Endoscopes Preventive Maintenance

The endoscope is a high-tech equipment that allows the doctor to see the inside of the human body through a television microchip or optical fibers that collects digitized images to be observed on a monitor and printed on photographs and recorded on video.

The internal organs are seen on a screen in the operating room. The doctor may also use pliers or scissors with the endoscope to remove tissue for biopsy, which is a much less invasive method than surgery would be.

An Endoscope

Endoscopies are a growing procedure worldwide, and the equipment can be expensive for clinics or hospitals to replace. That is why, as with so many other frequently used equipment, preventive maintenance is essential to keep costs down and the accidental transfer of bacteria. Infection control is a serious matter, and only the highest level of precaution will result in the patient safety. If you are given the job to inspect and apply a full preventive maintenance procedure (PPM) then we recommend that you have a look at the IPAC PPM checklist  

Patient safety is the number one concern with any medical procedure. Infections caused by improperly cleaned endoscopes are a frightening issue in the medical community and, above all, for potential patients. When not cleaned immediately or properly, the bacteria can form a biofilm that will not clear easily when cleaned. Due to the nature of endoscope's use, there is a variety of contaminants within the flexible tubes that can be difficult to clean properly, and due to their composition, some cannot be sterilized by safety heat. This equipment is of complex design, so paying attention to details and following procedures is crucial.

The American Society of Gastrointestinal Endoscopy notes that facilities in which a digestive endoscopy is performed must follow an effective quality control program to ensure that endoscopes are reprocessed correctly. Quality control programs for endoscopy should include systems that guarantee the availability of equipment and adequate supplies at all times, and strict procedures to report possible problems.

Preventive maintenance includes all periodic inspections of instruments and equipment, cleaning, lubrication, adjustment, verification and information of defective components that could fail, altering the operational status of the equipment before the next inspection.

Damage to an endoscope can cause costly repairs, so it is important to familiarize yourself with proper care and handling techniques. We hope these guidelines help your endoscope to function efficiently for years to come.

The best and most efficient way to clean this complicated equipment is immediately after using a pre-cleaning protocol and then a complete cleaning and disinfection or sterilization. The sequence of reprocessing of endoscopes should be as follows: Pre-cleaning, cleaning, rinse, drying, disinfection, wipe, drying and storage.

CLEANING THE ENDOSCOPES

GENERAL CLEANING PROCEDURES

The preliminary cleaning should be started before the endoscope is uncoupled from the video processor/light source. As soon as the endoscope has been removed from the patient, reprocessing can be started, observing the following steps:

1. Clear these macroscopic ones, sucking the detergent through the working channel (250 ml/minute).

2. Ensure that the working channel is not blocked.

3. Irrigate the channels with air and water, check that they are not covered by visualizing bubbling through the air channel and good aspiration through the working channel.

4. Perform leak test.

5. Dry the placement handle.

6. Verify marks of bites or other irregularities on the surface.

7. Uncover the endoscope of the video processor/light source.

8. Transfer the endoscope safely, avoiding environmental contamination, to the reprocessing room that has facilities for atmospheric extraction.

9. Perform a daily leak test and every time after therapy is performed.

So the above steps must be done by the nurse or the medical practitioner right after finishing the procedure.

Then disassemble the parts of the endoscope that can be uncoupled, removing the valves and the inlets of the water bottle, removing the detachable tips of the placement tube. All exposed internal and external surfaces must be cleaned by hand, rinsing them in accordance with the following recommendations:

- Use a detergent of low foam and safe quality, as the enzymatic detergents need variable times according to the manufacturer between 1-15 minutes of contact to act, it is preferable to use non-enzymatic detergents in centers of high population demand and scarce equipment.

- Use the appropriate dilution following the manufacturer's instructions.

- Rinse and brush the access channels to remove all organic waste.

- Use brushes of appropriate size for the channel, parts, connectors, and openings of endoscopes; the bristles must come into contact with all surfaces.

- Activate valves repeatedly during cleaning, to facilitate access to all surfaces.

-Try not to clean the terminals and the power input. Cleaning them can distort or consume the contacts, which could damage the video frame. In addition, the exterior surface should not be cleaned with rough materials and the surface should be scratched.

- Remove all items that were used for cleaning.

ULTRASOUND CLEANING

Ultrasonic cleaning of the reusable accessories of the endoscope and its components may be necessary to remove material from areas that are difficult to clean. The same detergent should be used for ultrasonic cleaning as for manual cleaning. Below are the recommendations:

-          A non-foaming detergent should be used that is suitable for both manual and ultrasonic cleaning.   Preferably use enzymatic detergent solutions.

-          In the case of enzymatic detergent, the specific contact time recommended by the manufacturer must be respected.

-          It is necessary to minimize the inhalation of aerosols and detergents that contain enzymes that can produce anaphylactic reactions, covering the detergent container.

DETERGENTS

To achieve an adequate cleaning of this equipment, enzymatic or non-enzymatic detergents and detergents containing antimicrobial substances can be used, it is suggested the use of those that do not foam. The foam can prevent contact of the liquid with the surfaces of the device and prevent a clear field of vision during cleaning, exposing the personnel to the risk of injury.

 The product used must be able to efficiently remove the organic and non-organic material so that the action of sweeping the detergent liquid and the rinse water the unwanted material. Avoid detergents that contain aldehydes in their composition, since they denature and coagulate the proteins. 

Do not use compounds that contain amines or glycoproteins in combination with glutaraldehydes since chemical reactions can produce colored residues. It is also necessary to discard the enzymatic detergents after each use since these products are not microbicidal and do not retard microbial proliferation. 

The enzymes of the detergents that contain them generally work more efficiently at a higher temperature than the environment, at more than 20-22 ° C. They should be used in accordance with the manufacturer's recommendations.

DISINFECTION OF ENDOSCOPES

GENERAL PROCEDURES

Endoscopes must be disinfected by trained personnel in rooms specially designed for that purpose, in the beginning, and between each patient. When the endoscope is stored in a clean environment, suitable for this purpose, it is accepted not to perform the reprocessing before the first study. High-level disinfection can be done by immersing the endoscope in a high-level disinfectant approved by ANMAT and during the times indicated by the manufacturer or using an automatic endoscope reprocessor, following the following steps:

- Perform the disinfection in an area specially designed for this purpose that has the atmospheric extraction.

- Immerse the entire endoscope with a high-level disinfectant or chemical sterilizer at the correct temperature and duration, instilling all the channels with the disinfectant.

- Then expel the disinfectant from the channels to proceed with the rinsing with potable water outside the container to prevent its dilution.

- Dry the rod with a clean cotton cloth and the channels with forced air.

- Prior to storage instill 70% ethyl alcohol or isopropyl alcohol through the channels to prevent the formation and multiplication of microorganisms that can be formed within the channel by the accumulation of water.

To protect personnel during the disinfection process, the use of:

- Saves long-sleeved waterproof powders; Switch between one patient and another.

- Vinyl gloves, as far as possible long enough to cover the forearms.

- Protective glasses to prevent conjunctival irritation and protect from splash and chinstrap type N95.

- Rooms with appropriate ventilation and air exchange designed for the use of disinfectants.

MANUAL DISINFECTION

Through manual cleaning, the endoscope and its segments must be completely inside the disinfectant or sterilizer, ensuring that all channels are immersed. The water container and the association tubes used to clean the focal point and flood in the middle of the endoscope should be disinfected in any case once a day. The water jug should be loaded with sterile or potable water.

AUTOMATIC REPROCESSING

Some manufacturers allow a process of Automatic reprocessing, in the automatic reprocessing of endoscopes (RAE), the endoscope and its components are placed in the reprocessor, all the channel connectors are connected according to the RAE manufacturer's instructions. The manufacturer states that the RAE ensures the exposure of all internal and external surfaces to the disinfectant.

If an RAE cycle is interrupted, it is not possible to ensure disinfection and the entire process must be repeated. The water used for rinsing in automatic reprocessors must be kept absolutely free of microorganisms and other particles, using bacterial filters, biocides, or other methods. If the water that comes through a pipe network is hard water, it is necessary to use softeners. 

The final water samples that come out of the automatic reprocessor must be subjected to microbiological tests at least once a week.

IMPORTANCE OF RINSING AND DRYING

Endoscopes usually do not dry after rinsing between consecutive exams. The drying process is intended to prevent the multiplication of microorganisms during storage. 

Colonized water or residual moisture can be a source of proliferation of microorganisms. Proper drying removes all moisture from the internal and external surfaces of the endoscope and before prolonged storage decreases the rate of bacterial colonization. Drying with forced air increases the effectiveness of the disinfection process.

Following are the recommended steps:

- After manual disinfection removes the instilled disinfectant from the endoscope and flushes the channels and the external surface with potable water.

- Discard the rinse water after each use or cycle.

- If it is the last procedure performed on the day irrigate the channels with 70% ethyl alcohol, isopropyl alcohol or compressed air.

DISINFECTANTS

The disinfectant must be effective against a wide range of microorganisms: viruses, fungi, bacteria, and mycobacteria. There is no disinfectant for prion proteins. Glutaraldehyde in contact for more than ten hours acts as a sterilizer and can act on bacterial spores. 

It must be compatible with endoscopes, accessories and endoscope reprocessors;  so having a look at the user manual could be a good idea to ensure best-recommended practices are followed. 

Disinfectants used should be harmless for users and its disposal should not harm the environment. Disinfectants should be used at the correct temperature and according to the manufacturer's instructions and the current recommendations of the official bodies agreed upon in the academic literature. They should be examined regularly with test strips and/or kits supplied by the manufacturers to ensure the optimal activity of the products.

Disinfectants for flexible endoscopes according to FDA and recommended times:

- 2% glutaraldehyde solution, minimum 20 minutes at 20º C.

- OPA: ortho-phthaldehyde between 5 and 12 minutes at 20º C.

- PAA: peracetic acid between 10 and 15 minutes 50º- 56º C.

- Electrolyzed acid water.

STERILIZATION OF THE ENDOSCOPE

Sterilization is used primarily to process accessories of the endoscope and is achieved by physical or chemical methods. It is important to stress that the sterilization does not mean disinfection and that there is no "partially sterile" state. Steam pressure, dry heat, ethylene oxide gas EtO, hydrogen peroxide H2O2, plasma gas and liquid chemicals are the main sterilization methods used in sanitary facilities.

Flexible endoscopes do not tolerate high processing temperatures that is greater than 60° Celsius and cannot be sterilized or disinfected in an autoclave with hot water or subatmospheric steam. 

However, Flexible endoscopes can be sterilized as long as they have been thoroughly cleaned and the manufacturer's processing criteria are met. Due to the composition of Flexible endoscopes material, most flexible endoscopes must be sterilized by ethylene oxide or hydrogen peroxide. Sterilization with ethylene oxide can fail in the presence of organic debris after inadequate cleaning and in the presence of biofilm in the internal channels of the endoscope.

ENDOSCOPE STORAGE

Below are general recommendations for storage:

-          Make sure that the endoscope has been dried correctly before storing.

-          Hang the endoscope preferably vertically to facilitate drying.

-          Remove plugs, valves, and other removable components, as indicated by the manufacturer's instructions.

-          Unroll the placement tubing.

-          Protect endoscopes from contamination by covering them with a disposable cover.

-          Use a well-ventilated and clean room or cabinet, where possible only dedicated to reprocessed endoscopes.

-          Clearly mark which endoscopes have been reprocessed.

-          Avoid contamination of disinfected endoscopes by contact with the environment or by prolonged storage in areas that may promote the multiplication of pathogens.

ENDOSCOPY ACCESSORIES

In general, disposable accessories should not be used more than once. If they are to be used more than once because resources are limited, it is imperative that they are subjected to a complete cleaning and that a sterilization cycle is made between each use provided that the material allows that reprocessing, ensuring the quality of the process.

The steps included are summarized below:

-          Disassemble, brush, rinse and dry.

-          The water of good quality (sterile, filtered, or portable) and a high quality, low foam detergent should be used.

-          If you have cleaned with ultrasound, always use it before the sterilization process. The entry of the material into the sterilization room and its supervision of correct prior cleaning ensure the reuse of the accessory material when sterilization is possible.

As mentioned many times earlier it is always best to follow the manufacturer recommended procedures to apply the needed care for the endoscope that you have, but we tried to cover the many aspects that are used in general for various types and brands of endoscopes, hoping to provide useful information for the user to apply good care of the endoscope that you have. 

The top 4 medical companies that make endoscopes are: 

• Olympus Medical is one of the few medical equipment companies that provide a wide range of endoscopes that meet almost all doctors requirements. 
• Smith And Nephew Medical mainly specialized in manufacturing great light sources 
• Karl Storz Medical they are mainly specialized in the production of gastro endoscopes and this German maker is one of the most professional and advanced endoscopes in the world. 
• Richard Wolf, This is yet another German medical equipment manufacturer that provides high-end high-quality endoscopy devices that are durable and innovative   
• Fujifilm Provides almost complete solutions for endoscopy devices from bronchoscopes, gastroscopes, colonoscopies and much more.   

If you have any additional information that can be added to this topic, or you have any ideas related to good practices to apply good care for an endoscope, please don't hesitate to post them in the comment section below. We appreciate your thoughts and ideas!