5 - Steam Flashcards
Why is steam used for sterilisation?
- carries a lot of energy
- non-toxic component
- can be recondensed and used again
- water is readily available
- no waste product except for water
Describe the water used for steam sterilisation.
- purified water
- de-ionised, distilled or sterile water
- organics, minerals and micro-organisms removed/filtered out
How is pressure created within the steam steriliser?
A small amount of water can create large amounts of steam in excess of 1000x greater, creating great pressure when enclosed
Describe a type-N steriliser.
- heats water in chamber
- steam passively forces air from the chamber
- can leave pockets of air which is not favourable
- wrapped instruments or instruments with lumens cannot be processed
- therefore instruments have been sterilised but are not sterile at point of use (instruments should be wrapped immediately after)
How do air pockets affect the sterilisation process?
- cannot maintain temperature in the same way as steam
- always cooler than the steam
- if instruments are in contact with the air pockets they may not achieve the sterilisation temperature for the required length of time
What is the pressure and temperature required for a type-N steriliser?
- 134-137 degrees
- 2.05-2.35 bar gauge pressure
- minimum 3 minutes
What is the pressure and temperature required for a type-B steriliser?
- 134-137 degrees
- 2.05-2.35 bar gauge pressure
- minimum 3 minutes
Describe a type-B steriliser.
- a vacuum pump removes all the air form the chamber before the steam is released
- the steam rushes into the chamber contacting all surfaces
- can penetrate the wrappings of instruments and sterilise those inside (instruments sterile at point of use)
- can sterilise instruments with lumens, as well as porous items such as cotton wool
Describe a type-S steriliser.
- specialised steriliser
- washes and lubricates handpieces
- vacuum cycle included but cannot process wrapped instruments
- achieves same pressure and temperature as type-N and -B sterilisers for 3 minutes
What is FIFO?
- first in first out
- storage management technique for sterilised instruments
What are the daily tests for generic sterilisers?
- check door seal and clean when necessary
- ensure chamber from from debris and instruments
- verify condition of load carrier
- fill and drain feed water every day
- drain used water reservoir at the end of each day
What are the daily tests for the type-B sterilisers?
Steam penetration test using Bowie Dick test pack
What are the weekly tests for the type-B sterilisers?
- air leakage test (vacuum)
- air detector function test (ADFT, safety)
