Institute for Environmental Medicine, Municipal of Vienna
Examination and validation
Examination and validation
for washer-disinfectors for
for washer-disinfectors for
flexible endoscopes
flexible endoscopes
Ulrike Prüfert-Freese
Ulrike Prüfert-Freese
Institute for Environmental
Institute for Environmental
Medicine, Municipal of Vienna
Medicine, Municipal of Vienna
Department of Physics and
Department of Physics and
Technical Hospital Hygiene
Technical Hospital Hygiene
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Legal Basis for the Examination
Legal Basis for the Examination
and Validation of WD
and Validation of WD
Basis for the cleaning and disinfection of medical devices for
Basis for the cleaning and disinfection of medical devices for
health institutions are the Austrian Medical Device Act (MPG),
health institutions are the Austrian Medical Device Act (MPG),
the ordinance acc. to ż 94 MPG, the recommendation of the
the ordinance acc. to ż 94 MPG, the recommendation of the
Robert-Koch-Institute (RKI)  Hygieneic Requirements for the
Robert-Koch-Institute (RKI)  Hygieneic Requirements for the
Processing of Medical Devices and the EN 15883 part 1 - 5.
Processing of Medical Devices and the EN 15883 part 1 - 5.
The examination and validation of cleaning and disinfection
The examination and validation of cleaning and disinfection
methods for the preparation of flexible endoscopes also poses
methods for the preparation of flexible endoscopes also poses
a challenge for testing methods.
a challenge for testing methods.
The work presented describes a method for the validation of
The work presented describes a method for the validation of
cleaning and disinfection method for the preparation of flexible
cleaning and disinfection method for the preparation of flexible
endoscopes according to EN ISO 15883 part 1 and prEN ISO
endoscopes according to EN ISO 15883 part 1 and prEN ISO
15883 part 4.
15883 part 4.
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Implementation of the
Implementation of the
Examination
Examination
The examination can be structured into the following steps
The examination can be structured into the following steps
depending on devices and programs to be tested:
depending on devices and programs to be tested:
Thermoelectric test for the validation of the temperature sequence
Thermoelectric test for the validation of the temperature sequence
in all cycles
in all cycles
thermoelectric test of the Self-disinfection cycle
thermoelectric test of the Self-disinfection cycle
Test of the dosage accuracy
Test of the dosage accuracy
Test of cleaning efficacy
Test of cleaning efficacy
Microbiological testing of the disinfection efficacy in cycles and part
Microbiological testing of the disinfection efficacy in cycles and part
of cycles
of cycles
Test of resources (e.g. quality of water supply)
Test of resources (e.g. quality of water supply)
Chemical and physical test of the final rinse water quality (chamber)
Chemical and physical test of the final rinse water quality (chamber)
Microbiological testing of final rinse water quality (chamber)
Microbiological testing of final rinse water quality (chamber)
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Thermoelectric Test: Validation of
Thermoelectric Test: Validation of
the Temperature Sequence
the Temperature Sequence
Multi-channel process chart recorder (or thermo-logger)
Multi-channel process chart recorder (or thermo-logger)
with 6 temperature sensors
with 6 temperature sensors
All programmes used
All programmes used
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of the dosage accuracy
Test of the dosage accuracy
The test can be performed volumetric or gravimetric
The test can be performed volumetric or gravimetric
Gravimetric Test:
Gravimetric Test:
Put the cleaner canister on the scales
Put the cleaner canister on the scales
Note the weight
Note the weight
Read the weight after the dosage is applied
Read the weight after the dosage is applied
Calculate the dosage minding the density
Calculate the dosage minding the density
Maximum deviation +/-10 %
Maximum deviation +/-10 %
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of cleaning efficacy of
Test of cleaning efficacy of
endoscope channels in dummy tests
endoscope channels in dummy tests
As test pieces we use Teflon tubes with a lenght of
As test pieces we use Teflon tubes with a lenght of
2000 mm and inner diameters of 2 mm and 1 mm respectively.
2000 mm and inner diameters of 2 mm and 1 mm respectively.
To contaminate the test pieces we inject soil (wheat flour,
To contaminate the test pieces we inject soil (wheat flour,
nigrosine, hen s egg  according to  MNE Prüfanschmutzung
nigrosine, hen s egg  according to  MNE Prüfanschmutzung
nach Koller ) into the Teflon tubes. After 60 minutes of drying,
nach Koller ) into the Teflon tubes. After 60 minutes of drying,
the tubes are purged with air in order to ensure they are not
the tubes are purged with air in order to ensure they are not
blocked.
blocked.
Per tested programme or cycle
Per tested programme or cycle
we prepare one pair of test pieces
we prepare one pair of test pieces
(1 x 1 mm, 1 x 2 mm inner diameter).
(1 x 1 mm, 1 x 2 mm inner diameter).
Additionally we perform a
Additionally we perform a
flexi-check test (blood and
flexi-check test (blood and
polysaccharide-test contamination).
polysaccharide-test contamination).
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of disinfection efficacy of
Test of disinfection efficacy of
endoscope channels in dummy tests
endoscope channels in dummy tests
Preparation of metal germ carriers
Preparation of metal germ carriers
Small metal plates with a length of
Small metal plates with a length of
55 mm, a width of 5 mm, and a
55 mm, a width of 5 mm, and a
thickness of 1 mm
thickness of 1 mm
Concentration on each plate
Concentration on each plate
1010 Enterococcus faecium
1010 Enterococcus faecium
(EK) ATCC 6057
(EK) ATCC 6057
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of disinfection efficacy of
Test of disinfection efficacy of
endoscope channels in dummy tests
endoscope channels in dummy tests
Preparation of the Test Body
Preparation of the Test Body
As test piece for the disinfection
As test piece for the disinfection
efficiency we use Teflon tubes with a
efficiency we use Teflon tubes with a
length of 1500 + 200 mm and an inner
length of 1500 + 200 mm and an inner
diameter of 2 mm and 1 mm and a test
diameter of 2 mm and 1 mm and a test
chamber (TOSI-Lumcheck) with metal
chamber (TOSI-Lumcheck) with metal
plates, with a suspension of test
plates, with a suspension of test
organisms (Enterococcus faecium
organisms (Enterococcus faecium
ATCC 6057) of 1010.
ATCC 6057) of 1010.
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of disinfection efficacy of
Test of disinfection efficacy of
endoscope channels in dummy tests
endoscope channels in dummy tests
Test cycles:
Test cycles:
Cleaning cycle (break after the cleaning stage):
Cleaning cycle (break after the cleaning stage):
RF: > 4 log step
RF: > 4 log step
Complete cycle:
Complete cycle:
RF: > 9 log step
RF: > 9 log step
RF: Reduction factor of the applied test organisms
RF: Reduction factor of the applied test organisms
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of water quality
Test of water quality
Ressource check (VE-water-inflow)
Ressource check (VE-water-inflow)
From the water inflow we take 350 ml water close to the WD.
From the water inflow we take 350 ml water close to the WD.
Acceptance criteria
Acceptance criteria
cfu 37°C: < 20 cfu / ml
cfu 37°C: < 20 cfu / ml
Pseudomonas aeruginosa: 0 cfu / 100 ml
Pseudomonas aeruginosa: 0 cfu / 100 ml
Enterococcaceae: 0 cfu / 100 ml
Enterococcaceae: 0 cfu / 100 ml
Enterobacteriaceae: 0 cfu / 100 ml
Enterobacteriaceae: 0 cfu / 100 ml
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Test of water quality
Test of water quality
Final rinse water
Final rinse water
Acceptance criteria
Acceptance criteria
cfu 22°C: < 20 cfu / ml
cfu 22°C: < 20 cfu / ml
cfu 37°C: < 20 cfu / ml
cfu 37°C: < 20 cfu / ml
Pseudomonas aeruginosa: 0 cfu / 100 ml
Pseudomonas aeruginosa: 0 cfu / 100 ml
Enterococcaceae: 0 cfu / 100 ml
Enterococcaceae: 0 cfu / 100 ml
Enterobacteriaceae: 0 cfu / 100 ml
Enterobacteriaceae: 0 cfu / 100 ml
Differentiation of germs (cfu 22°C and 37°C):
Differentiation of germs (cfu 22°C and 37°C):
no Staphylococcus aureus
no Staphylococcus aureus
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Results
Results
Cleaning cycle (break after the cleaning stage)
Cleaning cycle (break after the cleaning stage)
1 mm Dummy:
1 mm Dummy:
Reduction factor: 5
Reduction factor: 5
2 mm Dummy:
2 mm Dummy:
Reduction factor: 6
Reduction factor: 6
Complete cycle (1 mm und 2 mm Dummy)
Complete cycle (1 mm und 2 mm Dummy)
Reduction factor: > 9 log steps
Reduction factor: > 9 log steps
(no detection of the test organisms)
(no detection of the test organisms)
(5 machine types of 4 suppliers)
(5 machine types of 4 suppliers)
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Summary
Summary
The method is suitable according
The method is suitable according
to prEN 15883 part 4 in respect to
to prEN 15883 part 4 in respect to
required reduction factors of test
required reduction factors of test
organisms for part and full cycles
organisms for part and full cycles
Simple and suitable on-site test
Simple and suitable on-site test
method
method
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria
Institute for Environmental Medicine, Municipal of Vienna
Thank you for
Thank you for
your attention
your attention
International Congress for Reprocessing of Medical Products ÖGSV  WFHSS 2007,
May 3rd to May 5th 2007, Baden, Austria