Method and device for the removal of partially protein bound substances

• US 7,615,158 B2
• Filed: 03/25/2003
• Issued: 11/10/2009
• Est. Priority Date: 03/27/2002
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Sternby, Berit, Sternby, Jan
• Primary Examiner(s): KIM, SUN U
• Application Number:
  US10/500,478
• Publication Number:
  US 20050115898A1
• Time in Patent Office: 2,422 Days
• Field of Search: 210/636, 210/645, 210/646, 210/650, 210/651, 210/805, 210/167.01, 210/167.06, 210/175, 210/177, 210/185, 210/194, 210/195.2, 210/203, 210/199, 210/252, 210/253, 210/257.2, 210/258, 210/295, 210/321.6, 210/321.69, 210/321.72, 210/323.1, 210/340, 210/428, 604/4.01, 604/5.04, 604/6.01, 604/6.04, 604/6.09, 604/6.11, 604/28
• US Class Current: 210/650
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1607 before use, i.e. upstream of dialyser
• CPC Class Codes: A61M 1/1633 with more than one dialyser unit
• CPC Class Codes: A61M 1/1647 with flow rate measurement of the dialysis fluid, upstream and downstream of the dialyser
• CPC Class Codes: A61M 1/165 with a dialyser bypass on the dialysis fluid line
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/1696 with dialysate regeneration
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/3431 upstream of the filter
• CPC Class Codes: A61M 1/3465 using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3623 Means for actively controlling temperature of blood
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3324 PH measuring means
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: A61M 2205/3368 Temperature
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: B01D 61/243 Dialysis
• CPC Class Codes: B01D 61/244 comprising multiple dialysis steps

Abstract

A method and a device to increase the efficiency of dialysis for the removal from blood of substances that are more or less tightly bound to carriers such as albumin. According to the invention this is accomplished by a simultaneous significant increase of the flow rate of the dialysis fluid and of the area of the membrane that separates the blood from the dialysis fluid, compared to conventional dialysis.

Claims

1. A method for removing partially carrier bound substances from blood comprising a blood circuit, a fluid circuit, and a filter having a semipermeable membrane separating a fluid compartment from a blood compartment, the method comprising:

directing a mixture of blood and a cleaning fluid through the blood compartment; and

applying a pressure gradient across the membrane to create an ultrafiltration into the fluid compartment equal in size to the sum of a flow rate of the cleaning fluid and a desired weight loss rate of a patient, wherein

a water permeability coefficient L_pA of the filter is at least 10 ml/min/mm Hg;

the cleaning fluid flow rate is at least 1000 ml/min; and

a ratio between the cleaning fluid flow rate and a blood flow rate is at least 5.

2. A method according to claim 1, wherein the filter is replaced by several filters arranged in series or parallel, or a combination thereof.

3. A method according to claim 1 or 2, wherein the blood is heated before being returned to the patient.

4. A method according to claim 3, wherein the heating of the blood is performed in a final dialyzer along a blood path before the blood is returned to the patient.

5. A device configured to remove partially carrier bound substances from blood comprising a blood circuit, a fluid circuit, and a filter having a semipermeable membrane separating a fluid compartment from a blood compartment, provided with

means for mixing blood and a cleaning fluid and directing said mixture through the blood compartment, and

means to apply a pressure gradient across the membrane to create an ultrafiltration into the fluid compartment equal in size to the sum of a flow rate of the cleaning fluid and a desired weight loss rate of the patient, wherein

the filter has a water permeability coefficient L_Aof at least 10 ml/min/mm Hg;

the device is configured to sustain a cleaning fluid flow rate of at least 1000 ml/min to the filter; and

the device is configured to maintain a ratio between the cleaning fluid flow rate and a blood flow rate to the filter of at least 5.

6. A device according to claim 5, wherein the filter is replaced by several filters arranged in series or parallel, or a combination thereof.

7. A device according to claim 5 or 6, wherein a heater is arranged for heating the blood before it is returned to the patient.

8. A device according to claim 7, wherein the heater is a final dialyzer along the blood path before the blood is returned to the patient.