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?
Bugging Off!
Nicole
