Breathing assistance systems with lung recruitment maneuvers

• US 8,640,699 B2
• Filed: 03/23/2009
• Issued: 02/04/2014
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Baker, Clark R. Jr.
• Primary Examiner(s): Anderson, Lynne
• Assistant Examiner(s): PHILIPS, BRADLEY H
• Application Number:
  US12/409,406
• Publication Number:
  US 20090241957A1
• Time in Patent Office: 1,779 Days
• Field of Search: 128/200.24, 128/204.18, 128/204.23, 128/204.21, 128/204.22, 128/205.12
• US Class Current: 128/204.23
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 2205/584 having a color code
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/30 Blood pressure A61M2230/04 takes precedence
• CPC Class Codes: A61M 2230/46 Resistance or compliance of the lungs
• CPC Class Codes: A61M 2230/50 Temperature

Abstract

The disclosure provides a method for controlling the delivery of a breathing gas to a patient including automatic lung recruitment maneuvers. The method may include regulating the FiO₂ and the PEEP of the breathing gas delivered to the patient, determining a blood oxygenation level of the patient, automatically adjusting the FiO₂ of the breathing gas delivered to the patient based on at least the blood oxygenation level of the patient, and in response to determining that the FiO₂ of the breathing gas delivered to the patient exceeds a pre-determined value: automatically initiating a lung recruitment maneuver; and automatically increasing the PEEP of the breathing gas delivered to the patient.

Claims

1. A method for controlling a delivery of a breathing gas to a patient using a processor, the method including:

regulating a fractional inspired oxygen (FiO₂) and a positive end expiratory pressure (PEEP) of the breathing gas delivered to the patient;

determining a blood oxygenation level of the patient;

automatically adjusting the FiO₂ of the breathing gas delivered to the patient based on the blood oxygenation level of the patient; and

in response to determining that the FiO₂ of the breathing gas delivered to the patient exceeds a pre-determined value;

automatically initiating a lung recruitment maneuver to achieve a lung recruitment;

after completion of the lung recruitment maneuver;

setting a post-recruitment maneuver PEEP at a higher level than a PEEP level setting prior to the lung recruitment maneuver;

periodically determining, at a first specified frequency, whether to adjust the FiO₂ of the delivered breathing gas; and

periodically determining, at a second specified frequency, whether to reduce the PEEP;

wherein the second defined frequency of PEEP reduction determinations is lower than the first defined frequency of FiO₂ adjustment determinations such that the FiO₂ is allowed to reach equilibrium between successive PEEP reduction determinations.

2. The method of claim 1, wherein the blood oxygenation level is determined by measuring saturation of peripheral oxygen (SpO₂) in the patient.

3. The method of claim 1, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli.

4. The method of claim 1, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure, the pressure preset by a user; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli, the duration preset by the user.

5. The method of claim 1, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure, the pressure determined by a ventilation parameter; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli, the duration determined by the ventilation parameter.

6. The method of claim 1, further comprising inhibiting the adjustment of the fractional inspired oxygen of the breathing gas delivered to the patient during the lung recruitment maneuver.

7. The method of claim 1, wherein maintaining a duration of the lung recruitment after completion of the lung recruitment maneuver comprises automatically adjusting the PEEP of the breathing gas delivered to the patient based on variations in the fractional inspired oxygen of the breathing gas delivered to the patient.

8. The method of claim 1, wherein maintaining a duration of the lung recruitment after completion of the lung recruitment maneuver comprises automatically adjusting the PEEP of the breathing gas delivered to the patient based on both:

variations in the FiO₂ of the breathing gas delivered to the patient; and

a ventilation parameter including one cardiovascular indicator of the patient.

9. The method of claim 1, further comprising:

regulating a third gas delivery parameter of the breathing gas delivered to the patient;

automatically adjusting the third gas delivery parameter of the breathing gas delivered to the patient based on the blood oxygenation level of the patient; and

adjusting the pre-determined value for automatic initiation of the lung recruitment maneuver based on the value of the third gas delivery parameter of the breathing gas delivered to the patient.

10. A breathing assistance system configured to deliver a breathing gas toward a patient, the system comprising:

a gas delivery control system configured to regulate a fractional inspired oxygen (FiO₂) and a positive end expiratory pressure (PEEP) of the breathing gas delivered to the patient;

a parameter module configured to determine a blood oxygenation level of the patient;

wherein the gas delivery control system;

automatically adjusts the FiO₂ of the breathing gas delivered to the patient based at least on the blood oxygenation level of the patient;

automatically initiates a lung recruitment maneuver to achieve a lung recruitment when the FiO₂ of the breathing gas exceeds a pre-determined value; and

after completion of the lung recruitment maneuver;

sets a post-recruitment maneuver PEEP at a higher level than a PEEP level setting prior to the lung recruitment maneuver;

periodically determines, at a first specified frequency, whether to adjust the FiO₂ of the delivered breathing gas; and

periodically determines, at a second specified frequency, whether to reduce the PEEP;

wherein the second defined frequency of PEEP reduction determinations is lower than the first defined frequency of FiO₂ adjustment determinations such that the FiO₂ is allowed to reach equilibrium between successive PEEP reduction determinations.

11. The system of claim 10, wherein the parameter module is configured to measure saturation of peripheral oxygen (SpO₂) in the patient.

12. The system of claim 10, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli.

13. The system of claim 10, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure, the pressure preset by a user; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli, the duration preset by the user.

14. The system of claim 10, wherein the lung recruitment maneuver includes:

inflating lungs of the patient at a relatively high pressure, the pressure determined by a ventilation parameter; and

maintaining the inflation of the lungs for a duration long enough to distend collapsed aveoli, the duration determined by the ventilation parameter.

15. The system of claim 10, further comprising the gas delivery control system configured to inhibit the adjustment of the FiO₂ of the breathing gas delivered to the patient during the lung recruitment maneuver.

16. The system of claim 10, wherein maintaining a duration of the lung recruitment after completion of the lung recruitment maneuver comprises automatically adjusting the PEEP of the breathing gas delivered to the patient based on variations in the FiO₂ of the breathing gas delivered to the patient.

17. The system of claim 10, wherein maintaining a duration of the lung recruitment after completion of the lung recruitment maneuver comprises automatically adjusting the PEEP of the breathing gas delivered to the patient based on both:

variations in the FiO₂ of the breathing gas delivered to the patient; and

a ventilation parameter including one cardiovascular indicator of the patient.

18. The system of claim 10, further comprising:

the gas delivery control system configured to regulate a third parameter of the breathing gas delivered to the patient;

the gas delivery control system configured to automatically adjust the third parameter of the breathing gas delivered to the patient based on the blood oxygenation level of the patient; and

the gas delivery control system configured to adjust the pre-determined value for automatic initiation of the lung recruitment maneuver based on the value of the third parameter of the breathing gas delivered to the patient.

19. A computer-readable storage medium storing a set of instructions executable on a processor, the set of instructions comprising:

instructions for regulating a fractional inspired oxygen (FiO₂) and a positive end expiratory pressure (PEEP) of a breathing gas delivered to a patient;

instructions for determining a blood oxygenation level of the patient;

instructions for automatically adjusting the FiO₂ of the breathing gas delivered to the patient based on the blood oxygenation level of the patient; and

instructions for, in response to determining that the FiO₂ of the breathing gas delivered to the patient exceeds a pre-determined value;

automatically initiating a lung recruitment maneuver to achieve a lung recruitment; and

after completion of the lung recruitment maneuver;

setting a post-recruitment maneuver PEEP at a higher level than a PEEP level setting prior to the lung recruitment maneuver;

periodically determining, at a first specified frequency, whether to adjust the FiO₂of the delivered breathing gas; and

periodically determining, at a second specified frequency, whether to reduce the PEEP;

wherein the second defined frequency of PEEP reduction determinations is lower than the first defined frequency of FiO₂ adjustment determinations such that the FiO₂ is allowed to reach equilibrium between successive PEEP reduction determinations.

20. A breathing assistance system, comprising:

means for regulating a fractional inspired oxygen (FiO₂) and a positive end expiratory pressure (PEEP) of a breathing gas delivered to a patient;

means for determining a blood oxygenation level of the patient;

means for automatically adjusting the FiO₂ of the breathing gas delivered to the patient based on the blood oxygenation level of the patient; and

means for, in response to determining that the FiO₂ of the breathing gas delivered to the patient exceeds a pre-determined value;

automatically initiating a lung recruitment maneuver to achieve a lung recruitment;

after completion of the lung recruitment maneuver;

setting a post-recruitment maneuver PEEP at a higher level than a PEEP level setting prior to the lung recruitment maneuver;

periodically determining, at a first specified frequency, whether to adjust the FiO₂ of the delivered breathing gas; and

periodically determining, at a second specified frequency, whether to reduce the PEEP;

wherein the second defined frequency of PEEP reduction determinations is lower than the first defined frequency of determinations such that the FiO₂ is allowed to reach equilibrium between successive PEEP reduction determinations.