3rd year key points Flashcards
WD loading requirements
basket furniture
no shadowing/overlap
hinged items kept open
disassemble instruments
WD daily checks
load carrier - damage or debris/instruments spray arms rotating freely jets not blocked door seal intact strainer not blocked enough chemical detergent
how should you rinse items?
below surface in a separate sink
steriliser daily checks
door seal intact
load carrier and chamber
- no debris/instruments/damage
fill water reservoir - pure water
why should you manually wash below surface?
minimise contamination and aerosol production
sinner circle
chemicals
time
temp
energy
transport
ASAP container - rigid, durable, leakproof - tight fitting lid - easy to clean and disinfect - clearly labelled as contaminated
what water is used for rinsing?
RO
purified and easy to make in large quantities
4 types of demineralised/purified water
sterile
distilled
deionised
RO
cleaning
removal of contamination from an item to the extent necessary for its further processing and intended use
“a soil removing process that requires energy which removes a high proportion of all microbes present inc bacterial spores”
what does cleaning presuppose?
nature of any likely contaminant is known and that it is possible to define a level below which it will have no adverse effect
corrosion
resistance - protective passivation layer
- easier to clean and harder for bacteria to cling on to
avoid damage - avoid wire brushes
non-immersion cleaning
wiping
wipe with detergent solution
clean non-linting cloth
never use brushes - aerosols
immersion cleaning
brushing
30-35 degrees
scrub under water using long-handled brushes with soft plastic bristles
minimise aerosols - never scrub under running water
neutral enzymatic detergent
if you find an item dirty at any stage what should you do?
start the whole process again
what shouldn’t be processed in an US?
handpieces
how do US machines work?
apply high freq sound wave
produce microbubbles
cause cavitation when they implode
energy released helps remove soil
why should you degass first?
air will inhibit cavitation
water stages
manual wash US manual rinse WD steriliser
cold mains water
manual washing
US
WD
hot mains water
manual washing
WD
what suspended particles do you need to remove?
hard particles
soft particles
colloidal (insoluble) particles
water for manual washing
use as a solvent to dilute detergents
water v good as a wetting agent to break down soiling
how do detergents work?
suspend removed soil in water
hydrophobic end sticks to surface of soiling
leaves soiling coated in hydrophilic ends of the molecules so it ‘likes’ being in water and can be washed away
why do you need to change water/detergent solution in an US bath?
detergent loses its properties as the molecules become saturated by the soiling
validated with clean water
rinsing and water
need water with low mineral content
mineral deposits turn to limescale
- produced when water boiled off and minerals left behind
decon
sum of those processes required to make the used device available in a form that is safe and fit for use on subsequent pts
why use RO for final disinfection rinse?
one of the recommended waters low in mineral content
only one capable of making water in high enough vols quickly enough to keep up with the WD
how is RO water made?
RO membrane under pressure
how is distilled water made?
boiled - turns to steam
steam caught and condenses
how is deionised water made?
ion exchange resin - chemical process
how is sterile water made?
deionise then distil then sterilise
£££
LDU
segregation of dirty and clean
linear flow
decon life cycle of an instrument
(acquisition) cleaning disinfection inspection (disposal) packaging sterilisation transport storage use transport
disinfection
destruction of pathogenic and other MOs by physical or chemical means
less lethal than sterilisation
destroys most recognised pathogenic MOs, but not necessarily all microbial forms e.g. bacterial spores
doesn’t ensure margin of safety associated with sterilisation processes
90-95 degrees 12s
sterilisation
use of a physical/chemical procedure to destroy all MOs inc a large number of resistant bacterial spores
why disinfect if going to sterilise?
makes load and machine safe for operator
adds reassurance for safety of pt
inspection
visual (lit magnifier) vs protein residue detection
- assurance
- FMIs
to be “sterile”
theoretical probability of a viable MO after successful validated sterilisation ≤1 in a million
process to render reusable medical devices free from viable MOs
when are prions removed?
wash stage (not sterilisation)
advantages of using steam
rapid heating rapid penetration of load rapid destruction of MOs inc bacterial spores no toxic residues - no chemicals used low cost easily controlled and monitored
contamination with residual tissue, body fluids, oil or other deposits
prevent contact between steam and surfaces
might become fixed to items and be difficult to remove
might contaminate water in steriliser and encourage bacterial growth
could cause adverse effects in pts
dangers of steam
steam takes up much more vol than water - high pressure
to prevent explosion need a device to relieve the pressure
- pressure control valve - lifts at set pressure
WD detergent
neutral ph7 enzyme detergent
what is sterilisation?
exposing medical devices to conditions that are not detrimental to the device but which are lethal to MOs on device
a result of direct contact of medical devices with saturated steam in absence of air
need clean and dry prior
air in steriliser
can prevent attainment of temp and contact of load items with steam
what are steam sterilisers?
pressure vessels that generate and maintain steam under pressure
steam sterilisers legislation
Pressure Systems Safety Regulations 2000
can you reprocess single use items?
no
policy
overall statement of intent/set of rules/requirements to be followed to achieve a given process/outcome
procedure
guidelines of major methods to be used to meet the policies as defined by the company/practice
tells you who does what and when
work instructions
specific steps needed to carry out the procedures
- tells you how to do something
