Adaptive Support Ventilation in Acute Respiratory Distress Syndrome (ARDS)

The purpose of this protocol is to compare standard of care lung protective ventilation settings with an automated ventilator setting, called Adaptive Support Ventilation (ASV), in patients with acute respiratory distress syndrome (ARDS). This study will compare measurements (i.e. tidal volumes, driving pressure, respiratory rate (RR), compliance, peak airway pressures, plateau pressures, PEEP) with each ventilator technique, and will measure esophageal pressures to compare transpulmonary and respiratory system mechanics.

Study Overview

• Status: Completed
• Conditions: Acute Respiratory Distress Syndrome
• Intervention / Treatment: Other: ASV; Other: Lung Protective Ventilation

Detailed Description

This study will compare two different modes of mechanical ventilation: standard lung protective controlled mandatory ventilation and Adaptive Support Ventilation. The investigators will enroll adult patients with ARDS who are mechanically ventilated and admitted to intensive care units, capturing a population with respiratory failure and significant critical illness. Patient mechanics during each ventilation strategy will be compared before and after crossover.

After obtaining informed consent, the investigators will place an esophageal balloon which will be used for simultaneous measurements of airway pressures (Pao) and esophageal pressures (Pes), to estimate transpulmonary pressures (PL = Pao - Pes), while also measuring Flow and Volume. Use of esophageal balloon catheters is common practice in the ICUs, and standard of care at Beth Israel Deaconess Medical Center is to use these balloons in patients with ARDS. Both the respiratory therapy and physician staff are very comfortable with placement and use. The esophageal balloon will be left in place until extubation. If the balloon is dislodged or removed for clinical purposes, it will not be replaced solely for research purposes unless it occurs on the first day of study measurements.

Patients will then be randomized to be switched to ASV immediately or to be maintained on their current lung protective ventilation settings.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02215
      • Beth Israel Deaconess Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Patients ≥ 18 years of age
2. Receiving mechanical ventilation in an intensive care unit

3. ARDS, as defined by the Berlin definition:

   1. Hypoxemic respiratory failure with PaO2 / FiO2 ratio < 300 mmHg
   2. Bilateral alveolar/interstitial infiltrates on chest x-ray, with opacities not present for more than 7 days
   3. Respiratory failure not fully explained by cardiac failure or fluid overload
   4. Intubation on mechanical ventilation and receiving PEEP ≥ 5 cm H2O
4. Receiving mechanical ventilation from a Hamilton ventilator, on a controlled mode of ventilation.

Exclusion Criteria:

1. Clinical team refusal
2. Esophageal injury or contraindication precluding placement of the esophageal balloon

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: ASV; Patients in this arm will have the ventilator adjusted per results of recent arterial blood gas. Esophageal balloon placement will be confirmed. Study team will measure several tidal breaths, end-expiratory and end-inspiratory ventilator holds. Then PEEP will be adjusted to achieve desired end-expiratory transpulmonary pressures, Fraction of Inspired Oxygen (FiO2) adjusted as needed to achieve SpO2>95%, and Tidal Volume (Vt) adjusted to 6cc/kg (IBW). Respiratory Rate (RR) will be adjusted to target the same minute ventilation achieved prior to any change in Vt. Patients will then be switched to ASV mode. The percentage minute volume (%minVol) will be adjusted to target the same minute ventilation as was achieved before the change. Settings will be maintained for approximately 1-2 hours, after which breath hold measurements will be repeated and another blood gas drawn.	Other: ASV; Adaptive Support Ventilation; Other Names: Adaptive Support Ventilation
ACTIVE_COMPARATOR: Lung Protective Ventilation; Patients in this arm will have the ventilator adjusted per results of recent arterial blood gas. Esophageal balloon placement will be confirmed. Study team will measure several tidal breaths, end-expiratory and end-inspiratory ventilator holds. Then PEEP will be adjusted to achieve desired end-expiratory transpulmonary pressures, Fraction of Inspired Oxygen (FiO2) adjusted as needed to achieve SpO2>95%, and Tidal Volume (Vt) adjusted to 6cc/kg (IBW). Respiratory Rate (RR) will be adjusted (while leaving the Vt at 6cc/kg) to achieve the same minute ventilation. Patients will then be maintained on their current lung protective ventilation settings for approximately 1-2 hours, after which breath hold measurements will be repeated and another blood gas drawn.	Other: Lung Protective Ventilation; Targeted tidal volume of 6cc/Kg, Positive Inspiratory Pressure titrated per ARDS guidelines.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tidal Volume	Lung tidal volume in both ventilation modes (mL)	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Driving Pressure (cmH20)	Driving pressure in both ventilation modes	Day 1
Respiratory rate (BPM)	Respiratory Rate in both ventilation modes	Day 1
Oxygenation (SpO2%)	Oxygenation (SpO2%) in both ventilation modes	Day 1
CO2 clearance	CO2 clearance in both ventilation modes	Day 1
Blood Gas pH	Blood Gas pH (units) in both ventilation modes	Day 1
Blood Gas Partial Pressure of Oxygen	Partial pressure of oxygen (PaO2) (mm Hg) in both ventilation modes	Day 1
Blood Gas Partial Pressure of Carbon Dioxide (PaCO2) (mm Hg)	Partial Pressure of Carbon Dioxide (PaCO2) (mm Hg) in both ventilation modes	Day 1
Composite measure (lung protectiveness) - Asynchrony index	Asynchrony index	Day 1
Composite measure (lung protectiveness) - Number of Adjustments	Number of Adjustments	Day 1
Composite measure (lung protectiveness) - Time with tidal volumes under 6cc/kg	Time spent with tidal volumes less than or equal to 6cc/kg	Day 1
Composite measure (lung protectiveness) - Driving pressures less than 15	Time spent at or under Driving pressures less than 15	Day 1
Composite measure (lung protectiveness) - Plateau Pressure <30	Time spent at or under Plateau Pressure <30	Day 1
Composite measure (lung protectiveness) - Oxygen saturation by pulse Oximetry (SpO2) >88%	Time spent at or under Oxygen saturation by pulse Oximetry (SpO2) >88%	Day 1
Time to extubation	Time to liberation from mechanical ventilation (days)	30 Days
ICU length of stay	Time to ICU discharge (days)	90 Days

Collaborators and Investigators

• Sponsor: Beth Israel Deaconess Medical Center

Study record dates

Study Major Dates

• Study Start (ACTUAL): February 14, 2018
• Primary Completion (ACTUAL): November 2, 2020
• Study Completion (ACTUAL): January 31, 2021

Study Registration Dates

• First Submitted: August 15, 2018
• First Submitted That Met QC Criteria: October 19, 2018
• First Posted (ACTUAL): October 23, 2018

Study Record Updates

• Last Update Posted (ACTUAL): March 8, 2022
• Last Update Submitted That Met QC Criteria: March 7, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: ARDS; Mechanical Ventilation; Esophageal Pressure; Transpulmonary Pressure; Adaptive Support Ventilation
• Additional Relevant MeSH Terms: Pathologic Processes; Respiratory Tract Diseases; Respiration Disorders; Lung Diseases; Disease; Infant, Newborn, Diseases; Lung Injury; Infant, Premature, Diseases; Syndrome; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn; Acute Lung Injury
• Other Study ID Numbers: 2017P000596

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No