Class 6 Emulating Indicators: One Hospital's Journey

Over the past 17 years of my career, I have never scrubbed in on a surgery case, never set up a sterile field, never prepped a surgical site and never opened a sterile package, being ever so diligent to maintain the contents’ integrity. But what I have done is provided sterile instruments and supplies for hundreds of thousands of surgical operations.

When a patient consents to undergo a surgical procedure it is imperative that they have an inherent trust that the clinicians performing the surgery possess the knowledge and skills to provide a successful outcome. They’ve met with the surgeon and discussed the procedure including any complications that might transpire. But what about the instruments? Few patients, if any, put much thought into what instruments will be required and whether or not they will be sterile. Of course they will be sterile, right?

I tend not to discuss my job with family or friends who are not involved in the field of sterile processing since, as we all know, we cannot answer the aforementioned question with a 100 percent certainty. It is not practical to prove that an item processed through a sterilizer is, in fact, sterile. But what we can do is to afford the highest assurance as possible that the conditions required for sterility to occur actually did occur. This is considered the sterility assurance level (SAL) of 10-6. This means that there is less than or equal to one chance in a million that a single viable microorganism is present on a sterilized item. It is generally accepted that this SAL is appropriate for items intended to be used for invasive or surgical procedures. To achieve this level of sterility assurance, sterile processing professionals must employ all physical, chemical and biological monitors available to reduce the chance for a healthcare-acquired infection.

The objective of this article is not to offer a review of all of the SAL monitors that are available nor is it to promote any respective brand. My intention is to discuss the benefits and provide insight into the appropriate use in regards to sterilization process monitoring of a new chemical monitoring device recently approved for use in the United States, Class 6 emulating indicators. Please note, that as is the case with any type of sterilization monitoring device, it is crucial that the manufacturer’s instructions be consulted and followed for appropriate use.

Implementation of Class 6 Challenge Packs

I was approached early last year by a manufacturer of Class 6 emulating indicators and asked to conduct independent in-house testing of their Class 6 indicators on actual hospital sterilizers and compare them to the current biological indicators (BIs) that we were using. The testing was conducted by our own certified technicians and consisted of sterilizing full loads including both a BI challenge pack and a Class 6 challenge pack each according to the manufacturers instructions. We began to abort the respective cycles starting at 2.5 minutes of exposure and continued to reduce by 30 seconds then finally eliminating each subsequent vacuum pulse. The purpose of this test was to determine at what point the BI and Class 6 challenge packs would detect an incomplete or failed sterilization cycle.

At the end of each aborted sterilization cycle, the instruments trays were broken down and reassembled. We then processed the BI and Class 6 according to instructions and recorded the results. The results were astonishing. The Class 6 indicator was able to detect the aborted cycle at 0.5 minutes exposure. The BI did not detect the aborted cycle until after the third vacuum pulse. In other words, had this been a real load being released for surgery, the instruments could have been released based on the results of the BI even though the sterilizer was aborted before even initiating the exposure phase.

Based on the results of our study, I immediately instituted the addition of a class 6 challenge pack on all terminally sterilized prevac steam cycles. It is important to note, at this point, that I did not eliminate any biological monitors. In addition, although the manufacturer clearly indicates that you can use Class 6 emulating indicators for load release, regardless of content, I did not alter our hospitals policy in regards to sterility assurance monitoring. Our policy states that we monitor with a BI daily on all steam sterilizers and with every load including an implant. This policy meets the current recommendation of Association for the Advancement of Medical Instrumentation (AAMI) in regard to steam sterilization process monitoring. By including the addition of Class 6 challenge packs on all loads, we are not only meeting the current AAMI recommendation, but we are exceeding it.

Advantages Realized Due to Class 6 Challenge Packs

According to the manufacturer, Class 6 challenge packs monitor more of the critical sterilization parameters than BIs. BIs are an integral part of your department’s sterility assurance monitoring and should be continued to be used to provide sterilizer validation and qualification after installation and repairs. BIs provide proof that your sterilizer can kill a live bacterial spore and are a fundamental part of your sterility assurance protocol. Elimination of any of the available physical, chemical or biological monitors would not be prudent. However, due to the incubation period of BIs, they can be untimely in routine efficacy monitoring and sterile processing professionals need to explore other monitors such as Class 6 emulating indicators that provide immediate results.

Any sterile processing department would be remiss to state that it has never released a load prior to obtaining the results of a BI. Instrumentation is costly and hospitals can only afford to purchase a finite supply. Given these limited resources results in constant pressure to release instruments immediately upon completion of the sterilization process. Since the results of a BI cannot accommodate this requirement, Class 6 indicators are indispensable in providing immediate cycle-specific results for sterility assurance. No incubation or waiting period is required with Class 6 indicators.

In addition to instant release of loads, the implementation of Class 6 challenge packs has virtually eliminated sterilization load recalls. Since all of our terminal steam loads contain a Class 6 challenge pack providing an immediate result, no items from any failed sterilization cycle ever leave the department. Anyone who has ever attempted to recall instruments from a day to a week prior to a failed BI can attest to the futility of this practice.

Next, the Class 6 challenge packs that my department has adopted possess the ability to detect steam quality issues. Specifically, it will identify poor air removal, presence of non-condensable gas, wet steam or super heated steam. All of these conditions can interfere with your sterilizers ability to perform its intended function and thus render a load unsterile.

Finally, by implementing a Class 6 challenge pack on all prevac steam sterilizer loads, we have established a consistent level of sterility assurance for all critical devices whether or not they include implants. It is essential that implantable devices be sterile given the fact that they will remain in the patient. However, the instruments used to perform any invasive procedure should be given the same level of sterility assurance. If BIs are relied upon to provide the highest degree of sterility assurance for implants then they should be used for all loads and all loads should be quarantined until the results are determined. As we all know, this is not possible. Instrumentation is limited and surgical departments cannot always wait. The Class 6 challenge packs that we are using do provide a proven and reliable SAL with an instantaneous read.

I am not supporting the complete elimination of BI monitoring. BIs are a vital component of your department’s sterility assurance monitoring for sterilizer validation. However, the continued use of a BI does not preclude implementing any other monitoring devices including Class 6 emulating indicators. In addition, the incubation period required for obtaining a BI result renders them unacceptable for routine load monitoring. Sterilization modalities have continued to evolve with time as new technologies have developed. As have surgical procedures and improved instrumentation aimed at providing a better patient outcome. Why then should we not expect to have new, improved advancements in sterility assurance monitoring?

Manufacturers’ instructions state that their Class 6 emulating indicators can be used for immediate release of all loads regardless of content. In addition, they have also been recognized by AAMI, although no specific recommendation for use has been given. Even though Class 6 indicators have been widely accepted and used for years in Europe, it is not surprising that AAMI wants to be prudent before issuing a recommendation. AAMI does, however, specifically state, “As technology progresses, new sterilization process monitoring devices may be cleared by FDA... facilities should rely on the knowledge and expertise of their infection prevention and control, central service, and surgical services professionals in the selection and use of process monitoring devices.”

I would challenge any sterile processing department that is skeptical of the efficacy of the Class 6 emulating technology to contact a manufacturer and ask for a sample to perform your own independent testing. Class 6 technologies is a paradigm shift in sterility assurance monitoring and as AAMI states, each facility must rely on their professionals to at least investigate their benefits as part of your sterility assurance protocol. As a sterile processing professional, you need to be an agent of change and constantly strive to investigate and implement new, innovative methods to prevent surgical site infections. Class 6 emulating indicators are a technological advancement that will continue to allow sterile processing departments to provide a heightened assurance to our patients that the instruments we have processed are, in fact, sterile.

Richard P. Blasko, MBA, CRCST, is director of materials management/clinical processing at Robinson Memorial Hospital and an instructor in sterile processing technology at Cuyahoga Community College.