CET Infection Control & Sterilization Techniques 2 — Questions and Answers
Question 1: Which prion-specific reprocessing step is recommended by the CDC for endoscopes used on patients with suspected Creutzfeldt-Jakob disease?
- Standard high-level disinfection with glutaraldehyde
- Extended immersion in 2.5% sodium hypochlorite for 1 hour
- Immediate quarantine and single-use scope destruction
- Autoclaving at 134°C for 18 minutes followed by disposal (Correct answer)
Correct answer: Autoclaving at 134°C for 18 minutes followed by disposal
For prion-contaminated instruments, autoclaving at 134°C for 18 minutes (gravity cycle) followed by disposal or dedicated quarantine is the recommended approach, as standard HLD does not inactivate prions.
Question 2: What does the term 'reprocessing' encompass in the context of flexible endoscopes?
- Only high-level disinfection
- Pre-cleaning, leak testing, manual cleaning, HLD or sterilization, rinsing, drying, and storage (Correct answer)
- Rinsing with sterile water and drying only
- Autoclaving and packaging
Correct answer: Pre-cleaning, leak testing, manual cleaning, HLD or sterilization, rinsing, drying, and storage
Reprocessing is a multi-step process that includes pre-cleaning at point of use, leak testing, manual cleaning, high-level disinfection or sterilization, final rinsing, thorough drying, and proper storage.
Question 3: Which organism is considered the gold-standard biological indicator for monitoring steam sterilization?
- Bacillus atrophaeus
- Geobacillus stearothermophilus (Correct answer)
- Clostridium sporogenes
- Staphylococcus aureus
Correct answer: Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are used as biological indicators for steam sterilization because they are highly heat-resistant and reliably killed by proper steam cycles.
Question 4: A technician notices that a scope's biopsy channel shows discoloration and debris after manual cleaning. What is the correct action?
- Proceed to HLD since HLD will eliminate residual debris
- Advance to automated endoscope reprocessor immediately
- Return the scope to manual cleaning until visually clean before proceeding (Correct answer)
- Soak in enzymatic solution overnight then move to HLD
Correct answer: Return the scope to manual cleaning until visually clean before proceeding
Disinfection cannot be effective if organic debris is present; the scope must be returned to manual cleaning to achieve visual cleanliness before advancing to HLD.
Question 5: When using peracetic acid–based liquid chemical sterilant, what is the critical parameter the technician must verify before each cycle?
- Temperature of the soaking basin
- Minimum effective concentration using a chemical test strip (Correct answer)
- pH of the rinse water
- Color of the peracetic acid solution
Correct answer: Minimum effective concentration using a chemical test strip
Peracetic acid degrades over time and with use; chemical test strips must confirm the solution meets or exceeds the minimum effective concentration (MEC) before every cycle.
Question 6: What is the primary purpose of performing a leak test on a flexible endoscope before manual cleaning?
- To confirm the angulation controls function properly
- To detect internal damage that could allow cleaning fluids to damage the scope or allow organisms to harbor inside (Correct answer)
- To ensure the suction channel is patent
- To verify that the light source connector is intact
Correct answer: To detect internal damage that could allow cleaning fluids to damage the scope or allow organisms to harbor inside
Leak testing detects breaches in the scope's protective sheath or internal channels that could allow fluids to enter and damage internal components or create biofilm reservoirs.
Question 7: Which storage condition best prevents recontamination of high-level disinfected flexible endoscopes?
- Coiled horizontally in a sealed plastic bag
- Hanging vertically in a ventilated cabinet with caps removed (Correct answer)
- Submerged in sterile water in a closed container
- Stored horizontally in a drawer lined with sterile towels
Correct answer: Hanging vertically in a ventilated cabinet with caps removed
Scopes should be hung vertically in ventilated, dedicated cabinets with all caps and valves removed to promote drying and prevent moisture accumulation that supports microbial growth.
CET Infection Control & Sterilization Techniques 2
Which prion-specific reprocessing step is recommended by the CDC for endoscopes used on patients with suspected Creutzfeldt-Jakob disease?