- Certified Medical Device Reprocessing Technician Steam Sterilization Principles Questions and Answers Flashcards

What are the three critical parameters that must be achieved for effective steam sterilization?

Answer: Time, temperature, and steam quality (saturated steam with direct contact)

Steam sterilization requires saturated steam at the correct temperature (121°C or 132°C) maintained for the required exposure time with direct steam contact on all surfaces. All three parameters must be met simultaneously.

What is the difference between a gravity displacement sterilizer and a prevacuum sterilizer?

Answer: A gravity displacement sterilizer relies on steam displacing air downward by gravity, while a prevacuum sterilizer uses a vacuum pump to actively remove air before steam admission

In gravity displacement, steam enters the top of the chamber and pushes air out through a drain at the bottom. Prevacuum sterilizers actively pull air out using a vacuum pump before introducing steam, resulting in faster and more complete steam penetration.

What is the Bowie-Dick test and why is it performed daily?

Answer: A specific test for prevacuum sterilizers that verifies adequate air removal from the chamber, performed daily before the first patient load

The Bowie-Dick test uses a standardized test pack to detect air leaks and inadequate air removal in prevacuum sterilizers. Trapped air prevents steam contact with instrument surfaces and can result in sterilization failure.

Why is the drying phase important in steam sterilization?

Answer: Adequate drying prevents wet packs, which compromise the sterile barrier by allowing microbial migration through moisture on the packaging

Residual moisture on sterilized packages (wet packs) creates a pathway for microorganisms to wick through the packaging material, compromising sterility. The drying phase uses vacuum and heat to remove condensate.

What is a biological indicator (BI) and how is it used in steam sterilization monitoring?

Answer: A preparation of highly resistant bacterial spores (Geobacillus stearothermophilus) used to directly challenge the sterilization process and confirm microbial kill

Biological indicators contain a known population of Geobacillus stearothermophilus spores, which are among the most resistant microorganisms to moist heat. A negative BI result (no growth after incubation) confirms the sterilization process was lethal.

What is the concept of sterility assurance level (SAL) and what SAL is required for medical devices?

Answer: SAL of 10^-6 is required, meaning the probability of a viable microorganism surviving the sterilization process is no more than one in one million

A SAL of 10^-6 is the internationally accepted standard for medical device sterilization, meaning that after a properly validated sterilization cycle, the probability of any given device being non-sterile is less than one in a million.