Acute Respiratory Distress Syndrome, ARDS
Conditions
Keywords
Electrical Impedance Tomography, Ventilator, Lung, Respiration
Brief summary
Doctors follow a standard ventilator management strategy when making adjustments to the breathing machine to optimize the amount of oxygen into the lungs. The purpose of this study is to assess whether the EIT (electrical impedance tomography) device can be an additional useful tool for ventilator management and identifying the ideal positive end-expiratory pressure (PEEP).
Interventions
OTHERUsual care
Intervention is the standard basic lung protective ventilation strategy used at the University Hospital Respiratory Care at Michigan Medicine.
DEVICEPEEP titration by EIT
PEEP Titration procedure involves two phases: a recruitment phase followed by a gradual reduction in the end-expiratory pressure phase (Decremental PEEP).
Sponsors
University of Michigan
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Endotracheal ventilation for \< 1 week (168 hours) * Presence of all of the following conditions for \< 48 hours i. Partial pressure of oxygen to percentage of inspired oxygen (PaO2/FiO2) \< 150 with PEEP \> 5 cm water for \> 30 min. ii. bilateral opacities not fully explained by effusions, lobar/lung collapse, or nodules iii. respiratory failure not fully explained by cardiac failure or fluid overload -All criteria listed in (3) developed within 1 week of a known clinical insult or new or worsening respiratory symptoms
Exclusion criteria
* Lack of informed consent * Known pregnancy * Extracorporeal membrane oxygenation (ECMO) use * Severe chronic respiratory disease requiring home oxygen therapy or ventilation * Calculated BMI of greater than 50
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Mechanical Power | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment. | Mechanical power (MP) is the energy imparted to the lung from the mechanical ventilator. It is calculated as listed below, where respiratory rate = RR, tidal volume = TV, Ppeak = peak airway pressure, Pplat = plateau airway pressure and PEEP = positive end-expiratory pressure. Mechanical power determined for the difference between Treatment 1 and Treatment 2. Values shown represent data gathered at the end of the designated assignment listed below, regardless of whether that assignment was Treatment 1 or Treatment 2. MP = 0.098 X RR X TV (Ppeak-\[Pplat-PEEP/2\]) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Lung Inflammation as Measured by Physiologic Parameter: Plateau Pressure | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment. | Plateau pressure is a measurement of lung compliance and is the airway pressure obtained during a brief inspiratory hold after delivering a tidal volume breath during invasive mechanical ventilation. Plateau pressure determined for the difference between Intervention 1 and Intervention 2 |
| Lung Inflammation as Measured by Physiologic Parameter: Driving Pressure | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment. | Driving pressure is the force of airway push into the lung while receiving invasive mechanical ventilation and is calculated as Plateau pressure - Positive end-expiratory pressure. Driving pressure determined for the difference between Intervention 1 and Intervention 2 |
| Change in Lung Inflammation as Measured by Physiologic Parameter: Static Compliance | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment. | Static lung compliance is a measurement of lung stiffness due to disease, with a lower compliance representing stiffer lungs. It is calculated as: Tidal volume / (Plateau pressure - PEEP). Static compliance determined for the difference between Intervention 1 and Intervention 2 |
| Change in Lung Inflammation as Measured by Physiologic Parameter: Partial Pressure of Arterial Oxygen/Fraction of Inspired Oxygen (P/F Ratio) | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment. | P/F ratio is a measurement of oxygenation and, where arterial oxygen in mmHg is PaO2 and percentage of inspired oxygen is FiO2. It calculated as: PaO2/FiO2. P/F ratio determined for the difference between Intervention 1 and Intervention 2 |
| Dynamic Compliance (Cdyn) | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment. | Dynamic compliance is a measurement of the resistance of the lungs and airways to gas installation from the mechanical ventilator and is measured as Peak airway pressure / Plateau airway pressure - PEEP). Dynamic compliance determined for the difference between Intervention 1 and Intervention 2. |
| Change in Compliance Over the Last 20% of Inspiration (C20/Dyn) | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment. | C20 is the compliance that results when only the upper 20% of the applied pressure range is taken into account. The C20/Dyn ratio appears to effectively quantitate evidence of lung over distention during mechanical ventilation. This is a unit-less measure as both numerator and denominator are measured in cm water. C20/dyn determined for the difference between Intervention 1 and Intervention 2. |
| Ultrasound Surrogates of Lung Aeration | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment. | Lung ultrasound inflation scores are calculated by summing regional scores (0-3 points), with higher scores indicating worse condition of the lung. Scores were obtained in six regions of each lung (i.e., up and down anterior, medial, and posterior chest wall). This is a unit-less measure. Ultrasound lung surrogates of lung inflation determined for the difference between Intervention 1 and Intervention 2. |
| Partial Pressure of Arterial Oxygen (PaO2) | Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment. | PaO2 is the partial pressure of arterial oxygen measured in mmHg. PaO2 determined for the difference between Intervention 1 and Intervention 2. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Usual Care Then PEEP Titration by EIT Patients in the usual care first group will continue to receive mechanical ventilation according to the University of Michigan ARDS protocol high-PEEP arm
Usual care: Intervention is the standard basic lung protective ventilation strategy used at the University Hospital Respiratory Care at Michigan Medicine.
PEEP titration by EIT: PEEP Titration procedure involves two phases: a recruitment phase followed by a gradual reduction in the end-expiratory pressure phase (Decremental PEEP). | 6 |
| PEEP Titration by EIT Then Usual Care Patients in the high PEEP titration by EIT first will have receive ventilation with a PEEP determined by EIT titration procedure.
Usual care: Intervention is the standard basic lung protective ventilation strategy used at the University Hospital Respiratory Care at Michigan Medicine.
PEEP titration by EIT: PEEP Titration procedure involves two phases: a recruitment phase followed by a gradual reduction in the end-expiratory pressure phase (Decremental PEEP). | 6 |
| Excluded Patients in this arm were excluded per protocol. | 4 |
| Total | 16 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Randomization-Intervention 1 (~6 Hrs) | Physician Decision | 0 | 1 |
| Randomization-Intervention 1 (~6 Hrs) | Prone positioning after baseline data collection | 2 | 1 |
Baseline characteristics
| Characteristic | Usual Care Then PEEP Titration by EIT | Total | Excluded | PEEP Titration by EIT Then Usual Care |
|---|---|---|---|---|
| Age, Continuous | 59.5 years | 60.5 years | 67 years | 62 years |
| Ethnicity (NIH/OMB) Hispanic or Latino | 1 Participants | 2 Participants | 1 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 5 Participants | 14 Participants | 3 Participants | 6 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 1 Participants | 2 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) White | 5 Participants | 14 Participants | 3 Participants | 6 Participants |
| Region of Enrollment United States | 6 Participants | 16 Participants | 4 Participants | 6 Participants |
| Sex: Female, Male Female | 2 Participants | 6 Participants | 3 Participants | 1 Participants |
| Sex: Female, Male Male | 4 Participants | 10 Participants | 1 Participants | 5 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 16 | 0 / 16 |
| other Total, other adverse events | 0 / 16 | 0 / 16 |
| serious Total, serious adverse events | 0 / 16 | 0 / 16 |
Outcome results
Primary
Mechanical Power
Mechanical power (MP) is the energy imparted to the lung from the mechanical ventilator. It is calculated as listed below, where respiratory rate = RR, tidal volume = TV, Ppeak = peak airway pressure, Pplat = plateau airway pressure and PEEP = positive end-expiratory pressure. Mechanical power determined for the difference between Treatment 1 and Treatment 2. Values shown represent data gathered at the end of the designated assignment listed below, regardless of whether that assignment was Treatment 1 or Treatment 2. MP = 0.098 X RR X TV (Ppeak-\[Pplat-PEEP/2\])
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment.
Population: 3 participants in whom prone ventilation was initiated were excluded. 1 additional participant was excluded due to physician withdrawal from the trial. The remaining participants received invasive mechanical ventilation in the supine position for the duration of the protocol.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PEEP | Mechanical Power | 1.87 J/min | Standard Deviation 1.61 |
| Usual Care | Mechanical Power | -2.50 J/min | Standard Deviation 3.7 |
p-value: 0.002t-test, 2 sided
Secondary
Change in Compliance Over the Last 20% of Inspiration (C20/Dyn)
C20 is the compliance that results when only the upper 20% of the applied pressure range is taken into account. The C20/Dyn ratio appears to effectively quantitate evidence of lung over distention during mechanical ventilation. This is a unit-less measure as both numerator and denominator are measured in cm water. C20/dyn determined for the difference between Intervention 1 and Intervention 2.
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment.
Population: C20/Dyn was not recorded due to the attempt of investigative personnel to limit time exposure to COVID-19 in most study participants.
Secondary
Change in Lung Inflammation as Measured by Physiologic Parameter: Partial Pressure of Arterial Oxygen/Fraction of Inspired Oxygen (P/F Ratio)
P/F ratio is a measurement of oxygenation and, where arterial oxygen in mmHg is PaO2 and percentage of inspired oxygen is FiO2. It calculated as: PaO2/FiO2. P/F ratio determined for the difference between Intervention 1 and Intervention 2
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PEEP | Change in Lung Inflammation as Measured by Physiologic Parameter: Partial Pressure of Arterial Oxygen/Fraction of Inspired Oxygen (P/F Ratio) | 25.14 ratio | Standard Deviation 27.11 |
| Usual Care | Change in Lung Inflammation as Measured by Physiologic Parameter: Partial Pressure of Arterial Oxygen/Fraction of Inspired Oxygen (P/F Ratio) | -0.89 ratio | Standard Deviation 60.05 |
p-value: 0.2t-test, 2 sided
Secondary
Change in Lung Inflammation as Measured by Physiologic Parameter: Plateau Pressure
Plateau pressure is a measurement of lung compliance and is the airway pressure obtained during a brief inspiratory hold after delivering a tidal volume breath during invasive mechanical ventilation. Plateau pressure determined for the difference between Intervention 1 and Intervention 2
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PEEP | Change in Lung Inflammation as Measured by Physiologic Parameter: Plateau Pressure | 2.06 cm H2O | Standard Deviation 1.88 |
| Usual Care | Change in Lung Inflammation as Measured by Physiologic Parameter: Plateau Pressure | -2.48 cm H2O | Standard Deviation 3.22 |
p-value: 0.006t-test, 2 sided
Secondary
Change in Lung Inflammation as Measured by Physiologic Parameter: Static Compliance
Static lung compliance is a measurement of lung stiffness due to disease, with a lower compliance representing stiffer lungs. It is calculated as: Tidal volume / (Plateau pressure - PEEP). Static compliance determined for the difference between Intervention 1 and Intervention 2
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at baseline and end of treatment.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PEEP | Change in Lung Inflammation as Measured by Physiologic Parameter: Static Compliance | 3.24 ml/cm H2O | Standard Deviation 9.85 |
| Usual Care | Change in Lung Inflammation as Measured by Physiologic Parameter: Static Compliance | -4.6 ml/cm H2O | Standard Deviation 5.26 |
p-value: 0.008t-test, 2 sided
Secondary
Dynamic Compliance (Cdyn)
Dynamic compliance is a measurement of the resistance of the lungs and airways to gas installation from the mechanical ventilator and is measured as Peak airway pressure / Plateau airway pressure - PEEP). Dynamic compliance determined for the difference between Intervention 1 and Intervention 2.
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment.
Population: Dynamic compliance was not recorded due to the attempt of investigative personnel to limit time exposure to Coronavirus disease 19 (COVID-19) in most study participants.
Secondary
Lung Inflammation as Measured by Physiologic Parameter: Driving Pressure
Driving pressure is the force of airway push into the lung while receiving invasive mechanical ventilation and is calculated as Plateau pressure - Positive end-expiratory pressure. Driving pressure determined for the difference between Intervention 1 and Intervention 2
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment.
Population: ARDS patients
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| PEEP | Lung Inflammation as Measured by Physiologic Parameter: Driving Pressure | 1.34 cm H2O | Standard Deviation 1.31 |
| Usual Care | Lung Inflammation as Measured by Physiologic Parameter: Driving Pressure | -1.58 cm H2O | Standard Deviation 2.32 |
p-value: 0.003t-test, 2 sided
Secondary
Partial Pressure of Arterial Oxygen (PaO2)
PaO2 is the partial pressure of arterial oxygen measured in mmHg. PaO2 determined for the difference between Intervention 1 and Intervention 2.
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment.
Population: No PaO2 data was obtained or recorded as such. Physicians directly calculated PaO2/FiO2 data shown above in Outcome Measure 2.
Secondary
Ultrasound Surrogates of Lung Aeration
Lung ultrasound inflation scores are calculated by summing regional scores (0-3 points), with higher scores indicating worse condition of the lung. Scores were obtained in six regions of each lung (i.e., up and down anterior, medial, and posterior chest wall). This is a unit-less measure. Ultrasound lung surrogates of lung inflation determined for the difference between Intervention 1 and Intervention 2.
Time frame: Participants received Treatment 1 (either Usual Care or PEEP EIT) for approximately 6 hours after randomization and then received Treatment 2 for an additional 14-18 hours following crossover. Measurement was done at end of treatment.
Population: Lung ultrasound was not recorded due to the attempt of investigative personnel to limit time exposure to COVID-19 in most study participants.