1 Among the various strategies to solve nosocomial infection, avoiding infection during operation is considered to be an important key link in the whole treatment process [1]. From a long-term point of view, the effect of antibiotics gradually decreases with the increase of dosage, i.e. patients become resistant to antibiotics. The unreasonable use of antibiotics seriously threatens the health and safety of the people. The abuse of antibiotics not only destroys the micro-ecological balance of human body, but also damages health, and makes the number of drug-resistant bacteria increasing. The State Food and Drug Administration recently stipulated that all retail pharmacies throughout the country must rely on prescriptions from licensed physicians to sell all kinds of antibiotics that are not included in the list of OTC drugs from July 1, 2004. Because the clean operating room plays a certain role in preventing infection, it is an inevitable trend to establish a clean operating room. In recent years, with the development of our national economy, the enhancement of our country's comprehensive strength and the gradual improvement of people's living standards, some other hospitals have built clean operating rooms. At present, the upsurge of building clean operating room has developed to medium and small hospitals, and the establishment of clean operating room is regarded as one of the necessary measures to improve medical quality and avoid hospital infection. However, in the process of new hospital construction and hospital renovation, a large number of clean operating room projects have been launched, and a trend has been formed that hospitals compare with each other and improve the image of hospitals. This phenomenon increases the initial investment in hospital construction and wastes human and material resources.
2. The role of clean technology in controlling infection. Most of the planktonic bacteria in the air adhere to the dust carrier and maintain their lives with moisture and nutrients in the dust. They seldom exist alone. Generally, the relationship between the concentration of planktonic bacteria in the air and the amount of dust particles in the atmosphere (> 0.5 um) is about 1:100,000 [3]. That is to say, if the amount of dust in the air is large, the concentration of bacteria will be higher accordingly. According to Tianjin University's simultaneous comparative sampling and determination of dust and bacteria concentrations in hospitals, offices and outdoor atmosphere, the results show that the content of phytoplankton in the air and its changing regularity are related to the changing regularity of dust particles (> 3-5 microns). A series of bacterial filtration efficiency tests of air filters carried out by Tianjin University since 1983 have also proved that air filters have good filtering effect on bacteria. By comparing the filtration efficiency of bacteria and dust, the following conclusions can be drawn: 1. The filtration efficiency of bacterial particles is approximately the same as that of 4-5 micron particles in atmospheric dust, i.e. the equivalent diameter of bacteria is 4-5 micron; 2. If the filtration efficiency of 1.5 micron particles is 100%, the filter material can not be detected after filtration. Bacteria exist;
3. It is not economical to pursue filter blindly in biological purification. Because biological particles are generally larger, the filtration efficiency will be higher. Table 1 lists the efficiency of several domestic filters tested by Tianjin University.
In order to reduce the infection rate after operation, a lot of research has been done on the relationship between the infection rate and the planktonic bacteria in the operating room. Researchers in Switzerland and the United Kingdom conducted statistics on 6,000 femoral joint replacement operations. The results showed that when the concentration of bacteria in the air dropped from 400/m3 to 5/m3, the infection rate could be reduced from 4% to 1%[3]. J. Charnley, the world's orthopaedic specialist, has conducted more than ten years of continuous research at Wrightington Hospital, providing some important examples and data for clean technology. Surgical infection rates in different surgical environments arranged by Dr. Charnley. It can be seen that the clean technology reduces the bacterial concentration in the operating environment and reduces the infection rate from 8.9% to 0.5%. The above data show that clean technology has a certain role in controlling hospital infection.