Method and apparatus for vein fluid removal in heart failure

• US 6,890,315 B1
• Filed: 07/18/2000
• Issued: 05/10/2005
• Est. Priority Date: 05/23/2000
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: CHF Solutions, Inc.
• Inventors: Levin, Howard R., Gelfand, Mark, O'Mahony, John, Polaschegg, Hans-Dietrich
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): DEAK, LESLIE R
• Application Number:
  US09/618,759
• Time in Patent Office: 1,757 Days
• Field of Search: 604/6.09, 604/5.09, 604/6.11, 604/6.16, 604/6.06, 604 65- 67, 210/645, 210/649, 210/650, 210/651, 210/90
• US Class Current: 604/6.09
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/34 Filtering material out of the blood by passing it through a membrane, i.e. hemofiltration or diafiltration
• CPC Class Codes: A61M 1/341 by measuring the filtrate rate or volume
• CPC Class Codes: A61M 1/361 before treatment
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: A61M 2205/3393 by weighing the reservoir
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/7563 with means preventing clogging of filters

Abstract

A method and apparatus for ultrafiltration of blood operating by removing blood from a peripheral blood vessel at a rate of less than two percent of total cardiac output of a patient, extracting fluid at a rate of 0.1 liter to 1.0 liters per hour while retaining cells and proteins in the blood, and returning the concentrated blood to a secondary blood vessel is disclosed. Blood is removed and returned using small gage needles. As a pump circulates blood from the patient, a filter removes ultrafiltrate from the blood using duty cycle or pump control, and a transparent container collects the removed fluid.

Claims

1. A method for removing excess fluid from a patient comprising:

a. inserting a withdrawal catheter into a first peripheral blood vessel in the patient;

b. withdrawing blood through the catheter in the first peripheral blood vessel in the patient;

c. sensing a withdrawal pressure of the blood;

d. adjusting a withdrawal blood flow rate based on the sensed withdrawal pressure;

e. filtering the withdrawn blood through a filter to separate the excess fluid from the blood, wherein the filter has a filter membrane surface area of no greater than 0.2 m²;

f. infusing the filtered blood into a second peripheral blood vessel in the patient;

g. wherein a blood flow through the filter is less than two percent of a total cardiac output of the patient, and a flow of the excess fluid removed from the blood is no greater than 1.0 liters per hour.

2. A method as in claim 1 wherein the excess fluid removed from the blood is no greater than 30 percent of a volume of the removed blood.

3. A method as in claim 1 wherein the step of filtering is performed by sieving the blood through a filter to remove excess fluid.

4. A method as in claim 1 further comprising the step of pumping the withdrawn blood with a blood pump at a rate of less than 100 milliliters (ml) per minute.

5. A method as in claim 1 wherein a rate of blood withdrawal is in a range of 40 to 60 milliliters per minute, and a rate of removal of the excess fluid is no greater than 16 milliliters per minute.

6. A method as in claim 4 wherein the blood pump stops upon detection of a blockage of blood flow in the blood being withdrawn.

7. A method as in claim 1 wherein the blood pump stops upon detection of a air bubble in the withdrawn or filtered blood.

8. A method as in claim 1 wherein the first peripheral blood vessel is a vein.

9. A method as in claim 1 wherein the second peripheral blood vessel is a vein.

10. A method as in claim 1 wherein the first and second peripheral blood vessel are the same vein.

11. A method as in claim 1 wherein the filter includes capillary, hollow fibers.

12. A method as in claim 11 wherein the hollow fibers have filtering pores which retain in the blood solutes greater than 50,000 Daltons.

13. A method as in claim 11 wherein the hollow fibers have blood passages of approximately 0.2 mm or less in diameter.

14. A method as in claim 1 wherein the blood flow through the filter causes a wall shear rate of the blood between 1,000 sec⁻

1 per seconds and 2,500 per seconds.

15. A method as in claim 1 wherein the filtration is ultrafiltration.

16. A method as in claim 1 further comprising minimizing extraction of solutes during filtration.

17. A method as in claim 1 further comprising extracting primarily water as the fluid removed from the blood during filtration.

18. A method as in claim 1 wherein blood flows continuously through the filter during periods in which a blood pump is pumping the removed blood.

19. A method as in claim 1 wherein excess fluid removed from blood flows intermittently from the filter.

20. A method as in claim 19 wherein a valve in a flow path from the filter for removal of excess fluid cyclically stops and starts the flow of excess fluid from the filter.

21. A method as in claim 1 wherein a total amount of extracorporeal blood is not greater than 100 milliliters.

22. A method as in claim 1 wherein said fiber includes less than 1000 filtering fibers.

23. A method as in claim 1 wherein the withdrawn blood is returned to the patient within two minutes.

24. A method for removing excess fluid from a patient comprising:

a. withdrawing blood from a catheter inserted into a first blood vessel of the patient;

b. monitoring a pressure of the blood being withdrawn and controlling a blood withdrawal rate based on the monitored pressure;

c. condensing the withdrawn blood through a filter to separate the excess water from the blood, wherein the filter has filter membrane surface area of no greater than 0.2 m²;

d. returning the condensed blood into a second blood vessel in the patient;

e. wherein a blood flow through the filter is less than two percent of a total cardiac output of the patient, and a flow of the excess fluid removed from the blood is no greater than 1.0 liters per hour.

25. A method as in claim 24 wherein the excess fluid removed from the blood is no greater than 30 percent of a volume of the removed blood.

26. A method as in claim 24 wherein the step of filtering is performed by sieving the blood through a filter to remove excess water.

27. A method as in claim 24 further comprising the step of pumping the removed blood with a blood pump at a rate of less than 100 milliliters (ml) per minute.

28. A method as in claim 24 wherein a rate of the removal of blood is no greater than 60 milliliters per minute, and a rate of removal of the excess water is no greater than 16 milliliters per minute.

29. A method as in claim 24 wherein a rate of the removal of blood is in a range of 40 to 60 milliliters per minute, and a rate of removal of the excess water is no greater than 16 milliliters per minute.

30. A method as in claim 27 wherein the blood pump stops upon detection of a blockage of blood flow in the blood being removed in step (b).

31. A method as in claim 27 wherein the blood pump stops upon detection of a air bubble in the blood during any of steps (b), (c) and (d).

32. A method as in claim 24 wherein the first blood vessel is a vein.

33. A method as in claim 24 wherein the second blood vessel is a vein.

34. A method as in claim 24 wherein the first and second blood vessels are the same vein.

35. A method as in claim 24 wherein the filter includes capillary, hollow fibers.

36. A method as in claim 35 wherein the hollow fibers have filtering pores which retain in the blood solutes greater than 50,000 Daltons.

37. A method as in claim 35 wherein the hollow fibers have blood passages of approximately 0.2 mm or less in diameter.

38. A method as in claim 34 wherein the filter has a trans-membrane pressure (TMP) no greater than 250 millimeters (mm) of mercury (Hg).

39. A method as in claim 24 wherein the blood flow through the filter causes a shear rate of the blood between 1,000 sec⁻

1 per seconds and 2,500 per seconds.

40. A method as in claim 24 wherein the filtration is ultrafiltration.

41. A method as in claim 24 further comprising minimizing extraction of solutes during filtration.

42. A method as in claim 24 wherein blood flows continuously through the filter during periods in which a blood pump is pumping the removed blood.

43. A method as in claim 24 wherein excess water removed from the blood flows intermittently from the filter.

44. A method as in claim 43 wherein a valve in a flow path from the filter for removal of excess water cyclically stops and starts the flow of excess water from the filter.