Use of aortic pulse pressure and flow in bedside hemodynamic management

• US 6,776,764 B2
• Filed: 03/15/2002
• Issued: 08/17/2004
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Original Assignee: University of Pittsburgh of The Commonwealth System of Higher Education
• Inventors: Pinsky, Michael R.
• Primary Examiner(s): MALLARI, PATRICIA C
• Application Number:
  US10/098,655
• Publication Number:
  US 20030167010A1
• Time in Patent Office: 886 Days
• Field of Search: 600/300, 600/301, 600/481, 600/485-507, 600/508, 604/65-67
• US Class Current: 600/481
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/412 Detecting or monitoring sepsis
• CPC Class Codes: A61B 5/4839 combined with drug delivery

Abstract

A treatment algorithm for managing hemodynamically unstable patients is provided. Specifically, measurements of arterial pressure and stroke volume can be used to calculate pulse pressure variation, stroke volume variation, mean arterial pressure, elastance and cardiac power, the values of which guide treatment decisions and allow optimal management of critically ill patients. In an additional embodiment, a computer system implementing the treatment algorithm is provided.

Claims

1. A method of determining a treatment regimen for a hemodynamically unstable patient comprising:

(a) obtaining arterial pressure and stroke volume measurements in said patient;

(b) calculating pulse pressure variation, stroke volume variation, mean arterial pressure, elastance and cardiac power from said measurements; and

(c) providing a treatment algorithm based on said calculated values for pulse pressure variation, stroke volume variation, mean arterial pressure, elastance and cardiac power.

2. The method of claim 1, further comprising administering treatment to said patient, based on said treatment algorithm.

3. The method of claim 2, wherein said treatment comprises administering a fluid infusion to said patient.

4. The method of claim 2, wherein said treatment comprises administering a vasoactive drug to said patient.

5. The method of claim 2, wherein said treatment comprises administering an inotropic drug to said patient.

6. The method of claim 1, wherein said treatment algorithm comprises the following steps:

(a) if either pulse pressure variation or stroke volume variation is greater than about 10%-15% then administering an initial fluid infusion and repeating fluid infusions until pulse pressure variation or stroke volume variation becomes less than about 10%; and

(b) if mean arterial pressure remains less than about 55-65 mm Hg, or there is a decrease in mean arterial pressure of greater than about 15-25 mm Hg in a previously hypotensive patient, after said initial fluid infusion starting vasoactive therapy.

7. The method of claim 6, further comprising the following steps:

(a) if elastance is greater than about 1.2 withholding vasoactive therapy during said initial fluid infusion;

(b) if elastance is less than about 0.8 beginning vasoactive therapy at the same time as said initial fluid infusion and titrate vasoactive therapy upward until mean arterial pressure is greater than about 55-65 mm Hg; and

(c) if elastance is less than about 1.2 but greater than about 0.8 giving initial vasopressor therapy, optionally, to maintain mean arterial pressure greater than about 55-65 mm Hg.

8. The method of claim 6, further comprising the following steps:

(a) if pulse pressure variation or stroke volume variation become less than about 10-15% and vasoactive therapy is still needed to keep mean arterial pressure greater than about 55-65 mm Hg, if cardiac power is not within the normal range, beginning inotropic therapy; and

(b) if cardiac power remains below normal, titrate titrating the inotrophic therapy upwards.

9. A method of electronically determining a treatment regimen for a hemodynamically unstable patient comprising:

(a) providing a computerized data collection and analysis apparatus including a first collection apparatus for obtaining arterial pressure measurements in said patient,

a second collection apparatus for obtaining stroke volume measurements in said patient,

a microprocessor for storing said measurements and a software program containing said treatment regimen, and for calculating values for pulse pressure variation, stroke volume variation, mean arterial pressure, cardiac power and elastance, based on said measurements, and

apparatus for displaying information related to at least one of said measurements, said calculated values and said treatment regimen;

(b) using said first collection apparatus, collecting arterial pressure measurements from said patient;

(c) using said second collection apparatus, collecting stroke volume measurements from said patient;

(d) using said microprocessor apparatus, calculating pulse pressure variation, stroke volume variation, mean arterial pressure, elastance and cardiac power values from said measurements;

(e) using said treatment regimen, selecting a treatment based on said measurements and said calculated values; and

(f) providing output displaying said selected treatment regimen.

10. The method of claim 9, further comprising administering treatment to said patient, based on said selected treatment regimen.

11. The method of claim 10, wherein said treatment comprises administering a fluid infusion.

12. The method of claim 10, wherein said treatment comprises administering a vasoactive drug.

13. The method of claim 10, wherein said treatment comprises administering an inotropic drug.

14. The method of claim 9, wherein said treatment algorithm comprises the following steps:

(a) if either pulse pressure variation or stroke volume variation is greater than about 10%-15% administering an initial fluid infusion and repeating fluid infusions until pulse pressure variation or stroke volume variation becomes less than about 10%; and

(b) if mean arterial pressure remains less than about 55-65 mm Hg, or there is a decrease in mean arterial pressure of greater than about 15-25 mm Hg in a previously hypotensive patient, after said initial fluid infusion starting vasoactive therapy.

15. The method of claim 14, further comprising the following steps:

(a) if elastance is greater than about 1.2 withholding vasoactive therapy during said initial fluid infusion;

(b) if elastance is less than about 0.8 beginning vasoactive therapy at the same time as said initial fluid infusion and titrating vasoactive therapy upward until mean arterial pressure is greater than about 55-65 mm Hg; and

(c) if elastance is less than about 1.2 but greater than about 0.8 giving initial vasopressor therapy, optionally, to maintain mean arterial pressure greater than about 55-65 mm Hg.

16. The method of claim 14, further comprising the following steps:

(a) if pulse pressure variation or stroke volume variation become less than about 10-15% and vasoactive therapy is still needed to keep mean arterial pressure greater than about 55-65 mm Hg, if cardiac power is not within the normal range, beginning inotropic therapy; and

(b) if cardiac power remains below normal, titrating the inotrophic therapy upwards.

17. A treatment algorithm for providing treatment of a hemodynamically unstable patient, said algorithm comprising the following steps:

(a) obtaining arterial pressure and stroke volume measurements in said patient;

(b) calculating pulse pressure variation, stroke volume variation, elastance and cardiac power from said measurements;

(c) if either pulse pressure variation or stroke volume variation is greater than about 10%-15% administering an initial fluid infusion and repeating fluid infusions until pulse pressure variation or stroke volume variation becomes less than about 10%; and

(d) if mean arterial pressure remains less than about 55-65 mm Hg, or there is a decrease in mean arterial pressure of greater than about 15-25 mm Hg in a previously hypotensive patient, after said initial fluid infusion starting vasoactive therapy.

18. The treatment algorithm of claim 17, further comprising the following steps:

(a) if elastance is greater than about 1.2 withholding vasoactive therapy during said initial fluid infusion;

(b) if elastance is less than about 0.8 beginning vasoactive therapy at the same time as said fluid infusion and titrating vasoactive therapy upward until mean arterial pressure is greater than about 55-65 mm Hg; and

(c) if elastance is less than about 1.2 but greater than about 0.8 giving initial vasopressor therapy, optionally, to maintain mean arterial pressure greater than about 55-65 mm Hg.

19. The treatment algorithm of claim 17, further comprising the following steps:

(a) if pulse pressure variation or stroke volume variation become less than about 10-15% and vasoactive therapy is still needed to keep mean arterial pressure greater than about 55-65 mm Hg, if cardiac power is not within the normal range, beginning inotropic therapy; and

(b) if cardiac power remains below normal, titrating the inotrophic therapy upwards.

20. The treatment algorithm of claim 17, further comprising the following steps:

(a) obtaining arterial pressure and stroke volume measurements from said patient at additional time intervals; and

(b) assessing contractility, arterial tone and preload responsiveness, based on said calculated values for pulse pressure variation, stroke volume variation, elastance and cardiac power.

21. A computer readable medium comprising computer readable program code including a treatment algorithm for treatment of a hemodynamically unstable patient, said treatment algorithm comprising the following steps:

(a) if either pulse pressure variation or stroke volume variation is greater than about 10%-15% administering an initial fluid infusion and repeating fluid infusions until pulse pressure variation or stroke volume variation becomes less than about 10%; and

(b) if mean arterial pressure remains less than about 55-65 mm Hg, or there is a decrease in mean arterial pressure of greater than about 15-25 mm Hg in a previously hypotensive patient, after said initial fluid infusion starting vasoactive therapy.

22. The computer readable medium of claim 21 wherein said The treatment algorithm further comprises the following steps:

(a) if pulse pressure variation or stroke volume variation become less than about 10-15% and vasoactive therapy is still needed to keep mean arterial pressure greater than about 55-65 mm Hg, if cardiac power is not within the normal range, beginning inotropic therapy; and

(b) if cardiac power remains below normal, titrating the inotrophic therapy upwards.

23. The computer readable medium claim 21 wherein said treatment algorithm further comprises the following steps:

(a) obtaining arterial pressure and stroke volume measurements from said patient at additional time intervals; and

(b) assessing contractility, arterial tone and preload responsiveness, based on said calculated values for pulse pressure variation, stroke volume variation, elastance and cardiac power.

24. The computer readable medium of claim 21 wherein said treatment algorithm further comprises the following steps:

(a) if elastance is greater than about 1.2 withholding vasoactive therapy during said initial fluid infusion;

(b) if elastance is less than about 0.8 beginning vasoactive therapy at the same time as said initial fluid infusion and titrating vasoactive therapy upward until mean arterial pressure is greater than about 55-65 mm Hg; and

(c) if elastance is less than about 1.2 but greater than about 0.8 giving initial vasopressor therapy, optionally, to maintain mean arterial pressure greater than about 55-65 mm Hg.

25. The microprocessor of claim 24 wherein said treatment algorithm further comprises the following steps:

(a) if pulse pressure variation or stroke volume variation become less than about 10-15% and vasoactive therapy is still needed to keep mean arterial pressure greater than about 55-65 mm Hg, if cardiac power is not within the normal range, beginning inotropic therapy; and

(b) if cardiac power remains below normal, titrating the inotropic therapy upwards.

26. The microprocessor claim 24 wherein said treatment algorithm further comprises the following steps:

(a) obtaining arterial pressure and stroke volume measurements from said patient at additional time intervals; and

(b) assessing contractility, arterial tone and preload responsiveness, based on said calculated values for pulse pressure variation, stroke volume variation, elastance and cardiac power.