NHA Infection Control and Safety 2 — Questions and Answers
Question 1: Which disinfection level is required for semicritical medical instruments that contact intact mucous membranes?
- Low-level disinfection
- Intermediate-level disinfection
- High-level disinfection (Correct answer)
- Sterilization
Correct answer: High-level disinfection
Semicritical items such as endoscopes and laryngoscopes that contact intact mucous membranes require high-level disinfection, which destroys all microorganisms except high levels of bacterial spores.
Question 2: What is the mechanism by which an autoclave sterilizes medical equipment?
- Chemical immersion in glutaraldehyde solution
- Pressurized steam at high temperature (typically 121°C) (Correct answer)
- Ultraviolet light exposure for 30 minutes
- Ethylene oxide gas at room temperature
Correct answer: Pressurized steam at high temperature (typically 121°C)
An autoclave sterilizes by exposing items to saturated steam under pressure (typically 121°C at 15 psi for 15–30 minutes), which denatures proteins and destroys all forms of microbial life including spores.
Question 3: When should gloves be changed during care of a single patient?
- Only when gloves become visibly torn or soiled with blood
- Every 30 minutes regardless of activity
- When moving from a contaminated body site to a clean body site on the same patient (Correct answer)
- Only between different patients
Correct answer: When moving from a contaminated body site to a clean body site on the same patient
Gloves must be changed between tasks on the same patient when moving from a contaminated to a clean body site to prevent cross-contamination within the patient's own body.
Question 4: What is the correct procedure for disposing of a used needle after drawing blood?
- Recap the needle using the two-handed technique before disposal
- Place the uncapped needle immediately into a puncture-resistant sharps container (Correct answer)
- Break the needle at the hub to prevent reuse
- Wrap in gauze and place in a regular waste bin
Correct answer: Place the uncapped needle immediately into a puncture-resistant sharps container
Used needles must be placed immediately — without recapping — into a puncture-resistant, leak-proof sharps container to prevent needlestick injuries and pathogen exposure.
Question 5: Which PPE is minimally required when within 3–6 feet of a patient on droplet precautions?
- N95 respirator and full gown
- Surgical mask worn over nose and mouth (Correct answer)
- Gloves and gown only
- Face shield without a mask
Correct answer: Surgical mask worn over nose and mouth
Droplet precautions require wearing a surgical mask when within 3–6 feet of the patient because large respiratory droplets (>5 microns) do not remain airborne and fall quickly.
Question 6: What is the key difference between sterilization and disinfection?
- Sterilization removes visible dirt; disinfection kills microorganisms
- Sterilization destroys all microorganisms including spores; disinfection reduces but may not eliminate resistant spores (Correct answer)
- Disinfection is a higher level of decontamination than sterilization
- They are interchangeable terms in clinical practice
Correct answer: Sterilization destroys all microorganisms including spores; disinfection reduces but may not eliminate resistant spores
Sterilization destroys all forms of microbial life including highly resistant bacterial spores, whereas disinfection reduces microorganism levels but typically does not eliminate all spore forms.
Question 7: What is the immediate first-aid action after a healthcare worker sustains a needlestick injury from a patient?
- Apply a tourniquet above the injury site
- Wash the wound thoroughly with soap and water, then report immediately (Correct answer)
- Pour bleach or antiseptic directly into the wound
- Cover the wound with a bandage without washing
Correct answer: Wash the wound thoroughly with soap and water, then report immediately
The immediate response to a needlestick is to wash the wound with soap and water (do not squeeze or apply caustic agents), followed by immediate reporting and post-exposure evaluation per facility protocol.
NHA Infection Control and Safety 2
Which disinfection level is required for semicritical medical instruments that contact intact mucous membranes?