Cleaning, Disinfection, & Sterilization Flashcards

Which action should an infection preventionist recommend when a sterilizer fails its biological indicator (BI) test?

Answer: Remove the sterilizer from service and recall items from the failed load

A failed BI requires immediate removal of the sterilizer from service and recall of items from the failed load per AAMI and CDC guidelines.

The term 'log reduction' in disinfection refers to:

Answer: A tenfold reduction in the number of viable organisms

Each log reduction represents a 10-fold (90%) decrease in microbial count; a 6-log reduction eliminates 99.9999% of organisms.

Which of the following is the correct order of reprocessing steps for a reusable semi-critical medical device?

Answer: Clean → Rinse → Disinfect → Rinse → Dry → Store

Proper reprocessing sequence is: clean, rinse, high-level disinfect, rinse with sterile or filtered water, dry, then store in a protected manner.

Which practice is recommended to prevent biofilm formation in endoscope channels between reprocessing steps?

Answer: Flushing channels with air and alcohol immediately after each procedure

Immediate flushing of endoscope channels with air followed by 70% alcohol prevents biofilm formation and speeds drying before full reprocessing.

What does the 'D-value' represent in sterilization science?

Answer: The time required to reduce organism count by 90% under specific conditions

The D-value (decimal reduction time) is the time required under defined conditions to reduce the microbial population by one log (90%).

According to CDC guidelines, how long should flexible endoscopes be stored after high-level disinfection before they must be reprocessed again (if unused)?

Answer: 5–7 days (facility policy-based)

CDC and professional societies recommend that storage duration be based on facility policy, typically 5–7 days, provided the endoscope is stored dry in a ventilated cabinet.

Which chemical class is classified as an intermediate-level disinfectant and is effective against Mycobacterium tuberculosis?

Answer: 70–90% isopropyl or ethyl alcohol

Alcohols (70–90%) are intermediate-level disinfectants with tuberculocidal activity, making them appropriate for surfaces and non-critical equipment.