Sterilization of dressings is a mandatory measure that guarantees absolute purity and safety. Thanks to special cleaning methods, the death of any pathogenic microorganisms that can cause bacterial, viral and fungal diseases is ensured.
What is meant by the term "sterilization"
To date, the most common methods for cleaning dressings and medical devices under clinical conditions are:
- autoclaving;
- air sterilization in a dry oven;
- processing with chemical solutions, gas.
In some cases, resort to radiation treatment. Moreover, each of these methods consists of three main stages, including disinfection, pre-sterilization cleaning and direct sterilization.
What material is considered dressing
This category includes the types of tissues used to treat wounds, including the surgical field (tamponade, dressings, medical wipes, etc.). The material used for dressings has a high level of hygroscopicity, therefore, it quickly absorbs the liquid discharged from open wounds, dries instantly, but it must remain flexible and durable. In addition, in the preparation of sterile bandages, napkins, turundas and other types of gauze products, their hypoallergenicity is taken into account. An important role is played by the accessibility and cheapness of the dressing, since in most cases it requires a significant consumption. After sterilization, the dressing should not lose its properties.
Mostly common are gauze, cotton wool, lignin. Bandages, medical wipes, tampons, turunds and other products are obtained from gauze. Dressings can not do without the use of absorbent cotton wool. It is sold in any pharmacy, used for various purposes, depending on which they acquire non-sterile or sterile cotton wool. Both species have excellent suction capabilities, but in medical practice they often use sterile cotton wool. It does not allow dust, debris to enter the wound, protects it from shock, exposure to sunlight. At the same time, cotton wool is placed in the wound only on top of the sterile bandage, otherwise its fluffy fibers will become wet and stick to the epithelium.
Instead of cotton wool, lignin can be used (these are the thinnest corrugated paper sheets that are made of wood. To fix the dressings placed on the wound surface, use tubular and elastic bandages - this is also a dressing material, the sterilization of which allows reuse.
Types of processing medical devices for dressing
Depending on the mode of sterilization of the dressing, it is important to adhere strictly to the algorithm of actions and exercise control over the course of the processing process. Of fundamental importance in matters of sterilization of products and material is the shelf life of sterility. The period of absolute cleanliness of gauze, cotton products and medical bix specified by the manufacturer is also taken into account. Next, we consider in more detail each of the types of sterilization that are used in modern clinics.
What is autoclaving?
This is one of the common and affordable methods of sterilization, involving exposure to steam. The method is based on the simple laws of physics. As you know, when boiling (100 ° C), water forms steam, for this there is no need to create additional pressure. But if it is still increased by 0.5 atmosphere, then the steam will begin to be released at a higher temperature. These are ideal conditions for the death of all pathogenic microflora, including those microorganisms that are resistant to high temperatures.
The processing time of the dressing depends on the temperature at which it will occur:
- at 110 ° C the exposure lasts one hour;
- at 120-126 ° C - about 45 minutes;
- at 127-133 ° C, half an hour is enough;
- at a temperature of 134 ° C, microbes die in 15 minutes.
It is worth noting that dressing can be reused after washing only if it has been used in a non-purulent environment.
Sterilization device
An autoclave is a metal container with double strong walls. Between them fill water, then tightly close the cover with screws, and turn on the bottom of the heater. As soon as the water boils, steam begins to form, which fills the inside of the autoclave with the dressing.
After laying, the bix is closed with a lid, due to which the container becomes completely tight. Outside the sterilizer, the bix can be stored for no more than two days. Inside they are lined with fabric. When filling the autoclave, it is impossible to tamper the bixes; it is important to leave free space so that steam can penetrate inside. It is more convenient to fill containers for sterilization with homogeneous products.
In some cases, autoclaving involves sterilizing clothes in special bags. The same rules apply here as when laying down the bix. The only thing worth noting is the need to use paired bags dressed one on top of the other. This will keep it clean even if you untie the bag with non-sterile hands. The upper bag is shifted down, and the inner one is placed on a sterile surface and its contents are disassembled.
Autoclave action algorithm
The method involves the use of a powerful steam stream, but for its application you can not do without a special apparatus for sterilizing dressings. It is called an autoclave. In order to process the products properly and not doubt their absolute cleanliness, you need to follow a few simple rules:
- Before the procedure, be sure to treat the inside of the bix with medical alcohol.
- A clean sheet is laid at the bottom, and a container is placed on top of it with bedding, gauze and cotton products. Sterilization of rubber items and medical instruments is also allowed (they are wrapped with a towel and sent to the biks).
- Then, after loading the laundry for sterilization, several indicators are placed. After treating the dressings, they will indicate whether sterilization has taken place properly.
Sterility test according to Mikulich
To make sure that the dressing is sterilized in an autoclave, one of the simple tests is performed. The simplest and most common is the Mikulich test. It is performed as follows:
- Any word is written on a strip of paper with a pen, the indicator is lowered into a liquid more reminiscent of a paste consisting of starch and water. After that, the paper is allowed to dry.
- The dry strip is again wetted, but this time in Lugol's solution, so it darkens, turns blue and the written word on it disappears.
- The dried indicator is sent to the autoclave along with the sterilized dressing. If after exposure the piece of paper turns white again, then the processing was successful.
Bacteriological check
This is a direct way to find out if pathogenic flora has remained on the dressing. To make sure that the products are sterile, it is necessary to open the beaks directly in the operating room and draw on the treated materials with gauze rags moistened with an isotonic sodium chloride solution. Then the moistened gauze swabs are sent to a test tube. Bacteriological control is carried out several times a month. This method of monitoring cleanliness and sterility is considered the most reliable.
Bandaging aerial processing
During air treatment, the sterilizing effect can be achieved due to the powerful supply of dry and hot air. A distinctive feature of the method is the complete absence of moisture on the inner walls of the bix, in connection with which the sterility period is increased, and the metal container is not threatened with metal corrosion.
However, the air treatment method for dressings has a number of disadvantages. First of all, it is worth noting the prolonged and uneven heating of the products placed in the bix. In order to sterilize materials with dry, hot air, higher temperatures will be required. The minimum allowable temperature threshold is 160 ° C. Moreover, the duration of exposure in this mode should be at least 2 hours. To process the dressing in half an hour, you will need an air stream within 200 ° C.
If it is allowed to process rubber and polymer parts in an autoclave, the air method does not allow this. In addition, it is not possible to blow out packaging materials with hot air. The effectiveness of sterilization of dressings in a dry oven depends on how hot air evenly penetrates the products, and for this it is extremely important to observe the sterilizer loading standards and the forced air circulation speed (it must be at least 1 m / s).
Gas sterilization
Unlike other methods of processing dressings, air and steam are the safest and most environmentally friendly. Gas treatment of medical devices involves the use of ethylene oxide or formaldehyde. Vapors of these substances have a high toxic effect. The method of gas sterilization is resorted to, as a rule, if there is no possibility of steam or air.
To carry out gas treatment of dressings, you will need to create all the necessary conditions for this. In gaseous form, the chemical compounds of ethylene oxide do not harm products, do not provoke corrosive processes. Thus, any tissue can be processed: genuine leather, wool, paper, plastics, plastic, wood, etc. The vapors obtained during the sterilization process have a strong bactericidal effect and penetrate as deep as possible.
However, the toxicity and explosiveness of ethylene oxide are its main disadvantages. A pair of 40% alcohol formaldehyde vaporized from formalin is used to sterilize products and medical materials. Vapors of these substances are unsafe for medical personnel; moreover, the process of gas sterilization itself is very lengthy. That is why this method of processing dressings is rarely used.
Chemical Processing
Another auxiliary method of sterilization of dressings, which is used only if there is no possibility of using other methods. Chemical sterilization has a number of negative aspects, since the processed products are cleaned without protective packaging. In addition, after such a cleaning procedure, an additional rinse will be required, and this, in turn, can lead to secondary contamination. Moreover, the solutions that are used for chemical sterilization are available everywhere and do not require additional preparation of dressings.
Sterilized items are laid out in bixes without tampering. After the cleaning procedure is completed, the products are immersed several times in distilled water. If sterilization was carried out with hydrogen peroxide, rinsing is carried out twice, in other cases - at least three times. After each immersion of sterilized items, the water is changed.
Radiation method
It is used extremely rarely in medical practice, mainly when there is a need to sterilize products from thermolabile materials. As sterilizing agents, ionizing gamma and beta rays are used. The radiation treatment method for dressings involves the mandatory use of paper and plastic bags. The main advantage of this method is its long sterility period.
The radiation method is used in industry. Industrial enterprises engaged in the production of single-use sterile products have resorted to its use.