HSPA Sterilization and Disinfection 2 — Questions and Answers
Question 1: What three parameters must be achieved simultaneously for effective steam sterilization?
- Pressure, oxygen, and humidity
- Temperature, time, and steam quality (moisture) (Correct answer)
- Pressure, temperature, and chemical concentration
- Time, light exposure, and dryness
Correct answer: Temperature, time, and steam quality (moisture)
Steam sterilization requires correct temperature, adequate exposure time, and proper steam quality simultaneously.
Superheated steam cannot transfer sufficient heat. Wet steam causes wet packs. Insufficient temperature or time leaves organisms viable. All three parameters are monitored through physical, chemical, and biological indicators.
Question 2: What is the difference between high-level disinfection and sterilization?
- They are identical
- HLD kills all organisms except high numbers of spores; sterilization destroys all forms including spores (Correct answer)
- HLD only kills viruses
- Sterilization is faster
Correct answer: HLD kills all organisms except high numbers of spores; sterilization destroys all forms including spores
HLD eliminates most organisms but not all spores; sterilization achieves complete microbial destruction.
HLD is appropriate for semi-critical devices contacting mucous membranes. Sterilization is required for critical devices entering sterile body areas. The SAL for sterilization is 10^-6.
Question 3: Why must air be removed from the sterilizer chamber?
- Air makes the chamber cold
- Air acts as an insulating barrier preventing steam contact, creating cold spots (Correct answer)
- Air causes rust
- Air removal is only needed for gravity cycles
Correct answer: Air acts as an insulating barrier preventing steam contact, creating cold spots
Trapped air creates insulating pockets where sterilization temperature is never achieved.
Air pockets remain at lower temperatures than surrounding steam. Prevacuum sterilizers pull deep vacuum to remove air. Gravity cycles rely on steam displacing air downward.
Question 4: What is the Bowie-Dick test's purpose?
- To verify correct temperature
- To verify vacuum system adequately removes air from the chamber (Correct answer)
- To test biological kill
- To calibrate pressure gauge
Correct answer: To verify vacuum system adequately removes air from the chamber
The Bowie-Dick test evaluates the air removal capability of prevacuum sterilizers.
Performed as the first cycle daily in prevacuum sterilizers. A uniform indicator color change confirms proper air removal. If the test fails, the sterilizer cannot be used until repaired.
Question 5: What is immediate-use steam sterilization (IUSS) and when is it appropriate?
- Preferred method for all sterilization
- Emergency shortened cycle when no sterile alternative is available (Correct answer)
- Method for sterilizing implants
- Same as standard prevacuum sterilization
Correct answer: Emergency shortened cycle when no sterile alternative is available
IUSS is a shortened cycle for emergencies only when no sterile alternative instrument is available.
IUSS should not substitute for insufficient inventory or convenience. Items must be used immediately, cannot be stored, and should be biologically monitored. Never for implants.
Question 6: What is the minimum biological indicator testing frequency for each sterilizer?
- Monthly
- Weekly
- At least weekly, plus every load with implants (Correct answer)
- Only after maintenance
Correct answer: At least weekly, plus every load with implants
BIs should be run at least weekly in each sterilizer and with every implant load.
For implant loads, rapid-readout BI results should be available before use. BIs are also needed after installation, major repairs, and process changes. Many facilities test daily.
HSPA Sterilization and Disinfection 2
What three parameters must be achieved simultaneously for effective steam sterilization?