Decontaminate before its too late Flashcards
5 things needed to ensure safe decon
- We need a sufficient means of transporting contaminated and clean instrumentation
- We need an automated, reproducible process for cleaning and disinfection
- Our instruments need thoroughly inspected to ensure our process has taken place
- We need to support the process with the use of other pieces of equipment
- And that all our instrumentation must be processed through a steriliser
processing cycle/life cycle
Need equipment to carry stages out in line with requirements and standards
major factor in all stags of process cylce
time
how the period of time after the instruments are used influences the cycle
- Any blood or biological matter still present can start to dry in and adhere to the surface of the instrument
- There are products on the market such as sprays and sealed bags/packets for transport
- But the best course of action is to have the shortest amount of time between use and processing
6 stages where time influences the processing cycle
- How long since the instruments were used for a procedure
- How long does my wash phase need to be for cleaning efficacy
- How long is the WD cycle in total
- What are the critical time/temperature settings for thermal disinfection
- How long will the packaging and sterilisation process take
- How long does my processing cycle take overall
5 major factors in the processing cycle
- time
- temperature
- water
- chemicals
- energy
sinner circle
- developed in the 1950’s by a man named Herbert Sinner
It shows the 4 key elements that are required for a Successful cleaning process
His work was based within a laundry, but the principles of the circle apply to all successful washing and cleaning processes
- It is widely referenced If we decrease or increase any of the quarters we will impact what percentage they they play within the process
conductivity
As water travels from source to our facilities it picks up particulate along the way from hillsides, river banks & anything else it contacts
- Minerals - calcium, potassium
- Silicates - sand, glass, rock
- Organics - vegetation, colloidal particle
- Metals - iron, zinc, tin, mercury
The measure of this is called conductivity (a.k.a Total Dissolved Solids TDS)
e.g minerals, silicates, organics, metals
(µs)
conductivtiy measured in
unit = micro-siemens (µs)
using a conductivity metre
water used in sterilisation process
must be “pure water”
cannot be tap
“Pure water”
4 properties
- Distilled
- De-ionised
- Reverse osmosis
- Sterile
Pure water has had nearly all of the particulate filtered out or removed and has very low levels of bacterial and fungal presence
Conductivity = 4.3 µs
conductivity of pure water
Pure water has had nearly all of the particulate filtered out or removed and has very low levels of bacterial and fungal presence
Conductivity = 4.3 µs
detergents and disinfectants in processing cycle
don’t generally use chemical disinfectants for our process
there are a range of detergents used for different purposes
- High and Low Alkaline detergent for enclosed processes (not designed to be in contact with skin as can be quite harsh)
- Enzymatic detergent breaks protein down into smaller particles (generally used in the Ultrasonic but can be used for manually washing)
- pH neutral detergent is less harmful to operators skin (generally used for manual washing as high chance of skin contact/handling)
how detergents work
chemical molecule within detergents is designed to have hydrophilic and hydrophobic ends
- One end repels water and the other is attracted to it
- The hydrophobic end never contacts water, because of the repulsion
- This is where the contamination is drawn to and then flushed away as the hydrophilic end attaches to water molecules
- The hydrophobic end never contacts water, because of the repulsion
how to know what detergents to use
need to be validated against the cycle
if changing chemical - needs re-validated
cycle times decided
Cycle times are established based on cleaning efficacy of the chemical during the validation or periodic testing of the machine
- Manufacturers instructions should be followed for dosing volume and operating temperature of chosen detergent
‘energy’ in processing cycle
or ‘force’ that we are using for cleaning and contact
- When manually cleaning we use a scrubbing brush
- In the ultrasonic bath the force comes from high frequency sound waves causing cavitation
- The washer-disinfector uses a high pressure (1-1.5 bar) water jet or spray
- Note the WD is generally the least ferocious so we supplement the process with stronger chemicals
how are time and temperature of different processing cycles stages decided
cleaning stages the times are agreed at validation based upon the efficacy of the cycle (i.e. everything must be clean and free from contamination)
also established that temperatures are influenced by the chemical being used and that for primary stages it must be below 35 degrees (i.e. during the flush stage, manual washing or in the Ultrasonic)
Disinfection and sterilisation stages are different as the temperatures and times have already been established and must be achieved (i.e. the times and temperature for critical conditions are globally recognised)
- Manufacturers recommendations 42-58oC
- <35 oC prevents protein coagulating
- Steam sterilisation 134-137 oC 3 minutes, minimum
- Thermal disinfection 90-95 oC 1 minute, minimum
manual cleaning
water
tap water
ultrasonic cleaning
water
tap water
washer-disinfector
water
cleaning stages can use standard tap water
thermal disinfector (still in WD) needs to be water at a conductivity lower than 30µs
steam sterilisation
water
must be pure water
manual cleaning
temperature
less than 35oC
ultrasonic
temperature
less than 35oC
washer disinfector
temperature
dependening on the chemical validated with process (<65oC)
thermal disinfector (still in WD) 90-95oC
steam sterilisation
temperature
134-137oC
thermal disinfector
water
Water to be at conductivity of lower than 30 µs
thermal disinfector
part of
washer-disinfector
thermal disinfector
temperture
90-95oC
manual cleaning
time
dependent on operator allocation
ultrasonic
time
dependent on the validated cylce time
(20 mins)
washer-disinfector
time
dependent on the validated cycle time
(55 mins)
thermal disinfector
time
must be a minimum hold time of 1min
steam sterilisation
time
must be a minimum hold tie of 3 mins
manual cleaning
chemicals
pH neutral or enzymatic detergent
ultrasonic
chemicals
pH neutral or enzymatic detergent
washer-disinfector
chemicals
low alkaline or high alkaline detergent
thermal disinfector
chemicals
must be free from all chemicals
steam sterilisation
chemicals
must be free from all chemicals
manual cleaning
energy
scrubbing with brush
ultrasonic
energy
ultrasonic sound waves
washer-disinfector
energy
water jet/spray
thermal disinfector
energy
water jet/spray
steam sterilisation
energy
steam hear energy
