CST Surgical Asepsis & Sterilization 2 — Questions and Answers
Question 1: Which sterilization method is most appropriate for heat-sensitive fiber optic cables?
- Steam autoclave at 132°C
- Ethylene oxide (EtO) gas (Correct answer)
- Dry heat oven at 160°C
- Flash sterilization
Correct answer: Ethylene oxide (EtO) gas
Ethylene oxide gas sterilization is used for heat-sensitive items like fiber optic cables because it operates at low temperatures.
Question 2: What is the minimum exposure time for gravity displacement steam sterilization of wrapped instruments at 250°F (121°C)?
- 3–5 minutes
- 10–15 minutes
- 30 minutes (Correct answer)
- 45 minutes
Correct answer: 30 minutes
Gravity displacement autoclaves require 30 minutes at 250°F (121°C) for wrapped instrument packs.
Question 3: A scrub technician notices a package has a torn wrapper before opening. The correct action is to:
- Open carefully and use contents immediately
- Re-wrap and re-sterilize the package (Correct answer)
- Consider the contents sterile if the inner wrap is intact
- Report to the charge nurse and discard
Correct answer: Re-wrap and re-sterilize the package
A compromised package wrapper indicates loss of sterility; the item must be re-wrapped and re-sterilized.
Question 4: Which of the following is NOT a parameter monitored by a Bowie-Dick test?
- Air removal efficiency
- Steam penetration
- Chemical indicator color change
- Sterilant concentration in EtO cycles (Correct answer)
Correct answer: Sterilant concentration in EtO cycles
The Bowie-Dick test is specific to prevacuum steam sterilizers and evaluates air removal and steam penetration, not EtO concentration.
Question 5: When setting up a sterile field, items should be placed on the sterile drape at what distance from the edge?
- At least 1 inch (2.5 cm)
- At least 2 inches (5 cm) (Correct answer)
- At least 6 inches (15 cm)
- Distance does not matter if gloves are sterile
Correct answer: At least 2 inches (5 cm)
The outer 1-inch (2.5 cm) border of a sterile drape is considered non-sterile; items must be kept at least 1 inch from the edge — some sources cite 2 inches for safety.
Question 6: Hydrogen peroxide plasma sterilization is contraindicated for which type of item?
- Stainless steel instruments
- Cellulose-based (paper) packaging or items (Correct answer)
- Titanium implants
- Laparoscopic trocars
Correct answer: Cellulose-based (paper) packaging or items
Cellulose-based materials absorb hydrogen peroxide plasma and prevent sterilization from occurring, making them incompatible with this method.
Question 7: Which action by the scrub technician is correct when passing a sterile item to the surgeon?
- Hold the item above the sterile field and drop it
- Place the item directly on the sterile field without touching the surgeon's hand
- Hand the item handle-first while keeping hands below the surgeon's hands (Correct answer)
- Pass over the non-sterile zone if the route is short
Correct answer: Hand the item handle-first while keeping hands below the surgeon's hands
Items should be passed handle-first to the surgeon, with the scrub technician's hands positioned below to avoid contamination.
CST Surgical Asepsis & Sterilization 2
Which sterilization method is most appropriate for heat-sensitive fiber optic cables?