Patient Safety Flashcards
define sterile.
The theoretical probability of there being viable micro-organisms present is < or equal to 1 x10-6
define operator.
Person with authority to operate a steriliser/washer disinfector
This includes those involved in noting of device reading and housekeeping duties
what guidance do we use for the decontamination process?
SHTM 2010 & 2030
List the stages the washer disinfector goes through. (5)
Flush/prewash - saturates the contaminated instruments
Main wash - Detergents are used at this stage to increase the effectiveness
Rinse - removes residue
Removing prions/vCDJ:
Thermal disinfection - actively killing microorganisms with heated water
Drying - removes moisture before sterilisation
what temperature is the flush/prewash stage of the washer disinfector? - why?
< 35 degrees (to prevent coagulation of proteins)
what temperature is the main wash stage of the washer disinfector?
Depends on the chemicals used (generally 45-65 degrees)
what temperature is the rinse stage of the washer disinfector?
< 65 degrees
what temperature is the thermal disinfection stage of the washer disinfector and for how long?
Between 90 - 95 degrees for a minimum of 1 minute
what temperature is the drying stage of the washer disinfector?
No specific temperature but its usually between 90 - 110 degrees
list the order of decontamination.
HAND HYGIENE
DONN PPE
CHECKS
AWD
REMOVE AND REAPPLY PPE
remove moisture and INSPECTION
MANUAL WASHING AWD ULTRASONIC ??? RINSE STERILISATION
What areas should you inspect using the illuminated magnifier?
Check the hinge
Check the inside of the jaws of the instrument
after inspection of the instruments what do we use if they require further decontamination?
manual cleaning and then reprocessed in the AWD.
what happens to the instruments after the use of the AWD, inspection and manual cleaning?
reprocessed in the AWD
sterilise
how do we determine how to clean each instrument?
the spaulding classifications
according to the spaulding classifications, define critical instruments.
How are these decontaminated?
Devices that enter tissues i.e. PDL that are usually sterile or enter the vascular system
these require to be sterilised
according to the spaulding classifications, define semi-critical instruments and name how they are decontaminated.
Instruments which must have contact with an intact mucous membrane but does not penetrate sterile tissues
these require to be sterilised
according to the spaulding classifications, define non-critical instruments and name how they are decontaminated.
Instruments have contact with intact skin only
disinfected and cleaned
why do we need sterile instruments? (4)
Reduces probability of infection transmission
There is an international standard for surgical instruments
Legislative and professional standards i.e. GDC standards
In order to maintain a high quality of care for out patients
what are the properties of a transport container? (4)
Rigid, durable and leak proof
Tight fitting lid
Be easily cleaned and disinfected.
Be easily distinguishable
what are the 4 key elements to successful cleaning?
time
temperature
chemicals
energy
what temperatures prevent protein coagulation?
< 35 degrees.
what chemicals are used in the ultrasonic?
enzymatic detergents
what chemicals are used in the manual washing stage?
pH neural detergents
describe the energy used in AWD’s.
high pressure jet sprays
describe the energy used in the ultrasonic.
cavitation via sound waves
what kind of water has to be used in sterilisers?
water of less than 30us (micro-siemens)- pure water.
define conductivity.
Conductivity is a measure of all the particulate water has come into contact
particulates = silicates, organics, minerals and metals.
Describe the relationship between pure water and particulate.
no particulate in pure water
Why is the AWD used first instead of manual washing? (2)
The fresh water for each stage of the WD cycle ensures that contamination is removed from the instrument surfaces and the machine entirely.
WD makes the instruments safe for staff to handle and inspect and makes them safe to be sterilised.
Why is the manual washing NOT done first (before AWD)? (4)
there is a Risk of aerosol production (if manual washing isn’t done below the water level)
Risk of contaminating the surrounding environment (if manual washing isn’t done below the water level)
Potential for inconsistency due to human error
SHARPS risk
how much detergent is usually used in manual cleaning?
5ml per 1 litre of water
describe the bushes used in manual cleaning.
long handled, soft bristled, non-metallic brush which can be processed through a thermal washing cycle.
why do we scrub instruments below the water in manual cleaning? (3)
Increases the contact of the instrument and the detergent in the water
It minimises splashing - contaminating the enviro
Prevents aerosols being produced
describe how the ultrasonic works.
Cavitation
Uses sound waves at a high frequency to generate microbubbles.
The fluctuation in pressures generated by the waves causes the bubbles to expand and then collapse which has a scouring effect against the surface of the instruments.
what temperature is the ultrasonic?
24 degrees C
how long does the ultrasonic run for?
20 minutes
what must be recorded in the ultrasonics log book? (5)
The date The cycle number If detergent was added What the temperature is The time its ran for
what are the advantages of using steam to sterilise? (5)
carries large amounts of energy
Small amounts of water generate large amounts of steam
Is non-toxic
It can be recondensed and reused
There are no waste products
list the 3 types of sterilisers used in dentistry.
Type N
Type B
Type S - less commonly seen as it is specialised.
what temperature and how long does a Type N steriliser work for?
Works @ 134-137 degrees
maintained for 3 minutes
describe how a type N steriliser works.
Work by filling the chamber with steam and passively forcing air out of the chamber. (No vacuum)
what are the disadvantages of a Type N steriliser? (3)
Pockets of air can form within the chamber - this is unfavourable as these pockets offer do not sterilise the instruments
Because this steriliser cannot process wrapped instruments there is a danger of recontamination before the instruments can be used.
X - Cannot process wrapped, channelled or lumened instruments or hinged (due to the lack of vacuum capabilities)
what instruments can a type N steriliser not sterilise?
Cannot process wrapped, channelled or lumened instruments or hinged (due to the lack of vacuum capabilities)
describe how a type B steriliser works.
Pre-vacuum - Remove air by vacuum pump to create a negative pressure
Then chamber fills with steam - allows all surfaces of the instruments to be sterilised (even wrapped instruments)
Post-vacuum - removes remaining moisture to ensure the product is not saturated
what temperature and how long does a Type B steriliser work for?
Works @ 134-137 degrees and must be maintained for 3 minutes
what are the advantages of using a type B steriliser? (3)
Processes wrapped, channeled and lumened instruments
Since it can process wrapped instruments the instruments will be sterile at the time of use and can be stored for long periods of time.
can Process porous items i.e. cotton wool swabs
how do we know if wrapped instruments have been sterilised at the correct temperatures.
have a chemical indicator
what checks should be carried out for Type N sterilisers? (4)
Ensure the door seal is intact - no damage or debris
Check the Load carrier is not damage or has no debris/parts of instruments on it
Check there is no debris/instruments in the chamber itself
Ensure there is a sufficient amount of water within the reservoir
what checks should be carried out for type B? (6)
Ensure the door seal is intact - no damage or debris
Check the Load carrier is not damage or has no debris/parts of instruments on it
Check there is no debris/instruments in the chamber itself
Ensure there is a sufficient amount of water within the reservoir
carry out a “Bowie-Dick” or “steam penetration” test
carry out a vacuum test and an air detector function test.
what does a “Bowie-Dick” or “steam penetration” test ensure? (2)
ensures that;
- the correct temperatures have been achieved
- that sufficient air removal has occurred.
Anything less than 100% colour change is a fail
how do we load sterilisers & the AWD? (4)
No overlapping or shadowing instruments
Hinge jointed instruments should be open at the hinge - so they don’t close during the cycle.
Don’t overload
Disassemble assemblies
what checks do we carry out for the AWD? (5)
Spray arms rotate freely and without obstruction and none of the jets are blocked - spin it to test (both upper and lower)
Load carrier is not damage or has no debris/parts of instruments on it
The strainers and filters at the bottom are clear
The door seal is in tact and nothing preventing it from sealing
Ensure there is enough chemical within the reservoir in the machine
what PPE do we require for manual cleaning and why? (3)
Apron/gown - protect clothing from becoming contaminated by the splashing
nitrile gloves and heavy duty rubber gloves = used to prevent SHARPS injuries
face shield = protect eyes and mouth (mucous membrane) from the contamination from splashing
when do we Degas the ultrasonic? (1)
after every water change
why do we Degas the ultrasonic? (1)
To remove oxygen which inhibits cavitation = instruments are not fully decontaminated
