How to Care for Your Flexible Endoscopes in 6 Easy Steps

If all the instruments used in a surgery facility, flexible endoscopes are among the most difficult to clean and maintain. They can range from two to six feet in length, with long, narrow internal channels that are only a few millimeters wide. These channels are routinely contaminated with all manner of debris, including blood, stool, tissue, and saliva.

As a member of the Practice Committee of the Society of Gastroenterology Nurses and Associates, Inc., which has established protocols for the cleaning and disinfecting of endoscopes, I am well versed in endoscope care. I use these protocols every day as the administrator of a busy endoscopy center. In this article, I'll take you through our six-step process for preparing, testing, cleaning, reprocessing, drying, and storing endoscopes.

Step 1: Prepare the Endoscope for Cleaning
The initial reprocessing protocol begins immediately after removal of the insertion tube from the patient. Always wear personal protective equipment, such as gloves, eyewear, and impervious gowns when handling soiled endoscopes.

After completing a procedure, immediately immerse the scope's insertion tube in an enzymatic detergent, and suction the detergent through all the channels to clear it of debris.

After completing a procedure, immediately immerse the scope's insertion tube in an enzymatic detergent.

While the scope is still connected to the light source, alternate air and water flow through the air/water channel. This step is necessary for preventing the buildup of protein, especially if you cannot immediately clean the scope.

Step 2: Test for Leaks
Before you can start the cleaning process, you must leak test the scope. Leaks can adversely affect the endoscope's functional integrity and increase the risk of cross-contamination, since punctures make ideal habitats for microorganisms. Here's how to perform a thorough leak test:

- Disconnect the light source and, following the manufacturer's recommendations, attach your endoscope's leak tester to the scope. The leak tester is usually connected to the air vent located on the scope light guide.
- Turn the knob on the leak tester to pressurize the scope until the pressure reaches the level denoted on the tester gauge.
- Lower the scope's distal tip, which is composed of the thin, flexible rubber most likely to be damaged, into a liquid bath and look for air bubbles that signify a leak. I use the enzymatic detergent from step 1 as the leak test medium.

When you are confident that the scope is leak-free, manually scrub all valves and channels to loosen debris.

If you do not see bubbles, submerge the entire scope in the detergent and continue looking. Note that video scopes require soaking caps to be in place in order to protect the electrical contacts. If you still don't see any bubbles, proceed with the cleaning process. If you do, stop immediately, since any additional handling could further compromise the scope. We dry the scope and place it in a bright red bag or other container to identify it as not having been disinfected and to take it out of circulation. Then we send out the damaged endoscope to be repaired.

To prevent the accidental punctures that can cause leaks, instruct your staff to maintain short fingernails and remove all jewelry from their hands when handling the endoscopes, since any sharp or jagged edge can easily tear the rubber.

Step 3: Do Manual Cleaning
When you are confident that the scope is leak-free, the next step is to sponge and brush the scope inside and out. Remove and scrub all valves and use a long brush to scrub the channels and loosen debris adhering to the interior of the scope. It's critical to be thorough-any remaining debris may shield underlying microorganisms from the chemical germicide during the automatic reprocessing step. I alternate between brushing and suctioning. You should perform a visual inspection to determine when the manual cleaning process is complete (i.e. scrub the channels until the brush comes back clean). Note that certain channels on the endoscope may require special cleaning adapters (e.g. elevator channel for duodenoscopes).

I have found that using multiple-use brushes for manual cleaning is more cost-effective than using disposable brushes. To clean them, I place them in the automatic flexible endoscope reprocessor along with the scope. If you prefer single-use brushes, do not try to reprocess them-they may not hold up for more than one use.

Step 4: Reprocess
After manual cleaning, place the scope along with any multiple-use brushes in an automatic flexible endoscope reprocessor. Attach all channel adapters per the manufacturer's instructions. Our reprocessor washes the devices with an enzymatic detergent for four minutes, rinses them, and then soaks them for 20 minutes in a solution of 2% 14-day glutaraldehyde at 20?? ?C (i.e. room temperature). This chemical has been shown to effectively kill all vegetative bacteria, viruses, fungi, and mycobacteria, although not necessarily all bacterial spores. It is compatible with nearly all endoscopes. After disinfection, the reprocessor rinses the scopes again to remove the glutaraldehyde residue, and finishes with an air-dry cycle.

Attach the scope to an automatic flexible endoscopy reprocessor for high level disinfection.

Some centers use 28-day glutaraldehyde; I prefer 14-day because it does not contain surfactant. Twenty-eight day products usually contain surfactant and should be avoided; surfactant is difficult to rinse from the endoscope and so may result in clogged or blocked channels.

There is some debate over how long the scope should be immersed in the glutaraldehyde and whether or not the solution needs to be heated. I don't think it's necessary to soak the scope for longer than 20 minutes. Longer soak times are usually required for items that haven't been manually pre-cleaned, but in our center that's not an issue. In fact, you should always manually pre-clean your endoscope before the automatic reprocessing begins; automatic reprocessors alone are not always sufficient for removing organic debris. I also don't feel it's necessary to heat the glutaraldehyde solution. While it's true that elevating a disinfectant's temperature increases its biocidal properties, many studies1 have indicated that you can achieve adequate high-level disinfection of pre-cleaned items without doing so.

You can use the glutaraldehyde solution multiple times; however, you must test its minimum effective concentration every day. You can obtain chemical indicator testing strips from the maker of the solution; by dipping the strip in the solution and comparing the color change with a color key chart, you can determine whether the solution is still viable. I don't recommend using the solution for longer than two weeks, even if the testing strips indicate that it is still viable. Additionally, the quantity of treated endoscopes will lower the liquid chemical germicide's concentration by diluting the solution with residual rinse water; you should monitor how many times the solution was used. This will aid in your determining when to discard the germicide.

Step 5: Drying

After the air-dry cycle has stopped, purge all of the endoscope's channels with a 70% alcohol solution to aid in drying and to remove any microorganisms that may have been in the rinse tap water. Some centers purify the rinse tap water through a bacterial filter, but the alcohol rinse is nevertheless still necessary-in addition to killing most potentially pathogenic waterborne microorganisms, it facilitates drying. You can either manually flow the alcohol throughout the endoscope, or you can use the automatic reprocessor to flush the scope's channels. Finish drying by forcing air through the endoscope. You can do this one channel at a time by attaching an airflow device directly to an endoscope channel, or by forcing air through all of the channels simultaneously by using the automatic reprocessor. The reprocessor, which is still attached to all of the endoscope's channels from step 3, is capable of forcing air through the instrument. However, it is usually not sufficient by itself to fully dry the internal channels. It is essential that the endoscope dries thoroughly-any remaining moisture could allow bacteria to colonize. We use the alcohol purge and air dry after every cleaning cycle, regardless of whether or not we will be using the endoscope again that day.

Step 6: Storage
When the endoscope is not being used, it is vital that the instrument be stored in such a manner as to maintain its disinfected state. Here are a few tips on how this can be accomplished:

- Store the scope so it hangs straight down-keeping it coiled could allow moisture to pool instead of passing through the scope, thus allowing bacteria to colonize.
- Remove the scope's control valves to permit adequate airflow and prevent condensation.
- Store the scopes in a clean, dry cabinet (a padded cabinet may help minimize the risk of damage during storage).

Cleaning and care of endoscopes is an area that is fraught with misconceptions and debate, but this six-step process has served us well in avoiding complications. With a few minor modifications, you should be able to adapt this method to serve your center as well, resulting in optimal endoscope reprocessing.