Spontaneous Ventilation
Conditions
Brief summary
This study is being done to further the investigators' knowledge of the EIT system and to see if measures between two non-invasive ventilation systems routinely used clinically are equivalent.
Detailed description
Mechanical ventilation is life-saving technology but it can also inadvertently induce lung injury and increase morbidity and mortality. There currently is not an easy method of assessing the impact ventilator settings have on the degree of lung inflation. Computed tomography (CT), the gold standard for visually monitoring lung function, can provide detailed regional information of the lung. Unfortunately, it necessitates moving critically ill patients to a special diagnostic room and involves exposure to radiation like an X-ray. A technique introduced in the 1980's, electrical impedance tomography (EIT), can non-invasively provide similar monitoring of lung function, and without the exposure to radiation. This imaging technique applies small alternating currents of electricity to surface electrodes to construct cross-sectional images of the lung. Over that past several decades EIT has moved from the research lab to commercially available devices that are used at the bedside. EIT has also been applied to study the effects of various devices used to provide non-invasive ventilation. EIT may prove useful to optimally adjust non-invasive ventilation settings to improve ventilation and oxygenation. One such EIT system is manufactured by Draeger Medical. It is available in Europe and Canada but is not yet FDA approved for use in the United States. This study is being done with healthy volunteers to further the investigators' knowledge of the EIT system and to see if measures between two non-invasive ventilation systems routinely used clinically are equivalent. As this is a preliminary study looking at the EIT system vs 2 other devices, outcomes measures may be modified as the study progresses.
Interventions
Application of various levels of positive pressure
Sponsors
University of Michigan
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Age 18 years or older
Exclusion criteria
* Use of a cardiac pacemaker, an implantable cardioverter-defibrillator (ICD) or any other active implants
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Global Tidal Variation (TID) | 1 day | TID is the distribution of ventilation for a breath averaged over a defined section, the entire lung. TID is analogous to the tidal volume. Baseline is defined to be 100% and other measures are in comparison to baseline (eg, a value of 102 represents a 2% increase from baseline). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Regional Tidal Variation: Dorsal | 1 day | Distribution of ventilation for a breath averaged over a defined section, the dorsal lung regions. Reflects the percent of tidal volume distributed to that area. |
| Regional Tidal Variation: Ventral | 1 day | Distribution of ventilation for a breath averaged over a defined section, the ventral lung regions. Reflects the percent of tidal volume distributed to that area. |
| Global Change in End-expiratory Lung Impedance (EELI) | 1 day | EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device. |
| Regional Change in EELI: Dorsal | 1 day | EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device |
| Regional Change in EELI: Ventral | 1 day | EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device |
Countries
United States
Participant flow
Recruitment details
Volunteers were solicited via word of mouth from the medical staff and the respiratory therapy staff at our university hospital. Enrollment occurred from February 1, 2018 through March 27, 2018.
Pre-assignment details
All volunteers were screened for any contraindication to applying the electrical impedance tomography device (pacemaker, etc) before signing an informed consent document. No volunteer had such contraindications and all were successfully studied.
Participants by arm
| Arm | Count |
|---|---|
| Device 1, Then Device 2 Testing by applying noninvasive positive pressure ventilation via two different bilevel positive airway pressure (BiPAP) devices: Respironics V-60 (Device 1) and Drager V-500 (Device 2)
Device 1 is a continuous high flow, blower type of generator. | 12 |
| Device 2, Then Device 1 Testing by applying noninvasive positive pressure ventilation via two different bilevel positive airway pressure (BiPAP) devices: Respironics V-60 (Device 1) and Drager V-500 (Device 2).
Device 2 is a critical care ventilator that has a specific NPPV mode. | 8 |
| Total | 20 |
Baseline characteristics
| Characteristic | Device 2, Then Device 1 | Total | Device 1, Then Device 2 |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 1 Participants | 2 Participants | 1 Participants |
| Age, Categorical Between 18 and 65 years | 7 Participants | 18 Participants | 11 Participants |
| Age, Continuous | 43.8 years STANDARD_DEVIATION 14.4 | 42.6 years STANDARD_DEVIATION 1.3 | 41.8 years STANDARD_DEVIATION 13.2 |
| Race and Ethnicity Not Collected | — | 0 Participants | — |
| Region of Enrollment United States | 8 participants | 20 participants | 12 participants |
| Sex: Female, Male Female | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 8 Participants | 20 Participants | 12 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 20 |
| other Total, other adverse events | 0 / 20 |
| serious Total, serious adverse events | 0 / 20 |
Outcome results
Primary
Global Tidal Variation (TID)
TID is the distribution of ventilation for a breath averaged over a defined section, the entire lung. TID is analogous to the tidal volume. Baseline is defined to be 100% and other measures are in comparison to baseline (eg, a value of 102 represents a 2% increase from baseline).
Time frame: 1 day
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Global Tidal Variation (TID) | Baseline (no pressure) | 100 percentage of baseline | Standard Deviation 0 |
| Respironics V-60 | Global Tidal Variation (TID) | Continuous Positive Airway Pressure (CPAP) 5 | 101.7 percentage of baseline | Standard Deviation 16.4 |
| Respironics V-60 | Global Tidal Variation (TID) | Pressure Support (PS) 5, CPAP 5 | 131.8 percentage of baseline | Standard Deviation 39.5 |
| Respironics V-60 | Global Tidal Variation (TID) | PS 5, CPAP 10 | 128.6 percentage of baseline | Standard Deviation 47 |
| Draeger V-500 | Global Tidal Variation (TID) | PS 5, CPAP 10 | 126.4 percentage of baseline | Standard Deviation 45.5 |
| Draeger V-500 | Global Tidal Variation (TID) | Baseline (no pressure) | 100 percentage of baseline | Standard Deviation 0 |
| Draeger V-500 | Global Tidal Variation (TID) | Pressure Support (PS) 5, CPAP 5 | 118.1 percentage of baseline | Standard Deviation 32.8 |
| Draeger V-500 | Global Tidal Variation (TID) | Continuous Positive Airway Pressure (CPAP) 5 | 109.1 percentage of baseline | Standard Deviation 22.1 |
p-value: 0.26ANOVA
Secondary
Global Change in End-expiratory Lung Impedance (EELI)
EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device.
Time frame: 1 day
Population: Because one subject's EELI data did not record properly on device 2, that subject's data was excluded from analysis for both arms.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Global Change in End-expiratory Lung Impedance (EELI) | Baseline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Respironics V-60 | Global Change in End-expiratory Lung Impedance (EELI) | CPAP 5 | 45.9 percentage change from baseline | Standard Deviation 28.9 |
| Respironics V-60 | Global Change in End-expiratory Lung Impedance (EELI) | PS 5, CPAP 5 | 53.3 percentage change from baseline | Standard Deviation 33.3 |
| Respironics V-60 | Global Change in End-expiratory Lung Impedance (EELI) | PS 5, CPAP 10 | 135.2 percentage change from baseline | Standard Deviation 65.6 |
| Draeger V-500 | Global Change in End-expiratory Lung Impedance (EELI) | PS 5, CPAP 10 | 141.0 percentage change from baseline | Standard Deviation 101.3 |
| Draeger V-500 | Global Change in End-expiratory Lung Impedance (EELI) | Baseline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Draeger V-500 | Global Change in End-expiratory Lung Impedance (EELI) | PS 5, CPAP 5 | 61.0 percentage change from baseline | Standard Deviation 53.7 |
| Draeger V-500 | Global Change in End-expiratory Lung Impedance (EELI) | CPAP 5 | 70.7 percentage change from baseline | Standard Deviation 68.9 |
p-value: 0.283ANOVA
Secondary
Regional Change in EELI: Dorsal
EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device
Time frame: 1 day
Population: Because one subject's EELI data did not record properly on device 2, that subject's data was excluded from analysis for both arms.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Regional Change in EELI: Dorsal | Baleline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Respironics V-60 | Regional Change in EELI: Dorsal | CPAP 5 | 14.9 percentage change from baseline | Standard Deviation 13.8 |
| Respironics V-60 | Regional Change in EELI: Dorsal | PS 5, CPAP 5 | 17.5 percentage change from baseline | Standard Deviation 15.8 |
| Respironics V-60 | Regional Change in EELI: Dorsal | PS 5, CPAP 10 | 44.9 percentage change from baseline | Standard Deviation 27.3 |
| Draeger V-500 | Regional Change in EELI: Dorsal | PS 5, CPAP 10 | 36.4 percentage change from baseline | Standard Deviation 43.8 |
| Draeger V-500 | Regional Change in EELI: Dorsal | Baleline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Draeger V-500 | Regional Change in EELI: Dorsal | PS 5, CPAP 5 | 12.0 percentage change from baseline | Standard Deviation 26.3 |
| Draeger V-500 | Regional Change in EELI: Dorsal | CPAP 5 | 18.7 percentage change from baseline | Standard Deviation 31.2 |
p-value: 0.204ANOVA
Secondary
Regional Change in EELI: Ventral
EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device
Time frame: 1 day
Population: Because one subject's EELI data did not record properly on device 2, that subject's data was excluded from analysis for both arms.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Regional Change in EELI: Ventral | Baseline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Respironics V-60 | Regional Change in EELI: Ventral | CPAP 5 | 31.0 percentage change from baseline | Standard Deviation 19.1 |
| Respironics V-60 | Regional Change in EELI: Ventral | PS 5, CPAP 5 | 35.8 percentage change from baseline | Standard Deviation 21.9 |
| Respironics V-60 | Regional Change in EELI: Ventral | PS 5, CPAP 10 | 90.3 percentage change from baseline | Standard Deviation 43.2 |
| Draeger V-500 | Regional Change in EELI: Ventral | PS 5, CPAP 10 | 104.5 percentage change from baseline | Standard Deviation 72.8 |
| Draeger V-500 | Regional Change in EELI: Ventral | Baseline (no pressure) | 0.00 percentage change from baseline | Standard Deviation 0 |
| Draeger V-500 | Regional Change in EELI: Ventral | PS 5, CPAP 5 | 49.0 percentage change from baseline | Standard Deviation 40.2 |
| Draeger V-500 | Regional Change in EELI: Ventral | CPAP 5 | 52.0 percentage change from baseline | Standard Deviation 47.9 |
p-value: 0.136ANOVA
Secondary
Regional Tidal Variation: Dorsal
Distribution of ventilation for a breath averaged over a defined section, the dorsal lung regions. Reflects the percent of tidal volume distributed to that area.
Time frame: 1 day
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Regional Tidal Variation: Dorsal | Baseline (no pressure) | 56.8 percentage of global TID | Standard Deviation 14 |
| Respironics V-60 | Regional Tidal Variation: Dorsal | PS 5, CPAP 5 | 69.1 percentage of global TID | Standard Deviation 31.1 |
| Respironics V-60 | Regional Tidal Variation: Dorsal | CPAP 5 | 59.0 percentage of global TID | Standard Deviation 19.4 |
| Respironics V-60 | Regional Tidal Variation: Dorsal | PS 5, CPAP 10 | 71.3 percentage of global TID | Standard Deviation 39.8 |
| Draeger V-500 | Regional Tidal Variation: Dorsal | CPAP 5 | 60.9 percentage of global TID | Standard Deviation 18.4 |
| Draeger V-500 | Regional Tidal Variation: Dorsal | Baseline (no pressure) | 56.9 percentage of global TID | Standard Deviation 12.4 |
| Draeger V-500 | Regional Tidal Variation: Dorsal | PS 5, CPAP 10 | 67.0 percentage of global TID | Standard Deviation 32.9 |
| Draeger V-500 | Regional Tidal Variation: Dorsal | PS 5, CPAP 5 | 61.5 percentage of global TID | Standard Deviation 22 |
p-value: 0.342ANOVA
Secondary
Regional Tidal Variation: Ventral
Distribution of ventilation for a breath averaged over a defined section, the ventral lung regions. Reflects the percent of tidal volume distributed to that area.
Time frame: 1 day
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Respironics V-60 | Regional Tidal Variation: Ventral | Baseline (no pressure) | 43.2 percentage of global TID | Standard Deviation 14 |
| Respironics V-60 | Regional Tidal Variation: Ventral | CPAP 5 | 42.62 percentage of global TID | Standard Deviation 12.8 |
| Respironics V-60 | Regional Tidal Variation: Ventral | PS 5, CPAP 5 | 61.5 percentage of global TID | Standard Deviation 22 |
| Respironics V-60 | Regional Tidal Variation: Ventral | PS 5, CPAP 10 | 67.0 percentage of global TID | Standard Deviation 32.9 |
| Draeger V-500 | Regional Tidal Variation: Ventral | PS 5, CPAP 10 | 59.5 percentage of global TID | Standard Deviation 24.9 |
| Draeger V-500 | Regional Tidal Variation: Ventral | Baseline (no pressure) | 43.2 percentage of global TID | Standard Deviation 12.5 |
| Draeger V-500 | Regional Tidal Variation: Ventral | PS 5, CPAP 5 | 56.7 percentage of global TID | Standard Deviation 25.7 |
| Draeger V-500 | Regional Tidal Variation: Ventral | CPAP 5 | 48.2 percentage of global TID | Standard Deviation 21 |
p-value: 0.184ANOVA