judgement day: the machines have taken over

Question 1

what does AWD stand for

Answer 1

Automatic Washer-Disinfectors (AWD)

Question 2

what is there a legal requirement about with regards to AWD

Answer 2

Now a legal requirement for us to operate a WD and process our contaminated instruments through one

Question 3

What does IQ OQ PQ stand for

Answer 3

Installation Qualification Operation Qualification Performance Qualification

Question 4

what is IQ OQ PQ relevant for

Answer 4

These are in relation to the installation of any type of equipment in a decontamination environment and they will be put through these 3 expected qualifications to ensure the machine is operating correctly and these will need to be carried out be a competent person and they also need to be approved by an authorising engineer for decontamination [AE(D)]

Question 5

with regards to AWD what is the chamber

Answer 5

where the process takes place and all the different stages of it as well

Question 6

what is the load carrier

Answer 6

piece of equipment where we set out contaminated instrumentation to process it through the machine

Question 7

what is the control panel

Answer 7

For starting cycles / operating the AWD
There is a little screen on the upper part of it as well that offers forward information such as the stage that it is currently on, the time its been processing and the temperature that the current stage is at as well

Question 8

what are the pros and cons of manually washing instruments

Answer 8

• There is the potential for human error

• There can be variance of efficacy depending on the operator
○ Different people carrying out this process might not be doing it the exact same way

• They have significantly larger mechanical force
But that means you need to have an operator manually cleaning

Question 9

what does the automated process of washer-disinfectors do

Answer 9

Washer-disinfectors have an automated process meaning that after the operator has pressed the go button the machine will automatically cycle through stages, each serving a specific purpose to produce clean instrumentation free from contamination, thermally disinfected and dry

Question 10

what are the stages involved in an AWD

Answer 10

• Flush / pre-wash
○ This stage saturates the contaminated instrumentation

• Main wash
○ This stage is supplemented by detergent to more effectively remove contamination

• Rinse
○ This stage removes any remaining residue, biological or chemical before disinfection

• Thermal disinfection
○ This stage is actively killing micro-organisms with the use of heated water

• Drying
○ This stage removes any remaining moisture from the instruments before sterilisation

There is fresh water used for each individual stage that fills the SUMP and is then circulated throughout the chamber

Question 11

when must proteins or prions (vCJD)be removed and why

Answer 11

This is our only opportunity to remove proteins or prion (vCJD)
They must be removed during the wash stages

They cannot be deactivated through disinfection or sterilisation

High temperature can make them adhere to the surface of instruments which makes them more difficult to remove

They can survive higher temperatures for longer periods of time than temperatures and times of standard sterilisation processes (can survive sterilisation with temperatures in excess of 150˚C for prolonged periods of time ~ 2 hours at least)

We don’t get anywhere near that temperature or period of time with a standard sterilisation cycle so they must be removed during the wash process

So the cleaning stages are the points where we remove all of the protein residue or prion that is present on the surface of the instruments

Question 12

each stage of the process must be carried out at a certain temperature for a certain amount of time - what temperature should the flush / pre-wash stage be

Answer 12

§ Less than 35˚C
This is in relation to the coagulation of proteins ie once you breech that 35˚C mark there is the potential for proteins to begin to coagulate

Question 13

what temperature should the main wash stage be

Answer 13

§ Temperature dependent on chemical used for process

§ When you purchase a chemical from a manufacturer it will state on the chemical itself the expected operating temperature for the chemical

§ It could be between (roughly it’s a large band) 40 and 55˚C

The engineer (competent person) would be the individual who would decide on a temperature hypothetically 45˚C and then start to operate the cycle at that point to establish how well it is removing the contamination from the surface of the instruments

Question 14

what temperature should the rinse stage be

Answer 14

Less than 65˚C

Question 15

what temperature should the thermal disinfection be and for how long

Answer 15

Must be between 90-95˚C for a minimum of 1minute

Question 16

what temperature should the drying stage be

Answer 16

No specified temperature but generally between 90-110˚C

Question 17

when are stage times, chemical volume and wash temperature established

Answer 17

• Stage times, chemical volume and wash temperature are established during the validation of the equipment by a competent person

○ When you have a machine installed the cycle must be constructed when you are on site and this will be tested by a competent person

Question 18

who is a competent person

Answer 18

Competent person = somebody who is occupationally capable of carrying out this work to the standard that is required

Question 19

what is the only stage that has no change / variance from machine to machine

Answer 19

The only one that has no change really, the rest of them can all be agreed at installation and validation and then they become the cycle standard, is the thermal disinfection stage as it must be between 90 and 95 degrees for a minimum hold time of 1 minute

Question 20

why are washer-disinfectors the first step in the decontamination process

Answer 20

○ Why bother manually cleaning?
§ If you washer can remove all the contamination with an automated process, why monopolise a member of staff to do so

○ There is fresh water for each stage that not only remove contamination from the surface of the instruments but removes it from the machine entirely

○ The thermal disinfection makes the instrumentation safe for staff to handle so that a thorough inspection can take place then the instruments can be packaged for sterilisation

Question 21

what happens after the WD process is finished

Answer 21

After the WD process is finished, all the instrumentation must be inspected for damage or to see if there is still contamination present
We use an illuminated magnifier for this

Question 22

when would we incorporate manual cleaning

Answer 22

This is when we incorporate manual cleaning after the inspection stage if we have identified that contamination is still present

Question 23

what is an advantage of physical scrubbing with a brush

Answer 23

Physically scrubbing something with a brush has a greater mechanical force than that of the water jets within the WD

Question 24

what should be done after manual cleaning

Answer 24

Following manual cleaning, everything must be re-processed back through the WD because of the thermal disinfection stage

So even if we decide to manually clean something first it still must be processed through the WD because of the disinfection stage in there
That makes it safe for the operators to handle so that they can be inspected properly and any potential contamination can be identified if it is there

Question 25

what happens after WD has completed its cycle and we have verified there is no contamination still present

Answer 25

After our WD has completed its cycle and we have verified there is no contamination still present and that the instruments are not damaged in any way, we are ready to prepare out equipment for the sterilisation process

Question 26

what happens if an instrument is damaged

Answer 26

If the instrumentation is damaged it can either be sent

• for repair or
• For disposal at this stage

It would still have to be processed through a WD first before we identified that