MXPA00006247A - Hemodialysis assembly and method - Google Patents

Abstract

A hemodialysis system and method of operation includes providing a plasma separator, such as a centrifuge in a process control to remove the plasma fluid from the red and white blood cells so that only the plasma fluid is subjected to the contaminant removal in a downstream dialyzer. This shortened by half the time required to perform a hemodialysis treatment a compared to conventional systems.

Description

UNIT AND METHOD OF HEMODIALISIS BACKGROUND OF THE INVENTION Hemodialysis was proposed as a life-sustaining therapy for end-stage renal failure, when in about 1925 it was discovered that a thin film of re-constituted cellulose (celophane®) had the ability to separate chemicals while they were in solution by means of their uneven diffusion through a permeable membrane. This phenomenon worked particularly well with whole blood to differentially separate urea molecules. Over the years there have been many changes to gradually improve the hemodialysis process. However, the fundamentals remain the same. Hemodialysis essentially mimics the function of the kidney in processing whole blood. Total blood is composed of three main components: a) red blood cells, b) white blood cells, c) plasma fluid. Since the toxins or ureas to be eliminated are in the plasma solution portion of the whole blood, the cells only accompany them in the path. The cells are also very fragile, so although they do not participate in the dialysis process - directly, their presence dominates the speed at which hemodialysis can proceed. Typically, a hemodialysis process would take place over a period of time of six to eight hours per treatment, and generally such treatments would be required 2 to 3 times per week. The dialyzer used is also patient specific. It would be desirable if improvements could be made in the hemodialysis process, which would greatly reduce the cost and complexity: enough to effectively become a basically domestic therapy. SUMMARY OF THE INVENTION An object of this invention is to provide an improved hemodialysis unit, capable of achieving the wishes described above. A further object of this invention is to provide a method of hemodialysis that results from the use of such a unit. In accordance with this invention, the whole blood drawn from the patient is transported to a process control, which includes a plasma separator, preferably a centrifuge, to separate the plasma from the red and white blood cells and from the platelets if necessary . The plasma is then removed from the process control, and directed to a dialyzer, where it is treated to remove contaminants and thus purify. Alternatively, the plasma is collected in a bag or container for further purification. The cells are returned from the control of the process to the patient. By removing the cells from the plasma, the process can be shortened in time, since the cells are no longer present to adversely affect the speed of the process. In the preferred practice of the invention, sterile connection devices are used at various sites to facilitate the addition and removal of the various components or modules of the system in a fast, totally confined and sterile manner. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic diagram representing a prior art hemodialysis process used today; Figures 2 and 3 are schematic diagrams showing alternative hemodialysis units according to this invention; and Figure 4 is a schematic diagram showing the sterilization or removal of contaminants from plasma according to this invention.

- DETAILED DESCRIPTION OF THE INVENTION Figure 1 represents a current hemodialysis unit, of the prior art. As shown therein, a tube 10 is connected to the chest, or arm of a patient P. A pump 12 in process control 14 draws whole blood from patient P to tube 10. Total blood passes through a filter of bacteria 16, then removed from process control 14 through tube 18, which leads to a dialyzer 20. Dialyzer 20 can be, for example, a component commercially available from companies such as Baxter, Gambro and Fresenius. The whole blood is treated to remove the contaminants in the dialyzer filter 20, and then it is transported through the tube 22 by means of the pump 24 in the process control 14. The blood is then returned to the patient P through the tube 26, which incorporates an additional filter for bacteria 16. The dialyzer removes urea molecules from the plasma via Donan dialysis. However, because the cells are present, this process is particularly dangerous for red blood cells, which can cause cell rupture and fracture. To avoid the problems conventionally used hemodialysis is slow, due to the need to protect the fragile red blood cells from damage. The use of filters for bacteria is also a disadvantage, because such filters are not completely effective and also prolong the time involved in the process. Such a conventional process also incorporates a low pressure pump in the process control, and uses low pressure in the dialyzer. The process described in Figure 1 should be done in a clinical setting, which requires the patient to visit clinics approximately 2 to 3 times a week for dialysis treatment that lasts from 6 to 8 hours per visit. The inconvenience, loss of productive time for the patient, and the cost of clinical supervision all contribute to the excessive costs for routine health care. Figure 2 shows the system 30 according to this invention. As shown therein, whole blood would be removed from patient P through tubes 32 and 38 and transported to process control 34. In accordance with this invention, process control 34 includes a plasma separator 36 for Separate the plasma from the cells. A preferred separator is a centrifuge. For example, Haemonetics has used a continuous centrifuge bowl to separate the cells from the plasma. This system is referred to as apheresis, and has been in use since about 1950. Centrifuge 36 takes advantage of the different densities of plasma compared to blood cells. During operation with the centrifuge, the cells are collected in the outer wall of the centrifuge vat 42 due to their density, while the plasma, which is more similar to water or fluid, remains in the center of the vat. Platelets can also be separated from the plasma by a second "vigorous" centrifugation if necessary. Thus, the anticoagulated whole blood would be transported from the tube 32 to the upstream tube 38, and then pumped into the feeding tube 40 to enter the tub 42 at the bottom of the centrifuge 36. The centrifugal force rotates the denser cellular components by outside, leaving the plasma in the inner band. When the tub is full, the plasma flows out of the centrifuge 36 through the feeding tube 40, then through the effluent tube 44. From the tube 44 the plasma flows through the tube 46 downstream to the dialyzer 48, where the contaminants are removed and the plasma is purified. The renewed plasma is returned to the patient through the return tubes 50, 52.

After the plasma has been removed from the centrifuge 36, the centrifuge bowl stops rotating, and the blood cells are pumped through the feed tube 40 and back through the tube 38 and tube 32 to return to the patient. Thus, the processing in the dialyzer is only of the plasma and not of the blood cells. The process resulting from the use of the system 30 is such that it would be possible for the patient to perform the hemodialysis at home, at night, in no more than four hours. One of the factors that allows the system 30 to achieve its substantial improvements over the conventional system is the use of the sterile connection devices 54, 56, 58 at various sites in the system. Such sterile connecting devices may be of the type described in the U.S. Patent. Nos. 4,793,880, 5,141,592, 5,256,226, 5,279,685 and 5,674,333, all, the details of which are incorporated herein by reference thereto. As used herein, the term "sterile connecting device" is intended to refer to a device having a pair of spaced apart and aligned tube supports, each of which has at least one channel receiving a tube, and it includes a hot contact plate positioned to pass between the spaced tube holders to heat the plastic tubes placed therein. The connection or separation of such a plastic tube is done in a sterile manner. The ability to include a sterile connection device as part of the hemodialysis system ensures that the hemodialysis process can remain totally confined and sterile. The use of such sterile connecting devices 54, 56, 58 allows the various components of the system to be added or replaced in a fast and efficient manner, and particularly in a sterile manner. For example, tubes 32 and 52 can remain essentially permanently connected to the patient, and can be connected to system 30 through the use of sterile connecting device 54, which connects tube 38 to tube 32 and via sterile connecting device 58, which the tubes 50 and 52 are connected. Similarly, the tubes 50 and 52 can be disconnected and sealed by the sterile connecting device 58. The process control 34 can be installed or removed from the system by use of the sterile connecting device 54, which it selectively joins or separates the tubes 32 and the tubes 38. Thus, when the process control 34 is to be installed, the sterile connecting device 54 connects the tubes 32 and 38, and the sterile connecting device 56 connects the tubes 44. and 46. Air enters the system through device 56. The reverse process is used to separate the tubes and remove control from the process 34 after the treatment has been completed. or. Accordingly, process control 34 is a removable module. The sterile connecting device 58 is used to selectively connect or separate the tubes 50 and 52, which in conjunction with the sterile connecting device 56 allow the installation or removal of the dialyzer 48 from the system. Accordingly, the dialyzer 48 can also be a removable module. The dialyzer 48 can also be a commercially available component, such as that marketed by Baxter, Gambro and Fresenius. However, in this modality the dialyzer module is specific to the patient. Figure 3 illustrates an alternative system 60 in accordance with this invention. As shown therein, the system 60 includes the same tube arrangement 32, 38, 40 and 44, the same process control 34 with the centrifuge 36 and feeding tube 40, as well as the sterile connecting device 54 in the system 30. System 60 differs from system 30 in that the plasma extracted from the patient is not returned to the patient. Instead, the plasma from a different source 68 is fed to the patient. Thus, as with the system 30, in the system 60 the whole blood is transported through the tubes 32, 38 towards the separator 36, and the plasma is withdrawn and fed through the tube 44, after which the blood cells are returned to the patient through the tubes 38 and 32. The plasma fed through the tube 44 is fed then to a collection device such as a bag 62 via tube 64. A sterile connecting device 66 allows the installation or removal of the bag 62 and its tube 64 from the system. The air enters the system in the device 66. While the plasma is being collected in the bag 62, the sterile or purified plasma is fed to the patient P from a separate bag 68 and through the return tube 70 and then through the tube 72. The sterile connecting device 74 allows the selective installation and removal of the bag 68 and its tube 70 from the system 60. As is apparent, the process control 34 and the containers 62, 68 are each installable / removable modules.

The system 60 of Figure 3 is particularly advantageous, since the plasma can become non-specific to the patient while in the contaminated form. The plasma can be sterilized before dialysis, and later the sterilized plasma with a reduced content of contaminants is returned to the patient. Thus, in the system 60, the plasma to be cleaned is simply collected in the sterile bag 62, and when the bag 62 is filled, the bag is sealed, removed and replaced with a new empty sterile plasma bag. While this is done, the plasma of the new bag 68 is simultaneously returned to the patient. The plasma in the pouch 68 need not be plasma from the same patient. Figure 4 schematically illustrates a system for sterilizing or removing contaminants from the plasma. As shown in Figure 4, the contaminant removal system 80 includes providing a plurality of bags 62 containing plasma that has been sterilized by heat treatment or radiation, to remove viral and bacterial elements before being treated. By the use of several sterile connecting devices 82 the bags or manifolds 62 are selectively installed or withdrawn from the inlet manifold or common tube 84. The plasma is removed under the influence of the pump 86, and transported to the plasma cleaning center. or dialyzer 88, which may be of the plate and frame type, or may be of the hollow fiber type. A suitable dialyzer can be a component sold as PERMASEP®, which is marketed by the DuPont Company. In the 1960s this hollow fiber dialyzer was used to extract drinking water from seawater. The system was used in arid lands with access to the sea. This system is used for water purification, but its use has also been suggested for hemodialysis. The general operation of this type of dialyzer is to feed the liquid under pressure to a distributor tube, which runs through the center of a hollow fiber bundle. When the liquid moves through the beam around the fibers, the pressure causes the pure liquid to pass through the semi-permeable walls of the very small fibers into their hollow cores, leaving behind up to 99.2% of the contaminants. The rejected contaminants remain outside the fiber walls, and flow through an exit orifice at the feed end of the permeator. The use of sterile connection devices results in systems of a modular nature. For example, the system 30 shown in Figure 2 would include tubes 32 and 52, which would usually be permanently attached to the patient. A module is created by the sterile connecting devices 54, 56, which include the intermediate tubes 38 and 44, and the control of the process 34. This module is connected or removed from the system 30 by the sterile connecting device 54, which selectively connects or disconnects the tubes 32 and 38, and by the sterile collection device 56 which selectively connects and disconnects the tubes 44 and 46. An additional module includes tubes 46 and 50 and the intermediate dialyzer 48, which is connected or removed from the system by means of the sterile collection devices 56 and 58. In this aspect, the tubes 44 and 46 are selectively connected to each other, or disconnected by the sterile collection device 56, while the tubes 50 and 52 are selectively connected or disconnected one. of the other by the sterile collection device 58. The modules are also formed in the system 60 of Figure 3. The tubes 32 and 72 would generally be connected in a manner permanent to the patient. The supply container module, which includes the container or bag 68 and its tube 70 would be selectively connected or disconnected from the tube 72 - by the sterile collection device 74. Similarly, a module that includes the control of the process 34 and its tubes 38 and 44 would be selectively connected or disconnected to the system or removed therefrom by the sterile connecting device 54, which connects or disconnects the tubes 32 and 38, and via the sterile connection device 66, which connects or disconnects the tubes 44 and 64. Finally, a module is formed from the collection bag 62 by means of the collection device sterile 66, which selectively connects tubes 44 and 64 to one another, or separates tubes 44 and 64 from one another, or separates tubes 44 and 64 from each other. The pump 86 is a high pressure pump that operates, for example, at about 17,825 to 71,300 kg / cm2 (250 to 1000 pounds per square inch). Such a high pressure pump ensures proper feeding of the contaminated plasma to the dialyzer 88. The contaminated or clean plasma is removed from the dialyzer 88a, through the pressure reducer 90 to the manifold 92. From its common supply manifold 92 the sterilized plasma or Clean is fed to the bags 68. The containers 68 are selectively installed and removed from the system 80, and more particularly from its connection to the tube 92 by means of the sterile connecting devices 9. System 60, in addition to re-administering sterilized dialysate plasma can also be used to suppress the onset of AIDS, for example, for people who are HIV positive. The viral invasion to the body uses the blood as the transport route to locate and enter the cells. Once in a cell, they multiply and mature. When they mature, they re-enter the bloodstream to find and enter the cells as before. Viral infections once inside a cell are extremely difficult to eradicate. However, they are vulnerable, although in the bloodstream. Using the system 60 to sterilize the plasma fraction of the blood containing the free floating free viral agent, the path of reinfection can be cleared and under control. Although this is not a cure for the viral infections that reside within the cells, it opens a route to keep the proliferation of the infection under control. Viral proliferation methods are under intense study to inactivate the viral infection once the virus has bound to the cell membranes, the viral nucleic acid has been integrated into the cellular DNA and other cells infected by the virus. Methods such as cellular radiation, photosensitizing agents and drugs: all these efforts are directed towards a cure: although recommendable, this route is difficult, due to the rapid mutation of viral infections. The system 60 reduces the proliferation path to a manageable therapy mode. Keeping it online, until the cure is found. The use of sterile connecting devices 82 and 94 are key to allowing multiple sets of containers 62 and 68 to be processed simultaneously. The invention provides a number of distinct advantages over previously known hemodialysis systems and processes. As noted, the invention does not result in cell damage, reduces dialysis time, reduces the total cost of hemodialysis, and reduces trauma to patients. Peritoneal dialysis has been approved by the Regulatory Agency for Health Care (Health Care Regulatory Agency) (FDA) for home care, this invention seeks that hemodialysis also becomes a therapy for home care. To achieve this, known and tested technologies are combined in such a way as to make this possible. a) Sterile connection technology for total confinement. b) Cell-free dialysis c) Processing of cell-free plasma, to eliminate viral species during plasma processing such as HIV, HBV, HCV, or other viral infections. For example, patients who do not have end-stage renal failure, but need to fight viral HIV cell attack, could benefit from the new protocol. Viral infections must use plasma as a means of transport to find and attack the cells themselves. By keeping the viral population under control via plasma sterilization (heat, radiation) the onset of AIDS could also be brought under control. The protocol described in Figure 3 is a method for producing a plasma product that is disease-free and non-specific. The purified plasma could be placed back into the bags and distributed for patient care, similar to the protocols approved for peritoneal dialysis. In other words, the patient could be freed from current archaic hemodialysis procedures, and like peritoneal dialysis patients, enjoy a more normal lifestyle, not to mention the costs.

Claims (30)

1. - CLAIMS 1. A hemodialysis system comprising an upstream tube for connection to a patient for the extraction of blood containing red blood cells and white blood cells and plasma fluid, the tube being in communication with a process control, including the control of the process a separation structure to separate the plasma fluid from the cells, returning the process control the cells to the patient through a return tube of the blood cells, from a downstream plasma collecting tube, which goes of the process control to the plasma collector, of a plasma supply vessel, and of a plasma return tube that goes from the plasma supply vessel to the patient, to transport the non-contaminated plasma fluid to the patient.
2. 2. The system of claim 1, wherein the separation structure comprises a centrifuge.
3. 3. The system of claim 2, wherein the supply container is also the manifold.
4. 4. The system of claim 3, wherein the collector is a dialyzer for removing contaminants from the plasma fluid and transporting purified plasma fluid to the patient. The system of claim 1, including a first sterile connecting device, installed in the upstream tube, a second sterile connecting device installed in the downstream tube, and a third sterile connecting device installed in the tube of return The system of claim 5, wherein the process control and the supply container comprise separate modules, which are selectively removable, and installable in the system by means of the sterile connecting device. The system of claim 6, wherein the separation structure comprises a centrifuge. The system of claim 1, wherein the plasma collector and the plasma supply container are separate containers. The system of claim 8, including in combination therewith, a sterilization unit, the sterilization unit comprising a plurality of collection containers for containing the contaminated plasma fluid, a dialyzer for sterilizing the plasma fluid in the collection vessels, an inlet pipe connecting the collection vessel, a plurality of plasma supply vessels that communicate with the dialyzer after the contaminants have been removed from the plasma fluid, the supply vessels being connected to the dialyzer by means of an outlet pipe, a sterile connection device for each of the supply vessels installed in the outlet pipes, and being one of the supply vessels and one of the plasma collectors, the plasma collector and the supply for the hemodialysis system. 10. A plasma sterilization unit, comprising a plurality of plasma collection containers for containing contaminated plasma, a dialyzer for removing contaminants from the plasma, an inlet line connecting the collection vessels to the dialyzer, a plurality of plasma containers, plasma supply, outlet tubing that connects the dialyzer to the delivery containers to transport - sterilized plasma from the dialyzer to the supply vessels, a sterile collection device for each of the collection vessels, installed in the inlet line , to allow the selective installation and removal of each of the collection containers of the unit, a plurality of supply containers, to receive the non-contaminated plasma from the dialyzer, the supply containers communicating with the dialyzer by means of the supply, and a sterile collection device l for each of the supply vessels, installed in the outlet pipe to selectively install and remove each of the unit's supply containers. 11. The unit of claim 25, which includes a high pressure pump installed in the inlet pipe, and a pressure reducer in the outlet pipe. 12. A method of hemodialysis comprising installing a tube upstream to a patient for the extraction of whole blood containing red blood cells and white blood cells and plasma fluid of the patient, making the whole blood flow to the control of the process, separating the plasma fluid of the red blood cells by using a separation structure in the process control, flowing the plasma fluid towards a plasma manifold, returning the red blood cells and the white blood cells back to the patient, and supplying the patient with uncontaminated plasma from a supply container. The method of claim 12, wherein the plasma fluid is separated from the cells by a centrifuge having a tub that causes the cells to be collected on the side of the centrifuge tub, while the supply line of plasma install and selectively remove each of the supply containers of the unit. The method of claim 13, wherein the hemodialysis treatment is completed in no more than four hours. The method of claim 13, wherein the same container that receives the plasma fluid from the centrifuge is also the plasma collector, and the container is a dialyzer that removes contaminants from the plasma fluid. 16. The method of claim 13, wherein the plasma withdrawn from the centrifuge is discharged into the plasma collector, which is a container other than the plasma supply vessel. The method of claim 16, wherein the contaminants are removed from the plasma fluid by a plasma sterilization unit, in which a plurality of plasma manifolds containing contaminated plasma is installed in fluid communication via the tube. inlet to a dialyzer, which removes contaminants from the plasma fluid in the dialyzer, by providing a plurality of supply vessels in fluid communication with the dialyzer via the outlet line, and by collecting the sterilized plasma fluid in the supply vessels. The method of claim 17, wherein a sterile connection device is provided for each of the plasma manifolds in the inlet pipe, to allow selective installation and removal of each plasma manifold, and a device provided of sterile connection for each of the plasma supply vessels in the outlet pipe, to allow the selective installation and removal of each plasma supply vessel. The method of claim 12, wherein at least one sterile connecting device is installed to the pipe to allow selective cutting and connection of the pipe by the sterile connecting device, so that the system components used for the Hemodialysis method can be removed and selectively installed in the system. The method of claim 16, wherein the viral elements are removed from the treated plasma to control viral proliferation. The method of claim 20, wherein the method is used to reduce the uncontrolled spread of HIV within the patient, to reduce the likelihood that HIV + will become AIDS. 22. The method of claim 20, wherein the viral elements are removed by a heat or radiation treatment that removes the viral constituents. 23. The method of claim 12, wherein the method is performed as part of a home care treatment. The method of claim 12, which includes separating the platelets from the plasma fluid in the process control. The unit of claim 10, which includes a sterile connecting device for each of the collection vessels in the inlet pipeline, to selectively install and remove each of the unit's collection containers. - - 26. A hemodialysis system for removing substances from blood cells, comprising a blood cell supply containing substances, an elimination station, the elimination station having a rotating structure for receiving blood cells and substances, for separating blood cells of the substances, and a collection station under the disposal station, to collect the substances. The system of claim 26, wherein the rotating structure is a centrifuge, and the collection station includes a filter. 28. A method for removing substances from blood cells, comprising the steps of supplying the blood cells and substances to a rotating structure, by rotating the rotating structure to separate the blood cells from the substances, transporting the substances to a current collection station below, and collect the substances. 29. The method of claim 28, wherein both plasma and other substances are separated from blood cells in a centrifuge, and blood cells are separated by being placed against the wall of the centrifuge vat as a result of rotation. , while the plasma and other substances remain inside the centrifuge vat. 30. The method of claim 29, wherein the other substances are removed from the plasma at the collection station by means of a filter.