Sun28November0440PM 9

Are the following true with regard to sterilising medical equipment?

True / False

Dry heat sterilisation is the fastest process of sterilisation Correct

Sterilisation using ethylene oxide is a long, complex process Correct

Ethylene oxide is carcinogenic Incorrect answer selected

Duration of autoclave process is inversely proportional to the heat and pressure used Correct

The most commonly used commercial sterilisation process is radiation Incorrect answer selected

Explanation

Dry heat is a slow process that uses high temperatures for quite long periods, for example 30 minutes at 150°C.

Autoclaving uses a combination of heat and pressure. As the heat and pressure increase, the autoclave process times decrease. Process times can vary from 30 minutes if at 1 atmosphere and 122°C to three minutes at 2 atmospheres at 134°C.

Ethylene Oxide (EtO) sterilisation is mainly used to sterilise medical and pharmaceutical products that cannot support conventional high temperature steam sterilisation, particularly those that incorporate electronic components, plastic packaging or plastic containers.

Sterilisation using ethylene oxide is a long complex process. There is initial environmental "preconditioning" of the plastic product for 12-72 hours in a specialised room (heated to 47oC and moisture 65%). The product is then inserted into a chamber and subected to a series of cycles:

Nitrogen wash and creation of a vacuum

Injection of EtO gas (concentration 100%)

4-6 hour dwell time

The product needs to be washed by nitrogen and heated aeration to remove all molecules of EtO

Answer Statistics

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Average score: 63.43%

Times answered: 233