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By Nancy Chobin, RN, CSPDM
Chemical Disinfection and Sterilization UpdateEveryone isconcerned about improving patient outcomes. One area of concern is surgical siteand nosocomial infections. A review of some of the practices for chemicaldisinfection and sterilization follows, as well as what is new in these criticalareas.
There are three levels of disinfection: low level, intermediate level andhigh 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 bacteriumTB and some small numbers of spores.
Hierarchy of Microbes
The major change in the hierarchy of microorganisms is that we now mustinclude prions on the list and they take the place at the top, nudging sporesout of the top position. This is because prions require additional sterilizationexposure time, more so than spores.
|Prions||Extended sterilization times|
|Mycobacteria (TB)||High-level disinfection|
|Non-lipid/sm viruses||Intermediate-level disinfection|
|Vegetative bacteria||Low-level disinfection|
|Lipid/med. size viruses (HBV,HIV)||Low-level disinfection|
General Disinfectant Guidelines
Items must be thoroughly cleaned following the device manufacturer's writteninstructions for cleaning. Careful measurement of the disinfectant is important;the disinfectant as well as the water must be measured to ensure correctdilution.
There is much discussion about water quality and its impact on thedisinfection process. The quality of your water should be checked forimpurities, minerals, salts, etc. The temperature can also affect the process;some disinfectants work faster in elevated temperatures. However, this shouldnever be attempted unless the disinfectant manufacturer has provided specificguidelines 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. Thisproduct has many benefits, including a 12-minute high-level disinfection soaktime (note that the manufacturer recently received Food and Drug Administration(FDA) clearance for a five-minute high-level disinfection soak time when theproduct is used in automated endoscope reprocessors which can elevate thetemperature. This is the only situation in which the five-minute soak time iscleared to be used). As with any product, strict compliance with themanufacturer's instructions is needed. This product is non-forgiving in terms ofstaining protein; therefore, if the device is not properly cleaned, the proteinsoils will stain gray. This is a benefit. If the product is not thoroughlyrinsed off, the skin can also be stained; however, thorough rinsing ofglutaraldehydes was always a recommendation to ensure removal of alldisinfectant residues.
When using high-level disinfectants, the quality of the rinse water is anissue, as it can re-contaminate the device; therefore, you should know yourwater quality by having it tested.
All high-level disinfectants need to be tested for the efficacy of thesolution. This is known as minimum recommended concentration (MRC). MRC testingshould be performed daily, whenever the disinfectant is in use. The test stripsprovided by the disinfectant manufacturer are preferred for testing. All testingshould conform to the manufacturer's written instructions and all resultsdocumented. Solutions can become inactive before their stated expiration date.Manufacturers list a shelf date on the container (date the chemical must be usedby; this will vary by manufacturer). In addition, the disinfectant will have astated use life (e.g., 14 days). However, the product can become ineffectivebefore the use-life due to excessive water retained by items immersed in thedisinfectant. The expiration date of the solution when prepared/opened, shouldbe clearly indicated on the disinfectant basin/container.
All devices processed in high-level disinfectants for use on patients shouldbe documented on a log form (similar to a sterilization log) to verify the itemswere processed. These records should be saved with the records of the MRCresults.
As with all disinfectants, all surfaces of the device must make contact withthe disinfectant. All channels must be open and free of air, which can interferewith the action of the chemicals.
Read the product label for use and water restrictions (e.g., distilledwater). Read all safety information and always use chemicals in awell-ventilated area. Read and refer to the material safety data sheet for theproper personal protective equipment (this is especially true of gloves) becausesome 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 WorldHealth Organization (WHO). However, even one exposure to bleach can ruinsurgical instruments. Unless you plan to discard the instrument anyway, exposureto bleach or sodium hydroxide (the other chemical recommended by the WorldHealth Organization (WHO) for use on instruments exposed to prion disease) isnot 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 ofsterile products. This has caused the CS/SP departments to make some changes inhow we perform our jobs.
As with all sterilization processes, strict compliance with the devicemanufacturer's written instructions for processing must be followed. Inaddition, the sterilizer manufacturer's instructions for use of the sterilizermust also be followed.
The FDA recommended changes in the spores used to challenge sterilizers.During 2002, the spores used were changed from Bacillus Stearothermophilus toGeo Bacillus Stearothermophilus and the Bacillus Subtilis spore was switched toBacillus Atropheus.
The Association for the Advancement of Medical Instrumentation (AAMI)identified the five categories of chemical indicators as listed by the FDA:
A Major Challenge
A major issue facing CS/SP managers today is complying with the devicemanufacturer's instructions for processing. Having recently completed obtainingall manufacturer's written instructions for processing the numerous devices inour of our facilities, it quickly became apparent that unless CS/SP departmentsare obtaining this information, our patients can be put at risk of not receivinga device that would be considered safe for use.
Some examples are:
Once the manufacturer inserts this information in the packet insert, themanufacturer is off the hook. It is the direct responsibility of the CS/SPmanager to obtain this information and make sure it is disseminated to the CS/SPstaff for compliance.
This is a time-consuming job. In addition, some manufacturers have providedinstructions for cycles that are not used in CS/SP. For example, onemanufacturer provided instructions to sterilize their device as follows: Gravitydisplacement cycle 270 degrees F - 20 minutes - Wrapped.
The CS/SP departments use gravity displacement at 250 degrees F. After manytelephone conversations I contacted the FDA. I did so because in 1995 the FDArequired all device manufacturers to provide specific processing instructions toend-users. Since the manufacturer gave me a cycle I could not use (thesterilizer manufacturer did not validate the particular cycle) I contacted theFDA. After their intervention, the device manufacturer was able to locatepre-vacuum steam instructions for me (which, incidentally, identified aneight-minute exposure time for this device at 270 degrees F, pre-vacuum). Insome of our facilities, small sterilizers are being purchased just to run theitems requiring "special cycles" so as not to tie up a largesterilizer for these selected items.
There have not been any new sterilization methods introduced to the CS/SPprofession since the early 1990s when low-temperature gas plasma came onto themarket. Since that time, the low temperature gas plasma (STERRAD)system has shortened its cycle time to approximately 50 minutes. This is atremendous advantage for healthcare facilities that must quickly turn aroundoperating rooms and require processing of expensive devices for to-follow cases.
The low-temperature gas plasma sterilization process still has restrictionson lumen diameter and length, which limits some devices from being processed inthis system.
The STERIS system continues to meet a need in the surgicalsuite for immersible devices that need to be sterilized in between cases. Thisis a just-in-time process and should be located as close to the point of use aspossible. Devices processed in this system should also be documented on a logform and these records retained with the facility's other sterilization records.
CS/SP managers face issues concerning rigid containers and organizing casesprovided by specialty device manufacturers. The AAMI is developing a newdocument for manufacturers of these devices to ensure they are designed andtested for the instruments and devices that are being processed within them. Atissue is the fact that prior to discussions with the FDA, some manufacturers ofthese containers/cases had not validated their use with devices having lumens orspecialty devices such as power equipment. It is important that the CS/SPmanager obtain written documentation from these manufacturers regarding whatdevices have been tested for use inside of them.
Another issue is the multi-tiered trays (often with heavy orthopedic or neuroinstruments) that are in plastic cases. These cases are very difficult to drybecause the plastic does not retain heat as well as the metal cases. In manyinstances, 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 1of 3, part 2 of 3, etc.
Nancy Chobin, RN, CSPDM, is CS/SPD educator for the Saint Barnabas HealthCare System in New Jersey.