I, disinfection technology (a) to clarify the main object of disinfection should be a specific analysis of the pathway of infection, the media involved and the types of pathogenic microorganisms, targeted use of disinfectants. (B) to take appropriate disinfection methods according to the disinfection of the object to choose simple
I, disinfection technology
(A) clear disinfection of the main object
should be a specific analysis of the pathway of infection, the media involved and the types of pathogenic microorganisms, the targeted use of disinfectants.
(B) to take the appropriate disinfection method
according to the disinfection object to choose simple, effective, do not damage the goods, rich sources, affordable disinfection method.
Hospital diagnostic and therapeutic equipment according to the degree of harm that can be caused by contamination and in the human body in contact with different parts of the three categories:
1. Highly hazardous devices
through the skin, mucous membranes and into the sterile tissue or organ internal, or with broken skin and mucous membranes in close contact with the equipment, such as surgical instruments, syringes, cardiac pacemakers, and so on. Must choose a high-efficiency disinfection method (sterilization).
2. Moderately dangerous devices
Only in close contact with the skin, mucous membranes, but not into the sterile tissues, such as endoscopes, thermometers, oxygen tubes, ventilators and belonging to the instruments, anesthesia instruments. Should choose to use medium-effective disinfection method to kill a variety of microorganisms other than germ cells.
3. Low-risk equipment and articles
Not into the human body tissue, not in contact with mucous membranes, only directly or indirectly with the health of the skin contact, if there is not a sufficient number of pathogenic microbial contamination, there is generally no harm, such as masks, clothing, medication cups, etc., should be selected to use low-efficacy disinfection method or only general hygiene treatment. Only the removal of general bacterial propagules and lipophilic viruses is required.
(C) control of factors affecting the effect of disinfection many factors will affect the role of disinfectants, and the sensitivity of various disinfectants to these factors varies greatly.
1. Types of microorganisms
Different types of pathogenic microorganisms have different resistance to disinfectants, and therefore must be treated differently when disinfecting.
1) Bacterial propagules
Easy to be eliminated by disinfectants, generally Gram-positive bacteria are more sensitive to disinfectants, Gram-negative bacilli are often more resistant. The propagules are sensitive to heat, and disinfection methods are based on heat disinfection.
(2) bacterial cells
Bacterial cells have the strongest resistance to disinfection factors, the most reliable method of killing bacterial cells is heat sterilization, ionizing radiation and ethylene oxide fumigation. Among chemical disinfectants, glutaraldehyde and peroxyacetic acid can kill germ cells, but the reliability is not as good as heat sterilization.
(3) virus
The resistance to disinfection factors varies greatly depending on the species, and hydrophilic viruses are more resistant than lipophilic viruses.
(4) fungi
strong resistance to drying, sunlight, ultraviolet light, as well as most chemicals, but not heat-resistant (60 ℃ 1 hour to kill).
2. the number of microorganisms
The more the number of contaminated microorganisms need to be disinfected, the longer the time, the larger the dose.
3. the presence of organic matter
① organic matter on the surface of microorganisms to form a protective layer to prevent the disinfectant contact with microorganisms or delay the disinfectant's action, so that microorganisms gradually produce adaptability to the drug. ② Organic matter and disinfectant action, the formation of lower solubility than the original or bactericidal effect is weaker than the original compound. (iii) When part of the disinfectant interacts with organic matter, the concentration of action on microorganisms is reduced. Organic matter can neutralize part of the disinfectant. Disinfectants in heavy metals, surface activators, etc. by organic matter has a greater impact on glutaraldehyde has less impact.
4. Temperature
With the increase in temperature, the bactericidal effect is enhanced, but the change in temperature has different effects on various disinfectants. Such as formaldehyde, glutaraldehyde, ethylene oxide when the humidity rises by a factor of 1, the bactericidal effect can be increased by 10 times. And phenols and alcohol by the temperature effect is small.
5. PH value
Influence the bactericidal effect from two aspects. ① The role of the disinfectant: change its solubility and molecular structure. ② pH is too high or too low on the growth of microorganisms have an impact. Under acidic conditions, the negative charge on the surface of the bacteria is reduced, and anionic disinfectants are effective in sterilization. In alkaline conditions, the bacterial surface negative charge increases, which is conducive to the role of cationic disinfectants.
6. Treatment dose and monitoring
Ensure that the dose of disinfection and sterilization treatment, strengthen the monitoring of the effect to prevent recontamination.