WDs

Question 1

housekeeping duties

Answer 1

check spray arm for rotation/free movement and blockages
remove and clean strainers and filters etc
ensure sufficient additives available and that dosing system is fct
door seals for any wear/tears, wipe
check load carrier

Question 2

daily tests

Answer 2

housekeeping duties
check spray nozzles for blockage - paying particular attention to those fitted to carriages for cannulated instruments
note disinfection temp of 1st cycle
check grommets/seals holding control probes etc for deterioration due to chemicals used
PCD (optional)
check enough paper in printer (unless has SD card)
check no instruments/parts from prev cycles

Question 3

who carries out the daily tests?

Answer 3

user

Question 4

what document gives guidance?

Answer 4

SHTM30

Question 5

who carries out weekly tests?

Answer 5

user or CP(D)

Question 6

weekly tests

Answer 6

weekly safety checks
daily tests
water hardness (all process stages)
water conductivity (final rinse stage - thermal disinfect)
cleaning efficacy test (by residual soil detection)
 - test soil, PCD
protein detection
full ACT

Question 7

weekly test sheet

Answer 7

water conductivity (thermal disinfect)
cleaning efficacy
- test soil, PCD
protein detection

= batch number, expiry date, cycle number, result. Date of test, name, signature

Question 8

why is it preferred to manual cleaning?

Answer 8

automated cleaning more control and reproducibility
more readily validated
involves thermal disinfection

Question 9

stages of WD

Answer 9

prewash/flush
wash
rinse
thermal disinfection
drying

Question 10

temps of stages

Answer 10

prewash/flush 30-35
wash 60-65
rinse 40-45
thermal disinfection 90-95

Question 11

prewash/flush

Answer 11

remove largest part of any biological matter

low temp stage to hydrate and loosen any contamination

Question 12

why is prewash/flush at temp 30-35?

Answer 12

don’t want to coagulate proteins

Question 13

wash stage

Answer 13

heated with chemical

circulated for longer time to remove as much organic matter from the instruments as possible

Question 14

rinse stage

Answer 14

final stage of ‘cleaning’

98% of contamination should have been removed

Question 15

thermal disinfection - why is it important all proteins have been removed before?

Answer 15

because high temp can bake proteins onto the surface

of instruments

Question 16

which stage has water conductivity checked and what is measured?

Answer 16

thermal disinfection

TDS and identify if still high levels of particulate

Question 17

values of thermal disinfection

Answer 17

90-95 degrees for min 1min

essential contact time 12s

Question 18

aim of thermal disinfection

Answer 18

actively kill and remove bacteria

Question 19

drying

Answer 19

remove any excess moisture which may still be present after the prev stages
water has the potential to inhibit the sterilisation process as well as damage any wrappings

Question 20

function

Answer 20

wash load and inside of machine
disinfect load and inside of machine
dry load
perform the above without damaging the device
perform the above without contaminating the env
perform the above and fully drain the machine prior to the next load

Question 21

what is the ACT?

Answer 21

test automatic control of machine using a stopwatch
can verify that each stage achieves the temp set for that stage, as well as lasting for the required amount of time. Can also verify that this info is displayed properly

Question 22

how often should an ACT be carried out?

Answer 22

daily, do manual on a weekly basis

Question 23

advantage of ACT in terms of problems

Answer 23

can use diagnostically to identify potential problems/issues
if have record of data - can give it to service engineer who will be able to diagnose what is happening more accurately
- less time as is easier to diagnose an issue by analysing the recorded data
- less money and less downtime for repair

Question 24

ACT - when should test be considered as passed?

Answer 24

any visual display indicates ‘cycle complete’
during the whole of the operational cycle the values of the cycle variables, as recorded by the WD systems and any independent monitor are within the limits established by the manufacturer during the performance qualification testing
during the disinfection stage the WD record and any independent monitoring system are within the disinfection temp and hold period requirement defined in EN ISO 15883 and the performance qualification tests
the door cannot be opened until the cycle is complete
person conducting test does not observe any mechanical or other anomaly

Question 25

ACT info to record

Answer 25

for each stage: - temp - midpoint - time each stage is active for - disinfection start and end with stage duration - vol of chemical dosed - cycle time overall ``` date and time cycle no operator machine indicated cycle complete daily checks carried out ``` manually written record and machine print out/document

Question 26

which cycle should an ACT be done on?

Answer 26

short standard

Question 27

Ao value

Answer 27

in reference to the expended energy within the cycle and establishes a value that informs us of the kill rate of the disinfection within a WD time required to achieve a specified log reduction of MOs based on the temp of the thermal disinfection cycle described by ENISO 15883 number following the Ao symbol represents the number of seconds needed at 80 degrees to achieve the level of disinfection specified by the particular Ao designation combination of time and temp

Question 28

Ao required values

Answer 28

surgical instruments Ao 600 | EN ISO 15883 specifies WD must be capable of achieving Ao 3000

Question 29

ACT sheet and machine print out

Answer 29

sheet manually filled in machine print out produced by the data logger fitted to the machine certain info can only be obtained from the print out e.g. the cycle number or the volume of chemicals dosed check the record we created against this one for accuracy small deviations in the info are accepted as you can only look at one thing at a time - being a couple of seconds off or half a degree out are accepted, unless it goes outwith the temp or time bandings prewash time on machine longer - water needs to enter chamber and machine reach required temp

Question 30

what does the cleaning efficacy (soil) test verify?

Answer 30

it verifies soil removal - verifies all 4 elements of the Sinner circle set correctly

Question 31

cleaning efficacy (soil) test - when should you abort the cycle?

Answer 31

after wash at end of rinse - as soon as screen says disinfect press stop some equipment might have an access hatch that the instruments used, or the PCD, can be removed from

Question 32

PCDs

Answer 32

e.g. soil strip serious loading concerns FMIs and verified to suitable efficacy before production testing - otherwise false positives generally longer shelf lives can sometimes be temperamental during washing and produce false positives if not processed exactly to requirements

Question 33

test soil storage

Answer 33

generally needs to be stored in fridge and has short shelf life

Question 34

test soil - specific mixture

Answer 34

use Edinburgh test soil or Browne's dehydrated test soil

Question 35

purpose of test soil

Answer 35

coat and dry onto the surface of the instruments in the same way that biological matter would can then process this instrumentation and simulate the soil removal process that we subject our instruments to, and verify that it is being carried out properly

Question 36

coating instrument with test soil

Answer 36

put thin layer on surface - esp on hard to remove parts e.g. hinges dry 30mins-2hrs - ensure spread even and thin, no lumps

Question 37

parts of cycle for cleaning efficacy test and what to do after

Answer 37

pre-wash, wash, rinse | unload, inspect under illuminated magnifier

Question 38

when does the protein detection test take place?

Answer 38

once retrieved instruments/PCD

Question 39

function of protein detection test

Answer 39

to verify that all viable proteins have been removed from the surface of the instruments, and the wash process continues to be sufficient and effective

Question 40

how is the protein detection test carried out?

Answer 40

swab surface - jaws, hinges, textured part - can do on diff instruments than cleaning efficacy don't contaminate swab with any other proteins in env - own skin, hands, hair particles place swab in solution and break off stalk. Cap on top, set aside

Question 41

components of protein detection test

Answer 41

sterile swab and protein detection solution | - kits in batches - solution within each test kit will only ever be from a single batch - so controls verify it

Question 42

protein detection tests controls

Answer 42

swab instruments negative control - sterile swab, no colour change positive control - swab with protein source - often with kit solution, colour change

Question 43

after protein detection test

Answer 43

don't discard tests immediately they are identifying particles of protein so may take a while for colour change depending on ppm FMIs

Question 44

which stages is tap water usually fine?

Answer 44

cleaning - flush, wash, rinse | unless in high limescale areas conductivity should be verified to be <300uS

Question 45

what water should be used for thermal disinfection?

Answer 45

purified water or water of a sufficiently low conductivity and hardness limit <30uS for conductivity, <125mg/L CaCO3

Question 46

what does conductivity measure and what is the consequence?

Answer 46

identifies if there is particulate present within the water if used during the thermal disinfection stage may lead to mineral deposits and scaling on instrument surface this particulate (salts, Ca, Mg, strontium) can interfere with the efficacy of the chemical, potentially, and cause operational problems for WDs such as blocking spray jets or coating heating elements

Question 47

conductivity meter

Answer 47

placed within a sample of water and the conductivity reading will be displayed on the screen on the device

Question 48

what may need to be done to achieve the required low conductivity?

Answer 48

filter/install pure water supply

Question 49

who carries out quarterly checks?

Answer 49

CP(D)

Question 50

quarterly checks

Answer 50

weekly safety checks and functional check of engineering services carry out daily and weekly tests verification of calibration thermometric tests for disinfection cleaning efficacy test: using test soil - reference load - general instruments endoscope/ UIS instruments doors and door interlocks - cycle start, in-cycle interlock, double door WDs, fault indication on sensor failure chemical dosage check - ensure parameter remains within tolerance, calibration, limits and fct, inc fault/alarm, of the independent monitoring system

Question 51

WD key info

Answer 51

``` general - date - operator - cycle start time cycle data - cycle no - wash temp - disinfection temp - cycle duration was detergent added did cycle complete successfully ```

Question 52

info from first cycle of day

Answer 52

``` date time started operator cycle number disinfection temp daily tests performed detergent added disinfection successful machine identified cycle completed successfully ```

Question 53

fault register

Answer 53

``` not mandatory but should try to maintain one did any faults occur during processing? if yes describe corrective action did cycle complete successfully? ``` = this type of record keeping should take place for each individual piece of equipment in operation within the decon env

Question 54

designated person for weekly and daily tests

Answer 54

the person the user (or potentially the user themselves) has appointed to carry these tests out training and records kept

Question 55

quarterly cleaning efficacy test

Answer 55

carried out by CP(D) different uses a full standard load of instruments and is carried out several times for repeatability

Question 56

guidance for WDs

Answer 56

SHTM 2030