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