Decontamination textbook Flashcards
What are the 6 parts in the chain of infection?
- Infectious agent
- Reservoir
- portal of exit
- means of transmission
- portal of entry
- suceptible host.
what is the R0 number?
the number of cases one case generates on average over the course of its infective period.
what does an R0 <1 mean?
the infection will die out in the long run.
what does an R0 >1 mean?
the infection will be able to spread in a population.
compare small and large droplets in terms of their transmission ability.
Large droplets are good for infecting surfaces.
Small droplets can evaporate into the air where they can stay for minutes or hours.
discuss influenza action
influenza has 2 surface glycoproteins:
Hemaglutinin H1-15 which is a key component for interaction with the cell.
Neuroaminidase N1-9 which the virus uses to break out of infected cells.
What is Spaulding?.
This is used to describe the risk of infection:
Critical
Semi-critical
Non-critical
Minimal risk.
Discuss the relevance of COI pseudomonas aeruginosa?
It is a gram negative bacilli.
It can be found in contaminated water so can contaminate the dental system getting into the hand-piece and infecting aerosols.
What PPE do we use during disinfection?
Apron- to prevent ourselves from being contaminated
Gloves- to protect our hands
Visor- to protect our face and eyes
List the stages of disinfection?
Transport
Washer disinfector
Inspection
Packaging
Sterilisation
Storage.
What are the stages of the automatic washer disinfector?
Prewash - Saturates contaminated instruments
Main wash- Use detergents to effectively remove contamination
Rinse - Removes any remaining residue
Thermal disinfection- Uses heated water (90-95*) to kill the micro-organisms.
Drying- Removes any remaining moisture before sterilisation
How is contamination removed from the washer disinfector?
What do we use to inspect instruments and what are we looking for?
An illuminated magnifier
Looking for contamination and damage.
After inspection we have noticed an instrument is contaminated. How do we proceed?
We put clean the instrument through manual cleaning or ultrasonic before putting it through the AWD again.
Describe manual washing?
This requires 3 sinks (washing/rinsing/handwashing)
You need to wash under the water to contact water and disinfectant & prevent aerosol production.
When do we use manually scrubbing?
When the instrument can only be cleaned manually.
How does an ultrasonic work to clean instruments?
High frequency sound waves produce bubbles that expand and collapse scouring the hard surface
Why do we use steam to sterilise the instruments?
It is non toxic
Produces no waste except water
Carries alot of energy.
How does a type N steriliser work and what is it used for?
The steam forces the gas out.
It is used for rigid steel instruments with no pocket channels or lumen.
How does a type B steriliser work and what is it used for?
It removes the air from the chamber creating a vacuum and then fills the chamber with steam.
Which steriliser do we commonly use
Type B steriliser
What is the stage time and temperature recognised to achieve sterilisation.
3 minutes and 134-137 degrees Celsius
What are the 4 key elements for successful cleaning?
Energy, chemical, temperature, time.
Why do we limit the time between use and processing?
So that the blood or biological matter does not have time to dry in and adhere to the instrument.
What chemical is used in the washerdisinfectant?
High and low alkaline detergent
What chemical is used in the ultrasonic?
Enzymatic detergent
What chemical do we use in manual washing?
Ph neutral detergent
Compare the force used for cleaning of the manual, ultrasonic and washer disinfector.
Manual
At what temperature does manual cleaning occur ?
<35 degrees celsius
At what temperature and for how long does the ultrasonic work?
<35 degrees for 20 minutes
At what temperature and for how long does the washer disinfector work?
<65 degrees for 55 minutes
At what temperature and for how long does thermal disinfection occur.
between 90 and 95 degrees for a minimum of 1 minute.
At what pressure does steam sterilisation occur?
2-2.3 bar pressure
What type of water is used for sterilisation and why?
Purified water (so that there is a reduced conductivity and low levels of bacteria and fungals)
What container must be used when transporting used instruments?
Durable/leak proof container.
With a tight fitting lid
Can be easily cleaned and disinfected.
Compare guidance, legislation and standards in terms of decontamination
Guidance- documents directing peple about working in decontamination
Legislation- must be complied with.
Standards- provide details on how to carry out certain tasks
In terms of decontamination who is the user?
The person responsible for the sterilizer/washer disinfectant.
What is a medical device?
Any instrument used for procedures and the equipment used to reprocess the instrument.
Why do we test equipment?
