OR Best Practices: The Time is Right for Terminal Sterilization

According to experts, there is a definite move toward terminal sterilization in the OR.¹ Terminal sterilization means that a device has been processed in a system that delivers a sterility assurance level of 10^-6 and is packaged in a manner that will preserve its sterility and allow it to be transferred to a sterile operating field without contamination.

Cynthia Spry, RN, MSN, MA, CNOR, co-chair of the working group responsible for the document Comprehensive Guide to Steam Sterilization and Sterility Assurance in Healthcare Facilities NASI/AAMI ST79, recently stated that the “AAMI doesn't recommend flash sterilization or just in time sterilization any more than the CDC does...  It really focuses on terminal sterilization.”¹

This trend toward terminal sterilization, combined with the FDA’s recent requirement that users transition from the STERIS System I* (SS1), a just-in-time processor, may provide an ideal time for facilities to upgrade their technologies to enhance their standard of care in the OR. According to Spry, with terminal sterilization, “…you decrease the risk of contaminated instruments…which is all part of patient safety goals, that is, preventing patient injury.  ...Terminal sterilization is the gold standard. I can think of no reason why one shouldn't transition to it, and now is the perfect time.”¹

Barbara Trattler, RN, MPA, CNOR, CAN, director of clinical information for ASP, agrees. In a recent article in Infection Control Today, Trattler said of the move away from the SS1, “It’s a required transition, and that’s not going to change, so why wait if there is an opportunity to improve a standard of care?  It is an opportunity to move from a just-in-time sterilization practice to terminal sterilization.”²

Advancing the Standard of Care
Achieving this higher standard of care in instrument processing is possible by incorporating low-temperature hydrogen peroxide gas plasma technology for the terminal sterilization of instruments. For the busy surgical environment, this includes the compact STERRAD^® NX™ Sterilization System from ASP, a next-generation sterilizer compatible with a wide range of instruments—including most flexible endoscopes.

Compared with just-in-time processing, where devices emerge wet and unwrapped—with the potential for contamination—and must be used immediately, devices sterilized in the STERRAD^® System emerge dry and wrapped. They can be used immediately or stored for use when needed without requiring additional processing.

The rapid, low-temperature process and ability to sterilize multiple, complete sets of the STERRAD^® System also help facilities increase instrument utilization, potentially reducing the need to buy additional instruments. It also is gentle on instruments and reduces costly damage associated with steam and peracetic acid.^3,4

Easy Transition to Terminal Sterilization
The transition from a wet to dry sterilization process requires protocol changes that can be easily addressed. Installing the STERRAD^® NX™ System is simple—only a dedicated three-phase 208V outlet is needed.  And, because oxygen and water vapor are the only byproducts, no costly plumbing, ventilation, or monitors are required. 

In addition, while updating procedures might seem daunting, switching to the STERRAD^® System will actually simplify instrument processing. Users no longer have to deal with procedures to support the just-in-time process, such as how long devices can remain in the system and not be utilized or reprocessed. In fact, fewer steps are needed with the STERRAD System compared with the SS1. (See Sidebar)

Preparation also is simplified and processing is automated, increasing staff efficiency. Because devices emerge sterile, dry, and wrapped, additional tasks for OR nurses such as preparing instruments for transportation across the sterile field are eliminated.

Change is Good
Recent trends in instrument processing practices and technology advancements have combined to provide healthcare facilities with the unique opportunity to transition from problematic just-in-time sterilization to the gold standard—terminal sterilization—such as provided by hydrogen peroxide gas plasma technology. Healthcare professionals will find that the transition is easy and straightforward. When complete, they will reap the benefits of terminal sterilization in the OR. 

References
1. Sterilization expert offers advice regarding STERIS System 1. EndoNurse. 2010. http://www.endonurse.com/hotnews/cynthia-spry.html. Accessed June 2, 2010.
2. Pyrek K. Spend the System 1 transition time wisely, experts advise. Infection Control Today. 2010. http://www.infectioncontroltoday.com/articles/2010/04/spend-the-system-1-transition-time-wisely-experts.aspx. Accessed July 7, 2010.
3. Heller J. Revising instrument processing practices. AORN. 2001;74(5):716–721.
4. Jacobs P. Advances in low-temperature gas plasma sterilization technology. Infection Control and Sterilization Technology. 1999:17–20.

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IS IT STERILE? Clearing the Confusion About Liquid Chemical Sterilization

The controversy continues for hospitals using the STERIS System 1* (SS1) for “just-in-time” sterilization following the FDA mandate that hospitals transition to a legally marketed alternative. STERIS is offering a new liquid chemical sterilant processing system—the STERIS System 1E* (SS1E). At first glance, this unit might seem a viable alternative, but the use of non-sterile rinse water and the possible exposure of wet, unwrapped devices to the ambient room environment upon removal from the processor have led the FDA to conclude that devices processed in the SS1E cannot be assured to be sterile. 

Non-Sterile Rinse Water
The SS1E utilizes filtration and ultraviolet (UV) irradiation to treat water used to rinse devices at the end of the sterilization phase to remove residual chemical sterilant.¹ The lack of sterility assurance after rinsing recently was highlighted by the FDA:

The rinse water is tap (potable) water that has been filtered and exposed to ultraviolet rays. It is treated to minimize any bioburden that may be naturally occurring in the water. Because the rinse water is not sterile, devices processed using liquid chemical sterilization cannot be assured to be sterile.¹

Healthcare providers and facilities must understand potential issues associated with filtration and UV irradiation. For example, filters do not inactivate microorganisms, but physically trap them. The presence of live organisms on or within the filter raises concerns, since they may eventually penetrate the filter and contaminate the downstream portion of the filter, as well as the water passing through the filter. In this situation, the internal fluid path of the system may become contaminated. In addition, dead organisms on or in the filter may release endotoxins, potentially contaminating the water passing through the filter.^2,3 Additional reprocessing policies also must be established and monitored to ensure that filters are changed.

As a result of issues such as these, while filtration has been utilized in many applications for reduction of bioburden, it has not been generally recognized, including by the FDA, as a sterilization method capable of delivering a 10^-6 sterility assurance level. 

The same is true for UV irradiation, which has been used to treat water in a number of applications but also is not commonly recognized as a sterilization method. According to a May 10, 2010 Webinar presented by STERIS Corp., the SS1E has been shown to inactivate at least 10⁶ MS2 viruses (6-log reduction) as a surrogate for other viruses. As stated by Steris, the 6-log reduction of MS2 is equivalent to a 4-log reduction of adenovirus—the typical requirement for a surface disinfectant rather than a sterilization process.⁴ The result is that sterility cannot be assured for instruments processed in the SSIE, despite the filtration and UV processes.¹

Non-Terminal Sterilization
A second issue associated with liquid chemical sterilization is its inability to provide “terminal sterilization.” It is critical for a sterile device to be packaged in a manner that will preserve its sterility and allow it to be transferred to a sterile field without contamination. With the SS1E, however, devices are exposed to the ambient room environment during transport, providing the opportunity for contamination due to normal microflora found in non-sterile settings. According to the FDA:

The processed devices should be used immediately or stored in a manner similar to that of high level disinfected endoscopes. Users should be aware that currently all liquid chemical sterilant processing systems have the same limitations in that the final devices emerge wet and unwrapped from the processor.¹

Maintaining Device Sterility
Facilities transitioning from the SS1 should carefully evaluate the benefits and limitations of alternate processing technologies to ensure that the best decision is made to support the delivery of a high level of care and protect patient safety. For many facilities, the answer might be to increase the standard of care by achieving terminal sterilization of instruments—the gold standard in instrument reprocessing—such as provided by low-temperature hydrogen peroxide gas plasma sterilization. Instruments processed in ASP’s STERRAD^® Systems emerge sterile, dry, and wrapped, and can be used immediately or stored for later use. The entire suite of STERRAD Systems is founded on the principle of terminal sterilization, and the technology has a solid performance and safety record, with more than 14,000 STERRAD^® Systems installed and more than 60 million cycles performed worldwide to date.

Click here for more information about Maintaining Device Sterility and Terminal Sterilization in the OR Setting.

References:
1. FDA. STERIS System 1E (SS1E) Liquid Chemical Sterilant—K090036. April 5, 2010. http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/DeviceApprovalsandClearances/Recently-ApprovedDevices/ucm207489.htm
2. Block S. Disinfection, sterilization, and preservation. Fifth ed. Philadelphia: Lippincott Williams & Wilkins; 2001.
3. Maintaining Device Sterility. Irvine, Calif.: Advanced Sterilization Products;2010.
4. EN 14476. Chemical disinfectants and antiseptics—Virucidal quantitative suspension test for chemical disinfectants and antiseptics used in human medicine—Test method and requirements (phase 2, step 1). British Standards. 2005:6.

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