Disinfection and Cleaning Flashcards
1
Q
Outline the main stages of cleaning and disinfecting dental instruments?
A
- Cleaning
- Disinfection
- Inspection
- Packaging
- Sterilisation
2
Q
What standards of cleaning and disinfection to all healthcare practitioners/equipment providers have to adhere to?
A
BS EN 285 and 13060 standards. SHTM 01 - 01D guidance used in reference to these standards.
3
Q
What is meant by cleaning?
A
Removal of all biological matter from the surface of instruments.
4
Q
Why is cleaning the first step in the process?
A
- To minimise spread of infection
- To achieve steam contact
- To ensure functionality of the instrument
- Legal requirement to do so
5
Q
What is the primary method of cleaning instruments, and what back up options are there?
A
Washer-disinfector is the gold standard.
Ultrasonic bath is the secondary/back up method.
Manual cleaning should only be carried out if it is the only option.
6
Q
What is meant by sterilisation?
A
Instruments should be put through a steam steriliser after being cleaned, so that little-no trace of microbial activity is found on the instrument before use on a new patient.
7
Q
What is the main goal of the cleaning stage?
A
Removal of biological matter, in particular proteins/prions.
8
Q
What three pieces of PPE should be worn during manual cleaning?
A
- An apron to protect the person
- A face shield to protect face and eyes from splashing
- Rubber gloves and heavy duty marigold gloves to protect hands.
9
Q
Outline the process of manual cleaning.
A
- Dedicated sink for cleaning
- Fill with tap water at around 30-35 degrees Celsius
- Do not exceed 35, as proteins may coagulate making them harder to remove
- Chemical detergents added for manual cleaning specifically.
- Immersion/non-immersion cleaning
- Rinse in dedicated rinse sink
10
Q
Why should scrubbing be performed under the water?
A
- Instruments in constant contact with water and detergent
- Lowers risk of splashing
- Lowers risk of aerosol production
11
Q
What instrument should be used for immersion cleaning?
A
Long handled, soft bristled brush.
12
Q
When should manual cleaning be performed?
A
- When it is specifically recommended by manufacturer’s instructions
- If there is no other alternative
-The automated processes have failed to remove the contamination.
13
Q
What is the ultrasonic bath?
A
Ferocious process that uses sound-waves to remove contamination.
14
Q
Why should a degas cycle be run on an ultrasonic?
A
To remove any gas/air bubbles that have built up in the machine whilst it has been out of use. Failure to do so reduces the effectiveness of the ultrasonic.
15
Q
What temperature is the ultrasonic bath typically set to?
A
Between 20-30 degrees Celsius.
16
Q
What type of water should be added to the ultrasonic?
A
Tap water is fine.
17
Q
After either manual washing or ultrasonic, how should the instrument be processed?
A
- Rinsed in rinse sink
- Washer-disinfector
- Inspected
- Packaged
- Sterilised
18
Q
What are the benefits of manual/ultrasonic washing?
A
- Greater force applied
- Some equipment manual wash only
- Ultrasonic baths good at removing contamination
19
Q
What are the drawbacks of manual/ultrasonic washing?
A
- Member of staff required to be present
- Risk of aerosol production
- Risk of contaminating environment
- Human error
- Sharps injuries
- Potential to damage equipment
20
Q
What are the main stages of an AWD, and what temperature do they reach?
A
- Flush/prewash - <35 degrees
- Main wash - depends on chemical
- Rinse <65 degrees
- Thermal disinfection - 90-95 degrees
- Drying - typically around 100 degrees
21
Q
Describe the stages of an AWD.
A
- Flush/prewash - saturates contamination and removes gross debris
- Main wash - detergent used to effectively remove biological matter
- Rinse - removes biological/chemical residue
- Thermal disinfection - kills microorganisms with heated water.
- Drying - removes remaining moisture from surface of instruments.
22
Q
Why is it key that proteins/prions be removed during the washing stage?
A
As they cannot be deactivated through disinfection or sterilisation, and higher temperatures can make them adhere to instruments.
23
Q
What are the loading requirements of a washer disinfector?
A
- Available furniture must be used
- Clip trays must be positioned correctly
- No overlapping of equipment
- Hinged instruments must be open at hinge
- All assemblies should be disassembled before placing in AWD
24
Q
What should be done if an instrument is still contaminated after an AWD cycle.
A
Ultrasonic/manually cleaned, followed by another AWD cycle.
25
Why is steam ideal for sterilisation?
- Steam carries massive amounts of energy
- Non-toxic
- Requires only water
- Only waste product is water
26
What type of water should be used for the sterilisation process?
Purified water (RO, de-ionised, distilled, sterile). This water has had organics, minerals, and micro-organisms removed from it.
27
What is a type-N steriliser?
Basic process of steriliser, often termed gravity displacement, or autoclave. Does not use a vacuum.
28
What are the drawbacks of using a type-N steriliser?
- Cycle isn't entirely efficient
- Steam cannot penetrate instruments with pockets, channels, or lumens.
29
What temperature and pressure, and for how long do type-N and type-B sterilisers have to maintain for instruments to have been sterilised?
135-137 degrees Celsius
2.05-2.35 bar pressure
Minimum of three minutes
30
What is a type-B steriliser?
A steriliser that utilises a vacuum pump to remove all air from the chamber, before sterilising with steam. Has the ability to penetrate wrappings of instruments and sterile them from the inside.
31
Why can you use a type-B steriliser to process a handpiece, but not a type-N?
Handpieces have a channel and a lumen, which are difficult to penetrate without first creating a negative pressure, which the vacuum pump of a type-B does.
32
What is a type-S steriliser?
A specialised steriliser, that is designed for a specific piece of dental equipment.
For example a handpiece type-S steriliser lubricates hand pieces at the same time as washing them.
33
What are the advantages of a type-B steriliser, over a type-N steriliser?
- Wrapped instruments can be placed inside
- Vacuum pump which allows penetration into lumens and pockets
- Produces instruments sterile at point of use.
34
What two tests can be done to ensure a steriliser is functioning properly?
A Bowie Dick test, or a Helix test.
35
How can a piece of equipment be considered sterile?
When it has been processed in such a way that all viable micro-organisms have been destroyed.
36
What are the four factors of sinners circle?
- Temperature
- Energy
- Chemicals
- Time
37
How are disinfectants and detergents formed to remove contamination?
Hydrophilic and hydrophobic ends on the molecule. Hydrophilic attaches to water molecules, hydrophobic attaches to contamination. This allows contamination to be washed away.
38
What is the SHTM?
Scottish health and technical memoranda, the body which gives comprehensive advice and guidance on the design, installation, and operation of specialized building and engineering used in the deliver of healthcare.
39
What guidance is available to support good practice decontamination and medical device acquisition?
SHTM – Scottish Health Technical Memorandum
SHPN – Scottish Health Planning Note
NP 143 – National Procurement Framework
BS EN – British Standard, European Norm
BSI – British Standards Institute
ISO – International Organisation for Standardisation
MDR – Medical Device Regulation
40
If you are operating/installing equipment for an LDU, what guidance should be followed
If you purchase and operate a WD or Steriliser, it must be CE (UKCA) marked and comply with the conditions of the MDR 2017/745
The cycle must comply with the requirements outlined within SHTM 01 – 01 referencing BS EN 15883
When sterilising instrumentation, it must comply with SHTM 01 – 01 referencing BS EN 285
If you are operating a small steam sterilizer (bench top) the standard is BS EN 13060
When installing this equipment and designing a facility the SHPN documentation must be referenced
41
List four legislations for decontamination.
SHTM 01 - 01
MDR 2017/745
COSHH
BS EN 13060
42
Why do we need to test the washer disinfector/steriliser?
To ensure it is working correctly and to its optimum
Testing ensures validity of the machine and warranty
Testing helps detect procedural errors and equipment malfunctions
Chemical indicators verify that sterilising agent has penetrated the package and reached the instruments inside
43
Why do we need to do manual cleaning?
To remove gross contamination
For effective sterilization
To remove organic material
Any material left on instruments may become fixed during sterilization and be more difficult to remove later
Remove restorative materials
Medico-legal requirement
44
Name 5 key personnel involved in the decontamination process and give
a description of each of their roles.
Operator:
- Trained in the operation of all equipment and practices, simple housekeeping and maintenance
Manager:
- Person who is ultimately responsible for decontamination
- Generally the practice owner
Authorizing engineers:
- Provide expert advice and perform independent audits quarterly and annually, advises validation, maintenance and testing
Test person:
- Conducts and reports on validation and periodic tests, must be qualified >2year experience
Maintenance person:
▪ Routine and requested maintenance, qualified personnel.
45
What type of water is used for the final rinse cycle and why use this as opposed to mains water?
Demineralised water – reverse osmosis water; distilled water sterile water for irrigation or deionised water
▪ SHTM 2010 states that we need to use clean steam for sterilisation
▪ Demineralised water types do not contain bacterial endotoxins or minerals, rendering it safe for humans and prevents limescale build up.
46
Give 5 common reasons for Handpiece faults
Incorrect compressor settings and lack of maintenance
Damaged or over sized bur fitted damages the chuck
Incorrect instrument usage
Poor or inadequate cleaning including incorrect processing
Incorrect or inadequate lubrication
47
What maintenance and tests are carried out for sterilizers?
Daily:
▪ wipe clean door seal and chamber, check door safety device, drain and refill, check printer paper, change water, automatic control test, steam penetration with Bowie-dick or helix devices;
chemical colour change from yellow to blue when sterilized
o Weekly:
▪ automatic control test, vacuum leak test and air detection testing
48
What is a medical device?
Any instrument, appliance, software, implant, reagent, material or other article intended by the manufacturer to be used for specific medical purposes.
49
What PPE must be worn when carrying out manual washing of used instruments?
Face visor - protects from splashes and contamination into face and eyes
Gloves - Protects against infectious substances adhering to hands
Apron - Protects ourselves from splashes and contamination
50
Two methods used for manual cleaning of instruments and give example of instrument?
Washer disinfector - dental mirror
Ultrasonic cleaning - forceps
51
How often should ultrasonic cleaner be de-gassed?
- When first starting up and/or before every clean
52
What is removed by de-gassing?
- Air/oxygen removed from water
53
Why is de-gassing important?
- Ultrasonic cleaning may be less efficient
54
Why should dental handpieces not be placed in ultrasonic cleaner?
- Ultrasonic damage the high-speed turbine
- Steam cannot fully penetrate lumen of handpiece
- Type - S should be used instead
55
Why is it important to use de-mineralised water in steriliser?
- May be bacterial and fungal presence in tap water
56
What are the two types of manual washing?
- Immersion
- Non-immersion
57
What is the ideal instrument for manual washing?
- Stiff bristled, long handled brush
58
When using ultrasonic cleaner what should be done?
- Chamber filled with water and detergent and standard production cycle run with machine empty
- This effectively degasses it
- Naturally occuring air bubbles within water which prevents the efficiency of machine and impacts how cleaning effectiveness of machine
59
What is the definition of sterile?
- Probability of a viable microorganism being on the device less than 1X10^-6
60
Five things you can do to minimise healthcare asociated infections?
- PPE gloves, aprons, visors, face masks
- Aseptic technique
- Properly sterilised equipment
- Proper hand hygiene
- Operator competence
61
List the 10 SCIPs that should be followed in healthcare?
- Patient placement (assessment for infection risk)
- Hand hygiene
- Respiratory and cough etiquette
- PPE
- Safe management of care environment
- Safe management of care Linen
- Safe management of care equipment
- Safe management of blood and bodily fluids spillages
- Safe disposal of waste including sharps
- Occupational safety - prevention and exposure management inc sharps
62
List two agents that can be used for cleaning up blood psillages?
- Sodium hypochlorite
- Sodium dichloroisocyanurate
63
What strength of agent should you use and how long for for blood spillages?
- 10,000ppm chlorine solution for 3-5mins
64
How is the chain of infection broken when dealing wqiht dirty extraction forceps?
- Chain is broken at reservoir
- By cleaning, disinfecting and sterilising prior to use
65
List the steps you would take when cleaning a blood spillage?
- Wear PPE gloves apron vispr/goggles, face mask
- Contain with paper towel
- Assemble all equipment needed (spillage kit)
- Sprinkle chlorine releasing granules
- Clear affected area with paper towels and dispose of as clinical waste
- Wash area with water and detergent then dry
- Make sure any sharps are disposed of and dispose of single use items
- Perform hand hygiene
66
What are the 5 stages in correct order of the washer-disinfector cycle and describe the function/purpose of each stage?
- Flush/prewash - saturates contamination and removes gross contamination
- Main wash - supplemented with detergent to more effectively remove biologicals
- Rinse - Removes biological/chemical residue
- Thermal disinfection - Actively kills micro-organisms with heated water
- Drying - hot air to remove moisture SUMP from surface of instruments
67
What is the standard temperature banding for steam sterilisation?
- 134-137°
68
If chemical residue was being removed from the instrument what stage would the washer disinfector be at?
- Rinse
69
What is the first stage of vacuum capable Type-B steriliser?
- Air removal
70
What chemical would you use within an Ultrasonic bath?
- Enzymatic
71
A Bowie dick is carried out on a daily basis what is it testing for?
- Steam penetration
72
What is the standard disinfection temperature banding within our WD?
- 90-95°
73
What are the principles of waste disposal?
Follow the guidance on bin labels and posters to sort waste correctly.
Don't put general waste or recycling into clinical waste bins.
Use the yellow and black striped bags for non-infectious bandages, masks, and dressings.
Use the orange waste bags for infectious waste that is not chemically and/or medically contaminated, such as bandages and dressings.
Waste should be correctly segregated, appropriately labelled, packaged appropriately for transportation, stored safely and in a secure place away from areas of public access within the premise, and described accurately and fully on the label
74
How to keep an amalgam container safe?
Keep sealed when not in use
Keep away from sharps
Ensure lid is fully secured
Ensure it is taken away regularly
Ensure it is collected by the appropriate person
