The role of cleaning in the manual
reprocessing of medical devices
and quality assessment of
different cleaners
Nicole Hirth
BODE CHEMIE HAMBURG
WFHSS East European Workshop
Bydgoszcz, Poland
6. – 8.12.2007
The role of cleaning in the manual
reprocessing of medical devices
and quality assessment of
different cleaners
Nicole Hirth
BODE CHEMIE HAMBURG
WFHSS East European Workshop
Bydgoszcz, Poland
6. – 8.12.2007
Instrument Cleaning
I
I
ntroduction
ntroduction
R
R
esidues on instruments
esidues on instruments
R
R
equirements
equirements
C
C
leaning results
leaning results
C
C
leaning results in clinical pra
leaning results in clinical pra
ctice
ctice
M
M
icrobicidal efficacy
icrobicidal efficacy
O
O
utlook
utlook
Method of
Method of
reprocessing
reprocessing
Disinfectant
Disinfectant
Cleaner
Appearance of
Appearance of
instruments
instruments
and
and
soiling
soiling
Introduction
Influence on reprocessing success
Method of
Method of
reprocessing
reprocessing
Disinfectant
Disinfectant
Cleaner
Appearance of
Appearance of
instruments
instruments
and
and
soiling
soiling
Introduction
Influence on reprocessing success
National guidelines and recommendations differ
Germany
France
Switzerland
USA
Europe
Introduction
Introduction
SFED-recommendation on
reprocessing flexible
endoscopes (06/2002)
RKI-recommendation on hygienic
reprocessing of medical devices
(11/2001)
... surely effective
sterilization
takes place only
with
clean
medical devices
In recent years, national guidelines have started to acknowledge the
importance of thorough cleaning before the use of disinfectants
first cleaning
10 min
second
cleaning
5 min
Control Body
Distal
End
Light Guide Connector
Air-
/
Water
-Channel
Instrumental-
Channel
Water-Jet-Channel
Construction of the interior
endoscope channel system
Suction Tube
Air Nozzle
Water Nozzle
Instrument
Channel Inlet
Residues on instruments
Insufficient
Insufficient
cleaning:
cleaning:
Coloscope, air-channel
very heavy soiling
BODE-internal investigation
of different channels from
endoscopes in maintenance 1999
Thorough pre-cleaning is indispensable!
Residue of X-ray contrast media
IDEAL nutrient base !
IDEAL nutrient base !
Dilemma in cleaning:
• no standardized / required tests
• no defined cleaning power
• no European standard protocol for
cleaning (e.g. brushing)
• no European norms for cleaners
!?
Residues on instruments
The simple fact that a product is called "cleaner"
does not have any significance
What kind of cleaner is really
inside?
...a question that merits closer
examination....
Requirements
• no tests
• no norms
• no standards
Optimisation of
cleaning of
proteins
Tests in
clinical
practice
Compatibility
tests with
suppliers of
instruments
Optimisation of
cleaning of
biofilms
Requirements
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Time (min)
C
le
a
n
in
g
p
o
w
e
r
[%
]
Cleaner (non-ionic
+ amphoteric
tensides) 1%
Disinfectant (QAC
+ Amin) 3%
Disinfectant (PAA)
1500ppm
Disinfectant 3%
(GDA+FA-releas.)
Disinfectant 3%
(GDA)
Disinfectant ready
to use (2,1% GDA)
Cleaning results: Proteins
External in vitro investigation with different products, test on metal
plates, contaminated with a standardised blood contamination (dried
blood)
aldehydic and peracetic acid products left remarkable protein soil !
0
20
40
60
80
100
5 min
10
min
20
min
contamination rate [%]
Water
Disinf.
Cl.+Dis.
Ster.
Cl.+Ster.
HBV-contamination:
Success (failure) in disinfection
Study with angioscopes after contamination with duck-HBV
Disinfection : GDA, 2%ig
Sterilization: Ethylenoxid, 6h
X. Chaufour et al., Evaluation of disinfection and sterilization of re-usable
angioscopes with the duck hepatitis B model. J.Vasc. Surg. 1999; 30: 277 -282
Proving the Fixation
Proving the Fixation
15 minutes in a disinfectant (DGHM-conc.)
immerse in dist. water
5 minutes in a agitator (200 rds/min)
in a alcaline cleaner 1%
immerse in dist. water
Results 2
Cleaning results: Proteins
Results 1
Both active ingredients are not suitable for cleaning!
Fixation of blood on metalplates
ALDEHYDES
PERACETIC ACID
Cleaning results: Proteins
Biofilm
Channel
Flow
direction
Contamination
Disinfectant
Mucus
Interaction of biofilm with cleaner and disinfectant
Bacteria in biofilms are very resistant
to disinfectants !
A good pre-cleaning is important !
Cleaning results: biofilm
Cleaning results: biofilm
bi
of
ilm
re
du
ct
io
n
[lo
g
10
]
0
0,4
0,8
1,2
1,6
2
conventional
enzymatic
cleaner
conventional
neutral cleaner
cleaner based
on non-ionic
and aphoteric
tensides
There is a huge difference
in reduction of biofilms!
Significantly better!
Cleaning results in clinical practice
d
ec
o
n
ta
m
in
at
io
n
r
at
e
[%
]
n=97
n=129
n=100
50
60
70
80
90
100
conventional
cleaner
enzymatic
cleaner
cleaner based
on non-ionic
and aphoteric
tensides
Duodenoscopes
Source: Endopraxis, 2000, 02: 18 - 20
Interaction of blood with cleaner and disinfectant
Glass capillary:
left: cleaned with cleaner based
on non-ionic and aphoteric
tensides, disinfected with a
glutaraldehyde containing
disinfectant and rinsed with water
right: cleaned and disinfected
with a glutaraldehyde containing
disinfectant and rinsed with water
Working without cleaner, blood
coagulates and cannot removed
from channel systems
Microbicidal efficacy incl. cleaning
performance
Product based on
glutaraldehyde 2%
grounding microbial
with sterile activity
quartz sand
sheep blood
B. subtilis
Staph. aureus
metal plate
disinfection 15
min.
thorough rinsing
tap water
final rinse
sterile water
Product based on
aldehyde-free
aliphatic amines
Microbicidal efficacy incl. cleaning
performance
Staph. aureus
Staph. aureus
- results
- results
2.60
6.03
-
reduction
factor
3.43
0
6.03
cfu [log10]
Product based on
glutaraldehyde
2%* (mean of 4)
Product based on
aliphatic amines
(mean of 4)
Control
(mean of 4)
Product based on aliphatic amines with good cleaning
power confirms micorbial efficacy, aldehydic product without
cleaning power fails
* This test design is not relevant in case of clean instruments
Microbicidal efficacy incl. cleaning
performance
B. subtilis
B. subtilis
- results
- results
1.14
2.16
-
reduction
factor
5.14
4.12
6.28
cfu [log10]
Product based on
glutaraldehyde
2%* (mean of 6)
Product based on
aliphatic amines
(mean of 6)
Control
(mean of 4)
Product with good cleaning power and no
sporicidal activity shows better performance than the
sporicidal aldehydic without cleaning power
* This test design is not relevant in case of clean instruments
Microbicidal efficacy incl. cleaning
performance
Cleaning
Disinfection
Outlook
Safety by careful
Safety by careful
cleaning
cleaning