LOCATION, LOCATION, LOCATION Chemical indicators must be placed where it's difficult for steam to reach.

In my travels as a sterile processing educator and consultant, I've seen instrument reprocessing staffs make the same mistakes when using chemical and biological indicators, and reading sterilizer printouts. Let's review some common oversights to ensure you're not jeopardizing instrument sterility in your facility.

REPORT CARD Sterilizer printouts confirm successful cycles, if you know where to look.

1. Indicator placement
The proper placement of chemical indicators inside wrapped instrument trays or containers continues to be an issue at the front line. Be sure to place chemical indicators in the geometric center of a wrapped tray — the spot most difficult for steam to reach — to verify that the sterilant has reached the center of the tray as recommended by the Association for the Advancement of Medical Instrumentation. For rigid containers, check with the containers' manufacturers for the most challenging locations for chemicals indicator placement (usually at 2 opposite corners of the inside basket). For multi-level instrument sets, place chemical indicators on each level.

In far too many instances, however, operating room staffs want indicators placed on top of reprocessed instrument sets so they can immediately see that steam got to the instruments before touching the contents. (If a nurse takes apart the instrument set and discovers the indicator placed properly in the center of the tray didn't turn, her gloves might be contaminated and she'd have to break down the entire sterile field and start setting up the case again.)

But just because steam reached the top of a wrapped tray doesn't mean it reached the middle. Isn't it better to know the instruments you're about to use are safe instead of moving forward based on a chemical indicator that may or may not give you an accurate reading? Worries about case efficiency should never trump ensuring instrument sterility.

2. Indicator selection
Chemical indicators are grouped in classes (1 through 6) based on the parameters they measure. When deciding which indicator is best for use at your facility, determine how many parameters it monitors. I'd want at least a Class 4 indicator that monitors 2 or more of the critical parameters (time, temperature and presence of steam). Class 4 indicators work well for packs that are less challenging to reprocess, such as peel-packs or small instrument trays. Class 5 indicators, which simulate the reliability of a biological indicator but don't contain spores, are best used in denser packs, rigid containers and multi-level instrument sets.

The somewhat recent introduction of Class 6 indicators — emulating indicators that are specific to a cycle type, temperature and exposure time — caused a great deal of confusion in practice, as many facilities thought they could be used in place of biological indicators.

Carefully check an indicator's instructions for use, especially if you're running numerous loads filled with various devices that must be sterilized at different temperatures and exposure times, to know for which cycle type the indicator has been validated. Materials managers are, understandably, very interested in saving your facility money. But they might purchase less costly indicators that don't measure what's needed. It's your responsibility to know everything about the products brought into your facility, particularly when they impact the sterility of your instruments.

For example, a Class 6 indicator might be designed for pre-vacuum cycles run for 4 minutes at 270°F. Another could be intended for gravity cycles run for 30 minutes at 250°F. Class 6 indicators are likely a good option if you're running just a few cycles of the same instrument types. But if you're running multiple cycles filled with various instruments and devices that demand different exposure times and temperatures, the Class 6 indicators present an opportunity for user error and might not be the best option.

AAMI is working on recommendations for biological and chemical indicators intended for extended cycles. This is a big issue to address because of the growing number of sophisticated surgical devices — especially orthopedic tools and instruments — that must be run for 8, 10 or 12 minutes instead of standard 4-minute cycles. My facility recently had a urology transducer in for a trial that required a 1-hour pre-vacuum cycle run at 270°F. I called the device's manufacturer, figuring it was a misprint, but representatives say the FDA told them to recommend such a long exposure time because of the device's intricate design.

3. Report reading
Many central sterile staffers still don't know how to interpret sterilizer printouts and often sign off on records that indicate failed loads. They believe the temperatures and cycle times printed at the top of reports — 4 minutes at 270°F, for example — reflect loads that reached intended parameters. What they don't realize is that the printouts always note what the sterilizer was set at, so the top of load receipts appear correct to the untrained eye, even if the load failed.

Read the full report — the printouts provide a minute-by-minute breakdown of what's happening in cycles — to ensure the correct temperature was reached for the entire exposure time at the appropriate pressure. The "exposure" note on the cycle report is where the sterilization phase starts; the "exhaust" note is where steam is exhausted from the chamber and sterilization ends. For example, if you set your sterilizer for 4 minutes at 270°F, and exposure started at 3:28 p.m., the report should show 270°F was reached for the entire 4 minutes of the exposure phase, which ends at 3:32 p.m. Failing to reach the required temperature at any point results in an invalid cycle, and requires rewrapping and rerunning the entire load with new chemical indicators placed.

4. Biological testing
AAMI says biological indicators, which represent the ultimate challenge to the sterilization process, should be run at least weekly, but preferably daily. A good rule of thumb is to run a biological indicator in a full instrument load every day you're performing surgery. You must also run 3 consecutive biological indicator tests for each cycle type (gravity [if used] and pre-vacuum) followed by 3 Bowie-Dick tests in an empty chamber any time a new sterilizer is installed, moved or undergoes a major repair.

Finally, you must include a biological indicator in loads containing implants, for which the CDC wants a higher level of sterility assurance. AAMI recommends that biological test packs placed in implant loads include a Class 5 chemical integrator in the event the implant must be released before the results of the biological test is known. Buying biological test packs with Class 5 indicator already included is more costly, but it's one less thing for your central sterile staff to keep track of when running loads that include implants.

Place biological indicator test packs flat (not on their side) in a sterilizer's most challenging location. In non-tabletop sterilizers larger than 2 cubic feet, that spot is always over the drain-line basket on the bottom shelf. In tabletop sterilizers with chambers smaller than 2 cubic feet, biological testing is always done in a full load, even during re-testing after a repair. The most important item in biological indicator loads is the test pack. Never squeeze test packs wherever there's room; place them in the proper location before loading the sterilizer.