NCMA Infection Control & Sterilization 2 — Questions and Answers
Question 1: Steam autoclave sterilization is effective because it uses:
- Dry heat at 320°F for 2 hours
- Saturated steam under pressure at 121°C (250°F) (Correct answer)
- Ethylene oxide gas at room temperature
- Ultraviolet radiation for 30 minutes
Correct answer: Saturated steam under pressure at 121°C (250°F)
Autoclaving uses saturated steam under pressure (typically 121°C at 15 psi for 15–30 minutes) to denature proteins and destroy all microbial life including spores.
Question 2: Which chemical indicator confirms that a package has been exposed to the sterilization process?
- Biological indicator
- Chemical indicator tape (Correct answer)
- Mechanical indicator
- Color change strip inside the pack
Correct answer: Chemical indicator tape
Chemical indicator tape on the outside of a package changes color when exposed to the sterilization conditions, confirming the package was processed.
Question 3: Ethylene oxide (EtO) sterilization is preferred for which type of item?
- Stainless steel surgical instruments
- Linen and cloth items
- Heat-sensitive equipment such as endoscopes and plastics (Correct answer)
- Glass bottles and vials
Correct answer: Heat-sensitive equipment such as endoscopes and plastics
Ethylene oxide sterilizes at low temperatures and is therefore used for heat-sensitive items like plastics, rubber, and delicate electronic equipment.
Question 4: The Spaulding Classification categorizes medical instruments into three groups. Which category requires sterilization?
- Non-critical items
- Semi-critical items
- Critical items (Correct answer)
- All of the above
Correct answer: Critical items
Critical items (those entering sterile tissue or the vascular system, such as surgical instruments and needles) must be sterilized to prevent infection.
Question 5: How long should a medical assistant scrub their hands using the surgical hand scrub technique?
- 15 seconds
- 1 minute
- 3–5 minutes (Correct answer)
- 30 seconds
Correct answer: 3–5 minutes
The surgical hand scrub involves scrubbing hands and forearms for 3–5 minutes (or per facility protocol) to achieve surgical asepsis before sterile procedures.
Question 6: Which organism is most commonly associated with healthcare-acquired infections (HAIs) transmitted via contaminated hands?
- Staphylococcus aureus (MRSA) (Correct answer)
- Clostridium tetani
- Mycobacterium tuberculosis
- Varicella-zoster virus
Correct answer: Staphylococcus aureus (MRSA)
MRSA is a leading cause of healthcare-acquired infections and is frequently transmitted via the hands of healthcare workers from patient to patient.
Question 7: When cleaning a contaminated exam table, the medical assistant should use a disinfectant that is registered as:
- EPA-registered hospital-grade disinfectant (Correct answer)
- FDA-approved cleaning solution
- OSHA-certified germicide
- Any commercial bleach product
Correct answer: EPA-registered hospital-grade disinfectant
The EPA registers hospital-grade disinfectants that meet efficacy standards for killing pathogens found in healthcare environments; this registration is required for clinical surfaces.
NCMA Infection Control & Sterilization 2
Steam autoclave sterilization is effective because it uses: