Certified Surgical Technologist Aseptic Technique and Sterilization Questions and Answers — Questions and Answers
Question 1: A surgical technologist is setting up for a procedure and notices a wrapped instrument tray has a small, dry water stain on the outer wrap. The integrity of the packaging is not compromised, and the external chemical indicator has changed appropriately. What is the most appropriate action for the technologist to take?
- Use the instruments, as the indicator change and intact wrap confirm sterility.
- Remove the outer wrap and inspect the inner wrap before deciding to use the tray.
- Consider the tray contaminated and remove it from the sterile field. (Correct answer)
- Wipe the stained area with a sterile towel before opening the tray.
Correct answer: Consider the tray contaminated and remove it from the sterile field.
Any moisture that penetrates a sterile barrier, even if it has since dried, creates a pathway for microorganisms to enter. This is known as strike-through contamination. The presence of a water stain indicates a previous event that compromised the package's sterility, making the contents unsterile and unsafe for use.
Question 2: Which of the following provides the most definitive evidence that a sterilization cycle was effective?
- A chemical indicator strip inside the pack has changed to the correct color.
- The printout from the sterilizer shows all physical parameters were met.
- A biological indicator containing Geobacillus stearothermophilus spores shows no growth after incubation. (Correct answer)
- The indicator tape on the outside of the package has changed color.
Correct answer: A biological indicator containing Geobacillus stearothermophilus spores shows no growth after incubation.
A biological indicator (BI) is the gold standard for verifying sterilization efficacy. It directly challenges the sterilizer's ability to kill the most resistant microorganisms, such as Geobacillus stearothermophilus spores for steam sterilizers. A negative result (no growth) provides the highest level of assurance that the sterilization process was lethal. Chemical indicators and physical readouts only confirm that the items were exposed to certain conditions, not that sterility was achieved.
Question 3: During a surgical procedure, a circulating nurse reaches over the sterile back table to retrieve an item. Which principle of aseptic technique has been violated?
- Sterile items should be kept separate from non-sterile items.
- The edges of a sterile container are considered unsterile.
- Non-sterile individuals should not reach over a sterile field. (Correct answer)
- The sterile field should be created as close as possible to the time of use.
Correct answer: Non-sterile individuals should not reach over a sterile field.
A fundamental principle of aseptic technique is that non-sterile persons must never reach over a sterile field. Doing so can cause shedding of microbes, dust, or other particles from the non-sterile person onto the sterile surface, leading to contamination. Non-sterile personnel should always maintain a safe distance from sterile fields.
Question 4: The modern concept of 'event-related sterility' dictates that an item remains sterile until what occurs?
- The expiration date printed on the package is reached.
- The item has been stored for more than 30 days in a clean, dry area.
- An event compromises the integrity of the package. (Correct answer)
- The item is moved from central sterile supply to the operating room.
Correct answer: An event compromises the integrity of the package.
Event-related sterility (ERS) is the current standard, replacing time-related expiration dates. It posits that a product remains sterile until an 'event' occurs that compromises the package barrier. Such events include tears, punctures, moisture penetration, or broken seals, regardless of how long the item has been sterilized.
Question 5: A surgical technologist is preparing for a case involving heat-sensitive instruments, such as flexible endoscopes. Which sterilization method would be most appropriate for these items?
- Dry heat sterilization
- Steam autoclave
- Ethylene Oxide (ETO) gas (Correct answer)
- Ionizing radiation
Correct answer: Ethylene Oxide (ETO) gas
Ethylene Oxide (ETO) is a low-temperature sterilization method suitable for items that are sensitive to heat and moisture, such as flexible scopes, plastics, and delicate instruments. Steam autoclaving and dry heat use high temperatures that would damage such items, while ionizing radiation is typically used for industrial sterilization of pre-packaged goods.
Question 6: When donning a sterile gown and gloves using the closed-gloving technique, which part of the gown is considered non-sterile?
- The front of the gown from chest to the level of the sterile field.
- The sleeves from 2 inches above the elbow to the cuff.
- The back of the gown and the stockinette cuffs. (Correct answer)
- The entire outer surface of the gown once it is tied.
Correct answer: The back of the gown and the stockinette cuffs.
The back of the surgical gown is considered non-sterile because it cannot be continuously monitored by the wearer and may brush against unsterile surfaces. The stockinette cuffs are also considered non-sterile as they are designed to be enclosed within the glove, and the wearer's hands pass through them, making them prone to contamination.
Certified Surgical Technologist Aseptic Technique and Sterilization Questions and Answers
A surgical technologist is setting up for a procedure and notices a wrapped instrument tray has a small, dry water stain on the outer wrap.
The integrity of the packaging is not compromised, and the external chemical indicator has changed appropriately.
What is the most appropriate action for the technologist to take?