Sterilization Methods and Monitoring Flashcards

An implantable device has just been processed through a steam sterilization cycle. According to AAMI ST79 standards, what is the most critical requirement before this implant can be released for patient use?

Answer: The load must be quarantined until the biological indicator (BI) result is confirmed as negative.

According to AAMI ST79, loads containing implantable devices require the highest level of sterility assurance. This is achieved by monitoring the load with a Process Challenge Device (PCD) containing a biological indicator (BI). The load should be quarantined and the implant should not be released until the BI is incubated and shows a negative result, confirming the lethality of the sterilization cycle.

A sterile processing department must sterilize a set of delicate, heat-sensitive instruments. Ethylene Oxide (EtO) is chosen as the appropriate method. Which of the following is a critical post-cycle step unique to EtO sterilization?

Answer: A mandatory aeration period to remove residual toxic gas.

Ethylene oxide is a highly effective sterilant but is also toxic, carcinogenic, and a reproductive hazard. After the sterilization cycle, items retain residual EtO gas. A mandatory aeration period, which circulates warm air, is required to allow this toxic gas to dissipate, making the items safe for both patient use and staff handling.

Which of the following is the primary purpose of performing a daily Bowie-Dick test on a dynamic-air-removal steam sterilizer?

Answer: To check the efficacy of the air removal system and detect air leaks.

The Bowie-Dick test is a Class 2 chemical indicator used to evaluate the performance of the vacuum system in dynamic-air-removal (prevacuum) steam sterilizers. Its primary purpose is to ensure adequate air removal from the chamber, as trapped air can prevent steam from contacting all surfaces, leading to sterilization failure. It is performed daily in an empty chamber before the first processed load.

A Class 5 chemical integrating indicator is placed inside a wrapped instrument tray during a steam sterilization cycle. What does a successful "pass" result from this specific indicator signify?

Answer: The sterilant penetrated the package and all critical parameters (time, temperature, and saturated steam) were met.

A Class 5 chemical integrating indicator is designed to react to all critical variables of the steam sterilization process: time, temperature, and the presence of saturated steam. A successful pass result provides assurance that the sterilization conditions were met at the location of the indicator inside the pack. While it mimics the response of a BI, it does not prove sterility directly.

The microorganism used within biological indicators to test the efficacy of steam sterilization and hydrogen peroxide gas plasma sterilization is:

Answer: Geobacillus stearothermophilus

Geobacillus stearothermophilus spores are used in biological indicators for steam sterilization and hydrogen peroxide (H2O2) sterilization methods. This is because these spores are highly resistant to these specific sterilization processes. Bacillus atrophaeus spores are used to monitor Ethylene Oxide (EtO) and dry heat sterilization.

When an instrument is processed using an immediate-use steam sterilization (IUSS) cycle, which of the following is true regarding process monitoring?

Answer: The same physical and chemical monitoring protocols as terminal sterilization must be followed and documented.

Immediate-use steam sterilization requires the same rigorous monitoring as any terminal sterilization cycle. This includes using physical monitors (reviewing the cycle printout), an internal chemical indicator (preferably a Class 5 integrator), and documenting all cycle parameters for traceability. IUSS is a process that should be minimized and requires all critical reprocessing steps to be completed.