Method for performing renal replacement therapy including producing sterile replacement fluid in a renal replacement therapy unit

• US 6,649,063 B2
• Filed: 07/12/2001
• Issued: 11/18/2003
• Est. Priority Date: 07/12/2001
• Status: Expired due to Term

• Current Assignee: Nxstage Medical Incorporated (Fresenius SE & Co. KGaA)
• Original Assignee: Nxstage Medical Incorporated (Fresenius SE & Co. KGaA)
• Inventors: Brugger, James M., Treu, Dennis M., Burbank, Jeffrey H.
• Primary Examiner(s): Kim, John
• Application Number:
  US09/905,246
• Publication Number:
  US 20030010719A1
• Time in Patent Office: 859 Days
• Field of Search: 210/645, 210/646, 210/649, 210/650, 210/651, 210/739
• US Class Current: 210/650
• CPC Class Codes: A61M 1/1692 Detection of blood traces in dialysate
• CPC Class Codes: A61M 1/3437 downstream of the filter, e.g. post-dilution with filtrate
• CPC Class Codes: A61M 1/3441 Substitution rate control as a function of the ultrafiltration rate
• CPC Class Codes: A61M 1/3444 in which the collected ultra-filtrate expels an equal volume of substitution fluid from a reservoir
• CPC Class Codes: A61M 1/3462 Circuits for the preparation thereof
• CPC Class Codes: A61M 1/3465 using dialysate as substitution fluid
• CPC Class Codes: A61M 1/3643 Priming, rinsing before or after use
• CPC Class Codes: A61M 1/3644 Mode of operation
• CPC Class Codes: A61M 2205/12 with interchangeable cassettes forming partially or totally the fluid circuit
• CPC Class Codes: A61M 2205/705 Testing of filters for leaks
• CPC Class Codes: B01D 61/145 Ultrafiltration
• CPC Class Codes: B01D 61/18 Apparatus therefor
• CPC Class Codes: C02F 1/444 by ultrafiltration or microfiltration

Abstract

A method and device for renal replacement therapy is described that sterile-filters solution that can subsequently be used as a replacement fluid in the same unit. The devices and methods include a pump that can be reversed from its normal forward-pumping direction to sterilize a container of replacement fluid to produce sterile replacement fluid. The sterile replacement fluid is captured in a fluid bag. Upon sterilization of the contents of the container, the pump switches to run in its normal forward-pumping direction. The sterile replacement fluid produced by the previous process is now injected into a patient to perform renal replacement therapy. The waste produced during the renal replacement therapy can be trapped in the container that previously held the non-sterile solution. Systems for sterile filtration and subsequent renal replacement therapy that include pre-connected, sterilized, disposable kits for fluid management and batch collection of sterilized fluid are also described.

Claims

1. A method for performing renal replacement therapy including producing sterile replacement fluid in a renal replacement therapy unit, the method comprising the steps of;

providing a renal replacement therapy unit having a filter with a membrane having a pore size smaller than a non-sterile material, the membrane separating a waste side from a clean side of the filter;

a first container of a solution, the first container in fluid communication with the waste side of the filter;

a second container adapted to hold sterile replacement fluid, the second container in fluid communication with the clean side of the filter; and

an ultrafiltration pump in fluid communication with the first container and the second container, the pump capable of switching between a first direction that pumps fluid out of the first container and a second direction that pumps fluid out of the second container;

running the pump in the first direction to pump the solution from the first container into the waste side of the filter;

filtering the solution from the first container through the membrane of the filter to trap the non-sterile material on the waste side of the filter and produce sterile replacement fluid in the clean side of the filter;

collecting the sterile replacement fluid that flows from the clean side of the filter in the second container; and

switching the ultrafiltration pump to run in the second direction to pump the sterile replacement fluid from the second container into blood running through the clean side of the filter thereby injecting it into a patient during renal replacement therapy.

2. The method of claim 1, wherein the solution is dialysate solution.

3. The method of claim 1, wherein the solution in the first container is selected from the group consisting of water, ringers lactate, or saline, and wherein the unit further comprises a third container of a concentrated electrolyte solution, the third container in fluid communication with the first container and the waste side of the filter.

4. The method of claim 1, wherein replacement fluid is sterile infusate.

5. The method of claim 1, wherein the renal replacement therapy is hemofiltration.

6. The method of claim 1, wherein the renal replacement therapy is hemodiafiltration.

7. The method of claim 1, wherein the renal replacement therapy is hemodialysis.

8. The method of claim 1, wherein following the step of switching, the method further comprises the step of expelling the non-sterile material and waste into the first container.

9. The method of claim 1, wherein the entire content of the first container is sterilized through the filter membrane before the step of switching the ultrafiltration pump to run in the second direction.

10. The method of claim 9, wherein following the step of switching, the substantially empty first container that previously held the solution of suitable concentration for use as a replacement fluid is now used as a waste container, the method further comprising the step of expelling ultrafiltrate waste material from the waste side of the filter into the waste container during hemofiltration.

11. The method of claim 9, wherein the renal replacement therapy unit further comprises a venous air detector in fluid communication with the first container and the second container, the method further comprising the step of sensing air with the venous air detector upon the sterilization of the entire contents of the first container.

12. The method of claim 11, wherein the step of sensing air occurs prior to the step of switching the direction of the ultrafiltration pump.

13. The method of claim 12, wherein prior to the step of switching the direction of the pump, the method further comprises the step of triggering the switching of the pump when venous air detector senses air.

14. A method for performing renal replacement therapy including producing safe replacement fluid in a renal replacement therapy unit, the method comprising the steps of:

providing a renal replacement therapy unit having a filter with a membrane having a pore size smaller than pyrogenic material, the membrane separating a first side of the filter from a second side;

a source of replacement fluid in fluid communication with the second side of the filter;

a replacement fluid container adapted to hold pyrogen-free replacement fluid, the replacement fluid container in fluid communication wit the first side of the filter; and

a pump in fluid communication wit the source of replacement fluid and the replacement fluid container, the pump being capable of switching between a first direction that pumps fluid from the source of replacement fluid and a second direction that pumps fluid out of the replacement fluid container;

running the pump in the first direction to pump the solution from the source of replacement fluid into the second side of the filter;

filtering the solution from the source of replacement fluid through the membrane of the filter to trap pyrogenic material on the second side of the filter and produce pyrogen-free replacement fluid in the first side of the filter;

collecting the pyrogen-free replacement fluid that flows from the first side of the filter in the replacement fluid container; and

switching the pump to nut in the second direction to pump the pyrogen-free replacement fluid from the replacement fluid container into a blood line to be injected into a patient during renal replacement therapy.

15. The method of claim 14, wherein the solution is dialysate solution.

16. The method of claim 14, wherein replacement fluid is sterile infusate.

17. The method of claim 14, wherein the renal replacement therapy is hemofiltration.

18. The method of claim 14, wherein the renal replacement therapy is hemodiafiltration.

19. The method of claim 14, wherein the renal replacement therapy is hemodialysis.

20. The method of claim 14, wherein following the step of switching, the method further comprises the step of expelling waste from the second side of the filter.

21. The method of claim 14, wherein the source of replacement fluid includes a source fluid container and the entire contents of the source fluid container is filtered through the filter membrane before the step of switching the pump to run in the second direction.

22. The method of claim 21, wherein, following the step of switching, the substantially empty source fluid container is now used to receive waste, the method further comprising the step of expelling waste from the second side of the filter into the source fluid container during hemofiltration.

23. The method of claim 22, wherein the renal replacement therapy unit further comprises a venous air detector in fluid communication with the replacement fluid container and the source fluid container, the method further comprising the step of sensing air with the venous air detector upon the filtering of the entire contents of the source fluid container.

24. The method of claim 23, wherein the step of sensing air occurs prior to the step of switching the direction of the pump.

25. The method of claim 24, wherein prior to the step of switching the direction of the pump, the method further comprises the step of triggering the switching of the pump when the venous air detector senses air.