CER Endoscope Sterilization Methods 2 — Questions and Answers
Question 1: Which sterilization method uses peracetic acid as the active sterilant for heat-sensitive endoscopes?
- STERRAD system
- STERIS System 1E (Correct answer)
- Ethylene oxide (EO)
- Vaporized hydrogen peroxide (VHP)
Correct answer: STERIS System 1E
The STERIS System 1E uses liquid peracetic acid at approximately 50°C to sterilize heat-sensitive endoscopes.
Question 2: What is the minimum concentration of peracetic acid required for sterilization in the STERIS System 1E?
- 0.1%
- 0.2%
- 0.35% (Correct answer)
- 0.5%
Correct answer: 0.35%
The STERIS System 1E requires a minimum of 0.35% peracetic acid concentration to achieve sterilization.
Question 3: Ethylene oxide sterilization requires which post-sterilization step before an endoscope is safe to use?
- Rinsing with sterile water
- Aeration to remove toxic residuals (Correct answer)
- UV light exposure
- Alcohol wipe-down
Correct answer: Aeration to remove toxic residuals
EO-sterilized items must undergo aeration to allow toxic EO and its by-products (ethylene glycol, ethylene chlorohydrin) to dissipate to safe levels.
Question 4: A flexible endoscope cannot withstand steam sterilization primarily because of:
- Incompatibility with moisture
- Heat sensitivity of materials and adhesives (Correct answer)
- Risk of channel blockage from condensation
- Corrosion of metal components
Correct answer: Heat sensitivity of materials and adhesives
The high temperatures (121–134°C) of steam sterilization damage the heat-sensitive polymers, adhesives, and optical components used in flexible endoscope construction.
Question 5: Vaporized hydrogen peroxide (VHP) sterilization is contraindicated for endoscopes with long narrow lumens because:
- VHP cannot penetrate cellulosic materials
- Hydrogen peroxide condenses and loses efficacy in narrow channels (Correct answer)
- VHP reacts with stainless steel
- The process temperature is too high for endoscopes
Correct answer: Hydrogen peroxide condenses and loses efficacy in narrow channels
VHP cannot reliably penetrate long, narrow lumens because the vapor condenses before reaching all surfaces, leaving areas unsterilized.
Question 6: Which sterilization parameter is NOT part of the Spaulding classification framework for determining the required level of reprocessing?
- Intended use of the device
- Body site contacted by the device
- Material composition of the device (Correct answer)
- Risk of infection associated with device use
Correct answer: Material composition of the device
The Spaulding classification is based on the risk of infection according to where the device contacts the body, not on device material composition.
Question 7: After sterilization using the STERIS System 1E, endoscopes must be:
- Stored dry in a sealed container for up to 30 days
- Used immediately or stored in sterile packaging (Correct answer)
- Rinsed with tap water before use
- Re-packaged and resterilized if not used within 24 hours
Correct answer: Used immediately or stored in sterile packaging
Because the STERIS System 1E provides point-of-use sterilization without a sterile packaging system, items must be used immediately after processing.
CER Endoscope Sterilization Methods 2
Which sterilization method uses peracetic acid as the active sterilant for heat-sensitive endoscopes?