Bix

In the second half of the XIX century. in Moscow, G.V. Mendel suggested using zinc boxes to place dressings in them during sterilization. Later, for instruments during autoclaving, Braatz proposed wire baskets ( Braatz boxes ), and Dürssen (A. Diihrssen) offered tin cylindrical boxes with holes along the perimeter, in the bottom and the lid. K. Schimmelbusch used a tetrahedral box with a trellised bottom ( Schimmelbusch box ) to sterilize materials. ^[1] Later, in the middle of the 20th century, at the Tyumen Plant of Medical Devices, sterilization boxes with filters were developed and put into production, first rectangular, then round. In the USSR , sterilization boxes were made mainly at the Doschatka Medical Equipment Plant (DZMO) and the Tyumen Medical Equipment Plant (TZMI). They were manufactured according to then existing GOST- 402-41 Round sterilization boxes (bixes), as well as TU .

There are three types of sterilization boxes:

1. round sterilization boxes (KSK) - are a metal cylinder with a solid bottom and a lid, around the circumference of which (approximately in the middle or slightly lower) there are groups of holes for steam penetration, closed with a movable metal belt, which is fixed with a special lock . The sterility of the processed products in bottoms of this type is maintained for 3-5 days. At the moment, such bixes are almost completely obsolete, due to their low ability to maintain sterility.
2. round sterilization boxes with filters (KSKF, KF) - differ from the previous type with a solid cylinder (without holes) and the presence of holes for steam to penetrate in the lid and bottom, with filters made of textile materials installed on them ( filter diagonal, non-woven cloth, bleached calico , calico , Madapolam , etc.), one at a time, on the inside, which are held by metal plates with holes (clamps) and fixed to them with screws or locks . Filters change after 60 sterilization cycles. Sterility of materials, bixes of this type, are able to save up to 20-29 days.
3. rectangular sterilization boxes with a filter (KSPF) (much less common), they have the same design features as KSKF, and differ only in their shape, while their covers are completely removable, and the carrying handles are located on the ends of the case.

In the design of both types of sterilization boxes, there is a handle for holding them located on the lid and three metal legs on the bottom of the case, providing a gap that allows steam to pass when the boxes are installed on top of each other during sterilization in an autoclave. A reliable connection of the cover and the housing is provided by a hinge . After laying the material to be sterilized, the lid is fixed with one or two locks (depending on the size of the box), the design of which is different for different models and depends on the manufacturer . Bix covers of KSKF, KF and KSPF type can be equipped with a rubber or silicone sealant tube, which provides increased tightness of their connection with the housing.

Bixes are usually made of medical stainless steel or nickel-plated brass (rarely).

Round sterilization boxes are available in volumes of 3, 6, 9, 12 and 18 dm ³ and are accordingly marked : KSK-3, KSKF-12, KF-6, etc. Rectangular sterilization boxes are available in volumes of only 12, 16 and 36 dm ³ (KSPF-12, KSPF-16, KSPF-36).

In the field, in the absence of bixes, sometimes they use a design in the form of a metal frame with a fabric stretched over it (usually canvas ).

Bixes are intended for placement of medical items and materials in them such as dressings, heat-resistant syringes , operating linen, surgical materials, medical instruments and other medical items for the purpose of sterilizing them in steam sterilizers (autoclaves) and delivering them to the place of use, and also their sterile storage.

Sterilization using bixes is possible only in steam sterilizers (autoclaves). To do this, the inside of the bix is ​​usually lined with a layer of cotton fabric (usually a pillowcase ), on which the materials to be sterilized and / or tools are laid (from the edges to the center), after filling, the ends of the fabric are wrapped (pillowcases), the steam sterilization indicator is placed on top and closed cover. For KSK type bikes, openings are opened before installation by displacing the metal belt. After laying, an oilcloth label with the names of the products to be sterilized is attached to the handle of the bix , and the bix is ​​installed in the sterilization chamber of the autoclave. While the box is in the sterilization chamber, steam under pressure passes through the holes in its body, circulating on the surface of solid and in the thickness of porous materials, destroys microorganisms, thus ensuring their sterility. After the end of the sterilization cycle, steam holes are closed for KSK type bixes and the belt is locked, and the sterilization date is indicated on the label and the operator signs it.

In operating rooms, dressing rooms, treatment rooms , large bixes are often installed on special racks-stands for quick opening / closing of their covers by pressing the pedal , which provides quick access to their contents.

The sterilization and storage of materials and tools in the bix, has a number of significant drawbacks:

1. After sterilization of the lid of the bix, which is not tightly attached to the casing, and also between the casing and the belt, air can penetrate the bix after sterilization and reinfection of the products occurs. In a somewhat better way, in this regard, the situation is with sterilized boxes with bacterial filters. However, they also have a number of significant design flaws. To seal the boxes between the lid and the box body, a low-grade rubber gasket is used that does not withstand prolonged exposure to high temperature . As a rule, the rubber gasket is poorly fixed in the grooves of the lid, falls out of it after several sterilization cycles and the boxes lose their purpose. The case of the box is made of thick stainless steel . The weight of such boxes measuring 30 × 30 × 60 cm with full load sometimes exceeds 12-15 kg. Therefore, their use is a big problem.
2. Details of sterilization boxes are not strong enough, loops, locking devices often break off, the case is easily deformed , which reduces the reliability of maintaining sterility. Cases of reinfection of materials in bixes during unloading, transportation , storage (from 3.8 to 23%) are quite frequent.
3. Another significant minus of the bixes is the need to send the entire instrument and dressings after opening the bixes for re-sterilization, regardless of whether they were used or not.
4. The structure of coarse calico laying includes a pile , which over time can clog the sterilizer system. In this case, calico sometimes requires additional drying, because at the end of the sterilization process it remains moist, forming ideal conditions for the reproduction and growth of the number of bacteria .

• Bixes
• Loading bixes and preparing them for sterilization