CSFA Microbiology and Infection Control 3 — Questions and Answers
Question 1: A patient with a known latex allergy requires surgery. The CSFA's FIRST priority regarding infection control and safety is to:
- Administer prophylactic antihistamines pre-operatively
- Ensure the OR is set up as a latex-free environment before the patient enters (Correct answer)
- Use only powder-free latex gloves
- Notify risk management after the case
Correct answer: Ensure the OR is set up as a latex-free environment before the patient enters
The OR must be completely converted to a latex-free environment before the patient arrives to prevent anaphylaxis from airborne latex particles.
Question 2: Which of the following organisms is the most common cause of healthcare-associated surgical site infections?
- Escherichia coli
- Staphylococcus aureus (Correct answer)
- Pseudomonas aeruginosa
- Candida albicans
Correct answer: Staphylococcus aureus
Staphylococcus aureus, including MRSA strains, remains the leading cause of SSIs in healthcare settings due to its presence on skin flora.
Question 3: A surgical instrument contaminated with blood falls to the floor during a procedure. The CORRECT action is to:
- Wipe it with a sterile towel and continue using it
- Hand it off the sterile field and obtain a replacement sterile instrument (Correct answer)
- Rinse it with sterile saline and return it to the field
- Flash sterilize it if the case is urgent
Correct answer: Hand it off the sterile field and obtain a replacement sterile instrument
Any item that falls below the level of the sterile field or contacts a non-sterile surface is considered contaminated and must be removed and replaced.
Question 4: The recommended minimum internal temperature for steam sterilization (gravity displacement autoclave) of wrapped instrument sets is:
- 115°C (239°F) for 10 minutes
- 121°C (250°F) for 15–30 minutes (Correct answer)
- 134°C (273°F) for 3 minutes only
- 100°C (212°F) for 30 minutes
Correct answer: 121°C (250°F) for 15–30 minutes
Gravity displacement autoclaves typically require 121°C (250°F) for 15–30 minutes to achieve sterilization of wrapped instrument sets.
Question 5: Contact precautions are indicated for a patient infected with which of the following organisms?
- Mycobacterium tuberculosis
- Vancomycin-resistant Enterococcus (VRE) (Correct answer)
- Influenza A virus
- Neisseria meningitidis
Correct answer: Vancomycin-resistant Enterococcus (VRE)
VRE requires contact precautions — gloves and gown for all contact — because it spreads through direct contact with the patient or contaminated surfaces.
Question 6: Which type of wound classification carries the HIGHEST risk of postoperative infection?
- Class I: Clean
- Class II: Clean-contaminated
- Class III: Contaminated
- Class IV: Dirty-infected (Correct answer)
Correct answer: Class IV: Dirty-infected
Class IV dirty-infected wounds (e.g., perforated viscus, traumatic wounds with retained devitalized tissue) have infection rates of 40% or greater.
Question 7: When performing counts to maintain sterile field integrity, instruments with lumens require special attention because:
- They are heavier and more difficult to handle
- Retained objects or debris inside lumens are not visible to the naked eye (Correct answer)
- Lumen instruments are always considered contaminated
- They require a separate sterilization process
Correct answer: Retained objects or debris inside lumens are not visible to the naked eye
Lumened instruments (e.g., suction tips, trocars) can harbor retained material or organic debris inside that is not visible, requiring thorough inspection and cleaning.
CSFA Microbiology and Infection Control 3
A patient with a known latex allergy requires surgery.
The CSFA's FIRST priority regarding infection control and safety is to: