Infection Control Today: OR Topics

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 outcomes.

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 manner.

A Good Quality Control Program Starts With the Sterilization Equipment

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 with:

  • A biological indicator (BI) with enzyme-based early-readout capabilities
  • Multi-enzymatic products (without a biological indicator)
  • 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 Organism

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.

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