Proper sterilization of instruments and materials is a critical aspect of infection control, says Charles Hughes, general manager/educator for SPSmedical Supply Corp. in Rush, N.Y. Historically, healthcare professionals have sought a means to effectively and reliably manage sterilization by monitoring the parameters needed for sterilization (time, temperature, and pressure). Since microorganisms cannot be seen with the naked eye, the major difficulty in sterilization is determining when an item is considered sterile. In earlier days, a raw potato was sometimes placed in the sterilizer along with the load being processed and afterwards examined to see if it was cooked. If it was, then the load was considered sterile. As sterilization processes became more sophisticated, more scientific monitoring practices replaced this rather crude but tasty method.

Nowadays, there are many quality assurance tools at our disposal. They include:

  • Mechanical/electronic controls 

  • Chemical indicators/integrators 

  • Biological indicators (spore tests) 

  • Sterilizer maintenance 

  • Record-keeping 

Mechanical or electronic controls are the easiest for sterile processing personnel to use and interpret, and they provide the earliest indication of unsatisfactory sterilization conditions. While most sterilizers come with time, temperature and pressure gauges, these readings are limited as they only tell us what is happening at the probe site (usually in the drain) and not inside the packs being processed, adds Hughes.

Biological indicators (BIs) are considered the highest level of sterility assurance because they actually test the sterilizers ability to kill specific strains of highly resistant organisms. They are non-pathogenic and specific for the type of sterilization process being monitored.

Hughes references AAMI guidelines for sterilizer maintenance. These state that all sterilization equipment must receive periodic and routine maintenance to ensure accurate and reliable operations. For proper sterilization quality assurance, the following maintenance procedures are recommended:

  • Routine maintenance 

  • Preventive maintenance 

  • Scheduled maintenance 

  • Calibration 

Record-keeping, too, is essential for any sterile processing department. If there is an instrument recall, there must be a system in place for finding and reprocessing the items in question, he says.

Tam Maresca, LPN, CSPDM, is the sterile processing department manager at St. Clares Health System in Denville, N.J. New Jersey has been at the forefront of sterilization regulation and certification of staff to ensure that they are competent. Maresca has seen many changes in the sterile processing department (SPD) in the past 35 years, and one of the most recent is an advance in chemical indicators.

We have discussed if a biological indicator (BI) is better than a chemical indicator (CI), she affirms. A BI is a live organism, and although CIs mimic them, in my opinion, its not the same. However, the new Class 5 integrators do mimic the log death rate for BIs, and if you put them on a logarithmic scale, youll see that. However, there is a difference between a viable organism and a chemical one.

She continues, The documents from the Association for the Advancement of Medical Instrumentation (AAMI) say that you cant use a chemical indicator in place of a biological one.

A Class V integrator is a chemical indicator that measures more than one parameter of sterilization. It mimics how a BI responds, Maresca points out. Its a much better indicator than other CIs, she says. Its a higher level of assurance, a higher quality of assurance. It may cost five or six cents more, but that depends on your contracts and how many you use.

The goal of a BI or CI is to ensure 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, newer alternative monitoring products provide the same information more quickly. The fastest of these is the Class V integrator challenge pack, writes Heide Ames, BS, and Sandra Lee, BSM, RN, in Sterility Assurance Through Quality Control from the January 2005 issue of ICT.

Although integrator challenge packs are equivalent to BI test packs, AAMI recommends not using integrator challenge packs for the release of implants, they continue. A biological indicator with conventional spore growth or with an enzyme- based early-readout capability must be used for this purpose.

And, they add, to obtain the shortest turnaround time, both types of packs should be used integrator challenge packs for most cycles and BI test packs for the cycles with implants.

Occasionally, a medical emergency may occur in which an implantable device is needed immediately, before the final BI 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 V 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), they conclude.

Hospitals are becoming increasingly aware of the importance of the sterile processing department and the role it plays in patient safety. Theres no doubt in my mind anymore that the institutions recognize what goes on in our department, but I think there is still a lot of teaching to be done to get them to understand the costs involved, Maresca confirms. Its been a long time coming. For years, hospitals didnt really understand, but now a lot of attention is paid to what were doing, and theyre beginning to work hard to do what needs to be done. When youre talking in Jersey youre preaching to the choir, because the AAMI documents are law here, which makes us unique. We have a strong department of health thats helped us in many ways, as more and more SPD managers become educated. Youre seeing more people with a higher level of understanding, and youre seeing acceptance. Its juggling the budget thats tough, because all of a sudden, youre faced with these additional expenses, and you want to clarify that theyre of the highest importance, so now you need to look at your budget and find a way to get that in there.

I think we all recognize that we need to do it better, but sometimes it takes more than just a strong desire on an individuals part to do it better you need to get that acceptance, that recognition that they know what theyre saying and its absolutely necessary. I think the central sterile (CS) people have not done a good job in advertising who we are. We have lately weve worked very hard at it but I think we were slow to get it out there, Maresca adds.

Its only in the past thirty years that we really have become our own thing. Weve taken over the responsibility of being experts on sterilization from the operating room. Theyve become so much busier, but also the technology has changed so radically that they really didnt have the time to continue in that realm. It was kind of a natural progression.

AAMI is now preparing to release a technical information report on the quality of water in the department. Will that turn into a standard? Or law? We dont know, Maresca says. Right now, as these things become revised, the current revision automatically becomes the law.

The most recent changes in sterilization quality assurance (QA) have been improvements to the current devices, rather than replacements with entirely new products.

I see the biggest change as the introduction of steam BI test packs with early readout capabilities, says Hughes.

Originally, steam BI test packs included a 48-hour conventional BI with a process indicator that turned color when the sterilizer heated up. Next came the 3M RRBI test pack that includes a 48 hr conventional BI with a three-hour fluorescent enzyme early read-out. Its performance is documented to be equivalent to the BI. And finally, we now have conventional BIs with reduced incubation of 24 hours (i.e., SPSmedical, Getinge, Steris) with an immediate readout Class V integrating indicator FDA-cleared as equivalent in performance to the BI. The AAMI standard ST46, which was recently updated to ST79, responded by recommending that users release processed loads based on the three-hour early fluorescent readout or the immediate readout Class V device. This tremendously helps CS departments that are pressed for resources to service their customers (i.e., the OR) with instrument sets that are: 1) sterile, 2) complete, and 3) on time.

AAMI ST79 also recommends that a BI test pack with a Class V integrating indicator be used with all loads that contain implantables. This new standard (released in October 2006) allows users to release processed items immediately (including implants, if there is not time to wait for the BI results, which is often the case). Therefore, the use of Class V integrating indicators that have been FDA-cleared as equivalent in performance to the BI within BI test packs, as well as by themselves within critical packages, offers the greatest quality assurance for steam processed loads, Hughes adds.

A common error I see users make with sterilization QA is to assume that their packaging and BI test pack can be used in extended cycles without a statement in writing from the manufacturers that they have been validated in those cycles. For example, here is what the BI standard ANSI/AAMI/ISO 12161 says: Users should not over process the culture medium, as extended sterilization may induce changes that can affect its growth-promoting properties. The ability of the culturing medium to promote the growth of low numbers of microorganisms should be demonstrated. Instrument sets that contain implants commonly require extended cycles, and therefore the user (per AAMI standards) includes a BI test pack with the load. Unfortunately, running a self-contained BI whose medium may be damaged in the extended cycle can produce false negatives, causing the release of non-sterile loads, which certainly is a patient safety issue. SPSmedical has validated (via two independent labs) our SporView self-contained BIs in commonly used extended cycles, and we provide this information to customers in advance. We encourage all suppliers of BIs and packaging systems to do the same.

Heide Ames, product manager of sterility assurance for STERIS Corporation, also has much to say about the biological indicator test packs containing Class V integrating indictors. Products like the Verify® Biological Integrator Test Pack allow the user to know immediately that all critical parameters for sterilization were delivered, while at the same time providing a biological indicator challenge, she confirms. It eliminates the need for blind releases. Another benefit of Class V products is that the user will be able to reprocess cycles with failed Class V indicators immediately, which assists in the prevention of time-consuming and costly load recalls.

Some tools are just more effective than others. Others may not be suitable for general use, but are instead best used for specific applications. Just like the many tools in a toolbox, biological and chemical indicators have been designed with specific purposes in mind, Ames explains. Biological indicators provide the verification of microbial efficacy required for installation and repair qualification of sterilization equipment.

Biological indicators also serve as a routine efficacy check for sterilization equipment. Chemical indicators are used to verify the conditions of sterilization within every pack. They serve to identify processed from unprocessed items. Biological and chemical indicators cross paths when monitoring sterilization loads. Advantages and disadvantages exist for both products. Biological indicators provide a real-time measure of bacterial spore death, showing that the SPD staff have actually killed something. However, they can only monitor half of the sterility assurance level being delivered, Ames adds. The design of the self-contained biological indicators (dead-end lumens) contributes to the various performance differences when processed in different cycle types. The self-contained biological indicators can arguably simulate the physical challenges of lumened devices within the load. However, the resistance of a particular spore, or its ability to stay alive within a cycle, is set. It cannot be modified without changing the bacteria themselves or the packaging surrounding them. Biological indicators also require the use of additional equipment such as incubators or readers. Most importantly, biological indicators require time before the final results are known, which requires a quarantine period. These characteristics add to the overall cost of using biological indicators.

Chemical indicators, in contrast, provide immediate results. However, not all chemical indicators are the same. Only Class V integrating indicators may be used to release loads. And even then, AAMI only recognizes the use of Class V indicators for loads that do not contain implants, she continues. A great deal of performance variability exists among the integrators available from todays vendors. Not all integrators meet the Class V integrating indicator standards. On the other hand, a good Class V integrator is capable of monitoring the sterilization parameters beyond those required for a biological indicator. It can monitor the time, temperature and exposure parameters necessary to achieve the basic sterility assurance level, and can go beyond these parameters into the extended times built into some sterilization equipment as an additional safety margin. Using Class V integrators allows a high level of sterility assurance monitoring within packs and loads. Test packs that combine both a Class V integrator and a biological indicator offer the best of both worlds.

Biological and chemical indicators are both necessary implements in the toolbox of sterility assurance and must be used together as a system to provide the ultimate sterility assurance monitoring while maintaining compliance with guidance documents, she adds.

Despite recent media attention to the sterilization process, or the use of reprocessed devices, not everyone understands how, exactly, to do it right. I think that many organizations are doing the best they can with the knowledge they have, Ames asserts. Until recently, tools commonly used for quality improvement in other industries had not been applied to healthcare organizations. More and more, however, I see hospitals using programs like Six Sigma and methods like Failure-Modes-Effects Analysis (FMEA) to identify and prevent potential breakdowns and make improvements to their sterility assurance programs. The most common errors Ive seen have been related to the uses of sterility assurance products: not understanding the directions, assuming that all chemical indicators are the same, or not evaluating the products and systems currently in place on a regular basis. Furthermore, instructions or guidelines for sterilization may change without a hospital being aware of it. It is important that a system be in place as part of every quality assurance program to ensure continual evaluation, improvement, and updating of processes and procedures.

And, she says, The most common fallacy I hear is, If it aint broke, why fix it? It is the responsibility of the SPD manager to continuously challenge the system and make improvements. It is always better to prevent an error rather than clean up the mess after one has occurred, she confirms. Another common belief is that near-misses do not need to be monitored, because someone caught it before it became a problem. The near miss is just as important as an actual issue because of the potential for harm. All near-misses need to be discussed and resolved. Lastly, many organizations assign an individual to handle the entire sterilization quality assurance program. In reality, a cross-functional team should be responsible. Each function provides a unique perspective when improving a process and can prevent new issues from developing as improvements are implemented.

Using multiple tools is the best way to ensure sterility, says Dan J. Dwyer, healthcare marketing, Raven Labs. Often times, people are using only expensive fast readout products when a class V integrating indicator would give them the information and results they need without any sort of delay for their non-implant loads. Used in conjunction with a traditional biological indicator with actual spore results, chemical integrators can not only save time and money, they add another level of assurance. The discussion should not be which one is better (biological vs. chemical) but how facilities can use a combination of both to maintain their high level of sterility assurance.

When a positive biological indicator comes up, the first reaction of the SPD staff is, Is there something wrong with the BI? when it should be, Is there something wrong with the sterilizer? he adds. We have had people call us wanting to switch to our products because their current products no longer work in their sterilizer. As a BI manufacturer, I am not simply interested in providing indicators that work in your sterilizer. I want to provide you with the best tools possible to help maintain the proper and best functionality of your sterilizers, and it is my job to make you aware of any alteration of that. The goal is not to have negative BIs; the goal is to have properly sterilized products and safer patients. As BI vendors, we want to do everything we can to ensure that.

Another myth about sterilization is that anything will be sterilized in 15 minutes at 250 degrees F (121 degrees C), regardless of what you place in the autoclave chamber, Dwyer says. Chamber temperature and internal temperature of what you place within it are two very different things. Imagine that someone invites you over for a turkey dinner. You see them rely on an oven thermometer placed next to the turkey to determine if it is done. Relying on the oven (chamber temperature) without assessing the internal temperature of whatever is within the chamber can have serious consequences. Using multiple tools in various areas of the chamber will give you the highest level of assurance that the items are safe. 

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