SURE THING The Type 1 chemical indicator tape that seals blue-wrapped packages differentiates processed from unprocessed instruments.

Sterilization is an automated routine. After surgical instruments are cleaned and decontaminated, after assembled trays are blue-wrapped or dropped in rigid containers and placed in the autoclave, the steam does all the work. Or does it? To the next user, a sterile instrument may look just like a non-sterile one. How can they be sure that the sterilizer has done its job? Physical, chemical and biological monitoring methods go a long way toward answering that question.

Physical proof
When they're used correctly, sterilization assurance indicators can verify the integrity of your sterilizer. They provide an accurate account of what has occurred during the steam sterilization process and a confirmation that the items in the autoclave have been exposed to conditions that effectively terminate microbial life.

The most immediate indicators are the physical monitors incorporated into sterilization equipment. They register, record and report the parameters for every cycle, such as the elapsed time and the temperature and pressure conditions in the chamber. The data from these real-time assessments — which are provided through gauges, graphs and printouts — demonstrate that the system has met the prescribed parameters, or identify sterilizer malfunctions and the need for corrective action. All sterile processing team members should know how to review this data.

Physical monitors don't tell everything, though. For example, they can't tell you about the conditions inside of the wrapped trays or rigid containers that contain the instruments you're sterilizing. That's why you can't rely on physical monitoring alone to verify that sterilization has been achieved, and why chemical and biological indicators are also necessary.

Chemical choices
Like the data from physical monitors, chemical indicators don't directly establish that a processed package is sterile. They do, however, verify that it was exposed to sterilizing conditions, and in differentiating processed from unprocessed items, they can help your staff detect procedural errors and equipment malfunctions.

Unlike physical monitoring data, chemical indicators are also able to report internal conditions. FDA-approved, sterilizer manufacturer-recommended chemical indicators should be placed on the outside and inside of each package to be sterilized, unless the internal indicator is readable through the package material. Chemical indicators are grouped into 6 types, based on how they work (Type 1 and Type 5 indicators are currently the most commonly used). External indicators include:

• Type 1 (also called process indicators) are tapes or labels that change colors to show that the package has been exposed to the sterilization process. They should be applied to the outside of every package unless an internal indicator is visible.
• Type 2 (also called Bowie-Dick tests) detect air leaks, ineffective air removal and the presence of non-condensable gases. Intended for daily use in dynamic-air-removal sterilizers, they should be run through a cycle in an empty chamber before the first load of the day to test the system.

Internal indicators include:

• Type 3 are designed to react to a single parameter of the sterilization process, such as time, temperature or steam saturation.
• Type 4 are designed to react to multiple parameters of the sterilization process.
• Type 5 are integrating indicators, which react to all critical parameters over a specified range of sterilization cycles. These indicators include a spore strip, in which changing color signals the cycle's ability to eliminate microbes.
• Type 6 are emulating indicators, which react to all of the critical parameters of a specific cycle.

PLAN IN PLACE
When Sterilization Cycles Fail

TRAY ADDITION Chemical and biological indicators report the adequacy of sterilization conditions inside of instrument containers.

You need to have established procedures in place for sterile processing and surgical team members to follow in the event that the results of physical, chemical or biological monitoring indicate that sterilization cycles are ineffective. Start by following these response protocols.

• Terminate a sterilization cycle that doesn't meet the required parameters.
• Remove malfunctioning equipment from service for inspection, maintenance and testing.
• Reject the instruments or trays with indicators that show a failed result.
• Return incorrectly sterilized items to the sterile processing department for another round of processing.
• Root out the reasons for a sterilization assurance indicator failure.

— Sharon A. Van Wicklin, MSN, RN, CNOR, CRNFA, CPSN, PLNC

Biological evidence
There are advantages and disadvantages to biological indicators, which contain spores chosen due to their high resistance to sterilization.

On the plus side, they deliver certainty of sterilization. Unlike physical monitors and chemical indicators, biological indicators provide direct evidence that the sterilization cycle has effectively destroyed microbes that were in the chamber during its run.

However, biological indicators require incubation to demonstrate the absence or presence of microbial activity. Technological advances have shortened the wait from days to hours, but the testing still requires advanced planning, especially for loads containing implants, which cannot be released until the results are available.

Biological indicators are used for a weekly or preferably daily testing of sterilizer efficacy during routine loads. They're also a critical step in qualification testing after a sterilizer is installed or relocated, after it experiences a process failure or malfunction and after major repairs.

Indicators in practice
Always follow the manufacturers' instructions for use from both the indicator's and the sterilizer's manufacturer when using and interpreting sterilization indicators. Provide in-services and competency verification activities to all personnel with a role in reading indicator results.

Sterile processing techs should review the physical monitors and the data produced by the sterilizer after every load. In addition, surgical team members must determine whether all chemical and biological indicators have reached the correct endpoint before an instrument or tray is placed on the sterile field.

If it is discovered that any of these results have not achieved the expected endpoint, staff must react accordingly (see "When Sterilization Cycles Fail").

Always document sterilization activity. Keeping an accurate log of items processed for specified cases or ORs will prove invaluable if an indicator failure necessitates instrument recalls or patient notifications. Conduct periodic reviews and evaluations of sterilization monitoring processes to verify compliance, identify the need for improvement and trigger corrective action if improvement is not achieved or sustained. OSM