Verification of Washing
Strategies for RMDs
Presented By:
Lon BrusoVice President, SteriTec Products
Verification of Washing
• Quality system basics• Importance of washing verification• Blood residual as a test soil• Verification methods• Verification frequency• Prions
Quality System Basics
• Who did it?• When did they do it?• How did they do it?– Did they follow procedures?
• How effective was it?– Is it verified?
Why is verification of washing so important?
• If it isn’t clean, you can’t sterilize it– Sterilization process specifications are based upon
the assumption that the instruments are clean• What soil is most important to remove?– Blood
• Prions– Washing may be more important than sterilizing
Blood Contamination• Can contain pathogens• Starts as a liquid then coagulates– Flows into hinges and hidden areas– Cleaners must also flow into those areas and
dissolve blood away– Direct impingement and indirect
impingement• What component of blood is most
difficult to remove?– Fibrin
What is fibrin?
• Fibrous protein that is generated as blood clots– Knits a wound together– Generates a water-insoluble covering– White
• Generated by fibrinogen in blood– Fibrinogen polymerizes and forms fibrin as blood clots
Microscopic Fibrin Filaments
Blood Components
• Primarily proteins– Albumin (water soluble)– Hemoglobin (water soluble)– Fibrin (non-water soluble)• Whitish residue• 2-4% in blood
How do you verify?
Challenge the washerTest the items for cleanliness
Challenge the Washer
• Is it functioning properly?– Are the spray arms clogged?– Are the spray arms rotating properly?– Are the spray arms installed properly?
• Is it loaded properly?– Shadows
• Is the detergent working properly?– Temperature– Time– Dosing
Challenge the Washer
• Smear test soil on the item– Check for residuals
• Visibly clean• Inoculate and culture• Protein test
– Still have to clean again before reuse• Adulterated
• Use a pre-made test soil challenge– A washing PCD…Process Challenge Device
Washing PCDs
Wash Checks
Wash Checks H
Wash Checks H
Wash Checks H
Ultrasonic Cleaner PCD
Test the Item for Cleanliness
• Look at it– Visibly clean– Microscopic examination
• Test for residuals– Protein– ATP
• Transient• Expensive
– Need equipment
Protein Test
Protein Test
Frequency of Monitoring
• Traceability to the patient– Each tray?– Each shelf?– Each load?– Once a day?– Once a week?– Once a month?
• Each load is the minimum for traceability to the patient
• What does it cost?
Prions
Alpha Helix
Beta Pleated Sheet
Tissue Particle
Tissue Particle After Heating
A hard shell is created, protecting a core of prions from destruction
After Biological Digestion
When the hard shell is dissolved away through metabolic action, the prions are released
Prions
• Washing may be more important than sterilizing– Sterilizing methods must hydrolyze (cut) the prion
protein chain– Sodium hydroxide methods– Enzymatic methods
• Alpha helix • Beta pleated sheet
What have we learned?
• Cleaning needs to be monitored• Effectiveness of cleaning needs to be verified– Challenge the washer with a washing PCD– Test the items for cleanliness
• Protein test or ATP test
• Frequency of monitoring needs consideration– Each load is minimum for traceability to patient
• Prions are much more difficult to sterilize– Washing might be more important than sterilizing