Gas Sterilisation

Question 1

What gas is used?

Answer 1

ethylene oxide- inactivates micro-organism DNA, cellular reproduction

Question 2

Ethylene Oxide safety concerns?

Answer 2

toxic
irritant tissues
inflammable

Question 3

What factors influence?

Answer 3

temperature
concentration
pressure
exposure time
humidity

Question 4

Does a high temperature affect ethylene oxide?

Answer 4

more effective use, shorter cycle

Question 5

How much does an oxide cycle last up to?

Answer 5

12-24hrs

Question 6

Benefits of gas sterilisation?

Answer 6

gentle- sharp instruments not blunted
items damaged- heat/ stream sterilised by cameras/ phones
effective- small complex devices- tubing- against bacteria

Question 7

What are the considerations of an ET Oxide sterilising unit?

Answer 7

metal, ventilation inbuilt
prevents gas from entering environment
20’C room temp

Question 8

Packing/ Sterilisation considerations?

Answer 8

polythene liner
glass vial
probe- sealed
air purged from bag
close door/ lock

Question 9

How long should you leave equipment to sterilise for?

Answer 9

12hrs, switch pump to ventilate, futher 2hrs
leave for 24hrs
ventilated for anprolene

Question 10

What is the Procedure?

Answer 10

Wash- remove visible bioburden, internal spaces (flexible endoscopes)

Dis-assemble- remove bungs, caps

Dry- towel/ air, heated cause bacteria form spores, more resistant to ethylene oxide

Pack- paper, cloth, permeable plastic, (seal/ peel)- not nylon film

Sterilisation- 12hrs or 24hrs- 2 hours aretation

Question 11

What is important for testing sterilisation efficiency?

Answer 11

Dosimeter Strips- colour change when exposed (place in centre of load)

Indicator Tape- yellow to red, no guarantee of sterility, no indication for correct amount of time

Spore Strips- place in load, need 72hour intubation

Indicator Stickers- provided by manufacturer, yellow dots turn blue- useful not 100% reliable, dot will change colour/ prolonged light

SteriDot Discs- red to green