Machine Disinfection Review

1
Machine DisinfectionReview

• André Stragier, UCL St Luc, Brussels

2
Different opinions
If we draw the question  Should dialysis
machines be disinfected between two successive
dialyses? 

• Replies vary between countries between renal
  units!

3
Different PraticesMachine disinfection between
2 dialysesGermany yes (1998
Leitlinie)France yes (1998 Guide de bonnes
pratiques)Netherlands yes (Werkgroep Infectie
Preventie)Belgium no to yes evolution CDC
noUSA noSingapore no
4

• Machine disinfection between patients shifts
  raises two questions
• Reduces this patients infections and/or
  cross-infections?
• Improves this dialysate bacterial and/or
  endotoxin quality?

5
Which evidence of infections or cross-infections
from the dialysate do we have?
Question 1

• Membrane pore size -
• Single pass dialysis -
• (Genius, Aksys)
• Blood leakage problem?
• Literature research -
• However, we have two problems

6
Problem 1
Blood
Dialysate
Ultra - filtration
Back - filtration
If a membrane fibre would leak in the
back-filtration zone!!!
7
Transducer Protector problem!
Problem 2
Frequent TP replacements TP gets wet and
blocks. TP membrane breaks saline TP membrane
breaks blood

• Consequences
• 1.Patient infection and cross infection risk!
• 2.Nurses critique on infection control!

8
Transducer Protector problem!
Problem 2
Branger (1991) How does this happen? Single-needle
dialysis Prevention?

• Transducer Protector inspection and care need to
  be added to the general precautions!

9
An interesting HCV study(1)

• South-Belgium 15 units 963 patiënts
• No isolation nor dedicated machines
• 10/15 no disinfection between 2 sessions

Jadoul et al. Kidney Int 1998
Stragier et al. EDTNA/ERCA J 2003-2
10
An interesting HCV study(2)

• Yearly HCV sero-conversion
• 2,2 5 centres with syst. disinf.
• 1,1 10 centres without syst. disinf.

11
An interesting HCV study(3)
Successive periods
Applying stricter general precautions only!
12
What is the effect of machine disinfection
between sessions on the bacterial/endotoxin
qualityof the dialysate?
Question 2
13
Test

• First day of the week during 3 weeks
• AK-100 machines
• Two successive dialyses (2 x 4 hours)
• Four machines two with and two without
  disinfection between.
• Samplings begin and end-dialysis dialysate and
  begin-week RO water and liquid bicarbonate for
  bacteriology.
• Last week double dialysate sampling endotoxin
  assessment.

Stragier et al. EDTNA/ERCA J 2003-2
14
Test protocol First session of the day
Second session of the day AK 100-1
A - B No disinfection AK 100-1 A
- B Disinfection AK 100-2
A B No disinfection AK 100-2 A
- B Disinfection   AK 100-3 A - B
Disinfection AK 100-3 A - B
Disinfection AK 100-4 A - B
Disinfection AK 100-4 A - B
Disinfection RO water
...cfu/ml and liquid bicarbonatecfu/ml   A
start-dialysis sample, B end-dialysis sample

 
15
Results
 
First Week (cfu/ml)  
First session of the day
Second session of ther day AK 100-1 lt 1 - 1
No disinfection AK 100-1 lt 1 - lt
1 Disinfection AK 100-2 lt 1 - ? 1 No
disinfection AK 100-2 lt 1 - lt 1
Disinfection AK 100-3 lt 1 - lt
1 Disinfection AK 100-3 lt 1 -
lt 1 Disinfection AK 100-4 lt1 - lt1
Disinfection AK 100-4 ? 1 - ? 1
Disinfection RO water lt 1 cfu/ml and liquid
bicarbonate lt 1 cfu/ml
 

 
16
Results
 
Second Week (cfu/ml)  
First session of the day
Second session of the day AK 100-1 lt 1 -
lt 1 No disinfection AK 100-1 lt 1 -
lt 1 Disinfection AK 100-2
lt 1 - lt 1 No disinfection AK 100-2
lt 1 - ? 1 Disinfection AK
100-3 lt 1 - lt 1 Disinfection AK
100-3 lt 1 - lt 1 Disinfection
AK 100-4 lt1 - lt1 Disinfection
AK 100-4 lt 1 - ? 2 Disinfection RO
water lt 1 cfu/ml and liquid bicarbonate lt 1
cfu/ml
 

 
17
Results
 
Third Week (cfu/ml)  
First session of the day
Second session of the day AK 100-1 lt 1
- ? 1.5 No disinfection AK 100-1 lt 1 -
? 1 Disinfection AK 100-2
lt 1 - ? 15 No disinfection AK 100-2 lt 1
- ? 10 Desinfection . AK 100-3
? 10 - ? 3 Disinfection AK 100-3 lt
1 - ? 2 Disinfection AK
100-4 ? 1 - ? 1.5 Disinfection AK
100-4 lt 1 - ? 1 Disinfection RO water
? 2 cfu/ml and liquid bicarbonate lt 1
cfu/ml All endotoxin tests on dialysate (N16)
were negative (lt0.125 EU/ml)
 

 
18
Conclusion

• Bacteriological there is no difference between
• Start and end of a dialysis
• First versus second daily dialysis
• Disinfected machines between 2 sessions or not.
• Logic because the bacterial replication time is
  40!

19
Advantages of disinfection between successive
sessions?

• This offers more time for the exterior machine
  cleaning and disinfection safer!
• This allows more frequent cleaning of the machine
  hydraulics beneficial!

20
Action Disinfection Ca/Mg Carbonate Iron
Carbonate Organic deposits
Removal of

• Peracetic acid log 5.6a
  0?
  0
• Hypochlorite log 5.5a
  0 0
  
• Citric acid 85 log 7a
  
  
• Citric acid 40 0
  
  0
• Heat gt 85 log 5
  0 0
  0
• a Capelli, Blood Purif 2001
• Complete the 4 actions daily!
• Check the combination of your choice!

21
UCL option evolutionNoon time
hypochloriteEvening citric acid heat
Corrosion!

• Noon time citric acid
• Evening hypochlorite

22
Dialysate cfu and EU results also depend
onMachine typePrevious disinfection policy
(biofilm)Machine stagnation policyHansen
connector disinfection policy
23
A chain is only as strong as its weakest link!
Dialysate A-Concentrate OK B-Concentrate OK RO
water 93-97 of dialysate the weakest link!

24
Preserve your RO water quality!

• Norms lt 1 cfu/ml and lt 0.125 EU/ml
• Possible with any water distribution
• No bacterial filtration
• Using UV irradiation
• A monthly complete disinfection is required

Stragier A, Jadoul M, Clinical Nephrology
December 2004
25
Smeets et al. (Maastricht, The Netherlands)(Kidne
y Intern. 2003)

•  A new, frequently disinfected RO reduces
  biofilm, bacterial growth and
• endotoxin in the RO water.
• This is demonstrated in the line between the RO
  water distribution and the machines which are
  never disinfected 

26
Pontoriero et al. (Lecco, Italy) (NDT 2003)

• 24 dialysis centers (Lombardy)
• Report
• 1. RO water 15 gt 100 cfu/ml
• 2. 28 of the centers disinfect their RO
  water distribution at least monthly!

27
Conclusion 1Machine desinfection between
patients shifts allows a daily full cleaning of
the machine hydraulics! Better cfu and EU
results!
28
Conclusion 2
Long stagnation periods are a critical problem
for dialysis machines hygiene ! Weekend Spare
machines in repair!
29
Conclusion 3Strict application of the general
precautions, including inspection and care of
pressure isolators are mandatory!Blood through
TP machine replacement disinfection!
30
Conclusion 4Machine disinfection, whatever you
do, does not ensure sterile dialysate!Rationale
for sterile dialysate!
31
Conclusion 5The RO water distribution is the
weakest chain. Monthly complete disinfection is
required. Better insight allows now a better RO
water hygiene preservation!