sterilisers Flashcards
what is the guidance document?
SHTM 2010
daily info for sterilisation
date time started operator cycle no sterilisation temp daily tests performed sterilisation successful machine identified cycle completed successfully Type B - Bowie Dick successful
who carries out the daily and weekly tests?
on site staff
temp
134-137 degrees
time
min hold time 3mins
pressure
pressure equivalent gauge (from atmospheric) 2.05 to 2.35 bar
pressure equivalent absolute (from absolute 0) 3.05 to 3.35 bar
do all sterilisers achieve the same temp and pressure?
yes
daily tests
wipe door seal with clean, disposable, damp, non-linting cloth and carry out any other checks required by the manufacturer, check seal for damage/contamination
check load carrier and chamber for damage/debris/clean
fill and drain water reservoir
when switching power on, check that the ventilation louvers are not covered to avoid overheating
if recommended by the steriliser manufacturer, preheat the steriliser chamber before performing daily tests
record completion of the daily checks in the steriliser logbook
Type B: Bowie Dick (steam penetration) test
record daily sterilisation temps
which extra daily test is required for type B sterilisers?
Bowie Dick (steam penetration) test
sterilisation
a process undertaken to render a steriliser load sterile
sterile
condition of a medical device that is free from viable MOs
weekly tests
Type B - air detector function test and air leakage test
ACT
daily tests
weekly safety checks
weekly safety checks
examine door seal for signs of wear or damage
examine security and performance of the door safety features inc the hinges and locking mechanism as detailed in the MIs
if a fault is detected in the door seal or safety features, ensure this is corrected before carrying out weekly tests or using the steriliser
record satisfactory completion of the weekly safety checks in the steriliser logbook
type N steriliser - how does it work?
‘gravity displacement’
air passively displaced by steam
purified water introduced to the chamber and heated
as it boils and turns to steam, the chamber pressure increases
what instruments can be processed in type N?
rigid steel solid instruments
no wrapped/channeled/lumened
stages in type N
air removal - heating time
sterilising - holding time
condensing - cooling time
what instruments can be processed in a type B?
wrapped and non-wrapped (make sure not to damage wrappings)
channelled and porous instruments
porous loads e.g. cotton swabs
loading recommendations
no overlapping/shadowing
do not overload machine
assemblies should be disassembled beforehand
utilise the available basket/load carrier
type B - how does it work?
porous load/vacuum capable
has active air removal creating a vacuum in the chamber in its initial stage
so steam can contact all surfaces of device
because there is no air in the chamber, the vacuum rapidly draws the steam in from the generator
after sterilisation the machine draws another vacuum for drying, allowing water to vapourise at lower temps
B type - after processing
wrapping intact - ‘sterile’ at point of use
can store in env controlled atmosphere that is free from contaminants and moisture
N type - after processing
‘sterilised’
wrap as soon as remove from steriliser and transport to procedure room
either for immediate use or for non-sterile storage, transport and application
why should instruments be left to cool down after first?
if put hot instrumentation into transport box might cause condensation to build up, potentially damaging wrappings
for sterilisation of wrapped goods what must the residual gas not exceed?
3.5 ml per 100ml of condensed steam
air detector incorporated as a safety device to monitor the adequacy of the air removal process
what is residual gas?
remaining air and gases carried in the steam after the air removal stage
type S
products specified by the manufacturer of the steriliser inc non-wrapped solid products and ≥1 of the following: porous products, small porous items, hollow load products type A, hollow load products B, single wrapped products, multiple layer wrapped products
vacuum pump/some other active method to remove air from the chamber and load
what should dental handpieces be sterilised using?
a vacuum process
type S
obligations under H+S and Consumer Protection Act
ensure equipment:
- complies with safety requirements
- installed and maintained appropriately
- validated and routinely tested
- operated only in accordance with MIs and by properly trained operators
water and steam quality
good quality water to make good quality steam
water low in minerals to prevent depositing minerals onto the instruments (limescale) and making them harder to clean
waters recommended by manufacturers for use in sterilisers
= pure water RO distilled sterile deionised
basic stages of operation of Type B
1 - air removal (negative pulsing) 2 - steam admission (positive pulsing) 3 - equilibration 4 - sterilisation 5 - drying 6 - air admission (0.2micron fitted inlet)