NHA Certified Clinical Medical Assistant (CCMA)Clinical Patient CareHard
A medical assistant is assisting with a minor surgical procedure in the clinic. Which of the following is the most effective method for sterilizing heat-sensitive instruments?
- ABoiling water
- BEthylene oxide gas
- CDry heat sterilization
- DAutoclaving
Show answer & explanationAnswer & explanation
Correct answer: B. Ethylene oxide gas
Ethylene oxide gas sterilization is a low-temperature process effective for heat- and moisture-sensitive instruments. Autoclaving and boiling water are moist heat methods unsuitable for heat-sensitive items. Dry heat sterilization uses high temperatures and is also not suitable for heat-sensitive materials.
Why the other options are wrong
- A. Boiling water uses high temperatures and is not a true sterilization method (it only disinfects, not sterilizes, some spores may survive), and would damage heat-sensitive instruments.
- C. Dry heat sterilization uses very high temperatures for prolonged periods, making it unsuitable for heat-sensitive instruments.
- D. Autoclaving uses high-pressure steam and high temperatures, which would damage heat-sensitive instruments.
Sterilization Methods for Heat-Sensitive Instruments
Techniques used to eliminate all microorganisms, including spores, from instruments that cannot withstand high temperatures.
- Ethylene Oxide (EtO) gas: low-temp, penetrates packaging, toxic.
- Hydrogen Peroxide Plasma: low-temp, safe, rapid, limited penetration.
- Glutaraldehyde: liquid chemical sterilant, requires long soak times.
- Peracetic Acid: liquid chemical sterilant, rapid, no toxic residue.
Memory trick: Heat Harms, Chemicals Cleanse