METHOD FOR MEASURING CARDIAC OUTPUT VIA AN EXTRACORPOREAL CARDIOPULMONARY SUPPORT CIRCUIT

• US 20080033314A1
• Filed: 07/23/2007
• Published: 02/07/2008
• Est. Priority Date: 09/09/2004
• Status: Active Grant

• Current Assignee: Transonic Systems, Inc. (Measurement Innovations Corp.)
• Original Assignee: Transonic Systems, Inc. (Measurement Innovations Corp.)
• Inventors: Krivitski, Nikolai
• Granted Patent: US 8,162,843 B2
• Time in Patent Office: Days
• US Class Current: 600/526
• CPC Class Codes: A61B 5/0275 using tracers, e.g. dye dilution

Abstract

A method for determining cardiac output in conjunction with flow through an extracorporeal circuit, wherein flow through an arterial line of the extracorporeal circuit is temporarily reversed and an indicator is passed through the cardiopulmonary circuit. A dilution curve is measured in the arterial line of the extracorporeal circuit during the reversed flow, and cardiac output is determined corresponding to the measured dilution curve.

Claims

1. A method of measuring a patient cardiac output in a patient vascular system coupled to an extracorporeal cardiopulmonary support circuit, the method comprising:

(a) withdrawing blood from a venous portion of the patient vascular system through an extracorporeal venous line of the extracorporeal cardiopulmonary support circuit and delivering blood to an arterial portion of the patient vascular system through an extracorporeal arterial line of the extracorporeal cardiopulmonary support circuit;

(b) reversing a flow in the extracorporeal arterial line to withdraw blood from the arterial portion of the patient vascular system;

(c) measuring an indicator dilution curve in the extracorporeal cardiopulmonary support circuit; and

(d) determining the patient cardiac output corresponding to the measured indicator dilution curve.

2. The method of claim 1, further comprising introducing an indicator into the patient vascular system.

3. The method of claim 1 further comprising introducing an indicator into the venous portion of the patient vascular system.

4. The method of claim 1, further comprising introducing an indicator into the extracorporeal cardiopulmonary support circuit.

5. The method of claim 1, further comprising introducing an indicator into the extracorporeal arterial line.

6. The method of claim 1, further comprising measuring the indicator dilution curve in the extracorporeal arterial line.

7. The method of claim 1, further comprising prior to reversing the flow in the extracorporeal arterial line, introducing a forward flow in the extracorporeal circuit from the venous portion of the vascular system to an arterial portion of the vascular system.

8. The method of claim 1, further comprising reversing the flow in the extracorporeal arterial line by reversing a connection of extracorporeal venous line and the extracorporeal arterial line between the extracorporeal cardiopulmonary support circuit and the patient vascular system.

9. The method of claim 1, further comprising reversing the flow in the extracorporeal arterial line by passing blood flow through a bridge tubing in the extracorporeal cardiopulmonary support circuit.

10. The method of claim 1, further comprising introducing an indicator into the patient vascular system by one of changing one of a filtration rate of the blood and a treatment of the blood.

11. The method of claim 1, wherein measuring the indicator dilution curve in the extracorporeal cardiopulmonary support circuit includes sensing one of a temperature, electrical impedance, optical property, density, ultrasound velocity, glucose concentration, physical blood property and chemical blood property.

12. A method of determining cardiac output, the method comprising:

(a) passing a dilution indicator from a venous portion of the patient vascular system, through a cardiopulmonary system of the patient vascular system to an arterial portion of the patient vascular system;

(b) reversing a flow in an arterial line of an extracorporeal cardiopulmonary support circuit to withdraw blood from the arterial portion of the patient vascular system; and

(c) determining a cardiac output corresponding to the dilution indicator in the extracorporeal cardiopulmonary support circuit.

13. The method of claim 12, further comprising measuring an indicator dilution curve in the arterial line of the extracorporeal cardiopulmonary support circuit.

14. The method of claim 12, further comprising introducing the dilution indicator into the venous portion of the patient vascular system.

15. The method of claim 12, further comprising introducing the dilution indicator into the extracorporeal cardiopulmonary support circuit.

16. The method of claim 12, further comprising introducing an indicator into the patient vascular system by one of changing one of a filtration rate of the blood and a treatment of the blood.

17. The method of claim 12, further comprising measuring the indicator dilution in the extracorporeal cardiopulmonary support circuit by sensing one of a temperature, electrical impedance, optical property, density, ultrasound velocity, glucose concentration, physical blood property and chemical blood property.

18. A method of determining cardiac output, the method comprising:

(a) reversing a flow in an arterial line of an extracorporeal cardiopulmonary support circuit to withdraw blood from an arterial portion of the patient vascular system into the arterial line of the extracorporeal cardiopulmonary support circuit; and

(b) determining a cardiac output corresponding to a dilution indicator passing from a cardiopulmonary system to an arterial portion of a patient vascular system and into the arterial line of the extracorporeal cardiopulmonary support circuit.

19. The method of claim 18, wherein reversing the flow in the arterial line of the extracorporeal cardiopulmonary support circuit includes one of employing a line reversal device, line switching and re-clamping of a portion of tubing in the extracorporeal cardiopulmonary support circuit.