Hemodialysis monitoring system for hemodialysis machines

• US 5,518,623 A
• Filed: 05/09/1994
• Issued: 05/21/1996
• Est. Priority Date: 10/13/1992
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Emerson, Paul F., Luhring, David A., Keshaviah, Prakash, Ebben, James P.
• Primary Examiner(s): Drodge, Joseph W.
• Application Number:
  US08/239,936
• Time in Patent Office: 743 Days
• Field of Search: 210/85, 210/93, 210/96.2, 210/143, 210/321.71, 210/646, 210/647, 210/739, 210/746, 210/929, 204/153.14, 204/406, 604/4, 604/5, 604/6, 604/28, 604/29, 436/108, 364/413.01, 364/413.02, 364/413.07, 422/68.1
• US Class Current: 210/646
• CPC Class Codes: A61M 1/16 with membranes
• CPC Class Codes: A61M 1/1605 Physical characteristics of the dialysate fluid
• CPC Class Codes: A61M 1/1609 after use, i.e. downstream of dialyser
• CPC Class Codes: A61M 1/1613 Profiling or modelling of patient or predicted treatment evolution or outcome
• CPC Class Codes: A61M 1/1615 using measurements made at different flow rates
• CPC Class Codes: A61M 1/1619 Sampled collection of used dialysate, i.e. obviating the need for recovery of whole dialysate quantity for post-dialysis analysis
• CPC Class Codes: A61M 1/165 with a dialyser bypass on the dialysis fluid line
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: A61M 2202/0498 Urea
• CPC Class Codes: A61M 2205/15 Detection of leaks
• CPC Class Codes: A61M 2205/3334 Measuring or controlling the flow rate
• CPC Class Codes: Y10T 436/171538 Urea or blood urea nitrogen

Abstract

An improved on-line real time hemodialysis monitoring system for hemodialysis treatment. The hemodialysis monitoring system quantitates the rate and amount of a constituent, such as urea, removed during the hemodialysis treatment by measuring the constituent concentrations as a function of time in the spent dialysate effluent from a hemodialysis machine. A quantity of the spent dialysate effluent is removed from the dialysate effluent waste line periodically for testing. A urea concentration time profile can be analyzed to determined the urea removal, KT/V, URR, SRI and normalized protein catabolic rate (nPCR) indices. The hemodialysis monitoring system preferably can obtain a dialysate sample equilibrated with the blood prior to the start of a hemodialysis treatment. The hemodialysis monitoring system includes a two pool analysis for taking into account the constituent concentration differences in the extracellular and intracellular spaces in the hemodialysis patient during the hemodialysis treatment.

Claims

1. A method of monitoring a hemodialysis treatment in real time for utilization with a hemodialysis machine including a dialyzer and with dialysate waste effluent removed from the dialyzer, comprising:

providing a dialysate effluent constituent sensor and separately coupling a plurality of separate fluid portions of the dialysate effluent to said constituent sensor during a dialysis treatment;

detecting and measuring concentrations of said constituent in each of said dialysate effluent portions;

determining a dialysate constituent concentration-time profile from said dialysate constituent concentration measurements;

forming at least a two pool analysis to account for the differences in the constituent concentration in the extracellular and the intracellular spaces in a patient during the dialysis treatment; and

directly determining an indication of adequacy of said dialysis treatment from said dialysate constituent concentration-time profile.

2. The method as defined in claim 1 including said constituent being related to urea and providing a urea sensor to determine a urea concentration-time profile and determining at least one of urea removal, KT/V, PCR and URR from said urea concentration-time profile.

3. The method as defined in claim 2 including obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

4. The method as defined in claim 2 including obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

5. The method as defined in claim 2 including projecting a final urea concentration value for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment and projecting at least one of urea removal, KT/V, URR, PCR and a solute removal index (SRI) from said projected final urea concentration value.

6. The method as defined in claim 2 including calculating at least one of KT/V, PCR and URR from said two pool analysis.

7. The method as defined in claim 6 including forming two separate exponential fits of said urea concentration measurements to determine said urea concentration-time profile.

8. The method as defined in claim 6 including fitting said urea concentration measurements to a nonlinear function to describe said urea concentration-time profile.

9. The method as defined in claim 6 including obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

10. The method as defined in claim 6 including obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

11. The method as defined in claim 6 including projecting at least one of a final urea concentration value, final urea removal, final KT/V, final PCR, final URR and a final solute removal index (SRI) for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment.

12. The method as defined in claim 1 wherein said dialysate constituent time concentration profile is utilized for conducting a protein assessment.

13. An apparatus adapted for monitoring a hemodialysis treatment in real time for utilization with a hemodialysis machine including a dialyzer and with dialysate waste effluent removed from the dialyzer, comprising:

a dialysate effluent constituent sensor and means for separately coupling a plurality of separate fluid portions of the dialysate effluent to said constituent sensor during a dialysis treatment;

means for detecting and measuring concentrations of said constituent in each of said dialysate effluent portions;

means for determining a constituent concentration-time profile from said dialysate constituent concentration measurements;

means for forming at least a two pool analysis to account for the differences in the constituent concentration in the extracellular and the intracellular spaces in a patient during the dialysis treatment; and

means for directly determining an indication of adequacy of said dialysis treatment from said dialysate constituent concentration-time profile.

14. The apparatus as defined in claim 13 including said constituent being related to urea and including a urea sensor to determine a urea concentration-time profile and means for determining at least one of urea removal, KT/V, PCR and URR from said urea concentration-time profile.

15. The apparatus as defined in claim 14 including means for obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

16. The apparatus as defined in claim 14 including means for obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

17. The apparatus as defined in claim 14 including means for projecting a final urea concentration measurement for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment and projecting at least one of urea removal, KT/V, URR, PCR and a solute removal index (SRI) from said projected final urea concentration value.

18. The apparatus as defined in claim 14 including means for calculating at least one of KT/V, PCR and URR from said two pool analysis.

19. The apparatus as defined in claim 18 including means for forming two separate exponential fits of said urea concentration measurements to determine said urea concentration-time profile.

20. The apparatus as defined in claim 18 including means for fitting said urea concentration measurements to a nonlinear function to describe said urea concentration-time profile.

21. The apparatus as defined in claim 18 including means for obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

22. The apparatus as defined in claim 18 including means for obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

23. The apparatus as defined in claim 18 including means for projecting at least one of a final urea concentration value, final urea removal, final KT/V, final PCR, final URR and a final solute removal index (SRI) for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment.

24. The apparatus as defined in claim 13 further comprising means for conducting protein assessment from the dialysate constituent time concentration profile.

25. A method of monitoring a hemodialysis treatment in real time for utilization with a hemodialysis machine including a dialyzer and with dialysate waste effluent removed from the dialyzer, comprising:

providing a dialysate effluent urea sensor and separately coupling a plurality of separate fluid portions of the dialysate effluent to said urea sensor during a dialysis treatment;

detecting and measuring concentrations of said urea in each of said dialysate effluent portions;

determining a dialysate urea concentration-time profile from said dialysate urea concentration measurements;

forming at least a two pool analysis to account for the differences in the urea concentration in the extracellular and the intracellular spaces in a patient during the dialysis treatment; and

directly determining an indication of adequacy of said dialysis treatment from said dialysate urea concentration-time profile.

26. The method as defined in claim 25 including determining at least one of urea removal, KT/V, URR and PCR from said urea concentration-time profile.

27. The method as defined in claim 25 including obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and determining a solute removal index (SRD from said equilibrated concentration measurement and said urea concentration-time profile.

28. The method as defined in claim 25 including obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

29. The method as defined in claim 25 including projecting a final urea concentration value for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment and projecting at least one of urea removal, KT/V, URR, PCR and a solute removal index (SRI) from said projected final urea concentration value.

30. The method as defined in claim 25 including calculating at least one of KT/V, PCR and URR from said two pool analysis.

31. The method as defined in claim 30 including forming two separate exponential fits of said urea concentration measurements to determine said urea concentration-time profile.

32. The method as defined in claim 30 including fitting said urea concentration measurements to a nonlinear function to describe said urea concentration-time profile.

33. The method as defined in claim 30 including obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

34. The method as defined in claim 30 including obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

35. The method as defined in claim 30 including projecting at least one of a final urea concentration value, final urea removal, final KT/V, final PCR, final URR and a final solute removal index (SRI) for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment.

36. The method as defined in claim 25 wherein said dialysate urea time concentration profile is utilized for conducting a protein assessment.

42. The apparatus as defined in claim 34 including means for calculating at least one of KT/V, PCR and URR from said two pool analysis.

43. The apparatus as defined in claim 42 including means for forming two separate exponential fits of said urea concentration measurements to determine said urea concentration-time profile.

44. The apparatus as defined in claim 42 including means for fitting said urea concentration measurements to a nonlinear function to describe said urea concentration-time profile.

45. The apparatus as defined in claim 42 including means for obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

46. The apparatus as defined in claim 42 including means for obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

47. The apparatus as defined in claim 42 including means for at least one of a final urea concentration value, final urea removal, final KT/V, final PCR, final URR and a final solute removal index (SRI) for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment.

37. An apparatus adapted for monitoring a hemodialysis treatment in real time for utilization with a hemodialysis machine including a dialyzer and with dialysate waste effluent removed from the dialyzer, comprising:

a dialysate effluent urea sensor and means for separately coupling a plurality of separate fluid portions of the dialysate effluent to said urea sensor during a dialysis treatment;

means for detecting and measuring concentrations of said urea in each of said dialysate effluent portions;

means for determining a urea concentration-time profile from said dialysate urea concentration measurements;

means for forming at least a two pool analysis to account for the differences in the urea concentration in the extracellular and the intracellular spaces in a patient during the dialysis treatment; and

means for directly determining an indication of adequacy of said dialysis treatment from said urea dialysate concentration-time profile.

38. The apparatus as defined in claim 37 including said constituent being related to urea and including a urea sensor to determine a urea concentration-time profile and means for determining at least one of urea removal, KT/V, PCR and URR from said urea concentration-time profile.

39. The apparatus as defined in claim 37 including means for obtaining an equilibrated urea concentration measurement prior to starting the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

40. The apparatus as defined in claim 37 including means for obtaining an equilibrated urea concentration measurement after completing the dialysis treatment and means for determining a solute removal index (SRI) from said equilibrated concentration measurement and said urea concentration-time profile.

41. The apparatus as defined in claim 37 including means for projecting a final urea concentration measurement for the completion of the dialysis treatment from said urea concentration-time profile at a point in time significantly prior to completing said dialysis treatment and projecting at least one of urea removal, KT/V, URR, PCR and a solute removal index (SRI) from said projected final urea concentration value.

48. The apparatus as defined in claim 37 further comprising means for conducting protein assessment from the dialysate urea time concentration profile.