AUTOMATIC VENTILATOR CHALLENGE TO INDUCE SPONTANEOUS BREATHING EFFORTS

• US 20130053717A1
• Filed: 08/30/2011
• Published: 02/28/2013
• Est. Priority Date: 08/30/2011
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Doyle, Peter R., Vandine, J. Doug
• Application Number:
  US13/220,850
• Publication Number:
  US 20130053717A1
• Time in Patent Office: Days
• US Class Current: 600/532
• CPC Class Codes: A61B 5/0836 Measuring rate of CO2 production
• CPC Class Codes: A61B 5/087 Measuring breath flow
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/15003 for venous or arterial blood
• CPC Class Codes: A61B 5/150992 Blood sampling from a fluid line external to a patient, such as a catheter line, combined with an infusion line; blood sampling from indwelling needle sets, e.g. sealable ports, luer couplings, valves tubing connectors and couplings A61M39/00
• CPC Class Codes: A61B 5/153 Devices specially adapted for taking samples of venous or arterial blood, e.g. with syringes
• CPC Class Codes: A61B 5/155 Devices specially adapted for continuous or multiple sampling, e.g. at predetermined intervals devices loaded with multiple lancets simultaneously A61B5/15146
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61M 16/00 Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes stimulating the respiratory movement by mechanical, pneumatic or electrical means, iron lungs combined with gas breathing means A61H31/00
• CPC Class Codes: A61M 16/0063 Compressors
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0033 electrical
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)

Abstract

This disclosure describes systems and methods for configuring a ventilator for providing automatic, periodic ventilator adjustments to stimulate non-triggering patients to begin initiating spontaneous breathing efforts. Based on studies of respiration, a neural signal stimulating spontaneous breathing efforts is initiated when a patient'"'"'s arterial partial pressure of carbon dioxide (PaCO₂) reaches a certain threshold level, which threshold level may vary from individual to individual. Accordingly, an automatic, periodic ventilator challenge to stimulate spontaneous breathing efforts in a non-triggering patient is provided. An automatic, periodic ventilator challenge refers to an automatic, periodic reduction in the ventilation of a non-triggering patient intended to increase PaCO₂ levels within a clinically-acceptable range. By periodically increasing PaCO₂ levels, the systems and methods disclosed herein seek to achieve the patient'"'"'s individual PaCO₂ threshold level and, consequently, to evoke a neural signal stimulating spontaneous breathing efforts.

Claims

1. A ventilator-implemented method for stimulating spontaneous breathing efforts when carbon dioxide monitoring is available, the method comprising:

collecting ventilatory data associated with PaCO₂ or a surrogate for PaCO₂;

processing the ventilatory data to determine a first target PaCO₂ level;

determining a first reduction in ventilation projected to achieve the first target PaCO₂ level;

providing a first ventilator challenge based on the first reduction in ventilation;

determining whether spontaneous breathing efforts are detected in response to the first ventilator challenge; and

when spontaneous breathing efforts are detected, identifying a successful PaCO₂ level associated with the first ventilator challenge.

2. The method of claim 1, wherein the first ventilator challenge is provided until a first period of time expires or a threshold condition is detected.

3. The method of claim 1, wherein the first reduction in ventilation comprises a first reduction in minute ventilation, {dot over (V)}_E, and wherein the first reduction in {dot over (V)}_E comprises a reduction of at least one of:

respiratory rate (RR) and tidal volume (V_T).

4. The method of claim 1, wherein when spontaneous breathing efforts are not detected, the method further comprises:

identifying the first target PaCO₂ level as an unsuccessful PaCO₂ level; and

determining a second target PaCO₂ level higher than the unsuccessful PaCO₂ level.

5. The method of claim 4, further comprising determining a second reduction in ventilation projected to achieve the second target PaCO₂ level.

6. The method of claim 5, further comprising determining whether a set interval after the first ventilator challenge has expired.

7. The method of claim 6, further comprising:

when the set interval after the first ventilator challenge has expired, providing a second ventilator challenge based on the second reduction in ventilation.

8. The method of claim 7, further comprising:

determining whether spontaneous breathing efforts are detected in response to the second ventilator challenge; and

when spontaneous breathing efforts are detected, identifying a successful PaCO₂ level associated with the second ventilator challenge.

9. A ventilator-implemented method for stimulating spontaneous breathing efforts when carbon dioxide monitoring is not available, the method comprising:

determining a first test percentage for reducing ventilation;

providing a first ventilator challenge based on the first test percentage for reducing ventilation;

determining whether spontaneous breathing efforts are detected in response to the first ventilator challenge; and

when spontaneous breathing efforts are detected, identifying a successful test percentage associated with the first ventilator challenge.

10. The method of claim 9, wherein providing the first ventilator challenge comprises reducing minute ventilation, {dot over (V)}_E, by the first test percentage, wherein reducing {dot over (V)}_E by the first test percentage comprises reducing one of respiratory rate (RR) and tidal volume (V_T) by the first test percentage.

11. The method of claim 9, wherein when spontaneous breathing efforts are not detected, the method further comprises:

identifying the first test percentage as an unsuccessful test percentage; and

determining a second test percentage greater than the unsuccessful test percentage for reducing ventilation in a second ventilator challenge.

12. The method of claim 11, further comprising:

determining that a set interval after the first ventilator challenge has expired; and

providing a second ventilator challenge by reducing ventilation by the second test percentage.

13. The method of claim 12, further comprising:

determining whether spontaneous breathing efforts are detected in response to the second ventilator challenge; and

when spontaneous breathing efforts are detected, identifying a successful test percentage associated with the second ventilator challenge.

14. The method of claim 9, wherein the first ventilator challenge is provided for a first period of time.

15. The method of claim 12, wherein the second ventilator challenge is provided for a second period of time.

16. The method of claim 15, wherein the first period of time and the second period of time are different.

17. A ventilator processing interface for stimulating spontaneous breathing efforts, comprising:

means for determining a first test percentage for reducing ventilation to stimulate spontaneous breathing efforts;

means for providing a first ventilator challenge based on the first test percentage for reducing ventilation;

means for determining whether spontaneous breathing efforts are detected in response to the first ventilator challenge; and

when spontaneous breathing efforts are detected, means for identifying a successful test percentage associated with the first ventilator challenge.

18. The ventilator processing interface of claim 17, wherein the first ventilator challenge is provided for a first period of time.

19. The ventilator processing interface of claim 17, wherein the means for providing the first ventilator challenge comprises means for reducing minute ventilation, {dot over (V)}_E, by the first test percentage, wherein the means for reducing {dot over (V)}_E by the first test percentage comprises means for reducing one of respiratory rate (RR) and tidal volume (V_T) by the first test percentage.

20. The ventilator processing interface of claim 19, wherein when spontaneous breathing efforts are not detected, the method further comprises:

means for identifying the first test percentage as an unsuccessful test percentage;

means for determining a second test percentage greater than the unsuccessful test percentage for reducing ventilation in a second ventilator challenge; and

means for providing a second ventilator challenge based on the second test percentage for reducing ventilation.