SYSTEM AND METHODS FOR VENTILATING A PATIENT

• US 20100275920A1
• Filed: 04/30/2009
• Published: 11/04/2010
• Est. Priority Date: 04/30/2009
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Tham, Robert, Acker, Jaron Matthew
• Granted Patent: US 8,408,203 B2
• Time in Patent Office: Days
• US Class Current: 128/204.23
• 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 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2230/42 Rate
• CPC Class Codes: A61M 2230/435 partial O2 pressure (P-O2)
• CPC Class Codes: A61M 2230/46 Resistance or compliance of the lungs

Abstract

System and methods for ventilating a patient are provided. In one embodiment, the method comprises steps of placing a ventilator in a mode capable of delivering respiratory gas based on at least one fixed parameter and at least one variable parameter, the fixed parameters being tidal volume and peak airway pressure and the variable parameter being PEEP, identifying a first level for the PEEP, configuring the ventilator to deliver the respiratory gas at the peak airway pressure and the PEEP to achieve the tidal volume, monitoring respiratory gas flow over time to measure tidal volume, setting a second level for the PEEP based on the measured tidal volume, automatically adjusting the PEEP to the second level relative to the peak airway pressure and repeating the steps of configuring, monitoring, setting and automatically adjusting to achieve the ventilation.

Claims

1. A method of ventilating a patient, the method comprising:

placing a ventilator in a mode capable of delivering respiratory gas based on at least one fixed parameter and at least one variable parameter, the fixed parameters being tidal volume and peak airway pressure and the variable parameter being positive end expiratory pressure (PEEP);

identifying a first level for the PEEP;

configuring the ventilator to deliver the respiratory gas at the peak airway pressure and the PEEP to achieve the tidal volume;

monitoring respiratory as flow over time to measure tidal volume;

setting a second level for the PEEP based on the measured tidal volume;

automatically adjusting the PEEP to the second level, relative to the peak airway pressure; and

repeating the steps of configuring, monitoring, setting and automatically adjusting to achieve the ventilation.

2. The method of claim 1, wherein the peak airway pressure is peak inspiratory pressure.

3. The method of claim 1, wherein the mode of ventilation is selected from the group consisting of pressure control, flow control, volume control and pressure regulated volume control mode of ventilation.

4. The method of claim 1, wherein the first level for the PEEP is identified based on airway impedance of the patient.

5. The method of claim 4, wherein the airway impedance of the patient is dependent on one or more mechanical properties of the lung, one of the mechanical properties of the lung being lung compliance.

6. The method of claim 1, wherein the fixed parameter further comprises oxygen content of the respiratory gas, respiratory rate and inspiration time.

7. A method of ventilating a lung in a patient, the method comprising the steps of:

determining a first peak airway pressure;

selecting a first level for the PEEP;

providing respiratory gas to the patient at the first peak airway pressure and the PEEP to deliver a first volume of the respiratory gas;

varying the peak airway pressure to a second value;

monitoring respiratory gas flow over time to measure tidal volume;

determining a second level for the PEEP based on the measured tidal volume;

automatically adjusting the PEEP relative to the peak airway pressure; and

providing the respiratory gas to the patient at the second peak airway pressure and the PEEP to deliver a second volume of the respiratory gas;

wherein each of the volumes of the respiratory gas being delivered is based upon a corresponding predetermined PEEP.

8. The method of claim 7, wherein varying the peak airway pressure comprises increasing the peak airway pressure and measuring the tidal volume comprises measuring expiratory tidal volume.

9. The method of claim 7, wherein varying the peak airway pressure comprises decreasing the peak airway pressure and measuring the tidal volume comprises measuring inspiratory tidal volume.

10. The method of claim 7, wherein measuring the tidal volume comprises measuring ventilation flow rates.

11. A ventilator for respiratory treatment of a patient, the ventilator comprising:

a gas delivery unit for delivering respiratory gas to the patient based on at least one fixed parameter and at least one variable parameter, the fixed parameters being tidal volume and peak airway pressure and the variable parameter being PEEP; and

a regulation unit coupled to the gas delivery unit for controlling the gas delivery unit to deliver the respiratory gas at a pressure level corresponding to the peak airway pressure, the regulation unit further configured for controlling the gas delivery unit for adjusting the PEEP for each breath to maintain the tidal volume equal to a predetermined value.

12. The ventilator of claim 11, wherein the PEEP is determined by a recruitment maneuver.

13. The ventilator of claim 11, wherein the peak airway pressure is determined by a user operating the ventilator.

14. The ventilator of claim 11 further comprising an alarm coupled to the regulation unit, the alarm configured to be triggered when the value of PEEP exceeds a predetermined limit.

15. A computer readable media comprising computer readable program instructions for ventilating a patient, the computer readable program instructions comprising:

a routine for placing a ventilator in a mode capable of delivering respiratory gas based on at least one fixed parameter and at least one variable parameter;

the fixed parameters being tidal volume and peak airway pressure and the variable parameter being PEEP;

a routine for identifying a first level for the PEEP;

a routine for configuring the ventilator to deliver the respiratory gas at the peak airway pressure and the PEEP to achieve the tidal volume;

a routine for monitoring respiratory gas flow over time to measure tidal volume;

a routine for setting a second level for the PEEP based on the measured tidal volume;

a routine for automatically adjusting the PEEP to the second level, relative to the peak airway pressure; and

a routine for repeating the steps of configuring, monitoring, setting and automatically adjusting to achieve the ventilation.

16. The computer readable media of claim 15, wherein the peak airway pressure is peak inspiratory pressure.

17. The computer readable media of claim 15, wherein the mode of ventilation is selected from the group consisting of pressure control, flow control, volume control and pressure regulated volume control mode of ventilation.

18. The computer readable media of claim 15, wherein the first level for the PEEP is identified based on airway impedance of the lung.

19. The computer readable media of claim 18, wherein the airway impedance of the lung is based on one or more mechanical properties of the lung, one of the mechanical properties of the lung being lung compliance.

20. The computer readable media of claim 15, wherein the fixed parameter further comprises oxygen content of the respiratory gas, respiratory rate and inspiration time.