|
OZONE AND DISINFECTION OF HEMODIALISYS
MACHINES
I - INTRODUCTION
The ozone use to inhibit
growth bacterial and the removal of biofouling, is an efficient
way, in the daily pre-treatment of the water tanks, and the
hydraulic circuit of Units of HEMODIALISYS, as well it is used in many
places. There is no specific register of ozone job in monitors of
hemodialisys, that for its characteristics it contains circuits that
allows bacterial proliferation and development of biofouling. The water
that cames to the equipment of hemodialisys does not contain chlorine,
the dialysis solution presents nutrients as glucose and leave other
minerals, in the dialisate has also organic nutrients proceeding
from the patient, the bicarbonate concentrate is a risk well known for
infection and the leaving calcium and magnesium determines
formation of irregularities in the hydraulic circuit, who permits
of lodging, bacterial proliferation and biofouling. Moreover, it
can have hiddeen spaces in the internal hydraulic circuit and periods of
water stagnation, between dialysis sessions.
This is the first report published on the Ozone job for the internal
disinfection of machines of Hemodialisys, in comparative study with Acid
Peracetic. The Ozone besides being an excellent bactericidal and a
viruscid agent, also destroys spoors, endotoxins and biofouling
for its high oxidative capacity. Affecting the cytoplasm membrane ,
enzymatic systems and nucleic acid, determine lise of bacterial
cells, not allowing the immunity development or resistance. Inorganic
the mucilaginous material and precipitated that they constitute
biofouling are oxidized and eliminated with the ozonized water flow.
Also it removes precipitated of calcium and magnesium in the places for
where it circulates, in way that, with one exactly product can be gotten
disinfection it accomplishes e and the calcium removal from of
monitors of Hemodialisys
The induction of chronic
inflammatory reply in patients in Hemodialisys, as much for
Lipopolissacarídeos as Exotoxins is individualized assets. Recently
fragments of DNA of bacteria they had been detected in dialisate, with
proven capacity to induce immune reply. ( 1 ).
II-MATERIALS And METHODS
In 2 Units of Hemodialisys were compared the
efficiency of the disinfection of machines of Hemodialisys carried
through Acid Peracetic in the Unit and the Ozone in the Unit B, applying
itself protocol of counting of heterotrophic bacteria and test of
endotoxin. The e was collected a total 40 water samples of the dialisate
in the Unit 33 samples in Unit B. The collection was daily, occurring in
2 machines per day in each Unit. The samples had been gotten in aseptic
way, from connector Hansen of the machines - before the dialysis
solution entering in the capillary after 2 hours of Hemodialisys. All
machines were Gambro®, model AK 95, being evaluated 9 machines in the
Unit and the 10 in Unit B.The hydraulic tubing of machines, for where it
circulates the dialysis solution, the dialisate, water, concentrates
acid and bicarbonate, are elaborated with some types of materials
compatible with ozone, as: polymers (silica, santropeno, PVC ,
peek, pex,PP, psu, PVDF, ptfe), metals (stainless steel,
titanium, platinum) of carbon, ceramics ,aluminum oxide
, glass .The diagrams of the hydraulic circuit of the Units and
the B are shown in Figures I and II .
BACTERIOLOGICAL EXAMINATIONS
The
counting of bacteria heterotrophic were carried through the sowing in
way of culture Plate-Count-Agar, Merck®, approved for "Standard Methods
of will be the Examination Water and Wastewater ", supplying to the
results in UFC/ml (units of ml).The plates had been incubates 36º C, for
48 hours. The measure of the concentration of endotoxins was made
through limulus amoebocyte lysate (LAL) test, Pyrosate, Cape Cord
®, with one has limited of detention 0,25 I /ml.
DISINFECTION of MACHINES In UNIT
disinfection of the machines of Hemodialisys in the
Unit it was made with mixture of Acid Peracetic, Acid Ascetic and
Hydrogen Peroxide, with one final concentration of 0,05% of Acid
Peracetic, after the dilution of 1:35, being carried through daily after
the last turn of dialysis, per 28 minutes.
DISINFECTION of MACHINES In UNIT B
It was carried through with Ozone gotten solely for
an ozonizer OZONIC ®, through of effect Corona, for the application of
an electric discharge on oxygen super-dry, deriving of atmospheric air.
The Ozone generation was given local in the Unit of Hemodialisys B,
being the Ozone introduced in the water to be purified by means of an
injector, through the effect Venturi, to carry through such dissolution.
When the Ozone reached the concentration adjusted in the water of
looping (above of 700 mV), surveyed for the Monitor Enatron D. |
|
This disinfection with ozonized water was carried
through daily, after the last turn of dialysis.
accompaniment OF THE LEVELS OF OZONE
1)NA
OZONIZED WATER
The accompaniment of the Ozone
level dissolved in water (residual Ozone) was made through the
Monitorial equipment Enatron D.S. ®, that electrode makes the reading of
the Potential of Redox (ORP)e of its sensor ( ). The sensor was
installed in looping of water ozonized, before the return stops the tank
of storage and a signal, deriving of the electrode, fed the Monitor ORP,
that it supplied permanently, in a display of the equipment, the
concentration of ozone in mV.
2)
IN THE DIALYSIS MACHINE
The accompaniment of the ozone
concentration in dialysis machine was made through ozonized water
sample, collected in the drain of the machine, 15 minutes after the
disinfection. The reading was made through the dosage of total Chlorine,
for colorimetric, with addition of the reagent DPD (N,
N-dietil-p-fenilenodiamina). The chemical test was carried through
immediately after the collection of the sample of 5,0 ml, comparing
visually the gotten color after the DPD addition, in a comparative
scale, with water sample treated, not ozonized. The thus gotten values
are multiplied by one constant (0,68) to arrive itself at the final
ozone concentration dissolved in water in mg/L ( 2 ).
Conversion of values in mg/L for mV
Through a graph of Potential of Reduction of Oxygen or Potential of
Oxi-reduction, shown in Figure III easily the conversion of
values gotten in mg/L is made for mV (3 ).
DISINFECTION Of TUBING e TANKS
In The Unit it was made through solution I contend
Hypochlorite de Sodium in 1% concentration, applied monthly. In The Unit
B it was used Ozone, generated as described above, applied daily
after the last turn of dialysis, simultaneously with the disinfection of
the machines and four times for week, during 3 hours in automatized,
controlled way electronically. In this Unit also was carried through
weekly thermal disinfection, through warm water circulation enters 85 º
C the 95 º C for the looping one, during 100 minutes, being the heat
gotten for steel ®constructed a Albacete heater stainless 316, as well
as its 6000 resistances of volts each. The tubing of this unit they are
of PEX (reticulate polyethylene) that it possess great resistance for
high pressures and temperature (up to 140 ° C).
Removing Calcium from Of the MACHINES of DIALYSIS
In The Unit , the stage of removing calcium was made
with Acid solution of Ascetic, in 0,5% concentration. In The Unit B
no product was not used additional chemistry for calcium removal.
ANALYSIS STATISTICS
It
was carried through test U of Mann-Whitney and accurate test of Fischer,
with program SPSS- MS, presenting itself the results as counting
(percentile) and medium (interquartil amplitude P25-P75), being the
considered differences significant with P< 0,05.
III-RESULTS
I
How much clinical intercurrences, had not been registered abnormalities
in the patients treated in submitted machines the disinfection with
Ozone or Acid Peracetic, attributable to these procedures.
II
How much To CONCENTRATION OF OZONE in the looping one (origin)
and the water ozonized collected in the drain of each machine
(destination), had been found the following values average, after 30
measuring in each point, as shown in Table I.
TABLE I. AVERAGE CONCENTRATION OF OZONE In LOOPING and the MACHINES OF
HEMODIALISYS
Measure direct Conversion ( graph ORP)
__________________________________________________________________________________________________________
LOOPING (n=30) 1033 mV (1023 -1058 ) 2,25 mg/L
MACHINES (n=30 ) 0,350 mg/L (0,136- 0,476 ) 760 mV
___________________________________________________________________________________________________________
III-Quanto to COUNTING OF BACTERIA HETEROTROPHIC , in the Unit
(the Ac. Peracetic) medium of 17 colonies observed UFC/ml was, in
40 analyzed samples of dialisate. In Unit B (Ozone) medium of 10
colonies UFC/ml was, in 33 samples, as shown in Table II. Statically was
found p=0,045, (p< 0,05), evaluated for test U of Mann-Whitney, being
the presented data as medium (interquartil amplitude = P25-P75).
IV -
How much To positively of the Test of the LAL, stops ENDOTOXIN
(value > 0,25 EU/ml), in Unit (Ac. Peracetic) 14 positive tests had been
registered, in 40 samples, with a percentage of positively of 35 %.
Already in the Unit B (Ozone) 6 samples with Test of the positive
LAL had been observed, in 33 samples, with a percentage of 18,0%,como
appear in Table II.The analysis statistics of this material, carried
through for the accurate test of Fischer, it showed one significance of
p=0,123, being the presented data as counting ( percentage).
|
|
COMPARISON enters OZONE e ACID PERACETIC IN THE
DISINFECTION OF HEMODIALISYS MACHINES
Ác
characteristics. Peracetic Ozone p
Endotoxins: LAL [ + ], nº (% ) 14 (35) 6 (18) 0,123()
Counting Heterotrophy Bacteria. , U/ml 17 (9-28) 10 (3-26) 0,045(b
)
The
data are presented as counting (percentile) e medium
(interquartil amplitude = P25-P75). () Accurate test of Fischer; (b)
Test U of Mann-Whitney.
The
results comparing the job of Ozone and Acid Peracetic, graphical form,
how much endotoxins and counting of heterotrophic bacteria, are
represented in graphs I and II.
GRAPHICAL I. ENDOTOXINS in DIALISATE of HEMODIALISYS MACHINES USING
OZONE and ACID PERACETIC
GRAPH II
BACTERIOLOGICAL EXAMINATIONS in MACHINES OF HEMODIALISYS USING OZONE e
ACID PERACETIC
How
much the frequency of results, the distribution according to UFC number
/ml, after Acid Ozone and Peracetic, is shown in Graph III.
V
How much the abnormalities techniques in machines of Hemodialisys, had
been observed some spots of color brown, in the hydraulic circuit and
hoses, visible by rough estimate naked, in the machines where if it used
Ozone. Moreover, interference of this was evidenced coloration with some
alarms. Such spots had not been observed in the machines disinfected
with Acid Peracetic.
This
material one proved to be constituted of you leave iron, deriving of the
acid concentrate used for preparation of the dialisate. Residual
deposits I contend iron suffer oxidation for Ozone and assumes the
observed brown coloration.
A
chemical analysis of the concentration of iron in the acid concentrate
mg/L detected 5,44, while in bicarbonate solution (Bicart ®) this
concentration was of 1,2 mg/L.
With
the job of a solution I contend metabissulfito, in the hydraulic
circuit, with frequency weekly, it was gotten removal of these deposits,
not having plus none operational interference with the machines of
Hemodialisys.
They
had not been observed precipitated blockages or of you leave calcium and
magnesium to the long one of hydraulic circuit of the machines of
Hemodialisys that had been disinfected with Ozone.
IV
QUARREL
With
this study one demonstrates that Ozone reduces in significant way the
number of bacteria heterotrophic in monitors of Hemodialisys, an
comparison with Acid Peracetic. counting falls of 17 UFC/ml, after
disinfection with Acid Peracetic for 10 UFC/ml with Ozone, p< 0,05. Also
the presence endotoxins, evaluated for the tests of the LAL, with a
limit of detention of 0,25 UE/ ml, was well lesser in the samples of
water deriving of monitors dealt with ozone (18 %), in relation to
treated with acid Peracetic (35 %).
Exactly with all conditions favorable to the bacterial proliferation,
inherent to a monitor of hemodialisys, with ozone had been gotten
resulted, in bacteriological terms, that they satisfy the
recommendations of the Association of will be the Medical Advancement
Instrument (AAMI) (4) and lines of direction of the EDTA (5) for
dialisate of hemodialisys.
The
concentration of ozone dissolved in the water, measure in the drain of
the monitor of hemodialisys, during its application, varied of 0,136
mg/L the 0,476 mg/L, being enough stops to determine reaction of
oxi-reduction capable to exert the bactericidal effect desired.
Besides being more efficient that the regimen of disinfection with Acid
Peracetic, the protocol with Ozone it determines considerable reduction
in the time of the procedure, being able to be made daily after the last
turn of dialysis, in 30 minutes, since Ozone if minutos(2 transforms
after into oxygen about 15). does not have risk of residual chemical
product to remain in the circuit, nor necessity of cleanness of such
residues that it consumes time and great volume of treated water. Beyond
of this the final cost of Ozone is well inferior to the one of acid
Peracetic, therefore it is generated in the proper unit.
Using Ozone, as much the hydraulic net of the Unit as
the monitor of Hemodialisys, also the segment of connection between the
net and the monitor, are treated simultaneously. This very vulnerable
segment, between the Loop and monitor, in some protocols with chemical
agents is not reached, consisting in zone of high risk for development
of bacteria e biofouling (6), (7). During the period of comment, the
patients whose monitors had been dealt with Ozone, had not presented no
abnormality clinic.
The
monitors of Hemodialisys they had presented only spots of brown color,
decurrently of the oxidation of residues of iron gifts in calcium
deposited to the long one of the circuit hydro mechanical engineer. |
|
The
presence of biofouling it reduces the efficiency of used chemical agents
as normally disinfecting, as Hypochlorite de Sodium and Acid Peracetic,
generating a vicious cycle, therefore increase of biofouling intervenes
with the destruction of bacteria and endotoxins ( 8). The previous use
of physical agents with descamantes properties, as acid ascetic, acid
citric or acid oxalic, can facilitate the penetration more deep of the
deodorant in the structure of biofouling, thus increasing its
effectiveness. Although the adequate and periodic disinfection is the
best method to reduce the bacterial proliferation in monitors of
Hemodialisys, we make use but of protocols validated for elimination of
bacteria, lacking still protocols for prevention and eradication of
biofouling (9), (10).
Already ozone, for its properties of oxi-reduction,
in adjusted concentration, it also destroys for complete biofouling and
the its bacteria, also in studies carried through in removable segments
of hydraulic circuits of units of hemodialisys, registering this
effective destruction of biofouling for way of electronic microscopy
(11), (12).
A
highest level of decontamination of the monitor it is recommended
currently, exactly in Hemodialisys conventional, for the possibility to
occur chronic inflammatory reaction in patients with high levels of
endotoxins in the dialisate. However the effective decontamination of
monitors of hemodialisys continues being a difficulty operational.
The
ozone appears as safe, practical, cheap and highly efficient a method to
prevent e to remove bacteria and biofouling of monitors of hemodialisys.
REFERENCES
1)
Schindler R. , Beck W. , Deppisch R. , Aussieker M. , Wilde A. ,
Göhl H. e Frei U. Short Bacterial DNA Fragments : Detection in
Dialysate and Induction of Cytokines . J Am Soc Nephrol 15: 3207-3214,
2004
2)
Amato R. , Curtis J .
The practical application of ozone in dialysis . Neph
News &Issues 16 ( 9 ) :27-29,2002
3)
The Method of O3
Residual Control . In :Handbook of
Chlorination and Alternative Disinfectants. 4th Edition.
Geo.Clifford White : 1318-1319.
4)
Association
for the Advancement of Medical Instrumentation . Vol 3 : Hemodialysis
systems.ANSI/AAMI RD62-2001. AAMI , Arlington
, Va. , 2001
5)
European Best Practice Guidelines for Haemodialysis .Water
treatment system . Nephrol Dial Transplant 17 [ Supplement 7 ] : 45-62
, 2002
6)
Ledebo I. Ultrapure diálisis fluid : Improving conventional and
daily diálisis . Hemodialysis Int 8 ( 2 ) : 159-168 , 2004
7)
Marion-Ferey K. ,Enkiri F. , Pasmore M. et al. : Methods for
Biofilm Analysis on Silicone Tubing of Dialysis Machines. Artificial
Organs 20 ( 7 ) :658 , 2003
8)
Capelli G. , Tetta C. e Canaud B. : Is biofilm a cause of
silent chronic inflammation in haemodialysis patients ? A fascinating
working hypothesis . Nephrol Dial Transplant 20 ( 2 ) : 266-270 , 2005
9)
Lonneman G. When good water goes bad: how it happens , clinical
consequences and possible solutions .Blood Purif 22 : 124-129 , 2004
10)
Capelli G. , Sereni L. , Scialoja M. et
al. Effects of biofilm formation on
haemodialysis monitor disinfection . Nephrol Dial Transplant 18:
2105-2111 , 2003
11)
Penders C. , Kooman J. , Stobberingh E . et al. Does ultrapure
dialysate prevent the development of biofilm in dialysis therapy ?
Nephrol Dial Transplant 16: 1522-1524 , 2001
12)
Smeets E.,Kooman J. ,van Der Sande F.
et al. Prevention of biofilm formation in
dialysis water treatment systems .Kidney Int 63 ( 4 ) : 1574-1576 ,
2003
|
|