Speed is a militant force against sterilization," writes John Perkins in Principles and Methods of Sterilization in Health Sciences. Speed reduces the overall factor of safety. It becomes the accomplice of trapped air and dried-on debris. Speed requires a high degree of reliability in functional and mechanical control of all the variables so as to affect a minimum margin of doubt in the end result.

Perhaps nowhere else is speed more of an enemy than in endoscope reprocessing. This is partly because few rigid and even fewer flexible endoscopes can be steam sterilized. Instead, they need to be sterilized or high-level disinfected by various low-temperature chemical processes. Even if you can overnight sterilize by an EtO or plasma system, because instruments may be used four or more times per day, they often must be cleaned and disinfected between patients. Because there is often pressure to speed up the process, facilities may take risky shortcuts.

Contact Dan Mayworm at '[email protected]').

In this article, I'll review what you need to know about how to reprocess rigid and flexible scopes.

Cleaning rigid endoscopes
Rigid scopes, because they are straight, relatively short and primarily metal, are easier to clean and sterilize than flexible scopes. However, the telescopes used in endoscopic surgery are delicate, high-precision and expensive optical instruments that require handling and specific reprocessing techniques. Here are the steps for cleaning a rigid scope.

1. Unless contrary to the manufacturer's recommendations, immediately after use place the scope in a container with an enzymatic cleaner to prevent any soil from drying in or on the scope. Inject enzymatic solution into the lumens to ensure that the solution is in contact with all internal and external surfaces. Then, cover the container and transport it to the decontamination area.

2. Disassemble the scope and wash it in an automatic washing machine designed specifically for this purpose. If you are hand washing in a sink, cushion the sink bottom with a silicone or rubber mat. Use the proper sized brushes for the lumens that you are cleaning. Too large will potentially cause damage to the scope and too small will leave debris behind.

3. Clean the telescope lenses and light post gently with a manufacturer-recommended detergent and a soft, lint-free cloth. Ultrasonic cleaning is usually not recommended.

4. Rinse well under running water. Alcohol may remove some of the adhesive holding the lenses in place; therefore, see if your vendor recommends wiping the lenses with cotton containing isopropyl alcohol to remove any leftover residue. Inspect the telescope image and the clarity of the light post. Hold the telescope up to a bright light to observe the lens image at the distal tip and assess the amount of light projected through the light post. This is a critical step, and you should be trained to be able to make this assessment. Ensure all the parts of the scope are clean and dry before assembly and packaging for sterilization.

5. Package each scope by wrapping it in a protective surgical (lint-free) towel or specially molded open cell foam designed for the type of sterilization you will be using. Better yet are the perforated containers with suspension inserts.

Types of sterilization
Your four choices for sterilization include steam, EtO, gas plasma and peracetic acid.

• Steam sterilization. Rigid scopes that are designed to be heat and moisture stable can be steam sterilized. Some manufacturers do not recommend flash cycles for the scopes because the rapid infusion of pressurized steam for short cycles causes some scope components to expand more than others, causing potential disruption of the optics. This could also happen in some pulsing vacuum systems. Get approval from the scope manufacturer for the type of steam cycle you will be using.
• EtO and gas plasma sterilization. Scopes that are heat and moisture-sensitive can be sterilized with EtO or gas plasma. First, clean, dry and protect them. You can EtO sterilize them in either metal or plastic containers. Gas plasma sterilizers now are approved for lumened devices, but pay particular attention to the device and packaging. Check with the maker before trying to sterilize any device and using any packaging materials not specifically mentioned as safe. EtO cycles can vary between two hours and twelve, plasma cycles between 60 and 90 minutes.
• Peracetic acid sterilization. A fourth sterilization method for heat-stable as well as for heat-sensitive and moisture-stable scopes is liquid peracetic acid. First, clean the scopes and place them in a special cassette for sterilization. Since the scopes are not packaged, this method provides a just-in-time sterile scope for each use. If you are not using the scope immediately, clean, dry and wrap it to protect it from the environment, and then sterilize it just before use.

High-level disinfection
You can high-level disinfect rigid scopes as long as they are moisture stable. Here are my recommendations for high-level disinfection (HLD).

• Scrupulously clean and dry items to avoid contaminating and diluting the HLD solution.
• Ensure that employee exposure to the HLD fumes conforms to OSHA limits. You may have to modify the disinfection area and use evacuation hoods, monitoring badges, etc.
• Follow the total immersion times rigidly, as they vary greatly. Do not extend times to make up for diluted concentrations, as extended times may cause corrosion.
• Monitor and document the solution concentration and change it according to a prescribed protocol.
• Rinse the endoscope in two or three separate sterile water rinses to ensure that all HLD residue has been eliminated. Insufficient rinsing could cause a thin film build-up (biofilm).
• Do not blow-dry after disinfection unless it is in an air-filtered cabinet.
• Solution containers should be steam sterilizable and have tight-fitting covers to control fumes and prevent vaporization. The containers should have some system for cradling the scopes if more than one is disinfected at a time.
• Document use, institute preventive maintenance and audit repair assessments.

Whether you choose sterilization or HLD, remember that producing a safe endoscope requires that you consider the whole processing system rather than focus on the differences between disinfectants and sterilants. A sterilant used within a poorly designed system could produce unsafe endoscopes, while high level disinfectants used within a well-designed process can produce safe, and even sterile, scopes.

Flexible endoscopes
Reprocessing of flexible endoscopes differs from rigid scopes and other surgical equipment primarily because flexible scopes are made of elastomeric materials and have numerous lumens to perform the various functions of irrigating, suction, observing, excising, retrieving, etc. Some of these lumens are exceedingly small, which makes them difficult to clean and disinfect.

Flexible endoscopes cannot be steam sterilized, and very few can be EtO or plasma sterilized. The Steris system is the most widely used sterilization process. Because it is a liquid contact process without packaging and most of what we will say applies to liquid sterilization and HLD, this discussion will be limited to those processes (Steris and HLD) equally with noted exceptions.

The FDA helped determine that initial cleaning, rather than sterilizing or high level disinfection, is the most critical issue. The right time, temperature and concentration of sterilant or disinfectant on inner and outer surfaces will always provide safe and effective devices. Surfaces that are occluded with debris left over from the procedure cannot be disinfected or sterilized no matter how efficient the process.

The following is a small sample of a training skill checklist for endoscope cleaning staff. Only those who can demonstrate competence in each of these skills should manage any part of endoscope reprocessing:

1. Identify types of endoscopes and their intended use.
2. Be able to take apart and reassemble each type of scope that will be used.
3. Identify all the components by name and describe what they do.
4. Demonstrate each step in the cleaning and decontaminating/sterilization procedure, preferably from a printed checklist.
5. State supplies that will be needed and the rationale for each product.
6. Describe protective attire and their rationale for use.
7. Describe in detail the steps to be taken after a scope is used and transported to the cleaning area.
8. States the correct (min/max) time for the enzymatic soak.
9. Describe safety precautions and the functions of exhaust hoods, badges worn, etc. in the processing area.
10. Demonstrate how the automatic cleaning and disinfecting/sterilizing equipment works.
11. If hand cleaning, show how to identify proper brush size for each channel and demonstrate proper channel cleaning techniques.
12. Describe how to check for leaks.
13. Describe rinsing and drying protocol and rationale.
14. Show how to check for proper disinfectant concentration and temperature.
15. Describe proper soaking time and the problems of too short or too long a soak.
16. Describe rinsing and drying protocol and rationale after disinfecting/sterilizing.
17. Describe handling and storage after disinfection/sterilization.

You should spell out all of the above in a procedure manual that has been signed off by the various equipment and supplies vendors and the department supervisor responsible for furnishing safe-to-use scopes.

Equal-standard-of-care
There are some who feel that by sterilizing their scopes overnight each day and then disinfecting them between cases that they violate the code of "equal standard-of-care". This is not true. The Joint Commission has gone on record as saying that occasional sterilization is recommended even though you disinfect between cases. They make the point that "equal" does not mean "the same". By following the above recommendations, you are producing equally safe-to-use scopes regardless of the method used. That's an equal standard-of-care.