Endoscopic procedures are used in the diagnosis and treatment of diseases of the stomach, bronchi, colon, and other organs. However, when flexible endoscopes are used—despite their advantages over rigid instruments—certain issues arise, including the risk of transmitting infectious agents.
As a result of numerous studies, the need for proper cleaning, disinfection, or sterilization of endoscopes has been confirmed. Cleaning is the removal of all foreign substances from objects (salts, dirt, organic matter). Typically, cleaning is performed using water, mechanical action, and detergents or enzymatic agents.
Studies have shown that manual and mechanical cleaning of endoscopes reduces the number of contaminating microorganisms by approximately 10,000 times. Organic contamination (blood, feces, respiratory secretions) interferes with the penetration of microbicidal agents and their contact with microbial cells. Moreover, some disinfectants become inactivated when they come into contact with organic material. Therefore, before disinfection and sterilization, thorough mechanical cleaning must be performed to remove such material from the outer surface of the insertion tube and from the lumen of all accessible channels.
The ability of bacteria to form biofilms is also an important factor in the spread of endoscope-transmitted infections. It is known that biofilms attach to the inner surfaces of endoscope channels and prevent effective disinfection; therefore, they must be removed during mechanical cleaning before disinfection or sterilization. Initial cleaning of endoscopes with water should be carried out immediately after the instrument is used to prevent secretions from drying out (this part of the reprocessing is performed in the procedure room). Non-abrasive detergents—including enzymatic ones—recommended by the equipment manufacturer and intended for this category of medical devices are used for cleaning endoscopes. Before mechanical cleaning, all channels should be flushed with a sufficient amount of detergent solution or tap water to soften, moisten, and dilute organic residues, and the air channel should be purged with compressed air in accordance with the manufacturer’s recommendations. The insertion tube should be rinsed with a detergent solution and then with water. Accessible channels must be cleaned using a special brush to remove dense particles. The detergent solution should be pumped or aspirated through all channels to remove material lifted from the surfaces. For this purpose, channel flushing devices and some automated endoscope reprocessors can be used. All removable parts (caps and suction valves) should be removed and immersed in the detergent solution. Uneven surfaces of removable parts should be brushed to remove organic residues. Cleaning brushes are either single-use or, after each use, are thoroughly cleaned followed by high-level disinfection or sterilization. After mechanical cleaning, the parts are thoroughly rinsed with water.
Endoscopes that are not fully leak-tight should preferably not be used (new models are fully immersible). At all stages of equipment handling, it should be checked for damage. If damage is detected, the device should not be immersed in detergent solution or used further. You should contact the service center of the endoscopic equipment distributor. During shipment for repair, the endoscope should be treated as an infected medical device and must be transported with appropriate labeling.
There are several levels of further processing.
Sterilization is the complete destruction of all forms of living microorganisms by physical or chemical means.
Disinfection is a process in which many or all pathogenic microorganisms are eliminated from inanimate objects, except for bacterial spores. High-level disinfection destroys all microorganisms except large numbers of bacterial spores. Intermediate-level disinfection inactivates Mycobacterium tuberculosis, vegetative bacteria, most viruses, and fungi, but does not necessarily destroy bacterial spores. Low-level disinfection kills most bacteria, some viruses, and fungi, but this level cannot be considered a reliable method for destroying resistant microorganisms such as Mycobacterium tuberculosis or bacterial spores.
According to the recommendations of the Association for Professionals in Infection Control and Epidemiology (APIC) on the selection and use of disinfectants, endoscopes that enter body cavities (for example, esophagogastroduodenoscopes, colonoscopes, sigmoidoscopes, bronchoscopes) should be free of microorganisms, but may contain bacterial spores, because intact mucous membranes are generally an effective barrier against infection by spores of widely распространённых bacteria, yet they are susceptible to other microorganisms such as Mycobacterium tuberculosis or viruses. Therefore, gastrointestinal and bronchial tree endoscopes may undergo high-level disinfection rather than sterilization. The following stages of endoscope reprocessing for diagnostic examinations are distinguished:
1. initial cleaning;
2. initial disinfection of the endoscope;
3. rinsing the endoscope with clean water to remove residual disinfectant;
4. pre-sterilization cleaning;
5. rinsing with clean water to remove detergent residues;
6. sterilization;
7. rinsing off residual disinfectant (sterilant), drying the channels and the surface of the endoscope.
Endoscope reprocessing is one of the most complex and extensively studied issues. This is due to the complexity of endoscope design, their sensitivity to external воздействия, and the need to perform effective reprocessing in the shortest possible time. At the same time, the use of modern approaches to reprocessing different types of endoscopic equipment makes it possible to guarantee patient safety during endoscopic procedures, preserve the equipment, and significantly reduce processing time.
Please note! When you purchase an endoscope from Harwind, we provide training at a partner clinic not only for the physician, but also for the nurse, who will also have the necessary knowledge and skills for proper endoscope reprocessing.
