Systems and methods for monitoring, managing, and/or preventing fatigue during ventilation

• US 9,375,542 B2
• Filed: 11/08/2012
• Issued: 06/28/2016
• Est. Priority Date: 11/08/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Doyle, Peter, Kimm, Gardner, Angelico, Phyllis
• Primary Examiner(s): Douglas, Steven
• Application Number:
  US13/671,815
• Publication Number:
  US 20140123979A1
• Time in Patent Office: 1,328 Days
• Field of Search: 128/204.18, 12820421-20423
• US Class Current: 1/1
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• 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 16/04 Tracheal tubes catheters in general A61M25/00
• CPC Class Codes: A61M 16/0666 Nasal cannulas or tubing devices for improving normal breathing through the nose A61F5/08; nose filters A62B23/06; outside holding devices A61M25/02
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• 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 2230/005 Parameter used as control input for the apparatus
• CPC Class Codes: A61M 2230/40 Respiratory characteristics
• CPC Class Codes: A61M 2230/435 partial O2 pressure (P-O2)
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user
• CPC Class Codes: G16H 20/40 relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

This disclosure describes systems and methods for determining patient fatigue during ventilation of a patient. The disclosure describes novel notification and/or management of patient fatigue during ventilation. Further, the disclosure describes system and methods for preventing diaphragm fatigue or weakness.

Claims

1. A method for ventilating a patient with a ventilator comprising:

ventilating the patient based on a set mandatory mode of ventilation;

switching from the set mandatory mode of ventilation to ventilate the patient based on a spontaneous mode of ventilation;

monitoring at least one fatigue indicator during the spontaneous mode;

establishing a baseline for the at least one fatigue indicator during the spontaneous mode;

determining a change from the baseline based on the monitored at least one fatigue indicator during the spontaneous mode;

comparing the change to a corresponding fatigue threshold during the spontaneous mode;

detecting respiratory fatigue based on the step of comparing the change to the corresponding fatigue threshold during the spontaneous mode;

switching from the spontaneous mode of ventilation back to the set mandatory mode of ventilation in response to detecting respiratory fatigue; and

displaying a fatigue notification in response to detecting respiratory fatigue.

2. The method of claim 1, wherein the step of detecting respiratory fatigue comprises:

determining that the change breaches the corresponding fatigue threshold.

3. The method of claim 1, wherein the fatigue notification includes at least one of the following notifications:

fatigue detection;

level of fatigue;

fatigue index;

the corresponding fatigue threshold;

fatigue detected;

fatigue implicated;

fatigue warning; and

notice of fatigue.

4. The method of claim 1, wherein the fatigue notification includes a message.

5. The method of claim 1, wherein the spontaneous mode of ventilation is a positive feedback breath type.

6. The method of claim 1, further comprising:

monitoring for a rested fatigue indicator after a predetermined rest time,

wherein the predetermined rest time begins when the step of switching from the spontaneous mode of ventilation back to the set mandatory mode of ventilation is performed;

comparing the rested fatigue indicator to the baseline;

determining that the detected respiratory fatigue was mitigated by switching from the spontaneous mode of ventilation back to the set mandatory mode of ventilation based on the step of comparing the rested fatigue indicator to the baseline.

7. The method of claim 1, wherein the spontaneous mode of ventilation utilizes a breath type selected from a group of a proportional assist (PA) breath type and diaphragmatic electromyography adjusted (DEA) breath type;

and

wherein the set mandatory mode of ventilation utilizes a non-positive feedback breath type.

8. The method of claim 1, wherein the step of establishing the baseline includes receiving the baseline from clinician input.

9. The method of claim 1, wherein the monitored at least one fatigue indicator and the corresponding fatigue threshold are selected from a group comprising:

work of breathing decrease below the baseline,

the work of breathing increases above the baseline followed by a decrease below the baseline,

PaCO₂ increases by at least 10 mmHg from the baseline,

VCO₂ decreases by more than 20% from the baseline,

EMG of an accessory muscle indicates use of the accessory muscle,

E_di decreases by at least 25% from the baseline,

E_di stays the same while velocity of muscle shortening decreases below the baseline,

P_di decreases by at least 10% from the baseline,

P_di,max decreases by at least 20% from the baseline,

P_i,max decreases by at least 20% from the baseline,

a velocity of muscle shortening decreases at least 25% from the baseline,

EMG time domain is less than 50 uV,

EMG frequency domain decreases by more than 20% from the baseline,

P_esoph decreases by at least 10% from the baseline,

P_di Maximum Relaxation Rate decreases by at least 20% from the baseline,

P_mus Maximum Relaxation Rate decreases by at least 20% from the baseline,

presence of paradoxical breathing,

V_{e alv} decreases by at least 20% from the baseline,

respiration rate increases above 35 breaths a minute,

respiration rate increases by at least 25% from the baseline followed by a decrease,

V_t/T_i decreases by 30% from the baseline,

V_d/V_t increases by 20% from the baseline,

V_d/V_t is greater than 40% from the baseline,

P_0.1 increases above 4 cm of H₂O and then decreases by at least 2 cm of H₂O,

diaphragmatic position becomes flattened,

cardiac output does not increase with an increasing load,

V_t is below 4 mL/kg,

diaphragm movement imaging shows reduced movement compared to the baseline,

alternating abdominal/rib cage muscle contractions occur or increase in frequency compared to the baseline,

BIS LOS is normal,

RSBI increases above 105,

P_di/P_{di max} is above 40%,

T_i/T_tot is greater than 40%,

P_tid increases above 0.15,

T_i/T_tot/P_di/P_dimax is greater than 40%,

E_di increases while E_phr increases and P_di decreases,

the P_di,max increases from the baseline,

the P_i,max increases from the baseline,

E_di increases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, an increase in P_at, and a decrease in MV occurs, and

P_mus decreases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, and a decrease in MV occurs.

10. The method of claim 1, wherein the step of establishing the baseline includes averaging a set of measurements for each of the monitored fatigued indicators for a predetermined amount of time.

11. A ventilator system comprising:

a pressure generating system adapted to generate a flow of breathing gas according to a mode of ventilation, wherein the mode of ventilation is a mandatory mode of ventilation;

a ventilation tubing system including a patient interface for connecting the pressure generating system to a patient;

a plurality of sensors operatively coupled to at least one of the pressure generating system, the patient, and the ventilation tubing system, wherein the plurality of sensors monitor a plurality of parameters to generate sensor output;

a switch module sending instructions to the pressure generating system to switch from the mandatory mode of ventilation to a spontaneous mode of ventilation;

a baseline module determines a baseline for at least one fatigue indicator and determines a change in the at least one fatigue indicator from the baseline based on the sensor output during the spontaneous mode of ventilation;

a fatigue module compares the change to a corresponding fatigue threshold and determines that the patient is fatigued based on the comparison during the spontaneous mode of ventilation, wherein the switch module sends instructions to the pressure generating system to switch back to the mandatory mode of ventilation in response to determining that the patient is fatigued by the fatigue module;

a notification module determines an appropriate notification; and

a graphical user interface displays the appropriate notification received from the notification module, wherein the appropriate notification notifies a clinician that the fatigue module determined that the patient is fatigued.

12. The ventilator system of claim 11, wherein the fatigue module determines that the change breached the corresponding fatigue threshold.

13. The ventilator system of claim 11, further comprising:

an indicator module, wherein the indicator module derives the at least one fatigue indicator from the sensor output.

14. The ventilator system of claim 11, wherein the at least one fatigue indicator and the corresponding fatigue threshold are selected from a group comprising:

work of breathing decrease below the baseline,

the work of breathing increases above the baseline followed by a decrease below the baseline,

PaCO₂ increases by at least 10 mmHg from the baseline,

VCO₂ decreases by more than 20% from the baseline,

EMG of an accessory muscle indicates use of the accessory muscle,

E_di decreases by at least 25% from the baseline,

E_di stays the same while velocity of muscle shortening decreases below the baseline,

P_di decreases by at least 10% from the baseline,

P_di,max decreases by at least 20% from the baseline,

P_i,max decreases by at least 20% from the baseline,

a velocity of muscle shortening decreases at least 25% from the baseline,

EMG time domain is less than 50 uV,

EMG frequency domain decreases by more than 20% from the baseline,

P_esoph decreases by at least 10% from the baseline,

P_di Maximum Relaxation Rate decreases by at least 20% from the baseline,

P_mus Maximum Relaxation Rate decreases by at least 20% from the baseline,

presence of paradoxical breathing,

V_{e alv} decreases by at least 20% from the baseline,

respiration rate increases above 35 breaths a minute,

respiration rate increases by at least 25% from the baseline followed by a decrease,

V_t/T_i decreases by 30% from the baseline,

V_d/V_t increases by 20% from the baseline,

V_d/V_t is greater than 40% from the baseline,

P_0.1 increases above 4 cm of H₂O and then decreases by at least 2 cm of H₂O,

diaphragmatic position becomes flattened,

cardiac output does not increase with an increasing load,

V_t is below 4 mL/kg,

diaphragm movement imaging shows reduced movement compared to the baseline,

alternating abdominal/rib cage muscle contractions occur or increase in frequency compared to the baseline,

BIS LOS is normal,

RSBI increases above 105,

P_di/P_{di max} is above 40%,

T_i/T_tot is greater than 40%,

P_tid increases above 0.15,

T_i/T_tot/P_di/P_dimax is greater than 40%,

E_di increases while E_phr increases and P_di decreases,

the P_di,max increases from the baseline,

the P_i,max increases from the baseline,

E_di increases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, an increase in P_0.1, and a decrease in MV occurs, and

P_mus decreases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, and a decrease in MV occurs.

15. A computer-readable medium having computer-executable instructions for performing a method of ventilating a patient with a ventilator, the method comprising:

delivering ventilation based on a positive feedback breath type;

monitoring output from at least one sensor;

monitoring a plurality of fatigue indicators based on the output;

establishing a baseline for at least one fatigue indicator based on the output;

determining a change from the baseline based on the monitored plurality of fatigue indicators;

comparing the change to a fatigue threshold;

detecting respiratory fatigue based on the step of comparing the change to the fatigue threshold by the ventilator;

displaying a fatigue notification after the step of detecting respiratory fatigue;

implementing a basal level of support for the positive feedback breath type after the step of detecting respiratory fatigue;

monitoring for a rested fatigue indicator after a predetermined rest time, wherein the predetermined rest time begins when the step of implementing the basal level of support is performed;

comparing the rested fatigue indicator to the baseline; and

determining that the detected respiratory fatigue was mitigated by the step of implementing the basal level of support based on the step of comparing the rested fatigue indicator to the baseline.

16. A method for ventilating a patient with a ventilator comprising:

monitoring a plurality of fatigue indicators;

establishing a baseline for the plurality of fatigue indicators by averaging a set of measurements for each indicator in the plurality of fatigued indicators for a predetermined amount of time;

determining a change from the baseline based on the monitored fatigue indicators;

comparing the change to a corresponding fatigue threshold;

detecting respiratory fatigue based on the step of comparing the change to the fatigue threshold;

displaying a fatigue notification after the step of detecting respiratory fatigue;

switching from a spontaneous mode of ventilation to a mandatory mode of ventilation in response to the detecting respiratory fatigue; and

determining that the detected respiratory fatigue was mitigated by the step of switching to the mandatory mode of ventilation.

17. The method of claim 16, wherein the step of detecting respiratory fatigue comprises:

determining that the change breaches the fatigue threshold.

18. The method of claim 16, wherein the fatigue notification includes at least one of the following notifications:

fatigue detection;

level of fatigue;

fatigue index;

the fatigue threshold;

fatigue detected;

fatigue implicated;

fatigue warning; and

notice of fatigue.

19. The method of claim 16, further comprising:

ventilating the patient based on the mandatory mode of ventilation;

switching from the mandatory mode of ventilation to the spontaneous mode of ventilation,

wherein the monitoring the plurality of fatigue indicators, the establishing the baseline for the plurality of fatigue indicators, the determining the change from the baseline based on the monitored fatigue indicators, the comparing the change to the corresponding fatigue threshold, and the detecting respiratory fatigue are all performed during the spontaneous mode of ventilation.

20. The method of claim 16, wherein the fatigue notification includes a message.

21. The method of claim 20, wherein the message is selected from a group of the following messages:

consider switching to invasive ventilation;

consider switching to a negative feedback breath type;

consider switching to a PS, PC, VC, or VS breath type;

consider increasing support setting in a PA breath type;

consider increasing support setting in a DEA breath type;

consider increasing support setting in a positive feedback breath type;

consider increasing set respiratory rate;

consider utilizing a basal level of support in the PA breath type;

consider utilizing a basal level of support in the DEA breath type; and

consider utilizing a basal level of support in the positive feedback breath type.

22. The method of claim 16, further comprising:

delivering ventilation based on a positive feedback breath type;

implementing a basal level of support for the positive feedback breath type after the step of detecting respiratory fatigue.

23. The method of claim 22, wherein the basal level of support is at least 5 cmH₂O.

24. The method of claim 22, further comprising:

monitoring for a rested fatigue indicator after a predetermined rest time, wherein the predetermined rest time begins the step of implementing the basal level of support is performed;

comparing the rested fatigue indicator to the baseline;

determining that the detected respiratory fatigue was mitigated by step of implementing the basal level of support based on the step of comparing the rested fatigue indicator to the baseline.

25. The method of claim 16, further comprising:

delivering ventilation based on a breath type selected from a group of a proportional assist (PA) breath type and diaphragmatic electromyography adjusted (DEA) breath type; and

delivering ventilation based on a non-positive feedback breath type after the step of detecting respiratory fatigue.

26. The method of claim 16, wherein the monitored at least one fatigue indicator and the corresponding fatigue threshold are selected from a group comprising:

work of breathing decrease below the baseline,

the work of breathing increases above the baseline followed by a decrease below the baseline,

PaCO₂ increases by at least 10 mmHg from the baseline,

VCO₂ decreases by more than 20% from the baseline,

EMG of an accessory muscle indicates use of the accessory muscle,

E_di decreases by at least 25% from the baseline,

E_di stays the same while velocity of muscle shortening decreases below the baseline,

P_di decreases by at least 10% from the baseline,

P_di,max decreases by at least 20% from the baseline,

P_i,max decreases by at least 20% from the baseline,

a velocity of muscle shortening decreases at least 25% from the baseline,

EMG time domain is less than 50 uV,

EMG frequency domain decreases by more than 20% from the baseline,

P_esoph decreases by at least 10% from the baseline,

P_di Maximum Relaxation Rate decreases by at least 20% from the baseline,

P_mus Maximum Relaxation Rate decreases by at least 20% from the baseline,

presence of paradoxical breathing,

V_{e alv} decreases by at least 20% from the baseline,

respiration rate increases above 35 breaths a minute,

respiration rate increases by at least 25% from the baseline followed by a decrease,

V_t/T_i decreases by 30% from the baseline,

V_d/V_t increases by 20% from the baseline,

V_d/V_t is greater than 40% from the baseline,

P_0.1 increases above 4 cm of H₂O and then decreases by at least 2 cm of H₂O,

diaphragmatic position becomes flattened,

cardiac output does not increase with an increasing load,

V_t is below 4 mL/kg,

diaphragm movement imaging shows reduced movement compared to the baseline,

alternating abdominal/rib cage muscle contractions occur or increase in frequency compared to the baseline,

BIS LOS is normal,

RSBI increases above 105,

P_di/P_{di max} is above 40%,

T_i/T_tot is greater than 40%,

P_tid increases above 0.15,

T_i/T_tot/P_di/P_dimax is greater than 40%,

E_di increases while E_phr increases and P_di decreases,

the P_di,max increases from the baseline,

the P_i,max increases from the baseline,

E_di increases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, an increase in P_at, and a decrease in MV occurs, and

P_mus decreases from the baseline and at least one of a decrease in V_t, a decrease in VCO₂, a decrease in SpO₂, and a decrease in MV occurs.

27. A ventilator system comprising:

a pressure generating system adapted to generate a flow of breathing gas;

a ventilation tubing system including a patient interface for connecting the pressure generating system to a patient;

a plurality of sensors operatively coupled to at least one of the pressure generating system, the patient, and the ventilation tubing system, wherein the plurality of sensors monitor a plurality of parameters to generate sensor output;

a baseline module determines a baseline for at least one fatigue indicator and determines a change in the at least one fatigue indicator from the baseline based on the sensor output;

a fatigue module compares the change to a corresponding fatigue threshold and determines that the patient is fatigued based on the comparison,

wherein the fatigue module after determining that the patient is fatigued instructs the pressure generating system to deliver a baseline level of support for a predetermined rest time,

wherein the fatigue module after the predetermined rest time determines a rested fatigue indicator based on the sensor output, and

wherein the fatigue module compares the rested fatigue indicator to the baseline and confirms that the patient was fatigued based on the comparison of the rested fatigue indicator to the baseline;

a notification module determines an appropriate notification; and

a graphical user interface displays the appropriate notification received from the notification module, wherein the appropriate notification notifies a clinician that the fatigue module determined that the patient is fatigued.