The methods for processing medical devices are strictly regulated by guidelines that are approved by the head of the Department of State Sanitary and Epidemiological Supervision of the Ministry of Health of Russia.
The processing of tools and materials is carried out in order to prevent nosocomial infections in staff and patients. There are two types of treatment: disinfection and sterilization.
Disinfection of medical devices
Disinfection ensures the destruction of pathogenic and opportunistic pathogens - bacteria, viruses, fungi on the surface of the products themselves, as well as in their cavities and channels. Disinfection does not ensure the destruction of spore forms. Absolutely all products in contact with the patient are disinfected. After this type of cleaning, the instruments are either used for their intended purpose or further sterilized.
Disinfection is carried out by physical or chemical cleaning methods. The choice of method depends on the purpose and features of the product.
The physical disinfection method is more preferable , as it is environmentally friendly, reliable and safe for personnel. Physical (thermal) disinfection methods include:
- boiling medical instruments in distilled water or with the addition of sodium carbonate;
- steam (in an autoclave);
- air (dry heat sterilizer).
For physical disinfection, the same devices are used as for sterilization, but in milder modes of operation.
Chemical disinfection is carried out by complete immersion of instruments in a special solution. Only the following groups of compounds are allowed for disinfection: cationic surfactants, oxidizing agents, chlorine-based products, alcohol-based products, hydrogen peroxide, aldehydes. The instructions of the Ministry of Health strictly regulate the use of disinfectants: their list, the concentration of the solution and the exposure time, the type of infection being destroyed and the type of products being cleaned. After disinfection of the product, it is necessary to rinse it with running drinking water, and wash the remaining contaminants with mechanical means (brushes, ruffs, napkins).
Pre-sterilization cleaning
This type of cleaning is used after disinfection of products and their subsequent washing with running drinking water. The purpose of pre-sterilization treatment is the removal of mechanical, protein and fat contaminants, drug residues from products.
For cleaning instruments and materials before sterilization, solutions of chemical agents strictly regulated by the Ministry of Health are used, indicating their concentration, temperature and exposure time, method of cleaning and type of products being cleaned. If the selected solution has not only a washing, but also a disinfecting property, then the pre-sterilization cleaning may well be combined with disinfection.
Sterilization
Sterilization of medical instruments is carried out in order to physically destroy all non-pathogenic and pathogenic microorganisms on them, including spores.
All instruments and materials that were in contact with the wound surface, were in contact with the patient’s blood or the blood introduced into it, as well as with injection preparations; in contact with the mucous membranes or capable of damaging the mucous membranes.
For this, chemical and physical (thermal) sterilization methods are used. Choose a method depending on the properties of the sterilized products.
Physical (thermal) sterilization methods
These sterilization methods are carried out using:
- steam in autoclaves (steam method);
- hot air in dry heat cabinets (air method);
- glass balls;
- microwaves in a partial vacuum.
Sterilization in a steam sterilizer
In this method of cleaning instruments, saturated steam is used as a sterilizing agent under a pressure of 0.05-0.21 MPa with a steam temperature of 110-135 ° C. The cleaning is carried out in special medical autoclaves for sterilization. The principle of operation of the device: with increasing pressure, the boiling point of water increases. If at normal pressure the water boils at 100 ° C, then with an increase in pressure of only 1 atm, already at 120 ° C. Under such conditions, microorganisms die within 30 minutes. If you increase the pressure by 2 atm, the water will boil at a temperature of 134 ° C, microbes will die in 15 minutes.
The instruments are autoclaved in three stages:
- A vacuum is created with interval heating, which leads to the removal of air and prevents the formation of condensate.
- Directly sterilization.
- Vacuum drying to remove remaining moisture from tools.
When is an autoclave used for sterilization?
Apply an autoclave to sterilize:
- Manicure tools.
- Special and general surgical instruments.
- Glasses.
- Parts of instruments made of corrosion-resistant materials.
- Medical underwear, dressing and suture material.
- Rubber products (gloves, probes, catheters, tubes).
- Glass syringes.
Glass, textile products, made of corrosion-resistant materials, ligature suture material is treated with steam at a temperature of 134-126 ° C under a pressure of 0.21-0.14 MPa. Rubber products are cleaned at a temperature of 120-122 ° C. Plastic products (polyethylene, PVC) are sterilized under milder conditions: a pressure of 0.11-0.05 MPa and a temperature of 121-110 ° C.
Rubber gloves must be poured with talcum powder inside and out to prevent them from sticking together. Between the gloves you need to lay paper or gauze. In addition, each pair of gloves should be wrapped separately.
Cleaning in an autoclave of products is carried out in Bix - sterilization boxes. In addition, all products must be additionally packed in:
- double soft packaging;
- parchment;
- impregnated bag paper;
- heat-resistant bag paper;
- crepe paper;
- high-strength packaging paper.
If a sterilization box without a filter or double soft packaging was used for sterilization, the products are considered clean for 3 days, if parchment, paper is impregnated bag paper, heat-resistant bag paper, creped paper, high-strength packaging paper or filter sterilization box - 20 days.
Sukhozhar
Dry heat sterilization is used for products that cannot be exposed to wet steam or gas. Hot air circulating inside the device is used as a sterilizing agent. Sterilization mode in an air sterilizer: temperature from 160 to 200 ° C, holding time from 30 to 150 minutes. The higher the air temperature, the shorter the exposure time. At a temperature of 200 ° C, the products are processed for 30 minutes, 180 ° C - from 45 to 60 minutes, 160 ° C - 150 minutes. The choice of sterilization mode in the air sterilizer depends on the characteristics of the product. Time should be counted from the moment the air temperature inside the chamber reaches 180 ° C, and not from the moment the cabinet is turned on. The dry heat cabinet for sterilizing medical instruments is equipped with a temperature indicator, timer and thermostat.
Dry, high temperature air kills vegetative forms of microorganisms, as well as all spores. However, the breadth of application of this thermal sterilization method is very limited. The reason is the long duration of the cleaning process and the instability of many materials to such high temperatures (200 ° C).
In which cases a dry heat cabinet is used for sterilization?
Use a dry heat cabinet for sterilization:
- Medical instruments made of silicone rubber.
- Surgical instruments.
- Gynecological instruments.
- Dental tools.
- Glass syringes.
- Injection needles.
- Parts of devices made of materials that are not resistant to corrosion.
In a dry heat cabinet for sterilization, you can use the following types of packaging:
- Moisture-proof bag paper.
- Crepe paper.
- High-strength packaging paper.
You can also sterilize in open trays without packaging.
Sterilization rules
Carrying out sterilization in dry heat cabinets, the products are wrapped in one or two layers of packaging or put in trays. After loading the cleaned material, turn on the device. After the air in the cabinet warms up to 90 ° C, the doors are closed. Carry out directly sterilization. After the set time has passed, the device is turned off, and they wait for the air temperature to drop to 90 ° C. Only then will it be possible to open the doors and pick up clean tools and materials. Thus, the whole process lasts at least two hours.
Products treated with air in the package are kept sterilized for 20 days. Products that are cleaned with air without packaging must be placed on a “sterile table” and used during the work shift.
Only dry products should be placed in a dry-heat cabinet for sterilization, therefore they are dried after pre-sterilization preparation in drying cabinets at a temperature of 85 ° C.
Sterilization will be of high quality only if the hot air in the chamber is evenly distributed, for this it is necessary to load the device correctly. Products must be laid horizontally across the grooves of shelves or cassettes. If tools are processed without packaging, they should not touch each other. It is impossible to clutter up the chamber; it is necessary to place the instruments so that air is freely supplied to each of them. Care must be taken to ensure that ventilation grilles and purge windows are not blocked. So that bulk products do not interfere with the flow of air, they must be placed on the upper metal grill. You can load and remove products when the air temperature in the chamber drops to 50-40 ° C.
Glass Bead Sterilization
The cleaning agent is heated glass (glasperlenovye) balls. This method sterilizes dental equipment (diamond heads, burs, drills). Processing lasts 15-180 seconds.
Chemical sterilization
This cleaning method is used only if thermal sterilization methods of this product are not possible. Chemical treatment is applied to instruments and materials from thermolabile material with the condition of good access of the sterilizing agent to all cavities and surfaces of the object. The use of this cleaning method is limited, since the instruments cannot be sterilized in the package, which means they cannot be stored after processing. In addition, after sterilization with chemicals, the instruments must be washed, which is fraught with secondary seeding.
Features of processing products used to provide hairdressing and cosmetic services
Any procedure that could result in injury to the skin or mucous membranes should be performed with sterile instruments. If the product is used repeatedly for these procedures, then it must undergo disinfection, pre-sterilization cleaning and sterilization. In modern hairdressing and beauty salons, chemical disinfection, combined with pre-sterilization cleaning, is usually used, a heat exchanger or an autoclave is much less commonly used to sterilize manicure tools. The advantage of dry heat cabinets is the destruction of spore forms, affordable price and a large volume of the chamber, which allows you to sterilize a lot of tools at once. The disadvantages are huge energy consumption and damage to tools under the influence of too high temperatures.
After sterilization, clean products can be stored in the UV sterilizer for 3 days or in trays with hermetically sealed lids.
Sterilization control
The sterilization control system includes:
- Check the parameters of the sterilization mode. For this, physical (use of instrumentation) and chemical (use of indicators) methods are used. The temperature regime is checked using thermometers, which are placed in the regulated points of sterilization devices. Using chemical indicators, you can accurately determine the time and temperature of the treatment.
- Evaluation of processing efficiency. For this, bacteriological studies are used - biotests. A certain amount of spores is placed in insulin vials (steam and air sterilizers) or on filter paper discs (air sterilizers).
Sterilization is considered effective if there is no growth of the seeded test culture in combination with the positive results of checking the sterilization regimen.