Systems and methods for peritoneal dialysis

ES 2 339 239 T3

DESCRIPTION

Peritoneal dialysis system.

Field and background of the invention

The present invention relates generally to systems for administering peritoneal dialysis. More specifically, the present invention relates to systems for administering continuous flow peritoneal dialysis.

Due to illness, trauma, or other causes, a person's kidney system can fail. In renal failure produced by any cause, there are several physiological alterations. The balance between water, minerals and the excretion of the daily metabolic load is no longer possible in kidney failure. During kidney failure, toxic end products of nitrogen metabolism (eg, urea, creatinine, uric acid, and others) can accumulate in the blood and tissues.

Kidney failure and reduced kidney function have been treated with dialysis. Dialysis removes waste, toxins, and excess water from the body that would otherwise have been removed by properly functioning kidneys. Dialysis treatment to replace kidney function is essential for many people, as the treatment saves lives. A person with failing kidneys cannot go on living without replacing at least the filtering functions of the kidneys.

Hemodialysis and peritoneal dialysis are two types of dialysis therapies commonly used to treat loss of kidney function. Hemodialysis treatment removes waste, toxins, and excess water directly from the patient's blood. The patient is connected to a hemodialysis machine and the patient's blood is pumped through the machine. For example, needles or catheters can be inserted into the patient's veins and arteries to connect blood flow to and from the hemodialysis machine. As the blood passes through a dialyzer in the hemodialysis machine, the dialyzer removes waste, toxins, and excess water from the patient's blood and returns the blood to be infused back into the patient. Most hemodialysis machines use a large amount of dialysate, for example approximately 90-120 liters, to dialyze the blood during a single hemodialysis therapy. The used dialysate is then discarded. Hemodialysis treatment lasts several hours and is usually done in a treatment center about three times a week.

Another type of hemodialysis therapy is regenerative hemodialysis. This therapy uses a hemodialysis system that includes a cartridge for dialysate regeneration. One such cartridge is manufactured by Sorb Technology, Oklahoma City, Oklahoma, under the name REDY^TM. In this system, the dialysis fluid flow path must be properly cleaned before the hemodialysis machine can be used on another patient. Furthermore, the dialysis fluid flow path is not a closed system. In this sense, the dialysis fluid circulation path is open to the atmosphere so that airborne pathogens can come into contact with the system fluid and favor the growth of bacteria in it. Therefore, contamination of such a dialysis system can be problematic. In this way, the dialysis fluid that comes out of the REDY cartridge^TM not suitable for peritoneal dialysis.

Peritoneal dialysis uses a sterile dialysis solution, or "dialysate," which is infused into a patient's peritoneal cavity and brought into contact with the patient's peritoneal membrane. Waste, toxins, and excess water pass from the patient's bloodstream through the peritoneal membrane to the dialysate. The transfer of waste, toxins, and excess water from the bloodstream to the dialysate occurs due to diffusion and osmosis during a dwell period when an osmotic agent in the dialysate creates an osmotic gradient across the membrane. The used dialysate is drained after the patient's peritoneal cavity to remove debris, toxins, and excess water from the patient.

There are several types of peritoneal dialysis therapies including continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis. CAPD is a manual dialysis treatment, in which the patient connects the catheter to a fresh dialysate bag and manually infuses fresh dialysate through the catheter into the patient's peritoneal cavity. The patient disconnects the catheter from the new dialysate bag and allows the dialysate to remain within the cavity for the transfer of waste, toxins, and excess water from the patient's blood stream into the dialysis solution. After a period of residence, the patient drains the used dialysate, and then repeats the manual dialysis procedure. Tubing assemblies with “Y” connectors are available for solution and drainage bags that can reduce the number of connections the patient has to make. The tube sets can include pre-attached bags including, for example, an empty bag and a bag filled with dialysate.

In CAPD, the patient goes through several drain, fill, and dwell cycles during the day, for example, about four times per day. Each treatment cycle includes a drain, a fill and a soak, which lasts about four hours. Manual peritoneal dialysis by the patient requires a significant amount of time and effort on the part of the patient. This procedure leaves room for improvement of therapy in order to improve the quality of life of the patient.

Automated peritoneal dialysis is similar to continuous ambulatory peritoneal dialysis in that the dialysis treatment includes a drain, a fill, and a dwell cycle. However, a machine

ES 2 339 239 T3 dialysis automatically performs three or more cycles of peritoneal dialysis treatment, usually overnight while the patient sleeps.

With automated peritoneal dialysis, an automated dialysis machine is fluidly connected to an implanted catheter. The automated dialysis machine is also fluidly connected to a fresh dialysate source or bag and to a fluid drain tube. Dialysis machine pumps pass dialysate from the peritoneal cavity, through the catheter, to the drainage tube. The dialysis machine then pumps fresh dialysate from the dialysate source, through the catheter, into the patient's peritoneal cavity. The automated machine allows the dialysate to remain within the cavity so that waste, toxins, and excess water can be transferred from the patient's bloodstream to the dialysis solution. A computer controls the automatic dialysis machine so that the dialysis treatment occurs automatically when the patient is connected to the dialysis machine, for example when the patient is sleeping. That is, the dialysis system automatically and sequentially pumps fluid into the peritoneal cavity, allows a dwell period, pumps fluid out of the peritoneal cavity, and repeats the process.

Several drain, fill, and dwell cycles will occur during the treatment. Also, a lower volume "last fill" is typically used at the end of automatic dialysis treatment, which remains in the patient's peritoneal cavity when the patient is disconnected from the dialysis machine during the day. Automatic peritoneal dialysis frees the patient from having to manually perform the drain, dwell and fill phase during the day. Automatic dialysis can improve the patient's dialysis treatment and undoubtedly improves the patient's quality of life, compared to CAPD.

Since the 1970s, “continuous flow” peritoneal dialysis systems (“CFPD”) have been contemplated. These systems usually have an inward fluid flow and an outward fluid flow. That is, the dialysate enters a catheter lumen, through the peritoneum, and exits through another catheter lumen to the drainage line. The “used” dialysate (waste-laden dialysate) is collected in a drainage bag which is discarded or placed in a household waste collection bag or flushed down the drain. Known CFPD systems generally use a volume of dialysate once and then discard it. In this sense, the volume of dialysate necessary to carry out the treatment for a single use or pass continuous flow system can be large making the cost of its daily use prohibitive. For example, the volume of dialysate can exceed 120 liters for single pass CFPD systems.

Another type of a CFPD system is described in US 3,707,967. This system requires the use of a reconstitution device to remove dialysate residue after the dialysate has passed through the patient's peritoneum. Specifically, the reconstitution device includes a urea removal column that uses urease to enzymatically transform urea into ammonia. Ammonia must be removed after dialysate before reintroducing it into the peritoneal cavity in order to ensure the health and safety of the patient. However, the removal of ammonia can be problematic and therefore may not provide a fail-safe measure. Furthermore, additional sensors should be employed to monitor ammonia removal from the reconstituted dialysate. This can add to the complexity of the therapy and thus increase the associated cost.

In general, CFPD is known to be more effective compared to other forms of peritoneal dialysis therapy, including, for example, more conventional forms of peritoneal dialysis therapies, such as CAPD and APD that are commonly used require multiple exchanges of new dialysate during treatment. As explained above, several drain, fill, and dwell cycles are typically performed during CAPD and APD. An example of a modification of the more conventional forms of peritoneal dialysis therapy is presented in US Patent 4,618,343. An apparatus is described that allows the peritoneal cavity of the patient to be filled with a sterile dialysis fluid as in the case of CAPD. After a residence time, the dialysis fluid maintains metabolic waste from the patient's blood. A portion of the dialysis fluid containing metabolic waste is then pumped out of the peritoneal cavity and passed through a dialyzer to remove metabolic waste from the dialysis fluid. The dialysis fluid can be pumped back into the peritoneal cavity for reuse.

US-5,944,684 and US-6,409,699 describe peritoneal dialysis systems that include devices for regenerating used dialysis fluid.

Therefore, there is a need to provide improved dialysis systems. The systems should allow the patient to perform the procedure at home without having to store an excessive number of bags of fresh dialysate. The systems must also be automatic so that the procedure can be performed for the most part at night while the patient is sleeping.

Brief description of the invention

In accordance with the present invention, there is provided a system for facilitating peritoneal dialysis according to claim 1.

The present invention relates to systems for providing peritoneal dialysis. In particular, the present invention relates to continuous flow peritoneal dialysis employing a single closed fluid pathway through which the dialysate can

ES 2 339 239 T3 enter, pass through and exit the peritoneal cavity of a patient in order to effectively remove acceptable levels of solutes and excess water or ultrafiltrate from the patient during treatment.

In general, the present invention includes a fluid circuit that is coupled to the patient thereby defining a single closed fluid pathway through which dialysate can circulate and thus be reused throughout treatment. Preferably, the dialysate is delivered through the fluid path continuously. In this regard, the amount of dialysate required for effective treatment can be optimally minimized. In one embodiment, the present system can use six liters or less of dialysate during treatment. With this amount of reusable dialysate, effective treatment can be performed for time periods of up to 10 hours, preferably about 8 hours or less, more preferably about 7 hours or less.

Before reuse, the dialysate is cleaned as it flows through the closed fluid path. The present system includes a cleaning device that engages in the closed fluid path. The cleaning device can remove an acceptable level of solutes including uremic toxins or other metabolic waste products that have passed from the patient to the dialysate during treatment. The amount of solutes removed from the dialysate is necessary to maintain a diffusive gradient at a level sufficient so that the solutes and ultrafiltrate can be effectively removed from the patient by reusing the dialysate during treatment.

In this sense, it is believed that dialysate does not necessarily have to be cleaned or returned to its initial new state before reuse. Rather, the dialysate, after cleaning, can retain a certain concentration of solutes extracted from the patient, particularly urea. In one embodiment, the cleaning device employs a sipper material, such as carbon, to non-selectively remove a substantial portion of solutes from the dialysate. This may include, for example, toxins removed from the patient, such as creatinine, uric acid, medium molecular weight components, at least a part of urea, and other similar and equivalent low molecular weight components. Preferably, the cleaning device includes a binder material for selectively removing urea, phosphate, and / or other similar solutes.

Even after cleaning, if the dialysate maintains, for example, a part of the urea removed from the patient, it is believed that the dialysate can circulate through the closed fluid path to remove solutes from the patient following or exceeding the standard level of therapy, for example DOQI standards. It is believed that the volume of available therapy fluid that includes dialysate can be minimized, distributed, and cleaned in a controlled manner throughout treatment to achieve clinically acceptable levels of solute clearance. Furthermore, it is believed that the systems of the present invention can achieve better levels of solute clearance, compared to known therapies including, for example, APD.

The volume of therapeutic fluid available can be influenced by a number of factors, such as the amount of dialysate introduced into the closed fluid path, the amount of ultrafiltrate added to the closed fluid path, and the amount of additional solutions that can be added. add to the closed fluid path to improve the diffusive properties of the dialysate. In one embodiment, the therapeutic volume is adjusted in a controlled manner by the amount of dialysate that is introduced into the closed fluid path, in addition to the ultrafiltrate that passes from the patient to the closed fluid path during treatment. To compensate for the amount of ultrafiltrate, the volumetric capacity of the closed fluid path can be variably adjusted during treatment. In this sense, the addition of ultrafiltrate to the fluid circuit, in effect increases the ability to remove solutes, keeping the additional volume in contact with the closed circuit. In one embodiment, about 1.5 liters or less of ultrafiltrate is used during therapy.

Additional solutions can be added to the closed fluid path in controlled amounts to further improve the efficiency of solute removal during therapy. In one embodiment, a solution containing an osmotic agent, such as dextrose, can be added to the closed fluid path, in addition to the initial source of dialysate and the added source of ultrafiltrate. Preferably, about 3 liters or less of the additional osmotic agent solution is added. The dextrose-based solution can be used to replenish the diffusive properties of the dialysate before reuse. In one embodiment, the dextrose-based solution contains an amount of concentrated dextrose as compared to the amount of dextrose or other osmotic agent in the initial source of dialysate.

Furthermore, it is believed that the amount of available therapy fluid necessary for effective treatment can be minimized with increased cleaning efficiency. In one embodiment, the present system may utilize, in addition to carbon, binder or reagent materials that can selectively remove certain types of solutes from the dialysate as noted above. Binder materials can be used to remove urea, phosphates, and other desirable metabolic waste products that can remain in the dialysate even after carbon treatment. Preferably, the combination of non-selective and selective cleaning agents can be used to remove up to 70% or more of urea and other components from the dialysate.

An advantage of the present invention is to provide improved systems for providing dialysis therapy.

Another advantage of the present invention is to provide improved continuous flow peritoneal dialysis systems.

ES 2 339 239 T3

Yet another advantage of the present invention is to provide optimal use of dialysate during continuous flow peritoneal dialysis.

Yet another advantage of the present invention is to minimize treatment times while providing optimal use of dialysate during continuous flow peritoneal dialysis.

Another advantage of the present invention is to provide improved systems for performing dialysis therapy that can be safely and comfortably administered to a patient at home.

Another advantage of the present invention is to provide improved systems for providing peritoneal dialysis that can effectively clean used dialysate so that it can be distributed and reused during treatment in order to minimize the amount of dialysate required for effective treatment.

Other characteristics and advantages of the present invention are described and will become clear in the following detailed description of the invention and in the accompanying figures.

Brief description of the figures

Figure 1 schematically illustrates a dialysis system according to an embodiment of the present invention.

Figure 2 schematically illustrates a dialysis system according to another embodiment of the present invention.

Figure 3 schematically illustrates a dialysis system according to another embodiment of the present invention.

Detailed description of the invention

In general, the present invention employs a single closed fluid pathway through which a minimal volume of therapeutic fluid can flow so that therapeutic fluid can enter, pass through, and exit the peritoneal cavity of a patient connected to the closed fluid path. to effectively remove solutes, excess water, and the like from the patient during treatment. In one embodiment, the available volume of therapeutic fluid may include about 6 liters or less of an initial source of dialysate. It is believed that the available volume of therapeutic fluid can be circulated through the closed fluid pathway to remove solutes from the patient following or exceeding clinically acceptable solute removal levels, such as National Kidney Foundation DOQI levels. In one embodiment, acceptable solute clearance or clearance levels can be achieved within 8 hours or less, preferably 7 hours or less, during treatment.

For example, it is believed that a therapeutic level of clearance can be obtained for urea, creatinine, phosphate, β2-microglobulin, equivalents, and combinations thereof. Clearance levels can include, for example, between about 2.1 per week and about 2.6 per week for urea, between about 72 liters / week and about 90 liters / week for creatinine; about 3.5 grams g / week for phosphate; about 600 milligrams mg / week for microglobulin / 12 equivalents and their combinations. It should be noted that clearance levels can be determined in any suitable way. For example, urea clearance levels can be based on Kt / V calculations. In this sense, Kt / V is normally recognized in the state of the art as a dimensionless index corresponding to the clearance of urea.

As used herein, the term "continuous flow" or other equivalent terms that apply to dialysis therapy, such as peritoneal dialysis, mean that the therapeutic fluid that includes dialysate is continuously and simultaneously entering and leaving the peritoneum of the patient during treatment. In this sense, the residence period of the dialysate that is within the peritoneum, associated with typical peritoneal dialysis therapies, such as CAPD and APD, is effectively eliminated.

Preferably, the therapeutic fluid circulates continuously during the treatment. However, it should be noted that fluid circulation in the system of the present invention may include any suitable level of intermittent fluid circulation, in non-continuous, periodic and / or other equivalent amounts, in addition to continuous circulation during treatment. . For example, the present system can provide brief intermittent fluid circulation, for example during filling of a pump chamber, the closed fluid circuit, the patient and / or the like prior to treatment, brief periods of inactivity, or interruptions in treatment. therapy and / or other similar suitable conditions. In this regard, the present system can be controlled to provide a variety and number of suitable dialysis therapies, as desired. In one embodiment, continuous circulation into, through and out of the peritoneal cavity preferably occurs during the main therapeutic treatment, so that a stay in a last pocket, for example, does not restrict the characteristic of continuous circulation.

As used herein, the term "therapeutic fluid" or other similar terms mean any suitable fluid or solution that can be used during dialysis therapy. Therapeutic fluids may include, for example, a new source of dialysate solution that has not been used during therapy, a used dialysate laden with residues containing solutes, metabolic residues and the like extracted from the patient during therapy, a clean source of dialysate that has been cleaned with sorbent materials or the like, a source of ultrafiltrate that has been passed from the patient to mix with the dialysate during treatment, a solution that includes an osmo5 agent

ES 2 339 239 T3 in sufficient quantity to improve the diffusive properties of the dialyzer when added to the dialysate, other suitable solutions and combinations thereof.

In general, the present invention comprises a fluid circuit that is coupled to the patient thereby defining the only closed fluid path into which an effective amount of a new source of dialysate can first be added. The dialysate can then be circulated, preferably continuously, and cleaned through the closed fluid path and thus continuously reused to remove solutes, excess water, and the like from the patient.

It is believed that dialysate does not necessarily have to be cleaned or regenerated to return to its original clean state before reuse. Rather, the dialysate, after cleaning, can retain a certain concentration of solutes that were removed from the patient during therapy. This is particularly suitable for the removal of urea and other similar solutes.

In this sense, urea is usually removed by using an enzymatic process that converts urea into by-products, such as ammonia. By-products can be removed later. However, from a patient health and safety point of view, this type of cleaning process necessarily requires additional components, such as sensors or the like, to ensure that by-products, in particular ammonia, are effectively removed before use. circulate back to, through, and out of the patient. Even though urea or other similar solutes are not completely removed from the dialysate or to acceptable levels prior to reuse, it is believed that by reusing the dialysate during treatment, effective and clinically acceptable levels of solute removal can be achieved.

To compensate for the concentration of solutes that may be retained in the dialysate prior to reuse, the present invention can minimize, circulate and clean the available volume of therapeutic fluid in a controlled manner throughout treatment. The available volume of therapeutic fluid can be adjusted in a controlled manner based on a number of parameters, such as the amount of initial source of dialysate pumped into the closed fluid path, the amount of ultrafiltrate added to the closed fluid path, the amount of other additional solutions that include osmotic agents and / or other suitable components to improve the diffusive properties of the dialysate, and other equivalent parameters as described in detail below.

The available volume of therapeutic fluid necessary for effective treatment can also be influenced by the effectiveness of the cleaning process. As described below, carbon or other similar materials can be used to clean the dialysate as it flows through the closed fluid path. Cleaning efficiency can be increased with the use of materials that can selectively remove solutes in combination with the non-selective removal capabilities of carbon or other similar materials. This can be accomplished without the use of an enzymatic conversion process that produces non-reactive by-products, such as the transformation of urea to ammonia, thus effectively eliminating the need to remove by-products from solution before reuse.

The dialysis systems and methods of the present invention are believed to provide advantages over existing dialysis systems and therapies, eg, clinical benefits, economic benefits, and quality of life benefits. The present invention is believed to have clinical advantages, such as, for example, better blood pressure control, better fluid volume control, better therapeutic performance according to known clinical standards, such as the National Health Foundation standard. Kidney DOQI, higher clearance efficiency rates, lower glucose uptake, ultrafiltrate and glucose profiling management, reduced catheter channeling and / or equivalents.

The present invention is also believed to provide economic advantages, such as reduction of therapeutic costs. Furthermore, the present invention is believed to have advantages in terms of quality of life, for example, more time awake free from dialysis devices, better access to the patient, less complexity, less self-administration of medications, less therapy training. , elimination of the need for a water infrastructure in the home, less fluid that the patient has to control and handle, simpler recipes, elimination of the transport of patients to dialysis centers and / or the like.

The continuous flow dialysis systems of the present invention are believed to more closely mimic and replace the continuous functioning of the kidney, compared to typical intermittent dialysis therapies. This, in turn, can contribute to improving clinical outcomes, while minimally affecting the patient's lifestyle. The efficiency and convenience of the present system provides patients with relatively unrestricted renal replacement therapy. This allows these patients to have fewer limitations than patients using dialysis devices and conventional therapies. The present system can provide an easier entry into early dialysis therapy as the system can allow the physician to monitor the therapy while minimally affecting the lifestyle of the patient.

The continuous flow peritoneal dialysis therapy of the present invention can include a variety of different components and configurations to effectively remove solutes from the patient with a minimal volume of therapeutic fluid and within an optimal time period as noted above. . As shown in Figure 1, the present system includes a fluid circuit 10 in fluid communication with a catheter 12 that can be inserted into a patient 14 undergoing peritoneal dialysis. This defines a single closed fluid path 16

ES 2 339 239 T3 through which dialysate can be fed and circulated, preferably continuously, to remove excess water and solutes including toxins and metabolic wastes and the like from the patient as the dialysate enters, passes through and exits the patient's peritoneal cavity.

Catheter

Any suitable catheter or other medically acceptable access device can be used. In a preferred embodiment, a dual lumen catheter can be used. The dual lumen catheter provides circulation of the therapeutic fluid through the fluid path allowing it to enter, pass through, and exit the patient's abdominal cavity. The double lumen catheter is implanted in the patient for this purpose. An example of a catheter for use in the dialysis system of the present invention is described in US Patent 09/689, 508, filed October 12, 2000, and entitled "Peritoneal Dialysis Catheter." However, it should be noted that two catheters can be used as long as there is an inlet and outlet path for fluid to flow through the peritoneum.

Dialyzed

The new or initial source of dialysate can include any suitable amount and type of solution that can be used effectively to dialyze a patient. As explained above, the present system can achieve and / or exceed clinically acceptable levels of solute removal, while utilizing a minimal volume of therapeutic fluid. In one embodiment, the volume of dialysate used during therapy is about 6 liters or less. It is believed that the lower limit of dialysate volume can reach volume levels as low as about 5 liters or even lower as the cleaning efficiency of the dialysate circulating through the closed fluid path increases.

The dialysate solution can be introduced into the closed fluid path in a number of different suitable ways. In one embodiment, the full volume of the new dialysate source is introduced into the closed fluid loop at the beginning of therapy. This can be done with any suitable pump mechanism. The total volume can be in and fed from one or more suitable solution containers 18, for example conventional dialysis solution bags with a capacity of about 6 liters. On the other hand, dialysate can be generated and fed from an online dialysate generation system. In one embodiment, the dialysate can be intermittently and / or continuously introduced into the closed fluid pathway throughout therapy at suitable flow rates and / or amounts.

The dialysate solution can include any suitable type of dialysate solution. In one embodiment, the new source of dialysate solution includes an osmotic agent, such as dextrose or the like in any suitable amount. It should be noted that the amount of dextrose required for effective therapy may vary between patients. In this regard, the amount of osmotic agent can vary and include any clinically acceptable level, for example about 1.5% by weight, about 2.5% by weight, about 3.5% by weight, about 4.25% by weight or more to meet the specific needs of the patient. The dialysate can include any suitable amount and type of electrolytes in addition to the osmotic agent including, for example, calcium, sodium, potassium, equivalent components, and combinations thereof.

Cartridge

As shown in Figure 1, the present invention can include any suitable type of device 20, utilizing any suitable amount and type of material to effectively clean the therapeutic fluid as it circulates through the closed fluid path. This facilitates reuse of the therapeutic fluid to remove effective levels of solutes, excess water, and the like from the patient during therapy. In one embodiment, the cleaning device includes a material that can non-selectively remove solutes from the therapeutic fluid that have been removed from the patient during therapy. Preferably, the material includes any suitable sorbing material, such as carbon, activated carbon, and / or other equivalent material contained in a suitable shell, such as a cartridge, in any acceptable manner. As discussed above, it is believed that the non-selective removal of solutes from the dialysate, alone, can be used to clean the dialysate so that effective removal of solutes and excess water from the patient occurs upon reuse of the dialysate. dialysate.

In one embodiment, the present system may include other materials in addition to the types of materials that can non-selectively remove solutes from the dialysate. Additional other materials include, for example, materials that can selectively remove certain solutes or the like from solution. In one embodiment, additional materials include a binder material that can selectively remove urea, a binder material that can selectively remove phosphate, and / or equivalents.

In general, binder materials chemically bind solutes, eg, urea, to remove them from dialysate or other suitable fluid medium as described in more detail below. This process does not result in the release of harmful substances as reaction by-products compared to an enzymatic process. For example, urease is known to enzymatically transform urea into ammonia. However, ammonia must be removed after dialysate before it is reintroduced into the peritoneal cavity in order to ensure the health and safety of the patient. With the use of binder materials, the dialysate can be reintroduced into the peritoneal cavity, without having to further process the dialysate as a result of the agglutination process. As has already been

ES 2 339 239 T3 explained, the use of materials that can selectively remove solutes, in particular urea, can be used to improve the cleaning efficiency of the system of the present invention so that less volume of therapy is needed to provide effective therapy.

Materials that can selectively remove solutes from solution, for example binder materials, can include a variety of different and suitable materials including, for example, polymeric materials that can remove nitrogen-containing compounds, such as urea, creatinine, others. metabolic residues and / or the equivalent solution. In general, these types of materials contain a functional group or groups that chemically bond with urea or other similar solutes.

For example, US Patents 3,933,753 and 4,012,317 describe phenylglyoxal-containing alkenylaromatic polymers that can function to chemically bind urea. In general, the phenylglyoxal polymeric material is made by acetylation performed, for example, in nitrobenzene followed by halogenation of the acetyl group and treatment with dimethylsulfoxide as described in US Patents 3,933,753 and 4,012,317. Another example of a polymeric material that can selectively remove solutes, such as urea, from solution includes polymeric materials that contain a tricarbonyl functionality commonly known as ninhydrin as described in US Patent 4,897,200. However, it should be noted that the present system can include any suitable type of material or combinations thereof to selectively remove solutes, such as urea, from solution as already noted.

The cleaning cartridge of the present system can include various components in addition to materials that can remove solutes from the dialysate. For example, the cleaning cartridge may have the ability to remove all or a portion of the electrolytes, such as sodium, potassium, or equivalents, from the dialysate solution. In this case, an additional source of electrolyte solution may be necessary to replenish the dialysate after it has been cleaned. The cartridge can also be configured to release bicarbonate or equivalents into the system depending on the type of cleaning material used. This can facilitate regulation of the pH of the dialysate. If necessary, the cartridge may include a filter to prevent proteins, particulate matter, or equivalent components from being leached out of the cartridge and into the dialysate.

Treatment conditions

During treatment, therapeutic fluid, including dialysate, is dispensed, preferably continuously, and cleaned along the closed fluid path so that it can be continuously reused to provide effective patient treatment. Any acceptable flow rate of therapeutic fluid can be delivered. In one embodiment, the flow rate of fluid in the closed fluid loop can range up to about 300 ml / minute, preferably about 100 ml / minute or less. At these flow rates, the present system can provide effective treatment to the patient in 8 hours or less, preferably 7 hours or less. In one embodiment, the systems of the present invention can be performed overnight. Preferably, the treatment therapy is combined with a full day residence period in which an adequate amount of dialysate remains in the patient. In one embodiment, the full day stay includes about 2 liters or less of dialysate. It should be noted that this volume may vary between patients depending on the specific needs of the patient.

Peritoneal dialysis can be done in a number of suitable ways. For example, the full volume of the new dialysate source can be introduced into the fluid circuit at the beginning of the treatment. In this regard, the patient's peritoneal cavity is filled with approximately 3 liters of the new source of dialysate solution and the remaining part of the dialysate is pumped into the fluid circuit before dispensing the dialysate during treatment. It should be noted that the initial fill volume of dialysate within the patient's peritoneal cavity may vary from patient to patient. On the other hand, the treatment period can be carried out over several treatment cycles. For example, the treatment period may include two separate treatment cycles. In each cycle, approximately any suitable amount of the new dialysate source is initially introduced into the fluid circuit and then delivered over an effective treatment cycle period of about 4 hours or less. After the first cycle, the entire volume of therapeutic fluid that includes the dialysate plus any additional ultrafiltrate or solutions that were added to the fluid circuit during treatment, is drained from the fluid circuit. Once drained, the remaining part of the new dialysate is introduced into the fluid circuit and circulated until the end of the treatment.

Cycler

In one embodiment, the new source of dialysate can be pumped and distributed through the fluid circuit and drained from the fluid circuit after each treatment cycle with the use of a device that is commonly known in the art as a cycler (not it shows). As used herein, the term "cycler" or other similar terms refer to a pressure driven membrane-type volumetric displacement pump coupled to a fluid path (s) in any suitable way so that circulation can be automatically controlled. fluid. The cycler can determine the volume of fluid delivered as the difference in volume of a pump chamber before and after a pump stroke. The pumping chamber, in general, consists of two parts separated by a flexible membrane with air on one side and fluid on the other. The increased air pressure pushes the fluid out of the chamber expanding the volume on the air side.

ES 2 339 239 T3

It should be noted that the cycler can include any number and type of suitable components, such as pumps and valves, coupled in any suitably designed fluid circuit to provide effective and efficient automatic control of therapeutic fluid entering and leaving the chamber. closed fluid path 16. For example, the cyclers normally applied during automatic peritoneal dialysis and suitable modifications thereof may be employed.

Examples of a cycler are described in US patent applications: "Peritoneal Dialysis Systems and Methods Employing a Liquid Distribution and Pumping Cassette That Emulates Gravity Flow", filed March 3, 1993, Serial No. 08 / 027,328, published as US Patent 5,350,357; "Liquid Pumping Mechanisms for Peritoneal Dialysis Systems Employing Fluid Pressure" filed March 3, 1993, Serial No. 08 / 027,485, published as US Patent 5,431,626; "Peritoneal Dialysis Systems and Methods Employing Pneumatic Pressure and Temperature-Corrected Liquid Volume Measurements", filed March 3, 1993, Serial No. 08 / 026,458, published as US Patent 5,474,683; "Improved User Interface and Monitoring Functions for Automated Peritoneal Dialysis" filed March 3, 1993, Serial No. 08 / 025,531, published as US Patent 5,438,510; "Improved User Interface for Automated Peritoneal Dialysis Systems," filed March 3, 1993, Serial No. 08 / 025,547, published as US Patent 5,324,422; and "Peritoneal Dialysis Cycler," filed March 3, 1993, Serial No. 08 / 006,426, published as US Patent D 351,470. It should be noted that the cycler can be attached to the continuous circulation system in any suitable way, for example using any disposable cartridge that can be used as a fluid interface between the patient and the fluid circuit for quick and easy attachment. the patient to the fluid circuit as normally used during automated peritoneal dialysis and / or modifications thereof.

After treatment, the therapeutic fluid is withdrawn from the fluid circuit via a discharge port 22 that is coupled to the fluid circuit. The therapeutic fluid can be discharged in any suitable way, for example by any suitable pump mechanism coupled in the fluid discharge path. Discharged therapeutic fluid can be disposed of or, alternatively, it can be regenerated for previous use.

Additional osmotic agent

Referring now to Figure 2, the present invention may include a fluid source 28 in addition to dialysate and ultrafiltrate, which can be added to the fluid circuit during treatment. The additional fluid source may include one or more solutions, such as an aqueous solution containing an osmotic agent, such as dextrose or the like, in an amount sufficient to restore the diffusive properties of the therapeutic fluid during treatment. The amount of osmotic agent may include about 2.5% by weight, about 3.5% by weight, about 4.25% or more by weight of suitable amounts and combinations thereof. The additional solution source can also include an acceptable level and type of other components, such as electrolytes including calcium, magnesium, sodium, equivalents and combinations thereof, in addition to the osmotic agent. In one embodiment, the amount of osmotic agent solution added to the fluid circuit is about 3 liters or less, preferably about 2 liters or less. The osmotic agent solution can be introduced continuously or intermittently into the closed fluid path in a monitored manner and in any suitable manner.

It should be noted that the amount and type of osmotic agent solution necessary to facilitate effective treatment may vary from patient to patient. In one embodiment, a solution with a relatively high level of osmotic agent and electrolytes compared to existing therapeutic fluid can be introduced into the fluid circuit in volumetric amounts of about 1 liter or less. In one embodiment, the osmotic agent and electrolyte solution concentrate may include an osmotic agent, such as dextrose, at about 4.25% or more by weight and electrolyte concentration levels that are higher than existing levels in the solution. therapeutic so that the levels of the therapeutic solution can be adjusted to achieve optimal and physiological acceptable levels prior to reuse.

In one embodiment, the components of the solution concentrate can be individually infused into the fluid circuit. The components can include the types of components commonly found in dialysate solutions, including, for example, an osmotic agent, such as dextrose, bicarbonate, sodium, calcium, magnesium, equivalent components, and combinations thereof. The quantity of individual components introduced into the fluid circuit can be regulated and controlled in any suitable way.

For example, a sensing device (not shown) can be fitted into the system of the present invention that can be used to provide real-time, online monitoring of specific component levels during treatment. The sensor can then be configured to communicate with the infusion device (not shown) of each of the components to regulate the flow of components through the fluid circuit. This can also be used to monitor the level of ultrafiltrate removed from the patient. If more ultrafiltrate is desired, the sensor can be adapted to communicate with a pump to increase the flow of dextrose and thus increase ultrafiltrate removal from the patient. In one embodiment, the amount of individual components added during therapy can be regulated based on custom therapy profiles associated with each of the components.

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In one embodiment, the available volume of therapeutic solution may include the initial amount of fresh dialysate, the amount of ultrafiltrate, and / or other additional solutions, such as dextrose-based solutions as noted above. Instead of variably increasing the volumetric capacity of the fluid circuit, the volumetric capacity of the fluid circuit can remain relatively constant during treatment. In this sense, a quantity of therapeutic fluid is discharged from the fluid circuit at a rate similar to the infusion of the dextrose-based solution and the transport of ultrafiltrate to the fluid circuit. Preferably, the volumetric capacity of the fluid circuit can be set in this way as the cleaning efficiency of the therapeutic solution increases. In this sense, a variable increase in the available volume of therapeutic fluid is not required for effective treatment.

Deposit

In one embodiment, the present invention includes a reservoir 24 that is coupled to the fluid circuit. This can provide a variable increase in the volumetric capacity of the fluid circuit during treatment. In this sense, the ultrafiltrate that passes from the patient to the fluid circuit can mix with the dialysate and therefore increase the volume of therapeutic fluid available for effective treatment.

As already described above, the addition of ultrafiltrate to the dialysate, in effect, increases the ability to remove solutes by keeping the additional volume in contact with the closed fluid circuit. This can facilitate the cleaning process and thus effectively minimize the volume of fresh dialysate required for treatment purposes. As used herein, the term "ultrafiltrate" or other similar terms means the excess water that is removed from the patient as the dialysate acts to dialyze the patient. It should be noted that the reservoir can include any suitable component, such as any suitable container coupled to a pump that can act to variably increase the volume of the fluid loop in any suitable manner. The container may include any suitable type of container as long as a portion of the fluid in the closed fluid loop can be effectively pumped into and out of the container during therapy. Preferably, the accumulator container is not flexible. In this sense, the fluid pumped into the closed fluid circuit is designed to be pushed by pumps. Therefore, it would be difficult to control or regulate the flow rates through the fluid circuit with a flexible container acting as an accumulator or a variable reservoir.

As shown in FIG. 3, the present invention includes a fluid circuit 30 in fluid communication with a catheter 32 that can be inserted into a patient 34 undergoing peritoneal dialysis. Thus, a single closed fluid path 36 is defined. A source of dialysate is provided in a container 38 coupled in the fluid circuit 30. From the container, the dialysate can be pumped and circulated through the fluid circuit to remove metabolic waste and / or ultrafiltrate from the patient as it enters, circulates through, and exits the patient. A cleaning device 40 is attached to the fluid circuit to clean the dialysate as it circulates through the fluid circuit 30 as already described.

At the beginning of therapy, at least a portion of the dialysate is pumped into fluid circuit 30 to fill the patient's peritoneal cavity. The remaining part of the dialysate, if any remains, can be pumped into the fluid circuit at a later stage of therapy. As therapy continues, a portion of the therapeutic fluid that has circulated through the fluid circuit may be pumped into container 38, as the volume of therapeutic fluid increases, due, for example, to the addition of ultrafiltrate to the fluid circuit that an additional amount of osmotic agent solution (not shown) has been removed from the patient and / or added to fluid circuit 30 as already described. At least a portion of the container 38 can be filled with the therapeutic fluid continuously or intermittently. At least a portion of the therapeutic fluid that is in the container 38 can then be pumped back into the fluid loop 30. Any suitable amount of therapeutic fluid can be sent to or withdrawn from the container following any suitable time interval to adjust the volume of therapeutic fluid. available. This allows the portion of therapeutic fluid to be pumped into or out of the container, while the remaining portion of therapeutic fluid that is in fluid loop 30 continues to flow through fluid loop 30.

It should be noted that any suitable volume of therapeutic fluid can be pumped into or out of the container to compensate for a change in volume of therapeutic fluid during therapy. The flow of fluid circulating into or out of container 38 and while circulating through the fluid loop can be controlled at any suitable flow rate and with any suitable type and number of pumps. The pumps can be coupled to the system via a cycler or one or more of the pumps can be coupled separately to the system. In one embodiment, the flow of fluid into or out of the container can be controlled at a flow rate of about 75 ml / minute, while the flow of fluid flowing through the fluid loop can be controlled at about 250 ml / minute as shown in figure 3.

It should be noted that the systems of the present invention may utilize any suitable number and type of components to facilitate effective treatment of the patient by improving quality of life, economy, efficacy of treatment, and other similar treatment conditions. For example, the present system can make use of any acceptable number and type of pumps adapted in any suitable way so that therapeutic solutions, including dialysate, can be effectively introduced, distributed and drained from the single closed fluid circuit connected to the patient. .

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Monitors

In one embodiment, the dialysis system of the present invention is a closed, sterile system to prevent air, moisture, and other environmental contaminants from entering the closed fluid circuit. In this regard, the present system can include a variety of different components to monitor contaminant levels in the system. For example, the present system can include a gas sensor for monitoring atmospheric gases including oxygen and carbon dioxide. If detected, the present system can include any suitable device to remove gas from the system of the present invention so that the gas can be discharged to atmosphere.

In one embodiment, temperature sensors are provided at desired locations in the fluid loop. Temperature sensors monitor various fluid temperatures that can be used to monitor the temperatures of the fluids associated with the heater. When two or more heaters, such as an infrared heater and a plate heater, are provided in the dialysis system, the system, in one embodiment, includes independent temperature sensors for each heater, so that each heater can be individually controlled. .

The present invention, in one embodiment, also includes other different sensors for monitoring other different parameters. For example, fluid pressure sensors can be electrically coupled or communicated with a controller to provide a signal indicating the corresponding fluid pressure at certain locations in the closed fluid path. Based on the signals from the pressure sensors , the controller can actuate the fluid pumps and valves to obtain and maintain the pressurized fluid and desired flow rates in the closed circuit going to, through and from the patient.

In one embodiment, the pressure sensors are non-invasive pressure sensors. These pressure sensors do not come into physical contact (possibly contaminating) with medical or dialysate fluid. Of course, other fluid flow measurement devices, such as flow sensors, manometers, flow meters, pressure regulators, orifice plates, mass flow meters, capacitive fluid sensors, or other flow measurement devices known to those skilled in the art. , can be provided in any suitable quantity and adapted to the fluid circuit.

In one embodiment, a flow measurement or volume sensing device is provided, including a capacitance sensor that measures the volume of fluid pumped through a chamber, such as a pump chamber (not shown).

The capacitance C between two capacitor plates changes according to the function C = kx (S / d), where k is the dielectric constant, S is the area of ​​the individual plates, and d is the distance between the plates. The capacitance between the plates changes proportionally according to the function 1 / (R x V), where R is a known resistance and V is the voltage measured across the capacitor plates.

In one embodiment of the capacitance sensor, the sensor operates in cooperation with a cycler pump chamber. The cycler pump chamber, in one embodiment, includes covers or walls that define a fixed and known volume and a pair of flexible membranes that function between the covers, which expand to receive fluid and compress to discharge fluid. The capacitance sensor includes capacitor plates arranged on opposite sides of the pump chamber. As the volume of fluid in the fluid chamber or pump changes (that is, the pump chamber fills or empties), the dielectric property of the different fluids between the capacitance plates also changes. For example, the combined dielectric constant of dialysate and air changes as dialysate replaces air (or air replaces dialysate) within the constant volume covers of the chamber. This change in the entire dielectric constant has to do with a change in capacitance between the two plates, causing a change in voltage across the capacitance plates, whereby a voltage sensing device detects a corresponding change in voltage. The controller monitors the change in voltage by the voltage sensing device and correlates (after a sensor calibration) the change in capacitance with an amount of fluid pumped through the chamber.

In another embodiment, the volume of the chamber or the pump chamber may vary, for example, due to movement of one or both of the chamber covers. In this embodiment, the capacitance between the capacitor plates changes due to a variable distance d between the plates and / or a variable surface S of one or more of the plates, where the dielectric constant k is static since only one fluid resides at all times between the capacitor plates. In another alternative embodiment of the measurement device, the capacitance C between the capacitor plates changes based on any combination of a change in dielectric constant k, distance d, and surface S.

The controller collects a multitude of voltage signals from the capacitance changes due to a plurality of filling and emptying cycles of the chamber, and the controller calculates a total volume of medical fluid pumped over a period of time or a number of cycles of the bomb. The capacitance sensor monitors medical fluid, for example dialysate entering and leaving the pump chamber in real time and non-invasively.

The capacitance sensor allows the dialysis system to maintain the volume of fluid delivered to the patient in convenient amounts and flow rates. Maintaining fluid flow to the patient at desired levels is particularly advantageous for peritoneal dialysis therapies.

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It is also desirable to maintain the fluid that has been provided to the patient at physiological levels. Physiological control, such as detection and / or adjustment of parameters or fluids, can take place at different locations in the dialysis system. To this end, the system can include any combination of a number of different types of physiological level sensors. For example, the system can include one or more pH sensors. In one application, the cartridges discussed above in relation to Figure 1 may include a pH sensor that helps adjust the fluid to maintain a desired physiological level.

Heater

The present invention may include a fluid heater that can act flexibly to heat the fluid in the closed fluid circuit to a desired temperature in order to deliver the fluid to the patient. In this sense, the temperature of the dialysate at the initial filling of the system can be quite low, for example between 5 ° C and 10 ° C if the fluid is stored at a cold room temperature. In one embodiment, the fluid heater is an in-line heater (flow-through heater) that heats the fluid to the desired temperature as the fluid continuously circulates past the heater. In other embodiments, heaters other than in-line heaters may be used, eg, loose heaters, a double heater, and the like.

In one embodiment, the fluid heater is a dual heater (not shown), including an infrared heater and a plate heater. An example of such a double heater is described in US-7,153,285. Both the infrared heater and the plate heater are in-line heaters that heat medical fluid continuously circulating past the heaters. The radiant energy or the infrared heater emits infrared energy that is directed towards and absorbed by the fluid that is in the closed circuit of the patient, thus heating the fluid. The radiant energy or infrared heater is a primary or large capacity heater that can heat a relatively large volume of cold fluid to a desired temperature in a short period of time.

The plate heater is a secondary or maintenance heater with a relatively lower heating capacity relative to the infrared heater. The plate heater uses electrical resistance to increase the temperature of a plate which in turn heats the fluid circulating near the plate.

The heater, which includes both high and low capacity heaters, offers an efficient heater design that accommodates various fluid heating needs. For example, the radiant or infrared heater is particularly useful for rapidly heating cold dialysate (high thermal energy demand) that is supplied to the dialysis system, for example at initial filling of the system or if there is strong heat loss during dialysis treatment. The temperature of the dialysate at the initial fill of the system can be very low, for example between 5 ° C and 10 ° C if the fluid is stored at cold room temperature.

The plate heater is particularly useful in maintaining a desired temperature (demand for less thermal energy) of the fluid being delivered to the patient, for example due to a normal amount of heat loss during dialysis treatment. The infrared heater meets the high heat demand in a small amount of fluid exposure space, while the plate heater meets the heat demand and requires less input energy compared to the infrared or radiant heater . Furthermore, the heating capacity of the heater increases if both the infrared and plate heaters are used together to heat the fluid.

The infrared heater and the plate heater can be arranged in different configurations from each other. In one embodiment, the heaters are arranged so that fluid passes through the heaters sequentially (eg, first the radiant or infrared heater and then the plate heater or vice versa). In another embodiment, the fluid passes through the heaters simultaneously (through both heaters at the same time). The fluid flow path through the heaters can be a common fluid path for both heaters or include separate fluid paths for each heater. In addition, electrical, infrared, or radiant resistance heating and other types of heating such as convection, microwave, infrared ("IR"), or inductive heating can be used.

The heater can include a number of different components. For example, the heater can include a filter made of any suitable material and with any suitable filter size. The filter can be of any suitable material and include any suitable filter size. In one embodiment, the filter is about 0.3 microns in size, preferably about 0.22 microns. This means that the filter can remove solutes from solutions with a size of approximately 0.3 microns or larger with a filter of approximately 0.3 microns, or solutes of approximately 0.22 microns or larger for a filter size of around 0.22 microns. The filter can act in several different ways to improve the performance of the dialysis system of the present invention.

For example, the filter can be used in place of typical UV decontamination techniques or the like to disinfect the therapeutic fluid prior to entering, circulating through, and exiting the patient. This can effectively eliminate, or at least greatly reduce, infection in the patient as a result of treatment, for example peritonitis that can be contracted due to contact contamination during therapy.

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It should be noted that the filter (s) can be attached to the fluid circuit in any suitable position. In the patient, on the circulation side, the filter can act to disinfect the dialysate before entering the patient, as already described. The filter (s) can also be attached to the discharge path. At this location, the filter can be used to remove nutrients from the therapy fluid prior to discharge. The filter can then be cleaned by, for example, backwashing with a suitable solution, to remove the filtered nutrients for reuse and reintroduction to the patient. The filter can be constructed in any suitable way to improve its filtering efficiency.

It should be noted that the fluid path, fluid loop, closed fluid loop, and / or equivalents of the present system can be made with one or more interconnected fluid conduits in any suitable way. The fluid conduits can include any suitable material, including a flexible, inert, and sterile plastic such as polyethylene, polystyrene, polypropylene, polyvinyl chloride, and / or combinations thereof. In general, the fluid passages are transparent so that the fluid flowing through the passages can be visually observed.

It should be understood, that those skilled in the art will appreciate that changes and modifications of the presently preferred embodiments described herein are possible.