Residual Organic Soils on Patient used Instruments

(1)

Residual

Organic

Soils

on

Patient

‐

used

Instruments

Key Considerations for User Verifcation

Ralph J Basile, MBA

Vice President

(2)

What types of soil found on patient-used

instruments?

• blood

• carbohydrates

• synovial fluids

• lipids

• bone

• tissue

• other

(3)

Is

there

one

soil

or

marker

that

is

present

on

all

patient

‐

used

instruments?

• Protein

• Adenosine

Triphosphate (ATP)

• Total Organic Carbon

(TOC)

• Others?

(4)

Protein

Advantages

• Present in almost any

human secretion can

identify.

• Present in other microbial

contamination.

• Are quick and well studied

methods for testing.

Disadvantages

• False positives? Protein is

so ubiquitous that poor

testing technique could

yield a result (i.e.,

fingerprints)

• Is it harmful? Being so

ubiquitous, it is not possible

to determine whether a

threat to patient (if present

must assume harmful).

• Steps in reprocessing can

render it difficult to detect

(denaturing and insoluble).

(5)

ATP

(adenosine triphosphate)

Advantages

• Is present in bacteria and

viable human cells.

• Quick and easy to interpret

test are available.

• Provides a numeric result,

more objective than

colormetric result.

Disadvantages

• Like protein, ubiquitous

nature can lead to false

positives.

• ATP degrades rapidly,

particularly in presence of

reprocessing conditions

(heat, detergents)

rendering it undetectable

even when organic soils

remain.

• Like protein, what is a safe

level?

(6)

TOC

(total organic carbon)

Advantages

• Carbon is present in all

organic soils.

• Quick test methods are

available.

Disadvantages

• Like protein and ATP,

ubiquioutous nature can

lead to false positives.

• Like the other two

markers, what is a safe

level?

• Currently available test

methods necessitate

reprocessing any

(7)

More Specific Soils/Markers for Specific

Instruments (i.e. hemoglobin)?

Advantages

• Reduce chance for false

positives.

• Provide faster results.

• More sensitive tests (lower

level of detection.

• Can identify the risk (in

case of blood - none

should remain to eliminate

risk to patient).

Disadvantages

• Reprocessing staff need to

be better educated - which

test for which instrument.

• Greater the number of

tests, the greater the

diversity of results (e.g.,

different colors, or different

numbers, etc.).

(8)

Commercial products in the market

• hemoglobin

• sensitive down to 0.1ug hemoglobin.

• colormetric result - easy to interpret.

• limited chance for false positives (e.g.,

oxidizing agents which might be in cleaners

or disinfectants).

(9)

Commercial products in the market,

cont'd

• multi-parameter test strip

• hemoglobin/protein/carbohydrates.

• colormetric result - easy to interpret.

• flush method lends itself to testing

lumens, but not external surfaces.

(10)

cont'd

• protein

• variety of available tests.

• all feature a colorimetric result that is

easy to interpret.

• some will only work for soluble proteins

-which often is not the state of proteins

after reprocessing.

• some take an extended time to detect

insoluble proteins.

• sensitivity levels vary between products

-confusion for users.

(11)

cont'd

• ATP Tests

• quick result (less than 1 minute).

• provides an objective measure

(number).

• ATP is prevalent with viable

cells/organisms.

• ATP degrades over time and that is

accelerated in the conditions of

reprocessing. Organic soils may

remain when ATP no longer

present.

• Different brands of tests have

different RLU scales - confusion for

users.

(12)

Surrogate Device

-An alternative solution

For some device manufacturers, the best solution may be to

provide or recommend a surrogate test device rather than

specify the soil and methods for testing:

• Can be simple pass/fail.

• Will have the "right soil" for the target device.

• Can be "visually" clean not requiring chemistry, readers,

etc.

• Only for automated processes - not appropriate for

manual cleaning

(13)

Questions for the Summit to

consider:

• Is there a universal soil/marker that is always present on

patient-used instruments? Or should the marker(s) change

with the device?

• Is (are) there a soil(s)/marker(s) that can be practically tested

for in non-lab setting?

• What interference will reprocessing steps cause in testing for

targeted soil(s)?

• Is a surrogate testing device a better option when practical?

• What is a safe level? What is clean? What is the level of

detection?

• What guidance can we give the user for frequency of testing,

etc.?

(14)

References

AAMI Documents:

• AAMI TIR30:2011: A compendium of processes, materials, test methods, and acceptance criteria for cleaning reusable medical devices

• AAMI TIR12:2010: Designing, testing, and labeling reusable medical devices

for reprocessing in health care facilities: A guide for medical device manufacturers • ANSI/AAMI ST79:2010 &

A1:2010: Comprehensive guide to steam sterilization and sterility assurance in health care facilities

• ANSI/AAMI ST1:2009 (ISO 15883-1:2006, MOD), Washer-disinfectors, Part 1: General requirements, terms and definitions and tests

• ISO/TS 158835:2005, Washerdisinfectors -Part 5: Test soils and methods for

demonstrating cleaning efficacy of washer-disinfectors

References

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(16)

References

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