Disinfection and Sterilization Update


ICT speaks with experts charged with streamlining disinfection and sterilization practices to take a look at whats new today and what to watch for in 2007 and beyond.

Associations such as the International Association of Healthcare Central Service Materiel Management (IAHCSMM), the American Society for Healthcare Central Service Professionals (ASHCSP), and the Association for the Advancement of Medical Instrumentation (AAMI), to name a few, have been working feverishly over the years to make disinfection and sterilization practices safer and more efficient for both healthcare personnel and their patients. Many initiatives from these groups have occurred recently and still more are on the horizon.

Stephen M. Kovach, BS, director of education for Healthmark Industries and co-author of the cleaning, decontamination, and disinfection chapters that will be part of the new IAHCSMM Technical Manual due out this fall, points to three new standards/ guidelines that he says will improve practices:

  • ANSI/AAMI ST79 Comprehensive guide to steam sterilization and sterility assurance in healthcare facilities 

  • AAMI TIR 12 Designing, testing, and labeling reusable medical devices for reprocessing in healthcare facilities: A guide for medical device manufactures 

  • ASTM D7225-06 Standard guide for blood cleaning efficiency of detergents and washer-disinfectors 

Together these new and updated standards and guidelines help the users do a better job in the areas of disinfection and sterilization and provide guidance in how to verify many of their processes, Kovach says. The ANSI/AAMI ST79, released this year, covers steam sterilization in a comprehensive manner. The new standard updates and combines the following documents:

  • ANSI/AAMI ST 46 Steam sterilization and sterility assurance in healthcare facilities 

  • ANSI/AAMI ST42 Steam sterilization and sterility 

  • ANSI/AAMI ST42 Steam sterilization and sterility assurance using table-top sterilizers in office-based, ambulatory care medical, surgical, and dental facilities 

  • ANSI/AAMI ST37 Flash sterilization: Steam sterilization of patient care items for immediate use 

  • ANSI/AAMI ST35 Safe handling and biological decontamination of medical devices in healthcare facilities and in non-clinical settings 

  • ANSI/AAMI ST33 Guidelines for the selection and use of reusable rigid sterilization container systems for ethylene oxide sterilization and steam sterilization in healthcare facilities 

The new recommended practice provides a resource for all healthcare practitioners who use steam for sterilization and serves as a comprehensive guideline for all steam sterilization activities in healthcare facilities regardless of the size of the sterilizer or the size of the facility, according to Susan Klacik, CRCST, corporate director of sterile processing for Forum Health and an IAHCSMM alternate representative to AAMI. Klacik also authored the redesigned chapter on steam sterilization in the new IAHCSMM CS Technical Manual.

The ISO Technical Committee 198 will present harmonized international standards for traditional sterilization methodologies, namely: radiation, ethylene oxide (EO), and moist heat, according to Charles O. Hancock, RAC, BSEE, MBA, a medical device sterilization consultant and founder of Fairport, New York-based Charles O. Hancock Associates Inc. Hancock, an active member of sterilization standards committees and working groups including ISO, AAMI, and CSA, says these standards will have the format and organization of ISO 14937, and general requirements for characterization of a sterilizing agent and the development, validation, and routine control of a sterilization process for medical devices. This will eventually allow comparison of critical aspects of traditional and nontraditional (those not standardized) sterilization processes, he says.

Also, there is an initiative by the American National Standards Institute (ANSI) and AAMI to finally have a maximum set weight of 25 pounds, according to David Narance, RN, BSN, CRCST, manager of sterile reprocessing for MedCentral Health System in Mansfield, Ohio and co-author of the cleaning, decontamination, and disinfection chapters of the upcoming IAHCSMM Technical Manual. Set weights, especially with loaner sets, can be up to 35 pounds, and this amount of mass is very difficult to sterilize and it presents a risk of injury to central service staff during handling and transfer, he explains.

Of further interest, Kovach points out that there is a water quality document that is in draft form at AAMI right now. This document will help the users better understand the role water quality plays in their overall sterilization/disinfection process, he says. In addition, Kovach points out the AAMI EO document also is being reviewed and updated.

Finally, according to Martell Winters, BS, RM/SM (NRM), study director/consultant with Nelson Laboratories, Inc., AAMI is developing a number of new TIRs for the medical device industry. These include radiation sterilization of human tissue; polishing or adjunct processing of products (adding sterility assurance by including a sub-sterilization dose or cycle); and disinfection/sterilization of BSE/TSE (bovine spongiform encephalopathy/transmissible spongiform encephalopathy) agents.

Market Response

Hancock shares that means of measuring cleaning and disinfection status are currently being explored and this progress may be expected to achieve quantifiable results with meaningful and usable tools for the user becoming available commercially.

With so much being written recently on understanding cleaning and its importance in the overall process of sterilization/disinfection, the verification of the cleaning process, in my view, will be an area to watch, Kovach adds. He too says users will see new products for verification of the cleaning process, including those for endoscopes and other medical devices, and he says there is a growing recognition that test soils need to be developed that correlate to what is on the items.

The next area of focus will be in surface disinfection, he says. Many new advancements are taking place in this area and one is from a company called George Enterprises LLC in Michigan; they have a new technology for surface disinfection. The formulation contains materials that are affirmed as GRAS (generally recognized as safe), e.g., food-grade, to protect against possible misuse by the consumer. The technology relates to an aqueous food-grade formulation consisting of solubilizing agents and reactive compounds. It is inexpensive, does not itself contain or produce adverse health effects, is stable, and is fast acting by simply spraying it at room temperature on the contaminated area.

He also mentions a Canadian company named Virox that is looking at hydrogen peroxide- based detergents with germicidal properties. These are just two of the many advancements taking place in surface disinfection, he adds. 

Penny Sabrosky, BS, CSPDT, clinical manager at Hackley Hospital in Muskegon, Mich., and president of ASHCSP, says the market is always surprising the industry with new products. Solutions for disinfection are coming with multiple enzymes, lighter weight containers to reduce workplace injuries, and concentrated products to last three-to-five times longer than typical non-concentrates, she points out. These detergents are working more than ever with automated equipment to provide a superior clean. There are even products that can be placed through the wash/decontamination cycle to provide information on whether your automated washer equipment is running to maximum potential.

New sterilization technologies are also emerging, she explains. For previous decades, it was impossible to sterilize flexible scopes in a timely fashion. It is now possible to sterilize flexible scopes in less than a half hour with the Sterrad NX. Production of this piece of equipment is reaching peaks and heights. The wrapped, sterile product can be placed on the shelf. A huge advantage compared to the traditional sterilization method commonly used on the market.

Another move from traditional sterilization practices is the advent of ozone sterilization technology. This low temperature (less than 98 degrees F, in fact) surface sterilization uses a highly effective oxidative process and is cleared as a general purpose sterilizer.

Nancy Shoop, BSN, RN, CGRN, clinical specialist at TSO3 Inc., says the ozone sterilization process is safer and more environmentally friendly. She explains the process, You use medical-grade oxygen and you put it into the sterilizer and it goes into a generator that produces electricity that breaks the oxygen molecules apart. When they are broken apart, those single molecules attach to other oxygen molecules and become O3, which is ozone. Ozone, a highly effective sterilant, then goes into the chamber and we add a little bit of filtered water to give it a touch of moisture and it sterilizes the instruments. Then the ozone and moisture goes back through a catalytic converter and goes right back to oxygen and water, so it is very safe.

There is no toxic residue. It is also very safe because the chamber is sealed under vacuum through the entire process so there is no way the ozone can get out into the room. You buy no sterilant, and you have nothing to dispose of.

TSO3 Inc. received Food and Drug Administration (FDA) 510(k) clearance on its MODEL 125L named after its 125-litre/4.3-cubic-foot capacity in the fall of 2003. This summer, the FDA granted TSO3 clearance on expanded lumen claims.

Ozone is a very economical approach to sterilization, Sabrosky adds. This equipment can sterilize multiple items at one time for less than a dollar per cycle. It does not use toxic chemicals, and the cycle cost is less than a dollar per load. As more and more equipment is approved for this process, the more hospitals will realize the cost savings they can benefit from.

She continues, I have high aspiration to see EO completely eliminated within 10 years. With safer sterilization methodologies available, it is imperative that healthcare systems begin to take this into consideration. Although a concern for the worker exposure is of utmost concern, there should also be a consideration for the global effort to make our environment safer and less hazardous whenever possible.

Winters says NovaSterilis is developing a new sterilization system involving supercritical CO2, and that some companies are looking at chlorine dioxide as a sterilization option for medical devices.

As far as EO is concerned, Winters says that many contract sterilizers are implementing allin- one sterilization systems (preconditioning, sterilization, and outgassing) all in their sterilization chambers. For radiation, new VDmax tables are being published for 15-35 kGy in 2.5 kGy increments in a new document TIR 33. Also, he says the new 11137 series of standards are available, some of them with new guidance which was not in the previous versions.

As mentioned briefly above, Narance says one technology driver will be water and energy efficiencies. I would be looking for new washer technology to address water and energy concerns, he says. Several manufacturers are offering energy saver technology that should be considered whenever replacing existing or adding to central service/reprocessing departments.

All in all, Hancock says that while the industry can be on the lookout for exciting new cleaning technologies in the future, we will also see dedicated process equipment designs which address individual medical device sterilization challenges.

The Challenges

Were always dealing with misunderstandings and misinterpretations of sterilization and disinfection practices, Winters asserts. Such examples include the challenges of gathering the correct instructions and information from manufacturers and knowing the differences in sterilization cycle times for varying loads. While it is commonly recommended that the manufacturer be referred to for best practices, some are not answering the needs of the CS community. There seems to be a lack of information from manufacturers on proper sterilization instructions or the information they provide is not always clear to even the sterilization experts in the field, Sabrosky asserts. More and more products are coming from other countries with sterilization instructions that are foreign or with products that are not even allowed in the United States. I see a lot of these instruments that are used with radiation oncology procedures and radiology procedures. Clinical resources, when called, are often hard to understand or quite often tell you to sterilize in the normal fashion or refer to your sterilizer manufacturer (who in turn refers you back to the product manufacturer).

Another concern is the containers that manufacturers provide to sterilize instruments and implants. They are bulky, heavy, and break through the sterilization wrapper because of poor design. It is becoming increasingly harder to make sure a wrapped tray keeps its integrity throughout the sterilization process without having a breakthrough on the wrapper.

In addition, many instruments are just plain difficult to clean. Narance says it seems that the ability to clean an instrument effectively is dependent upon the experience and the knowledge of the person tasked with cleaning the instrument. Many cleaning/sterilization failures are a result of a lack of knowledge, he points out. Whenever any new instrument or set is brought into the facility, the CS staff should be instructed by the vendor on the safe handling and decontamination of the device prior to first use, he offers.

The second example involves extended cycle times. Kovach says that sterilization times with the orthopedic trays are one of the hot issues of today and really needs to be addressed. Many CS departments are having a difficult time with the different cycles, he explains, adding that there is a real need for products that can be used to monitor the extended cycles needed. Narance explains further. The traditional four minutes in a pre-vac at 270 degree F may not be a valid cycle for many neurological and orthopedic implant trays and instrument sets. Many of the sets are extended by the various manufacturers to anywhere from six minutes to 10 minutes, and we need to press the vendors to supply this information when these sets are brought in, he explains. Failure to recognize and address this, and a failure to adjust our sterilization cycle values to meet the manufacturers recommendations, will place patients and staff at risk, he asserts.

Klacik points out that standard sterilization times using the AAMI standard cycle times have been used to sterilize all medical devices, but different devices require differing protocol. Some manufacturers are now requiring extended cycle times due to the density and configuration of medical devices such as power equipment, saws, and drills, to name a few. Some of the extended times are based on the weight and configuration of a containment device such as the orthopedic loaner sets we routinely see.

Klacik says that the design and materials of some of the newer medical devices are challenging to clean and sterilize because some of the devices are complex to disassemble, clean, and re-assemble. Also, the weight and design of some of the loaner instrument trays make them difficult to decontaminate and sterilize. There is a whole array of containment devices (loaner trays) in use. They could be plastic, metal, or a combination of both. Some are single-layered; others are multi-layered. Multi-layered trays could be layered so that each layer could be removed from the set for use and cleaning. Based on the design or material of the containment device (loaner tray), the sterilization exposure or dry cycle may be required to be extended.

Winters says some people are trying to develop ways to optimize and reduce sterilization cycles or come up with new sterilization modalities to accommodate for these new combination devices.

Fighting Lurking Pathogens

The unfortunate reality of persistent, lurking pathogens on various medical and surgical devices remains a true challenge. Whats worse is Kovach says he believes we will continue to hear about new emerging pathogens. I cannot say what they will be but I feel if people follow the guidelines and have a quality process in place they should be able to handle what comes down the road. Hospital staff in all areas need to network and be informed on what is going on, not only in their area of work but in others because we all overlap.

For now, Kovach explains it is much of the same concerns that remain. We still have TSE, or prion diseases. Examples include Creutzfeldt- Jacobs Disease (vCJD) in humans and BSE in cattle. How we clean, sterilize/disinfect items infected by these diseases is still up for debate. Not everybody is following WHO (World Health Organization) recommendations, he says.

Recent findings with respect to the inactivation of prions are a concern, as Hancock points out, adding that methicillin resistant Staphylococcus aureus (MRSA) concerns seem to indicate a potential breakdown in established discipline within healthcare facilities or perhaps lapses in generally accepted and long-standing effective practices.

Narance says that both MRSA and vCJD present challenges to the central service department. Communication is a key factor, he offers. The user departments (customers) need to inform CS staff of any concerns and risks. As always, everything needs to be treated with respect treat everything as potentially pathogenic, and do diligence in the cleaning process.

Disinfection and sterilization are dynamic topics that are continuously being advanced from many fronts from the manufacture of products, new guidelines and standards, to consumer awareness. Today, mandatory certification is another such advancement industry professionals are hoping for. Narance says he believes that the recent passage in New Jersey for mandatory certification is a forecast for the future.

The job of processing instruments for use in a sterile field is extremely important, and should only be done by well-trained and knowledgeable staff, he says. Gone are the days of the glorified dishwasher. The central service staff are the experts in decontamination and sterilization, and should be respected as the first line of defense in prevention of infection. Certification will help to foster this respect, and it will serve as a means to measure competence within the field. Competent staff members excel at customer service and are valued members of the infection control and risk management team.

Hancock agrees that nothing can take the place of education and adhering to standard protocol. Everyone is looking for a silver bullet to solve their problems. No one, it appears, wants to strictly adhere to the known disciplines required to effectively reprocess reusable medical devices. Ongoing, continuous education will be required to train new personnel and keep old hands current with new technologies, he offers.

Kovach makes a good point when he says that people need to remember that disinfection/ sterilization is not just a one-step process. It is part of a circle that interacts. If you clean an item properly and sterilize it properly and have checks and balances in your system and somebody puts the sterilized item under their arm to deliver it to the end user, everything up to that point was for naught. The role of training and being responsible for your actions has to be stressed at all times.

Doing the right thing all the time regardless is very important. Henry Ford is attributed with this quote on quality: Quality means doing it right when no one is looking.

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