U.S. patent application number 10/694087 was filed with the patent office on 2004-05-06 for device and method for perfusing peritoneal dialyzing fluid.
Invention is credited to Sakai, Asahi.
Application Number | 20040087890 10/694087 |
Document ID | / |
Family ID | 17686242 |
Filed Date | 2004-05-06 |
United States Patent
Application |
20040087890 |
Kind Code |
A1 |
Sakai, Asahi |
May 6, 2004 |
Device and method for perfusing peritoneal dialyzing fluid
Abstract
An instrument and method for continuous recirculation of
peritoneal dialysate to infuse and drain out the dialysate
automatically through catheters implanted in a peritoneal cavity of
a human body. The recirculation instrument permits the reuse of
protein which is permeated out from a patient's body, as an osmotic
agent in peritoneal dialysate, in order to maintain a disinfected
recirculating line, and to improve an ultrafiltration rate and
clearance of uremic toxin. The recirculation method includes
continuously draining the dialysate out of the peritoneal cavity,
recirculating the dialysate through a closed line, filtering out a
portion of the dialysate through a semipermeable membrane on the
way, supplementing a comparable volume of fresh dialysate through a
semipermeable membrane having a maximum permeable molecule of up to
5,000 dalton, and returning the dialysate into the peritoneal
cavity.
Inventors: |
Sakai, Asahi; (Sakura-shi,
JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
17686242 |
Appl. No.: |
10/694087 |
Filed: |
October 28, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10694087 |
Oct 28, 2003 |
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09806686 |
Apr 4, 2001 |
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6666842 |
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09806686 |
Apr 4, 2001 |
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PCT/JP99/05535 |
Oct 7, 1999 |
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Current U.S.
Class: |
604/29 |
Current CPC
Class: |
A61M 1/284 20140204;
A61M 1/28 20130101 |
Class at
Publication: |
604/029 |
International
Class: |
A61M 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 7, 1998 |
JP |
HEI 10/285029 |
Claims
What is claimed is:
1. A recirculation method of dialysate which comprises continuous
flow of dialysate out of peritoneal cavity, recirculation through a
closed line, filtering out of a portion of the dialysate through a
semipermeable membrane on the way, supplementing a comparable
volume of fresh dialysate through a semipermeable membrane having a
maximum permeable molecule of up to 5,000 dalton, and returning
into peritoneal cavity.
2. The recirculation method of dialysate according to claim 1,
wherein polymer osmotic agents is added to the recirculation
line.
3. The recirculation method of dialysate according to claim 2
wherein polymer osmotic agents is plasma protein or
oligosaccharide.
4. The recirculation method of dialysate according to claim 1,
wherein osmotic agents selected from glucose, amino acids, fatty
acids, and peptides is added to the recirculation line.
5. The recirculation method of dialysate according to claim 1,
wherein reductants or anti-oxidants are added to supplementing
fluid.
6. The recirculation method of dialysate according to claim 5,
wherein reductants or anti-oxidants is glutathione, vitamin C or
vitamin E.
7. The recirculation method of dialysate according to claim 1,
wherein stabilizers preventing the recycled protein denatured is
added to supplementing fluid.
8. The recirculation method of dialysate according to claim 1,
wherein albumin is treated with reductants or anti-oxidants to
activate before infusing into peritoneal cavity.
Description
[0001] This application is a divisional application of U.S. Ser.
No. 09/806,686, filed Apr. 4, 2001, which is a national phase
application of PCT/JP99/05535, filed Oct. 7, 1999
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a peritoneal dialysis
instrument for improving dialysis efficacy in removing excess
liquid and uremic toxin by maintaining polymer osmotic agents in
place of glucose in a recirculation line without requiring outside
contact for the therapy of chronicle renal failure disease.
[0004] 2. Description of the Related Art
[0005] Peritoneal dialysis has been applied as an effective therapy
for renal failure patients. The dialysis is performed so that
dialysate is infused into the peritoneal cavity from the dialysate
bag through a catheter, which is implanted in the patient's
peritoneal cavity, and the dialysate is stored in the cavity for a
certain time. Then, the dialysate is drained out through the same
catheter. This procedure is repeated a few times a day.
[0006] This dialysis has a few advantages over hemodialysis from a
physiological point of view, as it purifies blood continuously
through the patient's peritoneum, while hemodialysis uses
artificial membranes. Also, peritoneal dialysis enables the
patients to participate in social activity, and as a result, the
dialysis has been widely applied.
[0007] In hemodialysis, ultrafiltration is achieved by raising the
pressure of the blood line over that of the dialysate line.
However, the same method can not be applied to peritoneal dialysis.
As a result, an osmotic agent is added into the dialysate so as to
raise the osmotic pressure of the dialysate over that of plasma,
and the dialysate is infused into the peritoneal cavity so as to
contact it to the peritoneum for removing excess liquid from the
patient's body. For this purpose, glucose has been used as an
osmotic agent. However, adverse effects such as the disfunctioning
of the peritoneum due to the absorption of such a large quantity of
the osmotic agent into the patient body are now recognized as a
serious problem.
[0008] For solving the aforementioned problem, the inventor of the
present invention has proposed an instrument and a method by which
serum protein, such as albumin, globulin and the like which are
permeated out through peritoneum into the dialysate, is recovered
and refined, and is then concentrated and reused with dialysate as
the most physiological substitutes of glucose.
[0009] In these proposed processes, the following were
disclosed:
[0010] (A) A method to dissolve the recovered and refined protein
in dialysate after which low molecular weight uremic toxin
substances not higher than 30,000 daltons are removed by the
repeated concentration/dilution procedures with a semipermeable
membrane, and to reuse it as a substitute of glucose. (Japanese
Laid Open Patent Application Hei 9-327511)
[0011] (B) A method to keep the abovementioned device and the
components disinfected. (Japanese Laid Open Patent Application Hei
10-85324)
[0012] (C) A method to separate the malignant solute in the solvent
and refine the protein by acidifying the protein and then
de-acidifying it through water dialysis so as to deposit it at
iso-electric pH (Japanese Laid Open Patent Application Hei
9-302388)
[0013] Also, for carrying out the invention (C), it was disclosed
that the device comprises the followings:
[0014] (D) An inflow line having a filter whose maximum pore size
is 100-300 nanometers for preventing bacteria invasion into the
peritoneal cavity; and
[0015] (E) A two step prefilter having a pore size between 5 and
200 microns to remove blood cells, peritoneum mesothelial cells,
fibrin and the like suspended in the effluent when it is drained
out from peritoneal cavity.
[0016] A few attempts have been reported to utilize serum protein
in ascites (Hwang, E. R., Richard, D. O. Sherman, A. et al.,
Dialytic Ascites Ultra-filtration in Refractory Ascites, Am. J.
Gastroenteral, 77(9) :652-654, 1982, for example)
[0017] However, they did not refer to removing uremic toxin,
because their target was not a renal failure patient.
[0018] Also, a method to add a peritoneum protecting component of a
molecular weight of not higher than 3,000 daltons recovered from
peritoneal dialysis effluent into dialysate (Japanese Laid Open
Patent Application Hei 8-337590). However the recovery and reuse of
the component of the molecular weight higher than 3,000 daltons is
not suggested.
[0019] When plasma protein that is permeated out of the patient
body is reused as an osmotic agent in place of glucose, the
following conditions need to be satisfied:
[0020] (I) To minimize the contact with atmosphere and foreign
matters so as to not denature the protein;
[0021] (II) To minimize plugging the semi-permeable membrane on the
recirculation line, and to decrease the frequency of exchange;
and
[0022] (III) To completely prevent the invasion of pathogenic
bacteria and endotoxin.
[0023] For the solution of the aforementioned (I) problem, it may
be suggested that a filter is set at the exit of the catheter, or,
as a further perfect protection, a hollow fiber type semi-permeable
membrane is set in a peritoneal cavity in order to keep the polymer
in the peritoneal cavity. However, in those cases, complicated
preventive means are required to avoid plugging of the membrane,
and the exchange of the filter requires skillful care.
SUMMARY OF THE INVENTION
[0024] The present invention has developed a practical method and
an instrument for solving the aforementioned problems, by the
combination of either one of the following technologies:
[0025] [I] The drained dialysate is warmed up to a preset
temperature, and then it is filtered through a prefilter for
removing foreign materials so as to prevent the plugging of the
filter.
[0026] [II] A semi-permeable membrane (having a cut-off point of up
to 30,000 dalton) filter is used for removing uremic toxin of low
molecular weight and of middle molecular weight.
[0027] [III] A supplemental electrolyte solution is supplied
through a semi-permeable membrane filter (having a cut-off point of
up to 5,000 dalton) for preventing the infection and invasion of
endotoxin.
[0028] Also, the present inventor has found that by the use of the
device, dialysate may be drained out of the peritoneal cavity and
may be recirculated in a closed line. In addition, a portion of the
dialysate may be filtered out through a semi-permeable membrane to
remove malignant component, and then, a fresh dialysate may be
supplemented through a semipermeable membrane and returned
automatically into the peritoneal cavity.
[0029] Briefly, the present invention relates to an instrument that
comprises (a) a prefilter, (b) a first filter that comprises a
semi-permeable membrane having a maximum permeable molecule of up
to 30,000 dalton, (c) a pump to lower the outside pressure of the
first filter (b) relative to the inside pressure, (d) a second
filter that comprises a semi-permeable membrane having a maximum
permeable molecule of 5,000 dalton, (e) and a pump to raise the
pressure of a supplemental liquor line relative to the inside line
of the second filter.
[0030] Also, the present invention relates to a method
characterized in that dialysate is drained out of the peritoneal
cavity and recirculated in a closed line, and a portion of the
dialysate is filtered out through a semi-permeable membrane. Then,
an equivalent volume of fresh dialysate is supplemented through a
semi-permeable membrane having a maximum permeable molecule of
5,000 dalton and is then returned into the peritoneal cavity.
[0031] As a favorable embodiment for carrying out the present
invention, the following technologies may be adapted:
[0032] (1) A bacteria-free filter (having a maximum pore size of
100-300 nanometers) is set up on the peritoneal cavity side of the
inflow line's joint.
[0033] (2) Dialysate in the peritoneal cavity is recirculated
through a perfectly closed and continuously connected and
previously disinfected line for keeping the protein not denatured
in the automatic dialysate recirculation instrument.
[0034] (3) A reverse flow prevention valve (anti-reverse flow
valve) is set up on the withdrawn line.
[0035] (4) A closed chamber, of which the inside can not directly
be contacted by fingers, is set up for disconnection and connection
procedure by remote operation from outside, after the infusion of
dialysate for the daytime cycle before getting up in the
morning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 illustrates a Peritoneal Dialysate Recirculation
Circuit in a nighttime state where the peritoneal dialysate
recirculation instrument is connected with the patient's outflow
and inflow catheters, respectively, and the dialysate is
recirculated.
[0037] FIG. 1(a) is an enlargement of the structure of the primary
filter and the secondary filter of FIG. 1 and illustrates the flow
of the dialysate and a supplemental solution therethrough.
[0038] FIG. 2 illustrates an exchanging method of an outflow line
joint and an inflow line joint for:
[0039] (a) a disconnecting operation of the joint, which has been
directly connected in the daytime (FIG. 3), and a rotation
operation of the parts; and
[0040] (b) a rotating operation of the disconnected part so as to
face the part of peritoneal cavity side and the part of
recirculation instrument side, and a connecting operation of the
parts so as to make ready for nighttime recirculation (FIG. 1).
[0041] FIG. 3 illustrates an O-shaped circuit of the catheter at an
extracorporeal side (during a daytime state when the patient leaves
and is away from the recirculation instrument for daily life) and
hollow fibers in the peritoneal cavity.
EXPLANATION OF THE REFERENCE NUMERALS
[0042] 1. Peritoneal Cavity
[0043] 2. Outflow Catheter
[0044] 3. Joint
[0045] 4. Anti-Reverse Flow Valve
[0046] 5. Outflow Line Joint
[0047] 5a. Patient Peritoneal Cavity Side Terminal of Outflow Line
Joint
[0048] 5b. Recirculation Instrument Side Terminal of Outflow Line
Joint
[0049] 6. Heater
[0050] 7. Prefilter
[0051] 8. Bacteria-free Filter
[0052] 9. Pump
[0053] 10. Primary Filter
[0054] 11. Secondary Filter
[0055] 12. Suction Pump
[0056] 13. Feeding Pump
[0057] 14. Supplemental Solution Vessel
[0058] 15. Pump
[0059] 16. Pump
[0060] 17a. Container
[0061] 17b. Reservoir of Osmotic Agents
[0062] 18. Warmer
[0063] 19. Inflow Line Joint
[0064] 19a. Patient Peritoneal Cavity Side Terminal of Inflow Line
Joint
[0065] 19b. Recirculation Instrument Side Terminal of Inflow Line
Joint
[0066] 20. Bacteria-free Filter
[0067] 21. Joint
[0068] 22. Inflow Catheter
[0069] 23. Reverse Osmosis Membrane Water
[0070] 24. Inlet Valve of Chemicals
[0071] 25. Loupe-shape Hollow Fibers
[0072] 26. Isolated Case
DETAILED DESCRIPTION OF THE INVENTION
[0073] The present invention will be explained with reference to
FIG. 1.
[0074] FIG. 1 illustrates an outflow catheter 2 and an inflow
catheter 22 in a peritoneal cavity 1.
[0075] It happens to be observed often that when liquor is
recirculated from an inflow entrance to an outflow exit at a
consistent rate, a localized flow, a so-called channeling, is
formed in the peritoneal cavity; then, a portion of the liquor
tends to stay at "dead spaces". For solving this problem, a certain
number of loop-shaped porous hollow fibers 25 are fixed at the end
of the inflow catheter so that the dialysate may flow throughout
the cavity as illustrated in FIG. 3. Instead of an outflow catheter
2, an outer lumen of a concentric double lumen catheter may
alternatively be used.
[0076] Outflow catheter 2 comprises joint 3, anti-reverse flow
valve 4, and outflow joint 5, and the flow catheter is connected
with heater 6 and prefilter 7 in series.
[0077] Outflow joint 5 comprises peritoneal side part 5a and
instrument side part 5b, as illustrated in FIG. 3. During
recirculation time, which occurs at night, the parts 5a and 5b are
connected together. The joint 5 has the structure of male/female
parts, which are directly adaptable to each counterpart of inflow
joint 19, as is discussed further below. During the daytime, which
is when dialysate is not recirculated but is stored in the
peritoneal cavity, the joint part 5a is connected with the joint
part 19a, and the joint part 5b is connected with the joint part
19b, thereby forming the circuit illustrated in FIG. 3.
[0078] The dialysis effluent that is drained out of the patient's
peritoneal cavity contains peritoneum mesothelium cells, leucocyte
cells, deposited fibrin, and the like. These foreign particles may
be separated from the filtrate with prefilter 7.
[0079] Fibrinogen in the dialysate effluent tends to be deposited
out as fibrin after prefiltration, and it plugs the filter. This
has often been experienced when plasma and humor is filtered. For
preventing the plugging problems, it is desirable to warm up the
effluent up to 55-60.degree. C. by means of a heater before
prefiltration.
[0080] After the dialysate is passed through a bacteria-free filter
8, it is flown by pump 9 to the first filter 10 and then to the
second filter 11. The first filter has a semi-permeable membrane of
a maximum permeable molecule of up to 30,000 dalton, greater than
that of 2-microglobulin, for example. By filtering out a portion of
the dialysate through this filter, middle molecule malignant
components, such as a 2-microglobulin of the molecular weight of
11,800 daltons, may be removed.
[0081] After filtering through the first filter, the partially
filtered dialysate is supplemented with a supplemental electrolyte
solution. The supplemental solution is added through the second
filter whose semipermeable membrane does not pass endotoxin. The
second filter has a semipermeable membrane of a maximum permeable
molecule of up to 5,000 dalton so that it can prevent invasion of
bacteria and endotoxin.
[0082] Endotoxins are lipopolysaccharides, of which the largest
ones have a molecular weight of a few hundred thousand dalton. The
smallest lipopolyssaccharides have a molecular weight of
6,000-8,000 dalton. On the other hand, supplemental chemicals and
additives are lighter molecules, such as 1,000 dalton, so that they
may pass through this semipermeable membrane of the second filter
11.
[0083] Due to the reduced pressure in the outside of the first
filter 10 by suction pump 12, dialysate in the first filter 10 is
suctioned out. The supplement solution in the second filter is
pressed by feeding pump 13 to feed in through the second filter 11.
The filtration in both filters is accelerated by these pumps 12 and
13.
[0084] FIG. 1(a) illustrates an enlargement of the structure of the
primary filter 10 and the secondary filter 11, and the flow of the
dialysate and the supplemental solution. As shown in FIG. 1(a), the
primary filter 10 and the secondary filter 11 each comprise a
number of hollow fibers. The sections labeled as Section A are
inside the hollow fibers which lead the dialysate rightward to the
secondary filter 11. The sections labeled as Section B are outside
of the primary filter 10 and lead the suctioned filtrate upward to
be discarded by the suction pump 12. The individual sections of
Section B appear to be isolated, but in fact, they are in a
continuous space leading to the suction pump 12. In the suctioned
filtrate, middle molecules of less than 30,000 dalton are thereby
removed as indicated by the upward arrow from primary filter 10 to
the suction pump 12.
[0085] The supplemental solution is stored in a supplemental
solution vessel 14, and it is sent to the second filter by feeding
pump 13 as indicated by the downward arrow from the supplemental
solution vessel 14 and the supplemental liquor line (sections
labeled as section C of the secondary filter 11) into the secondary
filter line (sections D on the inside of the hollow fibers of the
secondary filter 11). Amino acids, fatty acids, glucose, peptides
or any mixture thereof are added into the supplemental solution
through a line which is connected with a valve 24 that is equipped
in the supplemental solution vessel 14.
[0086] The above-mentioned supplemental solution may be: p1 (a) a
commercially available infusion solution or peritoneal dialysate
which is sterilized and packed in a supplemental solution vessel
14, or
[0087] (b) a hemodialysis concentrate or dry chemicals for
hemodialysis, which is diluted or dissolved with, reverse osmosis
water.
[0088] After partial filtration in the first filter 10 and
supplementation at the second filter 11, the dialysate is flown by
pump 16 through a warmer 18, where it is warmed up to a standard
corporeal temperature. Then, the dialysate is infused through
inflow joint 19, bacteria-free filter 20, and joint 21 so as to
pass into peritoneal cavity 1.
[0089] On the by-pass line 15-17a-9, a container 17a is set up,
where a portion of polymer components, which is stored in the
peritoneal cavity during the daytime, may be stored. The solution
can be circulated through the line by pump 15 so as to repeat the
concentration/dilution procedures. A cooling or freezing unit may
be equipped for the container 17a.
[0090] One of the present invention's aims is the reuse of
recovered plasma protein permeated from a patient's body through
peritoneum into the dialysate.
[0091] However, in the case where the recovered protein is not
enough to achieve sufficient ultrafiltration, other osmotic agents
may be supplemented. Such supplemental agents may be high or low
molecular weight substances.
[0092] High molecular weight substances may be oligosaccharides,
and low molecular weight substances may be glucose or amino acids.
Even when substances whose daily dose is restricted are used, usage
is within a tolerable quantity, and those osmotic agents may be
used so that the required osmotic pressure can be obtained. Low
molecular weight agents are added from a supplemental reservoir 14,
and high molecular weight agents are supplied from an osmotic agent
reservoir 17b into the container 17a, where the additives are mixed
with the dialysate.
[0093] The recirculation instrument is connected with peritoneal
catheters at night so as to automatically achieve peritoneal
dialysate recirculation. However, in the daytime, joint 5 and joint
19 are disconnected from the recirculation instrument and form a
daytime circuit as illustrated in FIG. 3. For such a disconnection
and connection operation, each joint comprises a respective part a
and part b as illustrated in FIG. 2. That is, joint 5 consists of
parts 5a (male) and 5b (female), and joint 19 consists of parts 19a
(female) and 19b (male). When parts 5a and 5b are disconnected from
each other and parts 19a and 19b are disconnected from each other,
parts 5a and 19a can be connected and parts 5b and 19b can be
connected as illustrated in FIG. 3. According to the present
invention, outflow joint 5 and inflow joint 19 are set up
adjacently in an isolated case 26 and manipulated from outside of
the case to be isolated and free from human contact.
[0094] By use of the recirculation instrument according to the
present invention, extraperitoneal recirculation procedures may be
achieved continuously and automatically in the following way.
First, before the patient begins sleeping, parts 5a and 19a and
parts 5b and 19b, which have been respectively connected in the
isolated case 26 during the daytime, are disconnected. Then, each
part is rotated by 90 degrees to the direction along the arrows as
illustrated in FIG. 2. Then, parts 5a and 5b are connected, and
parts 19a and 19b are connected to form a recirculating circuit as
illustrated in FIG. 1.
[0095] When the circuit line is set up, recirculation is started.
After concentrating the drained dialysate and removing uremic toxin
in the first filter, a portion of the concentrate is stored in the
container 17a.
[0096] The remaining concentrate is added to a fresh electrolyte
solution through the second filter 11, and then is infused into the
peritoneal cavity. If needed, concentrating/diluting procedures are
repeated a few times through a circulation circuit (16-17a-9). In
some cases, an electrolyte solution, such as amino acids, glucose,
fatty acids, or peptides, etc., is added.
[0097] Not only sodium caprilate and N-acetyltryptophan are added
as stabilizers to prevent the recycled protein from becoming
denatured, but acids, alkali, and anti-oxidants, such as,
glutathione, vitamin C, vitamin E and reductants, are also added to
the electrolyte solution so as to release urea, bilirubin, and S--S
bonded chemicals that are attached to cysteine, 34.sup.th amino
acid from N-terminal of albumin. By making albumin as active as
those of healthy persons by the abovementioned way before infusing
it into the peritoneal cavity, it may thereby improve the therapy
effect.
[0098] Thus, the dialysate in the peritoneal cavity is consistently
drained out, and is substituted partly with a fresh electrolyte
solution by the way of recirculation at night when the patient
sleeps.
[0099] Before getting up in the morning, all or almost all of the
dialysate in the peritoneal cavity is drained out, and the drain is
repeatedly concentrated and diluted. Then, the aforementioned
chemicals are added and infused into the peritoneal cavity. The
joints 5 and 19 are disconnected to form a circuit as illustrated
in FIG. 3 by directly connecting the corresponding part of joint 5
with the corresponding part of joint 19. Briefly, as in FIG. 3, on
the catheter side, an "O" shaped circuit is formed. On the catheter
side, part 19a is connected to a bacteria-free filter entrance 20
on the inflow line, and part 5a is connected to an anti-reverse
flow-valve exit 4 on the outflow line. On the recirculation
instrument side, the counter parts 5b and 19b are connected.
[0100] The above-mentioned operation can be manipulated in a
separate case so as to prevent human contact, and through which a
continuous recirculation of the dialysate can be performed.
[0101] By use of the instrument according to the present invention,
continuous recirculation can be achieved simultaneous to a partial
substitution of the dialysate.
[0102] By the instrument according to the present invention, safely
reusing the permeated out protein into the peritoneal dialysate,
and continuous recirculation of the dialysate can be achieved in
the simplest way. Briefly, every day, dialysate is drained out and
infused through a semipermeable membrane, and solution flows
through a completely closed circuit line so as to minimize the risk
of infection.
[0103] By the instrument according to the present invention,
continuous recirculation of the dialysate can be achieved
simultaneous to a partial substitution. As a result, continuous
draining of the dialysate out of the peritoneal cavity and partial
substitution of the dialysate with fresh electrolyte solution can
be achieved during the nighttime when the patient sleeps. After
getting up in the morning, the patient can be disconnected from the
instrument and thereafter enjoy a daily life in the daytime without
being connected to an external instrument.
[0104] It has been said that increasing the number of dialysis
cycles per day is effective for improving the dialysance of
peritoneal dialysis. However, too many cycles of peritoneal
dialysis increases the vacancy time of a peritoneal cavity. To
solve this problem, the use of tidal type recirculation has been
proposed. However, tidal type recirculation leaves a portion of
liquid in the peritoneal cavity, and it can not improve the
dialysance significantly.
[0105] The present invention, in contrast, can improve the
dialysance, as the dialysate recirculates without a vacancy time in
the peritoneal cavity. Another recirculating method in which the
dialysate is refined by extraperitoneal dialysis by use of an
artificial dialyser and extracoporial dialysate can improve the
dialysance, but this recirculating method requires a large volume
of dialysate. The present invention provides a much more economical
dialysis due to a partial substitution of recirculated dialysate.
This advantage is also valid in the case where no polymer component
is contained and recycled.
[0106] Instead of requiring large volumes of dialysate to be
delivered, on site preparation of dialysate by diluting the
dialysate concentrate or by dissolving dry chemicals is very
effective for reducing the cost of therapy. The water preparation
device for the dissolution and dilution by reverse osmosis membrane
may be equipped in the instrument according to the present
invention so as to provide a safe and low cost dialysate.
[0107] Infection can be prevented by the use of a previously
connected, packed and sterilized extracorporeal recirculation line.
Also, the infection rate at a periodical exchange can be
significantly reduced by having the outflow and inflow connection
parts fixed adjacent to one another in a closed case as illustrated
in FIG. 2, and the connection parts can be disconnected and
exchanged by outside manipulation free from contact of the
atmosphere and other foreign, e.g. human, contact.
[0108] By using the above-described method and instrument, the
present invention enables (I) minimizing contact with the
atmosphere and other foreign matters such as human contact, (II)
minimizing the plugging of the semi-permeable membrane on the
recirculation line, and (III) perfectly preventing the invasion of
bacterial and endotoxin from external sources.
* * * * *