage pipes shall be made of
materials which are not easy to crack and corrode. The sewage can be discharged
only after disinfection treatment and reaching the standard.
7. Real time intelligent monitoring must be carried out
Make full use of modern scientific and technological means
to monitor and manage the whole operation process of negative pressure
operating room, so that all parameters of operation can be seen, felt and used
conveniently.
All kinds of sensors and actuators are connected to each
other to send out instructions for the operation status of all equipment. At
the same time, the operation conditions of all equipment are monitored, and the
operation data are recorded in real time. The data are analyzed and the
possible fault conditions are given an alarm. It can also realize remote
management, monitoring and control of authorization through the Internet. From
the patient's condition, the doctor's duty, from the entrance guard to the
video surveillance, from the use of goods to the medical data, it can be
expanded in all directions.
By selecting appropriate GPS module, all extended modules
can synchronously collect information, signal, time, position and speed. It can
also work independently away from the computer, and can realize parameter
setting, real-time data transmission and interaction with the computer through
Wi-fi or USB interface, and can record all signals continuously for a long
time.
In each different area, obvious and reliable pressure
display devices are set up.
The whole process
of chip management was carried out on the clothing of staff in negative
pressure operation area. Contact identification technology is not recommended
for personnel management.
8. Treatment of negative pressure exhaust
system
The negative pressure fan should adopt
double fans, one for use and one for standby. The standby fan and duty fan can
be switched quickly. Low noise DC fan or variable frequency AC fan is
recommended. The front end of the unit is equipped with a double-layer
microporous plate muffler.
The outdoor discharge system consists of
disinfection filter section, check section, pipeline and outdoor discharge
outlet protection device. The location of the discharge outlet should be
located in the place where the wind has little impact on the surrounding
environment, and the height of the outlet should be 3 meters higher than the
top of the building. The drainage outlet is provided with vertical outlet
diversion sleeve and rainwater drainage outlet.
It is not allowed to replace the high-efficiency filter of negative pressure unit by non-professional personnel, but it must be replaced by professional personnel, professional clothes and professional equipment. The main replacement methods are "bag in bag out method" and "fumigation replacement method".
The production of negative pressure exhaust pipe should ensure no leakage, the path should be as short as possible, and it is better not to pass through other purification duct areas.
