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 the destruction of HIV. 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 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, the sheet on which the treatment will take place is laid out and ironed, then the necessary material is bent with water and ironed 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. 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 with hot water (40-50 °) with a 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 are cold and hot methods for sterilizing 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.
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 objects that tolerate humidity, high pressure (from 1 to 3.5 atmospheres above the external environment), as well as high temperatures (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 sterilization method
- 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 mosteffective sterilization method, 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 possible side effects, especially when it comes to sterilizing various electronic devices.
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. 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. Sterilization of cutting metal instruments
The main method of sterilization of cutting instruments is a cold chemical method using antiseptic solutions. Recently, in dressing rooms, cutting instruments, 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 surgical instruments is carried out by boiling, autoclaving and antiseptic substances. Non-cutting instruments are sterilized by boiling in a 1-2% sodium bicarbonate solution, which prevents metal oxidation and increases the boiling point. You can boil instruments in distilled water.
Instruments can be sterilized packed in bixes or wrapped in sheets in an autoclave for 30 minutes. at a pressure of 2 am. Dry-air sterilization is also used in drying cabinets at t ° 180-200 ° for 40 minutes. In emergency cases, sterilization of instruments by firing is allowed. Having laid them in a metal tray, they are doused with alcohol, which is set on fire. But from such sterilization, the instruments deteriorate, and the method is not reliable. Cutting instruments become blunt when boiled in water, so they are cold sterilized. After washing with a brush and soap, they are immersed for 2 hours in 96% alcohol. Alcohol of a lower concentration causes rust. The syringes are sterilized by boiling in distilled water for 30 minutes. Cylinders and pistons are boiled separately, wrapped in gauze. If the syringes are made of heat-resistant glass that can withstand temperatures above 200°C, dry-air sterilization at t° 200°C for 30 minutes is best. The needles are boiled with mandrin or filled with water using a syringe. Otherwise, air is stored in their lumen, which prevents the flow of water. New needles are cleaned of grease and three times for 20 minutes. boil in 2% sodium bicarbonate solution, changing the water each time. Then they are placed in gasoline for two hours and again boiled twice in a 2% solution of sodium bicarbonate. Keep the needles dry, with mandrin. Disassembled syringes and needles can be stored in 96% alcohol in special metal cases or in a glass vessel.
From a functional point of view, surgical instruments are divided into ordinary metal, cutting, plastic and rubber, as well as optical. The main regulatory document for the processing of medical instruments is: “Industry standard. Sterilization and disinfection of medical devices. Methods, means, modes ("I 42-21 - 2-85. Order M3 of the USSR dated 10.06.85.). Taking into account the unfavorable epidemiological situation for AIDS, the OST was supplemented by order of the GUZO and TsGSEN No. 222/80 dated 06.27.00. SanPiN 2.1. 3.2630-10 "Sanitary and epidemiological requirements for organizations engaged in medical activities" SanPiN 3.1.5.2826-10 "Prevention of HIV infection.
According to these documents, the following successive stages of processing medical devices are assumed: disinfection, pre-sterilization cleaning and sterilization.
Disinfection is carried out in order to protect medical personnel from infection when processing instruments after surgery. Physical disinfection methods (boiling, steam and air) are practically not used in a hospital due to bulkiness, lack of efficiency, or because of the rapid wear of tools. The following agents are used as chemical methods: a) 3% solution of chloramine - 60 min; b) 6% hydrogen peroxide solution - 60 min; c) 6% hydrogen peroxide solution + 0.5% detergent solution - 60 min; d) 4% formalin solution (for formaldehyde) - 60 min; e) 4% hydrogen peroxide solution - 90 min; f) preparation "Sydex" - 15 min. All instruments are filled with one of these solutions until they are completely immersed. After disinfection, they are washed with running water.
Pre-sterilization cleaning is carried out to remove protein, fat and mechanical contaminants, as well as drugs. During pre-sterilization cleaning, the following steps are performed in sequence: a) soaking for 15 minutes in a washing solution, which includes hydrogen peroxide 3% - 156 ml, detergent - 5 g and water to a volume of 1 l; b) individual washing of each product in the washing complex for 30 seconds; c) rinsing with running water after using detergents - at least 3 minutes; d) rinsing with distilled water to wash off salts; e) drying of tools until the moisture disappears completely.
actual sterilization. Previously used boiling retains its value only for disinfection or sterilization of instruments for individual use. If the previous steps are carried out during the sterilization of any instruments, regardless of their type, then with direct sterilization, various methods are differentially used depending on the type of instrument to be sterilized.
Ordinary metal instruments are sterilized in a dry oven or in a steam sterilizer (autoclave).
Sterilization of instruments in a dry-heat cabinet is carried out with hot air for 1 hour at a temperature of 180 C without packaging (open method). To control the quality of sterilization in a dry-heat oven, the following test indicators are used: hydroquinone (the indicator turns black) and thiourea (the indicator turns yellow to orange).
Sterilization in a steam sterilizer occurs as a result of exposure to water vapor. It consists of two metal chambers nested one inside the other and hermetically sealed with a front cover. Steam from the steam generator enters the outer chamber, from it into the inner chamber and then into the condenser. If the outlet valve of the inner chamber is closed, then the vapor pressure in the inner chamber begins to increase (maximum - up to 2 atm.). In parallel, the steam temperature rises to 132°C at 2 atm. Conventional metal surgical instruments are sterilized at a pressure of 2 atm. within 20 min. Modern steam sterilizers must be of a pass-through type, that is, they must have two front covers on opposite sides of the apparatus, and these covers must be located in different rooms for complete isolation of sterile and non-sterile material. In addition, steam sterilizers must be equipped with generators that create a pulsating vacuum to remove air from the sterilizer, which is a heat insulator and prevents effective sterilization. The instruments to be sterilized in a steam sterilizer are placed in Shimelbusch biscuits or biceps with a special bacterial filter, as well as in special bags for sterilization. Sterile instruments from a closed Shimelbush bix can be used within 3 days, from a closed bix equipped with a filter - within 20 days. After opening the bixes or packages, their contents should be used within 1 day, subject to all asepsis rules.
Packages for sterilization are of several types: a) crepe paper, which is wrapped in the form of an envelope (in the absence of violations of the integrity of the package, it retains the state of sterility of the contents for 3 days); b) paper packaging with a hot-melt adhesive strip and a sterilization indicator [class (unopened packaging keeps the contents sterile for 60 days); c) combined packaging, in which one side is made of laminated paper, and the other side is made of polyethylene film, has a hot-melt adhesive strip and a class I sterilization indicator (unopened packaging keeps the contents sterile for 1 year). Packaging bags for sterilization are produced by European companies Rexam (England), SPS - lab. (France), Steriking (Finland), etc. Open sterilization in a steam sterilizer should not be carried out!
There are chemical (cold) methods for sterilizing instruments: 6% hydrogen peroxide solution at 18°C for 6 hours, paraform or 16 "/formaldehyde solution in sealed chambers for 48 hours, 0.5% water-alcohol solution chlorhexidine for 5 minutes, sterilization in special chambers with ethylene oxide PO), as well as radiation sterilization.
Cutting metal instruments (scalpels, surgical needles, scissors, etc.) are sterilized by cold methods so that they do not become dull under the influence of hot steam. The most commonly used for this purpose is hydrogen peroxide or an alcohol solution of chlorhexidine. Scissors can be sterilized in a dry oven. Industrial radiation or ethylene oxide sterilization of scalpels and single-use atraumatic suture is optimal.
Plastic, rubber and optical instruments. Sterilization of rubber and plastic products is possible by the thermal method in a steam sterilizer under a pressure of 1.1 atm. within 45 min. Currently, disposable gloves are used, sterilized by industrial radiation, however, in extreme conditions, rubber gloves can be sterilized by autoclaving. For the chemical method of sterilization, formalin vapor, ethanol, ethylene oxide, etc. are used.
In addition to gas sterilization of optical instruments (endoscopes), a 0.5% alcohol solution of chlorhexidine, pervomur or sideks is used.
1.2.2. Sterilization of dressings and surgical linen. Dressings and underwear include large and small gauze napkins, gauze swabs, other special gauze and cotton products, as well as sheets, diapers and gowns. The set of material to be autoclaved is called a stack. Steam sterilization is carried out in Schimmelbusch cups, metal cups with filters, as well as in cotton sheets or diapers. Biks are supplied with labels, which should contain information about the contents of the biks and its belonging to one or another operating room or dressing room. The process of preparing dressings for surgery or dressing is divided into 3 stages.
I stage of pre-sterilization preparation of the material. The gauze cloth is cut into pieces of various sizes, depending on what is to be made - small napkins, large napkins, tampons, etc. The gauze should be soft and hygroscopic. The dressing is folded so that the free edges are tucked inside the napkins or tampons.
Stage II - laying and preparing the material for sterilization. There are 3 main types of bix styling. Universal stacking is usually used in dressing rooms and for small operations. At the same time, the material is placed in biks by sectors (in one sector - small napkins, and in the other - large napkins, in the third - tampons, etc.) so that you do not have to violate sterility when searching for one or another type of material. Targeted laying includes everything you need to perform typical manipulations, procedures and small operations (laying for tracheostomy, for catheterization of the subclavian vein, for epidural anesthesia, etc.). All the necessary tools, dressings and underwear are placed in the bix. View stacking is used when working in large operating units. At the same time, one type of dressing material or linen is placed in the bix (in one - dressing gowns, in the other - sheets, in the third - napkins, etc.).
Currently, single-use surgical underwear made of non-woven material (sheets, diapers, gowns, caps and masks), as well as packages with gauze wipes of industrial radiation sterilization, is increasingly being used.
III stage - sterilization. Sterilization of linen is carried out by a steam method under pressure of 2 atm. at a temperature of 132°C for 20 min. Before loading into the autoclave, check whether the holes in the bix are open. After sterilization, the hole in the bix is closed with a metal rotating tape on the case of the bix in the process of removing it from the autoclave and the date of sterilization is marked on it.
TREATMENT OF THE SURGEON'S HANDS
Processing (washing) the surgeon's hands is a very important procedure. There are certain rules for washing hands. Consistently it is necessary to carry out: mechanical and chemical (degreasing) treatment, exposure to antiseptic agents and tanning (closing the pores to maintain the sterility of the skin surface).
Modern methods of hand treatment do not require special tanning (film-forming antiseptics or antiseptics with a tanning element are used).
Mechanical and chemical processing
Mechanical and chemical treatment is carried out by washing hands under a tap with a brush and soap. Hands are thoroughly washed from the fingertips to the upper third of the forearm. At the same time, a certain sequence of processing is observed, which is based on the principle "do not touch the treated areas of the hands with less clean skin and objects."
The use of modern methods allows washing hands simply with soap or with liquid detergents (in the absence of domestic hand contamination).
