NHA Certified Clinical Medical Assistant (CCMA)Clinical Patient CareHard

A medical assistant is preparing to assist with a minor surgical procedure. Which of the following is the most effective method for sterilizing heat-sensitive instruments?

  1. ABoiling water
  2. BDry heat sterilization
  3. CEthylene oxide gas
  4. DAutoclave
Show answer & explanation

Correct answer: C. Ethylene oxide gas

Ethylene oxide gas sterilization is a low-temperature process that is highly effective for heat-sensitive instruments, as it sterilizes without causing damage from high heat or moisture.

Why the other options are wrong

  • A. Boiling water is a disinfection method, not sterilization, and would not destroy all microorganisms, including spores, nor is it suitable for heat-sensitive items in terms of sterility.
  • B. Dry heat sterilization uses very high temperatures for prolonged periods, making it unsuitable for heat-sensitive items.
  • D. Autoclaves use high-temperature steam, which would damage heat-sensitive instruments.

Sterilization Methods for Heat-Sensitive Items

Heat-sensitive instruments require low-temperature sterilization methods, such as ethylene oxide gas or chemical solutions, to prevent damage while achieving sterility.

  • Ethylene oxide (EtO) gas is common.
  • Hydrogen peroxide plasma/vapor also used.
  • Glutaraldehyde (high-level disinfection, not true sterilization).
  • Avoids heat and moisture damage.

Memory trick: Heat-Sensitive: EtO's the Go!

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