Sterilization of instruments: successes and pitfalls ... Part 3: sterilization failure -- what to do and how to identify the cause

    May 23, 2011

    By Leslie Canham, CDA, RDA

    This is the third segment in a three-part series on sterilization of instruments, the successes and pitfalls. The first segment (click here to read it) focused on types of sterilizers in dental offices, types of instrument packaging or wrap, and common pitfalls to achieving sterilization. The second segment (click here to read it) addressed how sterilization procedures are monitored and what to do in the event of sterilization failure. This final segment will cover what to do and how to identify the cause of sterilization failure.

    The Centers for Disease Control and Prevention recommend that proper functioning of the sterilization cycle be verified at least weekly for each sterilizer through the use of biological indicators. Biological indicators are also known as spore tests because they use highly resistant microorganisms (e.g., Geobacillus or Bacillus species) as test organisms. Because spores used in biological indicators are more resistant and present in greater numbers than the common microbial contaminants found on patient-care equipment, an inactivated biological indicator indicates other potential pathogens in the load have been killed.1

    But what happens if your spore test shows positive results, which means failure to kill spores? Immediate action must be taken for patient safety and to determine the cause of the positive results.

    Steps to follow in the event of positive spore test indication sterilization failure:
    1. Take the sterilizer out of service until the cause of the failure is determined.

    2. Collect all items that were sterilized since the last negative spore test. If you dated the sterilization packages or wraps, collecting the items dated after your last successful sterilization cycle will be easy. If not, it will be difficult to determine which instruments are truly sterile and which are not. In this case you will need to reprocess all instruments. Check with your state dental board to determine if dating instrument packages is required. If you have more than one sterilizer, note which sterilizer was used.

    3. Items that may not have been sterilized will need to be reprocessed. This means taking the instruments out of the pouches or wrapping them in new sterilization packaging. Then resterilize the items in another sterilizer. It is helpful if your office has a second properly functioning sterilizer. If not, you will need to get a loaner from your repair company. Before using a second sterilizer, be sure it has passed spore testing.

    4. Review the operation protocol for your sterilizer. Read the owner’s manual and make sure that all the steps were followed by each person responsible for instrument processing. Make sure the sterilizer was loaded properly, sterilization fluid levels were met, and the settings for time and temperature were correct. If it is possible that the proper procedures were not followed, the sterilization failure may be due to operator error and not the sterilizer.

    5. If operator error is suspected, retest the sterilizer and observe the cycle. Retest the sterilizer using the same cycle and approximate load that yielded the sterilization failure. Place a chemical indicator next to the biological indicator on the inside of a package. Observe the sterilizer gauges, lights, dials, and digital readouts during this repeat cycle to determine proper sterilization conditions. This mechanical, chemical, and biological monitoring retest after operating procedures are confirmed will determine whether the problem has been corrected or the sterilizer malfunctioned.

    6. If the spore test results are negative and the chemical indicator changes to an appropriate color, the sterilizer may be placed back into service. If the spore test is positive and one has confirmed that the packaging, loading, and operating procedures were performed correctly, contact the sterilizer service representative for repair or replacement.2

    Some possible causes of sterilization failure can include improper:
    • loading of sterilizer
    • type of packaging used for instruments
    • time
    • temperature

    Proper sterilization of instruments includes cleaning and removing all organic and inorganic material from the items to be sterilized. Then, instruments should be thoroughly dried and properly packaged before placement in the sterilizer. Instruments should be loaded according to the manufacturer’s directions, and the steps for proper operation of the sterilizer should be followed. Once sterilization is complete, including a complete drying cycle, instruments should be stored so as to prevent contamination.

    Author bio

    Leslie Canham is a dental speaker and consultant specializing in infection control and OSHA compliance. She has more than 36 years of experience in dentistry. Canham is the founder of Leslie Canham Seminars, providing in-office training, mock inspections, consulting, and online seminars and webinars to help the dental team navigate state and federal regulations. Reach Canham at (888) 853-7543 or Leslie Canham.

    References
    1 "Infection Control in Dental Settings — Sterilization Monitoring." Centers for Disease Control and Prevention . N.p., 14Oct2009. Web. 20 Mar 2011. <http://www.cdc.gov/OralHealth/infectioncontrol/faq/sterilization_monitoring.htm>.
    2 Miller C. Infection Control and Management of Hazardous Materials for the Dental Team. 4th . Canada: Mosby Elsevier, 2010. 156. Print