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
How do you verify? Challenge the washer Test 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
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?
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