Sterility Assurance Through Quality Control
By Heide Ames, BS, and Sandra Lee, BSM, RN
Sterility assurance plays a very
important role in the delivery of quality patient care. In healthcare facilities
worldwide, sterility assurance activities in the central service (CS) department
help reduce the possibility of cross-contamination and the risk of
healthcare-acquired infections. A comprehensive sterility assurance program is
essential for effective infection control. Every step of the sterile processing
cycle, from instrument handling in the operating room (OR) through
decontamination, preparation, sterilization and sterility maintenance, should be
audited and/or monitored for quality to effectively support optimal patient
A critical part of this process is the chemical and biological
monitoring of steam sterilization cycles. Testing standards and recommended
practices are provided in documents from the Association for the Advancement of
Medical Instrumentation (AAMI) and the Association of periOperative Registered
Nurses (AORN). These recommendations apply to any department or organization
that sterilizes items for use in patient care.
In todays world of sterile processing, the CS or OR manager
is not only responsible for ensuring that each instrument, basin and textile
pack is processed, but that all processing tasks are completed efficiently
following AAMI standards and recommended practices. This sometimes leads to
perceived conflict between the AAMI standards and the continual pressures to
increase productivity, which can lead to shortcuts that may jeopardize patient
safety. For example, how many times have implantable devices been released prior
to knowledge of the bacterial growth result? How often have in-pack indicator
strips not been used?
CS and OR managers do not have to lose sleep at night worrying
about how to monitor their processes properly while maintaining productivity.
The correct mix of biological and chemical indicators, along with a little bit
of planning and documentation and an AAMI quality control program, will help
provide a high degree of sterility assurance and patient safety in an efficient
A Good Quality Control Program Starts With the Sterilization
All steam sterilizers need to be verified for proper function
on a regular basis. This means that a microbial challenge must be processed in
the sterilizer weekly, and preferably daily, for each type of cycle that is run
in that sterilizer. The microbial challenge must be in a test pack sufficient to
create a difficult challenge to the sterilization process. Considering that the average sterilizer has at least two types
of cycles and usually two temperature choices, this testing quickly devours time
and money. In addition, the incubation periods for spore outgrowth require
between 24 hours and seven days, so the microbial testing can become even more
time-intensive and costly.
This time frame can be shortened considerably using
alternative monitoring technologies. Though AAMI standards still require a
weekly spore outgrowth test, the remaining days of the week can be monitored
- A biological indicator (BI) with enzyme-based
- Multi-enzymatic products (without a biological
- Class 5 integrator products
All of these should be placed within
appropriate challenge packs for this testing.
Not only do all of these systems meet AAMI standards and
recommended practices for a weekly conventional spore outgrowth test; they also
provide the fastest daily equipment check: one to three hours using biological
indicators with enzyme-based early-readout capability; 20 seconds for
multi-enzymatic products; or immediate results using integrator type products.
In addition to microbial challenges, steam sterilizers using
pre-vacuum cycles must also complete air removal tests as part of equipment
quality control. In this case, preassembled disposable test packs can provide
advantages for the user. First, preassembled disposable test packs may actually
cost less than self-constructed Bowie Dick test packs (although this is not a
common perception) since self-constructed pack costs include the labor
associated with washing and folding towels and the final assembly of each test
pack. In addition, the inconsistencies among construction techniques for
self-constructed packs can lead to questionable or invalid results.
Processes to Release Sterilized Items
To guard against equipment and process failures during the
day, several products have been developed to monitor the performance of each
cycle and provide assurance of a sterile process prior to a loads release for
use. The goal of any of these products is to provide assurance that all critical
parameters of sterilization have been met within an appropriate test pack.
Traditionally, this test has been conducted with a BI test pack requiring 24
hours to seven days to provide final results. However, the newer alternative
monitoring products described above provide the same information more quickly. The fastest of these is the Class 5 integrator challenge pack.
Although integrator challenge packs are equivalent to
biological indicator test packs, the AAMI Standards and Recommended Practices
document recommends not using integrator challenge packs for the release of
implants. A biological indicator with conventional spore growth or with an
enzyme-based early-readout capability must be used for this purpose.
In order to optimize turnaround time, both types of packs
should be used: integrator challenge packs for the majority of cycles those without implants in the load and BI test packs
for the few cycles with implants. Efficiencies can be further improved by
planning for the processing of all scheduled implantable devices to be done in
one or two separate loads.
Occasionally, a medical emergency may occur in which an
implantable device is needed immediately, before the final biological indicator
results are available. In such cases, the implants may be released as long as
the early release is documented by the sterilizer operator, and the operator
reviews the sterilizers cycle printout and other indicators used to monitor
the cycle. BI test packs containing a Class 5 integrator provide immediate
assurance that all the critical parameters of sterilization have occurred, which
are correlated to the death of the organisms on the biological indicator.
Ultimately all results must be recorded and the early release documented per
AAMI standards (ST 46 and ST 37).
Quality Control of Packs
Although the load release monitoring products described above
provide information that the sterilization cycle completed satisfactorily, they
do not address the conditions within each pack. Successful sterilization of the
items within a pack is dependent on thorough decontamination, proper
preparation, proper packaging, and appropriate placement of items in the
sterilizer. A non-sterile pack could lead to considerable cost ramifications for
both the hospital and the patient if a healthcare-acquired infection occurs.
The best way to control the quality of packs is to use in-pack
monitoring with Class 5 integrators. These products confirm that the internal
confines of the pack were exposed to all the critical parameters necessary to
kill a BI.
Documenting Your Program
Of course, a quality control program will not be effective
unless all data is documented. Establishing and following policies and
procedures, including the recording of the results of all the tests we have
discussed here, are critical for maintaining quality awareness and procedural
consistency in a sterility assurance program. Both written formats and computer
programs are available for documenting and tracking a departments critical
process monitoring data. The bottom line is: documenting everything helps to
ensure that no sterility failures are missed.
Sterility assurance is critical in any quality control program
for limiting the risks associated with cross contamination and
healthcareacquired infections. CS and OR managers can operate an efficient,
consistent, and reliable sterility assurance program by following AAMI standards
and recommended practices. By executing those guidelines with effective
planning, proper use of todays new technologies, and the right combination of
biological and chemical indicators, any CS department and OR can maintain best
practices while improving overall efficiency. ICT
Heide Ames, BS, is associate product manager, and Sandra Lee,
BSM, RN, is senior manager of professional education for the STERIS Corporation.
Epidemiologists Trace Outbreak of Antimicrobial Resistant
BALTIMORE, Md. Infection control experts at the Johns Hopkins Hospital
(JHH) say tighter rules governing use of a hand-held, highpressure,
water-pumping tool to wash and clean wounds should be adopted to improve the
safety of wound care. The Hopkins finding comes in response to the investigation
of an outbreak of the antimicrobial-resistant bacterium Acinetobacter
baumannii at JHH during a two-month period in 2003. The organism infected 11
patients and was traced back to use of pulsatile lavage equipment for wound
care. Three of these patients required admission to the intensive care unit for
sepsis and respiratory distress.
In the future, staff using the water-gun like equipment will have to wear
masks, gowns and gloves during procedures, which must also now be performed in
private treatment rooms that are fully disinfected between patients to reduce
the chances of cross contamination between patients and staff. As an added
response, the Food and Drug Administration (FDA), which supervises device
safety, along with a leading manufacturer of the device, have agreed to change
the products labeling to include use of routine infection control procedures.
Hopkins already has instituted the new infection control procedures. Changes
at Hopkins and results of the study should change the way this common procedure
is performed at other acute-care hospitals and long-term care facilities, says
senior study investigator and hospital epidemiologist Trish Perl, MD, an
associate professor of medicine and pathology at the Johns Hopkins University
School of Medicine.
The Hopkins case study is believed to be the first investigation to relate an
outbreak of this bacterium to the pulsatile lavage device, and its results were
published in the latest edition of the Journal of the American Medical
Association online Dec. 22, 2004.
The Hopkins investigative team traced the infection to the pulsatile lavage
tool made by Bard-Davol Inc., and determined that the equipment sprayed the
potentially dangerous bacteria into the air and onto surfaces in an open
treatment room, with other patients nearby.
This was true even though staff correctly followed procedures for its use,
Perl adds. Germs were spread when patients and staff came in close contact with
each other during procedures and possibly when fewer equipment parts were
changed between patients. Guidelines for its use also applied only to healthcare
workers, not to patients, prior to the outbreak.
Since finding the cause of the outbreak at Hopkins, the specific strain of
the bacterium involved in the outbreak has not reappeared, even after 11 months
of follow-up testing.
Antimicrobial resistance is a growing problem for patient safety in
healthcare settings, such as hospitals and long-term care facilities, because
traditional drugs are not effective for treating these infections, particularly
among vulnerable groups of sick and elderly patients, Perl notes. To solve the
problem, we are increasingly forced to rely on our basic tools of scientific
investigation: finding the initial contact point, or source, of infection and
putting in place the necessary steps to prevent an outbreak from happening in
the first place.