At times, nothing can be more polarizing than the discussion of how to reprocess semi-critical and critical devices. I've experienced this first hand as a member of the Reprocessing Subcommittee for the CSA Z314.8-14 standard. A room full of experts with differing opinions on the concept of A0 is something to behold (not quite as good as a fight between siblings mind you), but passion abounds around A0!
This brings me to this week's blog and can devices be chemically sterilized? In keeping with the Talk Clean To Me blog, my focus will be on liquid chemical disinfectants that are registered by Health Canada or by the US FDA for use in reprocessing of semi-critical or critical devices. First, I apologize, definitions by their nature are boring...generally I just hyperlink to avoid making everyone read them but for the purpose of this discussion I need to set the stage:
"A Sterilant is a substance, or mixture of substances, capable of destroying or irreversibly inactivating all forms of microbial life present on inanimate objects, including all forms of vegetative bacteria, bacterial spores, fungi, fungal spores, and viruses, present on inanimate objects. These are also referred to as chemical sterilants or chemosterilants, and include substances which at the time of use are liquids, gases or vapours."
As one would expect, there are approved test methods that a company must use in order to obtain a claim for high level disinfection and chemical sterilization. In Canada, a company can use either a Quantitative Carrier Test (ASTM E2111-12) which provides proof of a 10-6 or greater log reduction against Bacillus subtilis and Clostridium sporogenes the US FDA approved AOAC 966.04 Suture Loop / Penicylinder method in which the spore concentration must be 10-6 or greater and 0 of the 60 carriers can be positive for spore growth. In general, by definition used in Canada and the US, chemical sterilization equals a sporicidal reduction of 6 Logs (10-6).
What does this mean from an application perspective? Well, liquid chemical disinfectants are generally used for reprocessing of heat sensitive devices. Certainly, for non-heat sensitive devices, the gold standard is the use of steam or thermal sterilization where the process can be monitored to verify that the correct time and temperature has been reached in conjunction with the use of biological indicators to verify sterility should be used. However, there are times when access to such devices is impossible and alternative methods for reprocessing needs to be considered and do have a role to play in reprocessing of semi-critical and critical devices.
Why? First, they are effective (they achieve the required 6 Log reduction against bacterial spores). Second, they are approved for sale and use as a sterilant in both Canada and the US and third, they are approved for use by North American Infection Prevention and Control Guidelines.
When should they be considered? As noted above, the primary use is for reprocessing of heat-sensitive devices. However, another consideration is use by healthcare workers (HCWs), healthcare or other facilities who do not have access to mechanical sterilizers and perhaps most importantly, consideration for use should be given by those who do not have the appropriate training and ability to develop a preventative maintenance program to ensure sterility is achieved. I realize this seems counterintuitive, however, simply having and using a steam sterilizer does not ensure sterility is achieved. Many smaller clinics or homecare nurses do not the support of an acute care facility and access to a Medical Device Reprocessing Department. Case in point, a few years ago, I met a group of nurses who had pooled together funds to jointly buy a steam sterilizer. They were so excited! When I spoke to them, they had had their sterilizer in place for about 6 months. They did not have a process in place to trace their reprocessing batches, and had just learned that while they were doing biological tests, they were not conducted correctly and that the machine they purchased was not intended to sterilize wrapped instrument sets! The long and the short was that all clients they saw over that time period were put at risk.
There are some cases where I think we need to look not only at the risk of transmitting disease and what level of disinfection or sterilization is needed, but also to look at the user and their capabilities. There are times when perhaps the use of a chemically sterilized instrument is safer than a false sense of security of a device that has "gone through a sterilization cycle".
What do you think?