Medical Device Reprocessing Association of Ontario (MDRAO) Practice Exam

What type of sterilization uses a vacuum to remove air and steam?

1. Gravity sterilization

2. Flash sterilization

3. Pre-vacuum sterilization

4. Dry heat sterilization

The correct answer is: Pre-vacuum sterilization

Pre-vacuum sterilization is a method that employs a vacuum to eliminate air from the sterilization chamber prior to the introduction of steam. This is crucial in ensuring that steam effectively penetrates and reaches all surfaces of the items being sterilized, especially in hard-to-reach areas of complex instruments. The vacuum phase enhances the performance of the steam by creating a low-pressure environment, allowing it to condense on the surfaces of the instruments more effectively. This method is particularly useful for sterilizing porous loads and items with lumens, making it a preferred choice in many healthcare settings. In contrast, gravity sterilization relies on the natural force of gravity to displace air, which can be less effective in achieving uniform steam penetration. Flash sterilization, while also involving steam, is used for expedited processing of unwrapped items and does not utilize a pre-vacuum phase. Dry heat sterilization deploys hot air and does not involve steam or vacuum, making it unsuitable for items that require steam sterilization. These distinctions clarify why pre-vacuum sterilization is the most appropriate answer for the described process involving both vacuum and steam.