Respiratory filters are used when carrying out to patients of artificial ventilation of the lungs, an anesthesiology grant and other types of respiratory therapy. They are subdivided into heatmoisture exchange and barrier (bacterial and bacterial and virus). Besides, filters can combine several functions.
As task of heatmoisture exchange filters serves heat preservation and moisture in a rebreathing system. It matters when carrying out long operations, at long artificial ventilation of the lungs in chamber of an intensive care, the operating room or when transporting patients. The moistened and warmed gas mix prevents damage of a ciliate epithelium mucous respiratory tracts, disturbance of a drainage of a phlegm in a gleam of bronchial tubes, development of bronchial obstruction, an atelektazirovaniye, reduces risk of development of infectious complications.
Use of barrier filters also has huge value. First, they allow to refuse frequent sterilization of reusable rebreathing systems when carrying out anesthesia. On condition of change of the bacterial filter which is distalny the Y-shaped tee hit of infectious agents in a contour is excluded that allows to use it during the whole operational day. Secondly, use of barrier filters allows to avoid cross infection of patients in chamber of an intensive care.
Bacterial and virus filters were developed in 1963 and intended for sterilization of room air. Three principles of removal of particles are considered:
Physical removal of the particles having the size more than 1 micron;
Inertial removal for particles of 0.5-1 microns in size;
Diffusion capture due to inclusion of particles less than 0.5 microns in size in Brownian motion.
On the action mechanism all filters can be divided into acting by the principle of mechanical filtration and electrostatic filtration. Also filters can be divided into hygroscopic and hydrophobic. In hygroscopic filters as the filtering basis the special paper processed by chemicals which detain water is applied. Due to continuous process of condensation and evaporation of liquid in a filter-bed there is a warming and moistening of the inhaled gas. Hydrophobic filters are arranged in such a way that do not pass liquid through a filter-bed. For production of membranes of such filters mainly hydrophobic synthetic materials are used: the mechanical membrane — glass microfibres, the made foam polymer (polyurethane), an electrostatic membrane contains polypropylene fibers. The liquid droplets which are not getting into a filter-bed are condensed on the filtering surface, moistening the inhaled air. Bacteria, viruses, dust parts are filtered thanks to the small size of a time and electrostatic field. The guarantee of impermeability of a hydrophobic membrane for water is at the same time an impermeability guarantee for the infections extending in the airborne way, and ability of filters to detain blood cells, large proteinaceous molecules and other biological liquids is protection against a parenteral viral hepatitis of B, C, D and HIV infection that is confirmed a number of clinical tests.
Microflora of respiratory tracts at the healthy person can be provided by streptococci, diphtheroids, moraksella, pseudo-monads. In addition, meet a neysseriya, a korinebakteriya, staphylococcus. Also pathogenic strains meet: meningokokk, pyogenic streptococci, pneumococci, causative agents of whooping cough. In case of carrying out artificial ventilation of the lungs to the patient with a respiratory infection, pneumonia, the number of the available infectious agents can be considerable big. The role of these microorganisms in cross infection of patients is rather considerable.
The efficiency of modern respiratory filters for their use as a barrier of various flora is very high. Data of numerous researches estimate extent of bacterial and virus filtration of filters of various producers as 99.999%. At the same time both mechanical, and electrostatic filters are equally effective.
The basic rules when using bacterial and heatmoisture exchange filters include:
A clear idea of what filter is used and what its opportunities;
Placement of the filter in close proximity to the patient, most proksimalno as at the same time the possibility of inadvertent extubation, decannulation or excess of a tube is considered;
Observance of the strict rule: one filter — one patient and also terms of operation of the filter;
Immediate replacement of the respiratory filter in case of its pollution by biological liquids.
Our company is ready to provide to your attention very wide choice of heatmoisture exchange, bacterial and virus and bacterial filters. In more detail you can get acquainted with them in our catalog.