CNOR Surgical Asepsis and Sterility 5 — Questions and Answers
Question 1: The principle of 'strike-through' contamination refers to:
- An instrument puncturing through a sterile drape
- Moisture passing through a sterile barrier, rendering it contaminated (Correct answer)
- A needle strike penetrating a glove during suturing
- A scrub person's gown touching a non-sterile surface
Correct answer: Moisture passing through a sterile barrier, rendering it contaminated
Strike-through occurs when moisture migrates through a sterile barrier (drape or packaging), creating a pathway for microorganisms and contaminating the field.
Question 2: Which sterilization method leaves the most toxic residue that requires extended aeration before the item is safe to use?
- Steam autoclave sterilization
- Hydrogen peroxide plasma sterilization
- Ethylene oxide (EtO) sterilization (Correct answer)
- Dry heat sterilization
Correct answer: Ethylene oxide (EtO) sterilization
EtO leaves toxic ethylene oxide residue that requires a mandatory aeration period (often 8–12+ hours) before items are safe for patient use.
Question 3: A scrubbed team member accidentally bumps into an unsterile mayo stand. The correct action is to:
- Wipe the contaminated area of the gown with a sterile towel
- Consider the gown contaminated and change it immediately (Correct answer)
- Continue if only the side of the gown made contact
- Inform the circulator and continue monitoring for signs of contamination
Correct answer: Consider the gown contaminated and change it immediately
Any contact between a sterile gown and an unsterile surface contaminates the gown; the scrubbed person must regown immediately.
Question 4: Which action ensures proper sterile technique when a circulator opens a rigid sterilization container for the scrub person?
- The circulator hands the tray directly to the scrub person
- The scrub person reaches into the container to retrieve instruments
- The circulator holds the container while the scrub person retrieves items, or tips the tray onto the sterile field (Correct answer)
- The circulator places the open container on the back table
Correct answer: The circulator holds the container while the scrub person retrieves items, or tips the tray onto the sterile field
The scrub person retrieves items from the container held by the circulator, or the circulator tips sterile contents onto the sterile field, preventing the unsterile exterior from entering the sterile field.
Question 5: Which indicator is considered the gold standard for confirming sterilization efficacy?
- Class 5 chemical integrating indicator
- Mechanical printout showing correct time, temperature, and pressure
- Biological indicator using resistant bacterial spores (Correct answer)
- Type 1 process indicator (autoclave tape)
Correct answer: Biological indicator using resistant bacterial spores
Biological indicators using resistant spores are the gold standard because they directly test whether the sterilization process killed microorganisms.
Question 6: During sterile gloving using the closed-glove technique, which statement is correct?
- The gown cuff is pulled back to expose the hand before donning the glove
- The hands remain inside the gown sleeves while the gloves are donned (Correct answer)
- The circulator assists by holding the glove open for the scrub person
- The gloves may be donned before the gown to protect the hands
Correct answer: The hands remain inside the gown sleeves while the gloves are donned
In closed-glove technique, the hands remain inside the gown sleeves throughout glove donning, preventing ungloved skin from touching the exterior of the sterile glove.
Question 7: A sterile back table will not be used for 2 hours after setup. Which is the correct action?
- Leave it uncovered in the locked OR
- Cover it with a sterile drape and document the setup time
- Consider it contaminated and re-establish it when needed (Correct answer)
- Cover it with a clean (non-sterile) impervious cover to protect from dust
Correct answer: Consider it contaminated and re-establish it when needed
A sterile field left unmonitored for any period cannot be guaranteed to remain sterile and must be considered contaminated and re-established before use.
CNOR Surgical Asepsis and Sterility 5
The principle of 'strike-through' contamination refers to: