Methods of sterilization of surgical instruments. Thermal methods of sterilization of medical instruments. Sterilization by boiling. Drying cabinet. Medical autoclave Sterilization of instruments after surgery
Sterilization of surgical instruments is carried out in two stages.
First stage - pre-sterilization treatment, second- direct sterilization. The sequence of pre-sterilization preparation depends on the degree of bacterial contamination of the instruments.
Pre-sterilization preparation includes: disinfection, washing and drying. Due to the high risk of spreading AIDS and performing operations on patients who have had hepatitis, the rules for pre-sterilization preparation have been changed and equated to methods for processing instruments that provide a guarantee of the destruction of the human immunodeficiency virus. Instruments after purulent operations in case of anaerobic infection, patients who had undergone for 5 recent years hepatitis, as well as at risk of AIDS, are treated separately from other
Immediately after the operation, the instruments are immersed in disinfectants (3% chloramine solution for 40-60 minutes or 6% hydrogen peroxide solution for 90 minutes, 0.5% polydez solution for 60 minutes, combined instrument disinfectant for 60 minutes). After disinfection, the instruments are transferred to a washing solution (washing powder, hydrogen peroxide and water) at a temperature of 50 ° C for 20 minutes, then each instrument is washed with a brush in disassembled form and washed under running water. Currently, the “Stages and modes of pre-sterilization processing of products from various materials” approved by the Ministry of Health of the Russian Federation in 1997 are used (Table 1).
Tab. one.
Stages and modes of pre-sterilization cleaning of instruments combined with disinfection with 10A dye.
The quality of pre-sterilization treatment is checked by setting azopyramic, phenolphthalein and benzine samples for the presence of residual components of the detergent, blood and fat. At least 1% of the batch of instruments that were simultaneously processed are subject to control. In addition, the quality control of pre-sterilization treatment is carried out by the Hygiene and Epidemiology Center once a quarter. With a positive sample, the entire batch of instruments is subjected to repeated pre-sterilization processing.
The next step is to dry the instruments in a dry oven at 80°C for 20 minutes.
The choice of sterilization method depends on the type of surgical instruments to be sterilized.
All general surgical instruments are conditionally divided into three groups:
Metal - cutting (scalpels, scissors, suture needles, amputation knives, etc.), non-cutting (syringes, injection needles, clamps, tweezers, hooks, probes, etc.);
Rubber and plastic (catheters, probes, drains, etc.);
Optical - laparoscopes, gastroscopes, choledochoscopes, cystoscopes, colonoscopes, bronchoscopes, etc.
Sterilization of surgical metal instruments and products made of glass produced in the following ways.
Sterilization with dry hot air (aerosterilization) is carried out in dry heat cabinets (Fig. 3). Instruments and syringes
Fig.3. Drying cabinet.
unassembled chickens are placed in special metal mesh or packed in kraft paper and sterilized at a temperature of 180-200 ° C for 1 hour. After sterilization, surgical instruments are transferred to an ultraviolet chamber to maintain sterility during their use (Fig. 4.). Products sterilized in kraft paper are kept sterile for 3 days.
Fig.4. UFC 2.
For steam sterilization, the instruments are placed in Schimmelbusch cups, loaded into autoclaves and sterilized at a pressure of 1.1 atm - 60 minutes, 1.5 atm - 45 minutes, 2 atm - 30 minutes. Shelf life in biks with a filter - 3 days, without a filter - 24 hours.
Disposable instruments are sterilized in sealed bags with ionizing radiation (y-rays), ultraviolet rays and ultrasound. At present, y-ray sterilization is preferred. For these purposes, the isotopes "" "Co" and "" C. are used. Sterilization must be carried out in compliance with safety measures in the factory. While maintaining the tightness of the packages in which the sterilization was carried out with y-rays, sterility lasts 5 years.
Boiling as a method of sterilization is not currently used and refers to disinfection. Disinfection of instruments by boiling is carried out in electric sterilizers of various designs and capacities, on grids immersed in distilled water with the addition of 2% sodium bicarbonate solution for 30 minutes. Sterilization of cutting and stabbing instruments is carried out at the factory with y-rays, gas method and cold chemical method with the use of antiseptics. In dressing rooms, cutting and stabbing instruments are sterilized in dry-heat cabinets.
Chemical methods of sterilization include sterilization in the sterilization chambers of an air sterilizer (one- or two-chamber) with a capacity of 80 dm 3 or more with formalin vapor. Formalin is placed at the bottom of the chamber at the rate of 10 g per 10 dm 5 of the chamber, the sterilization time is 16 hours. Ebonite-based instruments, telescopes, all laparoscopic instruments, instruments with optics, especially precise and expensive instruments, are sterilized by the chemical gas method. Before gas sterilization, laparoscopic instruments are disinfected in a 3% solution of aldezone by washing in one container, then they are soaked in the second container for 1 hour and after the time has elapsed, they are rinsed under running water from disinfectants.
The processing of all instruments includes the sequential execution of two stages: pre-sterilization processing and sterilization itself. The method of sterilization primarily depends on the type of instruments.
Pre-sterilization preparation.
Pre-sterilization preparation consists of disinfection, washing and drying. All types of instruments are subjected to it. The type and volume of pre-sterilization treatment in the recent past depended on the degree of infection of the instruments. So, before, the processing of instruments after clean operations (dressings), purulent operations, operations in patients who had hepatitis and were at risk for AIDS was significantly different. However, at present, given the high risk of the spread of HIV infection, the rules for pre-sterilization preparation have been tightened and equated to methods for processing instruments that provide an unconditional guarantee of HIV destruction. It should be noted that instruments after purulent operations, operations in patients who have had hepatitis over the past 5 years, as well as at the risk of HIV infection, are treated separately from others. All pre-sterilization procedures must be performed with gloves!
Disinfection (disinfection).
Immediately after use, the instruments are immersed in a container with disinfectants (accumulator). In this case, they must be completely immersed in the solution. As disinfectants, a 3% solution of chloramine (exposure 40–60 min) or a 6% solution of hydrogen peroxide (exposure 90 min) is used. After disinfection, the instruments are washed with running water.
The washing up.
Tools are immersed in a special washing (alkaline) solution, which includes detergent (washing powder), hydrogen peroxide and water. Solution temperature 50 - 60 "C, exposure 20 min. After soaking, the tools are washed with brushes in the same solution, and then in running water.
Drying can be done naturally. Recently, especially during subsequent hot air sterilization, the instruments are dried in a dry oven at a temperature of 80 C for 30 minutes. After drying, the instruments are ready for sterilization.
actual sterilization.
The choice of sterilization method primarily depends on the type of surgical instruments.
All surgical instruments can be divided into three groups:
metal (cutting: scalpel, scissors, surgical needles, etc.) (non-cutting: syringes, needles, clamps, tweezers, hooks, etc.)
rubber and plastic (catheters, probes, drains, enema tips, etc.)
optical (laparoscope, gastroscope, choledochoscope, cystoscope, etc.).
The main method of sterilizing non-cutting metal instruments is hot air sterilization in a dry oven or autoclave under standard conditions. Some types of simple instruments (tweezers, clamps, etc.) intended for single use can be sterilized by radiation.
Sterilization of cutting metal instruments.
Sterilization of cutting tools using thermal methods leads to their blunting and loss of the necessary properties. The main method of sterilizing cutting instruments is a cold chemical method using antiseptic solutions. The best sterilization methods are considered to be gas sterilization (in an ozone-air chamber) and radiation sterilization in the factory. The latter method has become widespread using disposable scalpel blades and surgical needles (atraumatic suture material).
Sterilization- This is the process of eliminating all forms of life, including infectious agents (fungi, bacteria, spores, viruses) that are present on surfaces, contained in liquids.
The following must be subject to mandatory sterilization:
Objects that come into contact with the surface of the wounds have contact with blood and injectables
Diagnostic equipment that comes into contact with mucous membranes and can cause damage to them.
There are three main stages of sterilization:
Disinfection
Pre-sterilization cleaning
Sterilization
Sterilization is achieved by the application of thermal, chemical or radioactive treatment.
The quality of sterilization largely depends on the contact of the sterilizing agent with the surface of the sterilized instrument. The choice of agent is related to the nature of the instrument to be sterilized.
The sterilization process takes place in a special device called a sterilizer.
Sterilization Methods
1) Thermal sterilization method
- Steam sterilization (autoclaving)
During heat treatment, living organisms die. This process is accelerated by the addition of moisture, but regular steam is not sufficient for sterilization. Pressure is needed, more than atmospheric, which will allow raise the temperature of the steam to thermally destroy microbial life. Pressurized steam causes denaturation and coagulation of the protein and its enzymes in the cells.
The device in which steam sterilization takes place is called an autoclave. The entire sterilization cycle in an autoclave can take from 15 to 60 minutes, depending on the pressure, temperature and material of the instruments to be sterilized.
Autoclavingsuitable for items that tolerate moisture, high pressure(from 1 to 3.5 atmospheres above the external environment), as well as high temperature (from + 121 ° C to + 148 ° C). For example, surgical instruments.
An excellent representative of devices for steam sterilization is a series of autoclaves Statim . Compact cassette sterilizers extend the life of fragile instruments.
- Air sterilization (dry oven)
dry heat in the form of hot air is mainly used to sterilize objects based on anhydrous oils, petroleum products and powders, which cannot be sterilized by steam and gas. The death of microbial organisms occurs due to oxidation and the slow process of burning protein in cells. In the absence of moisture, higher temperatures are required during the sterilization process.
- Microwave sterilization
Under the action of non-ionizing microwave radiation, hyperthermic conditions are created that disrupt the vital processes of microorganisms. The cycle temperature is lower than with steam sterilization. The cycle time is much less - 30 seconds. Metal instruments can be sterilized by placing them under partial vacuum in a glass container. This type of sterilizer is perfect for small sterilization volumes.
2) chemical method sterilization
- Gas sterilization
Ethylene oxide. Basic The sterilization cycle consists of five stages and takes about 2.5 hours, excluding the aeration time. The gas enters into a chemical reaction with amino acids, proteins, DNA and prevents the reproduction of microbial organisms.
This sterilization methodsuitable for items that cannot withstand the high temperature and humidity required for steam sterilization. Due to the low temperature conditions (+30° to +60°C), this sterilization method is well suited for medical devices with built-in electronics. The disadvantage of the method is easy flammability.
Formaldehyde.Gas kills microorganismsby protein coagulation in cells. This sterilization method is complex and less effective than other sterilization methods. Its use for sterilization has almost been abandoned in the United States, Canada and Australia, but it is still used in some countries in Europe and Asia.
- Plasma sterilization
Plasma isa state of matter other than a solid, liquid, or gaseous state. This state is achieved by creating a strong electric or magnetic field. Free radicals of hydrogen peroxide interact with cell membranes, enzymes, nucleic acids and disrupt the vital functions of microorganisms.
Main Loop Plasma sterilization consists of four stages (vacuum generation, H2O2 injection, diffusion, plasma discharge). The process takes 1 to 3 hours.
This sterilization method is suitablefor objects that cannot withstand the high temperature and humidity required for steam sterilization.
- Ozone sterilization
Ozone is form of oxygen. The sterilization process occurs through oxidation, the destruction of organic and inorganic substances. Ozone penetrates the cell membrane, causing it to explode. Ozone is an unstable gas but can be easily generated from oxygen. Cycle time - up to 60 minutes depending on chamber size or load.
3) Radiation sterilization method
It is the most effective method sterilization, but limited to commercial use only.
ionizing radiationproduces ions that knock electrons out of atoms. These electrons strike an adjacent atom and either join or knock an electron out of a second atom. Ionic energy is converted into thermal and chemical energy. This energy causes the death of microorganisms by destroying the DNA molecule, which prevents cell division and the spread of biological life. The main sources of ionizing radiation are beta particles and gamma rays.
Each method sterilization has its own characteristics. When choosing one or another method, one should take into account the possible side effects, especially when we are talking about the sterilization of various electronic devices.
The processing of all instruments includes the sequential execution of two stages: pre-sterilization processing and sterilization itself. The type and volume of pre-sterilization treatment is determined by the degree of infection of the instruments, and the method of sterilization primarily depends on the type of instruments.
a) Pre-sterilization preparation
Pre-sterilization preparation consists of disinfection, washing and drying. All types of instruments are exposed to it.
The type and volume of pre-sterilization treatment in the recent past was determined by the degree of infection of the instruments. So, before, the processing of instruments after clean operations (dressings), purulent operations, operations in patients who had hepatitis and in the AIDS risk group was significantly different. However, at present, given the high risk of the spread of AIDS, the rules for pre-sterilization preparation have been tightened and equated to methods of processing instruments that provide an unconditional guarantee of the destruction of the human immunodeficiency virus. It should only be noted that instruments after purulent operations, operations in patients who have had hepatitis over the past 5 years, as well as at the risk of AIDS, are processed separately from others.
All pre-sterilization procedures must be performed with gloves!
Disinfection
Immediately after use, the instruments are immersed in a container with disinfectants (accumulator). In this case, they must be completely immersed in the solution. As disinfectants
funds use a 3% solution of chloramine (exposure 40-60 minutes) or 6% hydrogen peroxide solution (exposure 90 minutes). After disinfection, the instruments are washed with running water.
the washing up
Tools are immersed in a special washing (alkaline) solution, which includes detergent(washing powder), hydrogen peroxide and water. Solution temperature 50-60°C, exposure 20 minutes. After that, the tools are washed with brushes in the same solution, and then in running water.
Drying
Drying can be done naturally. Recently, especially during subsequent hot air sterilization, the instruments are dried in a dry oven at 80°C for 30 minutes. After drying, the instruments are ready for sterilization.
The choice of sterilization method primarily depends on the type of surgical instruments.
b) Actually sterilization
All surgical instruments according to the characteristics of the materials used and other qualities can be divided into three groups:
- metal (cutting and non-cutting),
- rubber and plastic,
- optical (Fig. 2.7).
SURGICAL INSTRUMENTS
t
syringes, needles, clamps, tweezers, hooks, zoids, plates, screws, rods, etc.
scalpels, scissors, surgical needles, amputation knives, etc.
catheters, probes, drains, enema tips, etc.
laparoscope, gastroscope, choledochoscope, cystoscope, etc.
Rice. 2.7
The main types of surgical instruments
Sterilization of non-cutting metal instruments
The main method of sterilization is hot air sterilization in a dry heat cabinet or in an autoclave under standard conditions. It is also possible to use boiling. However, it is not recommended to boil instruments after operations for anaerobic infections and in the hepatitis risk group. Some types of simple instruments (tweezers, clamps, probes, etc.) intended for single use can be sterilized by radiation.
Sterilization of cutting metal instruments
Sterilization of cutting instruments using thermal methods leads to their blunting and loss of properties necessary for the surgeon.
The main method of sterilization of cutting instruments is a cold chemical method using antiseptic solutions.
Recently in dressing rooms cutting tools, as well as non-cutting ones, are sterilized in a dry-heat cabinet, which leads to some decrease in their sharpness, but ensures absolute sterility.
The best methods of sterilization are gas sterilization and especially radiation sterilization in the factory. The latter method has become widespread using disposable scalpel blades and surgical needles (atraumatic suture material).
Sterilization of rubber and plastic instruments
The main method of sterilization of rubber products is autoclaving. With repeated sterilization, the rubber loses its elastic properties and cracks, which is some disadvantage of the method. Boiling rubber products for 15 minutes is also acceptable.
Single-use plastic products, as well as catheters and probes, are subjected to radiation factory sterilization.
Special mention should be made of the sterilization of gloves. Recently, disposable gloves that have undergone radiation factory sterilization have been most commonly used. With repeated use, the main method of sterilization is autoclaving in a gentle mode: after pre-sterilization treatment, the gloves are dried, sprinkled with talc (prevents sticking), wrapped in gauze, placed in bix and autoclaved at 1.1 atm. within 30-40 minutes or
- 5 atm. - 15-20 minutes.
After putting on sterile gloves, they are usually treated with a ball of alcohol to remove talc or other substances from the surface that prevent rubber from sticking.
Sterilization of optical instruments
The main method of sterilizing optical instruments that require the most gentle treatment with the exception of heating is gas sterilization. All instruments for laparoscopic and thoracoscopic interventions are processed in this way, which is associated with their complex design and high cost.
When sterilizing fibrogastroscopes, choledochoscopes, colonoscopes, it is also possible to use cold sterilization using chemical antiseptics (ethyl alcohol, chlorhexidine, sidex - a two-component preparation based on glutaraldehyde).
It should be especially noted that in the best possible way prevention of contact infection is the use of disposable instruments that have undergone radiation factory sterilization!
Sterilization of dressings and surgical underwear. Sterilization by autoclaving - very reliable way. Sterilized in an autoclave in Schimmelbusch cups. Most often, dressings and surgical linen, sometimes porcelain and glassware, enameled basins, etc. are sterilized under pressure. Before autoclaving, the material and linen are placed (not tightly) in biks, and if they are not available, in canvas bags or bags. The holes on the side wall of the bix are opened before loading the autoclave and closed after sterilization. The duration of sterilization depends on the readings of the pressure gauge: at 1 atm. / 126.8 ° - 30 minutes; at 2 atm. / 132.9 ° - 20 minutes.
Steam Sterilization carried out either in a special Koch fluid-steam sterilizer, or a pot or bucket with a lid is used. Water is poured into the vessel to 1/3 of its height, a lattice partition is inserted above the water level, on which the materials to be sterilized are placed in cloth bags or bix. Having closed the vessel with a lid, in which there should be several small holes for steam to escape, the heating is turned on. The beginning of sterilization is considered the moment when steam begins to emerge from under the lid in a continuous stream, the temperature of the steam reaches 100 °. The duration of sterilization is at least 30 minutes.
Sterilization by ironing linen and dressings is allowed only in cases where other methods cannot be used. Usually the temperature of the iron reaches 150°. First, lay out and iron the sheet on which the treatment will take place, then bend it with water necessary material and iron it on both sides, while the iron is moved slowly 2-3 times in one place. The ironed linen with sterile tweezers is folded into a sterile bix or bag.
Preparing the surgeon's hands
Preparation of the surgeon's hands. Since the hands of a veterinarian are constantly in contact with objects contaminated with microorganisms, the preparation of hands before the operation is of particular importance. great importance. The treatment of the surgeon's hands consists of two stages:
1. mechanical cleaning
2. treatment with antiseptic and tanning agents.
Hands are prepared in one of the following ways:
- Olivkov's method. Hands are first washed for 5 minutes hot water(40-50°) brush and soap. After that, wipe dry with a rough towel and process for 3 minutes with swabs moistened with an alcohol solution of iodine 1:3000. Additionally, the subungual spaces and nail beds are treated with a 5% alcohol solution of iodine.
- Spasokukotsky-Kochergin method. Hands are washed in two basins with 0.5% ammonia solution for five minutes. Then wipe with a towel and treat with 70 ° alcohol for five minutes. Subungual spaces are treated with 5% iodine solution;
- Kiyashov's method based on the use of a 0.5% ammonia solution, in which hands are washed with brushes for five minutes and wiped with a towel. Completes the preparation of the hands with a 30% zinc sulfate solution for three minutes, and the subungual spaces and nail beds with an additional 5% iodine solution.
During the castration of the boar, the hands were processed according to the Spasokukotsky-Kochergin method.
Sterilization of surgical instruments
Sterilization of surgical instruments. There is a cold and hot ways sterilization of instruments. Hot ones include: sterilization by boiling in water, flombing and others; cold - sterilization in the triple solution of Karetnikov and others.
Sterilization by boiling in water. Spend it in sterilizers. Washed instruments, syringes, needles and others are boiled for 30 minutes in distilled or boiled water.
To increase the sterilization effect, the instruments are boiled in a 3% solution of bicarbonate soda or 0.25% sodium hydroxide solution for 10-15 minutes.
Cold method of sterilization in Karetnikov's triple solution. The solution consists of 20 grams of formolin, 3 grams of phenol and 1 liter of distilled water. Exposure 30 minutes.
Pre-sterilization of instruments. For emergency operations, it is necessary to sterilize the instruments in advance. Pre-sterilization can be carried out according to the Andreev method. The tools are placed in a two-layer linen bag, which is tightly tied and lowered into a boiling 20% solution of carbon dioxide for 15 minutes. After that, the bag is removed, suspended to drain the solution and dry.
Boiling instruments in a 20% carbonic soda solution without wiping them down does not cause corrosion. Instruments remain sterile for several months.
With this operation, sterilization by boiling in water is most acceptable.
Operation field preparation
Preparation of the operation field consists of mechanical cleaning, degreasing, treatment with an antiseptic, isolation of the operation field.
mechanical cleaning includes washing with soap, removing hair by shaving or clipping. The size of the field of operation should be sufficient to ensure sterile conditions.
Prepare the operation field in one of the following ways:
- Grossif-Filonchikov method. The fat-free operation field is “tanned” and asepticized with a 5% iodine solution immediately after mechanical cleaning, and then immediately before tissue incision. The interval between treatments should be at least five minutes;
-mouse way consists in the fact that after shaving, mechanical cleaning and degreasing, the operation field is treated with a 10% aqueous solution of potassium permanganate.
During the operation, the field was prepared according to the Grossif-Filonchikov method.