Sterilization Methods and Monitoring Flashcards

A Class 5 chemical indicator is used to monitor a steam sterilization cycle. What does a successful color change on this indicator signify?

Answer: That all critical parameters of the sterilization cycle (time, temperature, and steam) have been met.

A Class 5 chemical indicator, also known as an integrating indicator, is designed to react to all critical variables of the steam sterilization process: time, temperature, and the presence of saturated steam. A correct color change provides assurance that these conditions were met inside the pack, correlating with the conditions required to kill a biological indicator.

A medical device reprocessing technician is preparing a load for a low-temperature vaporized hydrogen peroxide (VH2O2) sterilizer. Which biological indicator is most appropriate for monitoring the efficacy of this sterilization method?

Answer: Geobacillus stearothermophilus

Geobacillus stearothermophilus spores are highly resistant to both steam and vaporized hydrogen peroxide (VH2O2) sterilization processes. For this reason, they are the standard microorganism used in biological indicators to monitor the effectiveness of these sterilization methods.

A single, wrapped instrument is dropped on the floor in the operating room and is needed urgently for the ongoing procedure. Which of the following is the most appropriate action according to Canadian standards?

Answer: Send the instrument for Immediate-Use Steam Sterilization (IUSS) following all required cleaning and decontamination steps.

Immediate-Use Steam Sterilization (IUSS), formerly known as flash sterilization, should be kept to a minimum and used only in situations where there is insufficient time to process an item by the preferred terminal sterilization method. The instrument must first be properly cleaned and decontaminated before undergoing the IUSS cycle. Wiping with a disinfectant or rinsing is insufficient, and if a sterile replacement is unavailable, IUSS is the appropriate emergency response.

What is the primary purpose of performing a Bowie-Dick test in a pre-vacuum steam sterilizer?

Answer: To detect air leaks and ensure adequate air removal from the chamber.

The Bowie-Dick test is a Class 2 chemical indicator used specifically to monitor the effectiveness of the air removal (pre-vacuum) stage of a pre-vacuum steam sterilizer. Inadequate air removal can create air pockets that prevent steam from contacting all surfaces of the load, leading to sterilization failure. The test does not confirm temperature or kill spores directly but ensures the conditions for effective steam penetration are met.

Which of the following sterilization methods is most suitable for processing heat-sensitive and moisture-sensitive flexible endoscopes?

Answer: Peracetic acid liquid sterilization

Peracetic acid liquid sterilization is a low-temperature method that is safe for heat-sensitive and moisture-sensitive devices like flexible endoscopes. It uses a chemical sterilant at a relatively low temperature (around 50°C) to achieve sterilization without damaging the delicate components of the endoscope. Steam and dry heat methods operate at high temperatures that would destroy the device.

When monitoring a sterilization load, what type of monitoring provides a direct measure of the lethality of the process?

Answer: Biological indicators

Biological indicators (BIs) are the only method that directly monitors the lethality of the sterilization process because they contain a known population of highly resistant microorganisms (e.g., Geobacillus stearothermophilus). If the BI test is negative after incubation, it provides a high level of assurance that the sterilization process was effective in killing all microorganisms. Mechanical and chemical monitors verify that the physical parameters of the cycle were met, but do not directly prove microbial kill.