METHOD AND APPARATUS FOR AIRWAY COMPENSATION CONTROL

• US 20080091117A1
• Filed: 10/16/2006
• Published: 04/17/2008
• Est. Priority Date: 10/16/2006
• Status: Active Grant

• Current Assignee: Gary J. Choncholas, Ronald L. Tobia
• Original Assignee: General Electric Company
• Inventors: Choncholas, Gary J., Tobia, Ronald L.
• Granted Patent: US 8,312,879 B2
• Time in Patent Office: Days
• US Class Current: 600/538
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/0402 Special features for tracheal tubes not otherwise provided for
• CPC Class Codes: A61M 16/042 with separate conduits for in-and expiration gas, e.g. for limited dead volume
• CPC Class Codes: A61M 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 16/0858 Pressure sampling ports
• CPC Class Codes: A61M 16/0866 Passive resistors therefor
• CPC Class Codes: A61M 16/12 by mixing different gases
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/1025 the O2 concentration
• CPC Class Codes: A61M 2016/103 the CO2 concentration
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2230/432 partial CO2 pressure (P-CO2)
• CPC Class Codes: A61M 2230/435 partial O2 pressure (P-O2)

Abstract

A ventilator for ventilating a patient also assists a clinician in determining a suitable PEEP for the patient. For this purpose, a graph or tabular display of a series of different value PEEPs and corresponding functional residual capacities of the patient may be provided. Or, the relationship between lung compliance and a series of different values of PEEP may be provided. Or, the amount of the lung volume recruited/de-recruited at various levels of PEEP may be determined for use in selecting a desired PEEP. To this end, the functional residual capacity of the lungs is determined for a first PEEP level. The PEEP is then altered to a second level and a spirometry dynostatic curve of lung volume and pressure data is obtained. The lung volume on the dynostatic curve at a lung pressure corresponding to the first PEEP value is obtained. The difference between the functional residual capacity of the lungs at the first PEEP level and that determined from the dynostatic curve represents the lung volume recruited/de-recruited when changing between said first and second PEEPs.

Claims

1. A ventilator for ventilating a patient and for determining a relationship between a ventilator parameter and the functional residual capacity of the patient, said ventilator comprising:

(a) means for causing alteration in a parameter of the ventilation supplied to the patient;

(b) means for determining the functional residual capacity of the patient at a plurality of parameter values;

(c) means for displaying data relating functional residual capacity to corresponding parameter values.

2. The ventilator according to claim 1 wherein means (a) is further defined as means for causing an alteration in the PEEP supplied to the patient, means (b) is further defined as means for determining the functional residual capacity of the patient at a plurality of PEEPs, and means (c) is further defined as means for displaying data relating functional residual capacity to corresponding PEEP levels.

3. The ventilator according to claim 2 wherein means (a) is further defined as incrementing or decrementing the PEEP.

4. A ventilator according to claim 1 wherein said means (b) is further defined as determining the functional residual capacity of the patient by an inert gas wash-in or wash-out technique.

5. The ventilator according to claim 2 wherein said means (c) is further defined as displaying data relating PEEP to the corresponding functional residual capacity in graphic form.

6. The ventilator according to claim 2 wherein means (c) is further defined as means for displaying data relating PEEP to the corresponding functional residual capacity in tabular form.

7. The ventilator according to claim 6 wherein the tabular display includes an indication of PEEPe and PEEPi with the corresponding functional residual capacity.

8. The ventilator according to claim 2 including means for setting one or more of initial PEEP, end PEEP, number of measurements, or increment/decrement of PEEP alteration.

9. The ventilator according to claim 1 further defined as including means for storing data relating functional residual capacity to corresponding parameter values.

10. The ventilator according to claim 9 wherein said means (c) is further defined as means for displaying data obtained at different times.

11. The ventilator according to claim 1 wherein means (a) is further defined as means for causing an alteration in one of a respiration rate, expiration time, or inspiratory:

expiratory ratio parameter;

means (b) is further defined as means for determining the functional residual capacity of the patient at a plurality of different values for the altered parameter, and means (c) is further defined as means for displaying data relating functional residual capacity to corresponding parameter values.

12. The ventilator according to claim 2 wherein means (a) is further defined as carrying out a recruitment maneuver and means (c) is further defined as displaying data obtained prior and subsequent to the recruitment maneuver.

13. A method determining a relationship between a ventilation parameter and the functional residual capacity of a ventilated patient, said method comprising the steps of:

(a) causing alteration in a parameter of the ventilation supplied to the patient;

(b) determining the functional residual capacity of the patient at a plurality of parameter values; and

(c) displaying data relating to functional residual capacity to corresponding parameter values.

14. The method according to claim 13 wherein step (a) is further defined as causing an alteration in the PEEP supplied to the patient, step (b) is further defined as determining the functional residual capacity of the patient at a plurality of PEEPs, and step (c) is further defined as displaying data relating functional residual capacity to corresponding PEEP levels.

15. The method according to claim 14 wherein step (a) is further defined as incrementing or decrementing the PEEP.

16. The method according to claim 14 wherein step (b) is further defined as determining the functional residual capacity of the patient by an inert gas wash-in or wash-out technique.

17. The method according to claim 14 wherein step (c) is further defined as displaying data relating PEEP to the corresponding functional residual capacity in graphic form.

18. The method according to claim 14 wherein step (c) is further defined as displaying data relating PEEP to the corresponding functional residual capacity in tabular form.

19. The method according to claim 18 wherein step (c) is further defined as displaying an indication of PEEPe and PEEPi with the corresponding functional residual capacity.

20. The method according to claim 14 including a step for setting one or more of initial PEEP, end PEEP, number of measurements, or increment/decrement of PEEP alteration.

21. The method according to claim 13 further defined as storing data relating to functional residual capacity to corresponding parameter values.

22. The method according to claim 21 further defined as displaying data obtained at different times.

23. The method according to claim 13 wherein step (a) is further defined as causing an alteration in one of a respiration rate, expiration time, or inspiratory:

expiratory ratio parameter;

step (b) is further defined as determining the functional residual capacity of the patient at a plurality of different values for the altered parameter, and step (c) is further defined as displaying data relating functional residual capacity to corresponding parameter values.

24. The method according to claim 14 further including step of carrying out a recruitment maneuver and step (c) is further defined as displaying data obtained prior and subsequent to the recruitment maneuver.

25. A ventilator for indicating recruitment/de-recruitment of lung volume in association with varying levels of PEEP for a ventilated patient, said apparatus comprising:

(a) means for ventilating the patient from a ventilator, said means ventilating the patient with a first level of PEEP, altering the PEEP to a second level, different than said first level, and ventilating the patient with the second level of PEEP;

(b) means for measuring the functional residual capacity of the patient at one of the first and second levels of PEEP;

(c) means for determining a spirometry dynostatic curve for the breathing action of the patient at the other of said first and second levels of PEEP;

(d) means for determining a lung volume difference for the functional residual capacity at the one level of PEEP (530) and a point (540) on the dynostatic curve for the other level of PEEP corresponding to the one level of PEEP; and

(e) means for displaying the lung volume difference as recruited/de-recruited volume in the lungs when changing between the first and second levels of PEEP.

26. The ventilator according to claim 25 where means (a) alters the PEEP from a higher level to a lower level.

27. The ventilator according to claim 25 wherein said means (c) is further defined as determining a spirometry dynostatic curve on an absolute scale using functional residual capacity.

28. The ventilator of claim 25 wherein means (e) is further defined as displaying the lung volume differences at various PEEPs in conjunction with functional residual capacities of the lungs.

29. The ventilator of claim 28 wherein means (e) is further defined as graphically displaying the lung volume differences and functional residual capacities.

30. The ventilator of claim 28 wherein means (e) is further defined as displaying the recruited/de-recruited volumes and functional residual capacities in tabular form.

31. The ventilator of claim 25 further including means for performing a recruitment maneuver on the patient.

32. A method for indicating recruitment/de-recruitment of lung volume in association with varying levels of PEEP for a ventilated patient, said method comprising the steps of:

(a) ventilating the patient with a first level of PEEP, altering the PEEP to a second level, different than said first level, and ventilating the patient with the second level of PEEP;

(b) measuring the functional residual capacity of the patient at one of the first and second levels of PEEP;

(c) determining a spirometry dynostatic curve for the breathing action of the patient at the other of said first and second levels of PEEP;

(d) determining a lung volume difference for the functional residual capacity at the one level of PEEP and a point on the dynostatic curve for the other level of PEEP corresponding to the one level of PEEP; and

(e) displaying the lung volume different as recruited/de-recruited volume in the lungs when changing between the first and second levels of PEEP.

33. The method of claim 32 wherein means (a) alters the PEEP from a higher level to a lower level.

34. The method of claim 32 further including an initial step of performing a recruitment maneuver on the patient.

35. The method of claim 32 wherein step (c) is further defined as determining a spirometry dynostatic curve on an absolute scale using functional residual capacity.

36. The method of claim 32 further defined as displaying the lung volume differences at various PEEPs in conjunction with functional residual capacities of the lung.

37. The method of claim 36 further defined as graphically displaying the lung volume differences and functional residual capacities.

38. The method of claim 36 further defined as displaying the recruited/de-recruited volumes and functional residual capacities in tabular form.

39. The method of claim 32 further defined as repeating the steps of the method by ventilating the patient at the other of the first and second levels of PEEP, altering the PEEP to a third level, and carrying out the corresponding steps of the method.

40. A ventilator for ventilating a patient and for determining a relationship between a ventilator parameter and a functional residual capacity characteristic of the patient, said ventilator comprising:

(a) means for causing alteration in a PEEP supplied to the patient;

(b) means for determining the functional residual capacity of the patient at a plurality of PEEP values;

(c) means for determining the relationship between increments in the alteration in PEEP and resulting differences in functional residual capacity; and

(d) means for displaying data presenting the relationship determined by means (c) to corresponding values of PEEP.

41. The ventilator according to claim 40 wherein means (a) is further defined as incrementing or decrementing the PEEP.

42. A ventilator according to claim 40 wherein said means (b) is further defined as determining the functional residual capacity of the patient by an inert gas wash-in or wash-out technique.

43. The ventilator according to claim 40 wherein said means (d) is further defined as displaying data presenting the relationship determined by means (c) to corresponding PEEP values in graphic form.

44. The ventilator according to claim 40 wherein means (d) is further defined as means for displaying data presenting the relationship determined by means (c) to corresponding PEEP values in tabular form.

45. The ventilator according to claim 44 wherein the tabular display includes an indication of PEEPe and PEEPi with corresponding PEEP values.

46. The ventilator according to claim 40 including means for setting one or more of initial PEEP, end PEEP, number of measurements, or increment/decrement of PEEP alteration.

47. The ventilator according to claim 40 further defined as including means for storing data relating the relationship determined by means (c) to corresponding PEEP values.

48. A method determining a relationship between a ventilation parameter and a functional residual capacity characteristic of a ventilated patient, said method comprising the steps of:

(a) causing alteration in a PEEP supplied to the patient;

(b) determining the functional residual capacity of the patient at a plurality of PEEP values;

(c) determining the relationship between increments in the alteration in PEEP and resulting differences in functional residual capacity; and

(d) displaying data presenting the relationship determined in step (c) to corresponding values of PEEP.

49. The method according to claim 48 wherein step (a) is further defined as incrementing or decrementing the PEEP.

50. The method according to claim 48 wherein step (b) is further defined as determining the functional residual capacity of the patient by an inert gas wash-in or wash-out technique.

51. The method according to claim 48 wherein step (d) is further defined as displaying data presenting the relationship determined in step (c) to corresponding PEEP values in graphic form.

52. The method according to claim 48 wherein step (c) is further defined as displaying data presenting the relationship determined in step (c) to corresponding PEEP values in tabular form.

53. The method according to claim 52 wherein step (d) is further defined as displaying an indication of PEEPe and PEEPi with the corresponding PEEP values.

54. The method according to claim 48 including a step for setting one or more of initial PEEP, end PEEP, number of measurements, or increment/decrement of PEEP alteration.

55. The method according to claim 48 further defined as storing data relating the relationship determined in step (c) to corresponding PEEP values.