Infection Control Today - 06/2003: Improving Patient Outcomes

Improving Patient Outcomes

By Nancy Chobin, RN, CSPDM

Chemical Disinfection and Sterilization UpdateEveryone is concerned about improving patient outcomes. One area of concern is surgical site and nosocomial infections. A review of some of the practices for chemical disinfection and sterilization follows, as well as what is new in these critical areas.

There are three levels of disinfection: low level, intermediate level and high level. Environmental disinfectants usually are low and intermediate level. Disinfectants used for patient-care devices (e.g., flexible fiber optic scopes) require high-level disinfection. High-level disinfectants inactive the bacterium TB and some small numbers of spores.

Hierarchy of Microbes

The major change in the hierarchy of microorganisms is that we now must include prions on the list and they take the place at the top, nudging spores out of the top position. This is because prions require additional sterilization exposure time, more so than spores.

Microbe: Requires:
Prions Extended sterilization times
Spores Routine sterilization
Mycobacteria (TB) High-level disinfection
Non-lipid/sm viruses Intermediate-level disinfection
Fungi Intermediate-level disinfection
Vegetative bacteria Low-level disinfection
Lipid/med. size viruses (HBV,HIV) Low-level disinfection
Source: Block SS,3 modified to add prions)

General Disinfectant Guidelines

Items must be thoroughly cleaned following the device manufacturer's written instructions for cleaning. Careful measurement of the disinfectant is important; the disinfectant as well as the water must be measured to ensure correct dilution.

There is much discussion about water quality and its impact on the disinfection process. The quality of your water should be checked for impurities, minerals, salts, etc. The temperature can also affect the process; some disinfectants work faster in elevated temperatures. However, this should never be attempted unless the disinfectant manufacturer has provided specific guidelines about how this is accomplished.

Today, many facilities have switched to the non-glutaraldehyde based, high-level disinfectant, Ortho-phthaldehyde (0.55 percent) Cidex OPA. This product has many benefits, including a 12-minute high-level disinfection soak time (note that the manufacturer recently received Food and Drug Administration (FDA) clearance for a five-minute high-level disinfection soak time when the product is used in automated endoscope reprocessors which can elevate the temperature. This is the only situation in which the five-minute soak time is cleared to be used). As with any product, strict compliance with the manufacturer's instructions is needed. This product is non-forgiving in terms of staining protein; therefore, if the device is not properly cleaned, the protein soils will stain gray. This is a benefit. If the product is not thoroughly rinsed off, the skin can also be stained; however, thorough rinsing of glutaraldehydes was always a recommendation to ensure removal of all disinfectant residues.

When using high-level disinfectants, the quality of the rinse water is an issue, as it can re-contaminate the device; therefore, you should know your water quality by having it tested.

All high-level disinfectants need to be tested for the efficacy of the solution. This is known as minimum recommended concentration (MRC). MRC testing should be performed daily, whenever the disinfectant is in use. The test strips provided by the disinfectant manufacturer are preferred for testing. All testing should conform to the manufacturer's written instructions and all results documented. Solutions can become inactive before their stated expiration date. Manufacturers list a shelf date on the container (date the chemical must be used by; this will vary by manufacturer). In addition, the disinfectant will have a stated use life (e.g., 14 days). However, the product can become ineffective before the use-life due to excessive water retained by items immersed in the disinfectant. The expiration date of the solution when prepared/opened, should be clearly indicated on the disinfectant basin/container.

All devices processed in high-level disinfectants for use on patients should be documented on a log form (similar to a sterilization log) to verify the items were processed. These records should be saved with the records of the MRC results.

As with all disinfectants, all surfaces of the device must make contact with the disinfectant. All channels must be open and free of air, which can interfere with the action of the chemicals.

Read the product label for use and water restrictions (e.g., distilled water). Read all safety information and always use chemicals in a well-ventilated area. Read and refer to the material safety data sheet for the proper personal protective equipment (this is especially true of gloves) because some chemicals require special gloves (e.g., butyl rubber).

There are still too many facilities using bleach on surgical instruments. Some of this is a reaction to the CJD recommendations published by the World Health Organization (WHO). However, even one exposure to bleach can ruin surgical instruments. Unless you plan to discard the instrument anyway, exposure to bleach or sodium hydroxide (the other chemical recommended by the World Health Organization (WHO) for use on instruments exposed to prion disease) is not recommended.

Sterilization: Just When You Thought Things Had Stabilized ...

The greatest impact on the central supply/sterile processing (CS/SP) profession came with the FDA recognition of our departments as manufacturers of sterile products. This has caused the CS/SP departments to make some changes in how we perform our jobs.

As with all sterilization processes, strict compliance with the device manufacturer's written instructions for processing must be followed. In addition, the sterilizer manufacturer's instructions for use of the sterilizer must also be followed.

The FDA recommended changes in the spores used to challenge sterilizers. During 2002, the spores used were changed from Bacillus Stearothermophilus to Geo Bacillus Stearothermophilus and the Bacillus Subtilis spore was switched to Bacillus Atropheus.

The Association for the Advancement of Medical Instrumentation (AAMI) identified the five categories of chemical indicators as listed by the FDA:

  • Class 1: Process indicators which identify if the device has been through a particular process.
  • Class 2: Indicators for specific tests (e.g., Bowie-Dick).
  • Class 3: Single-parameter indicators (designed to react to one of the critical parameters and to indicate exposure to a sterilization cycle at a stated value of the chosen parameter).
  • Class 4: Multi-parameter indicators (designed to react to two or more critical parameters of the cycle).
  • Class 5: Integrating indicators (designed to react to all critical parameters over a specified range of sterilization cycles; the performance is correlated to the performance of a BI under the same conditions of use.2

A Major Challenge

A major issue facing CS/SP managers today is complying with the device manufacturer's instructions for processing. Having recently completed obtaining all manufacturer's written instructions for processing the numerous devices in our of our facilities, it quickly became apparent that unless CS/SP departments are obtaining this information, our patients can be put at risk of not receiving a device that would be considered safe for use.

Some examples are:

  • Orthopedic screws/plates requiring eight minutes of exposure at 270 degrees F. (pre-vac)
  • Orthopedic loaner sets requiring 15 to 35 minutes of exposure at 270 degrees F (pre-vac)
  • Cath lab cables requiring five to seven days of aeration at 130 degrees F.
  • Limits on the number of times a device can be re-sterilized making it necessary to track the usage of the device.

Once the manufacturer inserts this information in the packet insert, the manufacturer is off the hook. It is the direct responsibility of the CS/SP manager to obtain this information and make sure it is disseminated to the CS/SP staff for compliance.

This is a time-consuming job. In addition, some manufacturers have provided instructions for cycles that are not used in CS/SP. For example, one manufacturer provided instructions to sterilize their device as follows: Gravity displacement cycle 270 degrees F - 20 minutes - Wrapped.

The CS/SP departments use gravity displacement at 250 degrees F. After many telephone conversations I contacted the FDA. I did so because in 1995 the FDA required all device manufacturers to provide specific processing instructions to end-users. Since the manufacturer gave me a cycle I could not use (the sterilizer manufacturer did not validate the particular cycle) I contacted the FDA. After their intervention, the device manufacturer was able to locate pre-vacuum steam instructions for me (which, incidentally, identified an eight-minute exposure time for this device at 270 degrees F, pre-vacuum). In some of our facilities, small sterilizers are being purchased just to run the items requiring "special cycles" so as not to tie up a large sterilizer for these selected items.

An Update

There have not been any new sterilization methods introduced to the CS/SP profession since the early 1990s when low-temperature gas plasma came onto the market. Since that time, the low temperature gas plasma (STERRAD) system has shortened its cycle time to approximately 50 minutes. This is a tremendous advantage for healthcare facilities that must quickly turn around operating rooms and require processing of expensive devices for to-follow cases.

The low-temperature gas plasma sterilization process still has restrictions on lumen diameter and length, which limits some devices from being processed in this system.

The STERIS system continues to meet a need in the surgical suite for immersible devices that need to be sterilized in between cases. This is a just-in-time process and should be located as close to the point of use as possible. Devices processed in this system should also be documented on a log form and these records retained with the facility's other sterilization records.

Rigid Containers

CS/SP managers face issues concerning rigid containers and organizing cases provided by specialty device manufacturers. The AAMI is developing a new document for manufacturers of these devices to ensure they are designed and tested for the instruments and devices that are being processed within them. At issue is the fact that prior to discussions with the FDA, some manufacturers of these containers/cases had not validated their use with devices having lumens or specialty devices such as power equipment. It is important that the CS/SP manager obtain written documentation from these manufacturers regarding what devices have been tested for use inside of them.

Another issue is the multi-tiered trays (often with heavy orthopedic or neuro instruments) that are in plastic cases. These cases are very difficult to dry because the plastic does not retain heat as well as the metal cases. In many instances, the only way to achieve drying is by wrapping each layer separately (as three separate trays for the three-tiered trays) and labeling them as part 1 of 3, part 2 of 3, etc.

Nancy Chobin, RN, CSPDM, is CS/SPD educator for the Saint Barnabas Health Care System in New Jersey.

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