Comparison of Different PEEP Titration Strategies Using Electrical Impedance Tomography in Patients With ARDS

Study Overview
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Brief Summary
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The aim of the this study is to assess the short term physiological effects of 3 ventilation strategies for adult patients with ARDS admitted to intensive care unit. Two of those strategies are based on electrical impedance tomography (EIT) monitoring.

Official Title
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Comparison of Different Positive End-expiratory Pressure Titration Strategies Using ELectrical Impedance Tomography in Patients With Acute Respiratory Distress Syndrome : the DELTA Physiological Study

Conditions
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ARDS (Acute Respiratory Distress Syndrome), Electrical Impedance Tomography (EIT), Positive End Expiratory Pressure (PEEP), Acute Lung Injury

Intervention / Treatment
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* Other: Ventilation strategy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with moderate to severe ARDS, defined by the Berlin consensus, at 12 to 48h from diagnosis PaO2/FiO2 ratio < 150 mmHg Patient affiliated to or beneficiary of a health care plan Consent obtained from patient's SDM Exclusion Criteria: Pneumothorax Contraindication to the insertion of a nasogastric tube with an esophageal balloon Contraindication to the use of Electrical impedance tomography Pregnancy, lactating or parturient woman

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: We use a crossover sequential model, with all 3 strategies tested in both arms. A reference strategy, based on the Express method (PEEP level adjusted to reach a plateau pressure of 28-30 cmH2O), is applied at the begining of the study and during a wash-out period (between the 2 periods of application of the 2 EIT-based strategies). The 2 EIT-based strategies are applied in a randomized order.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: A-B-A-C<br>Four consecutive steps (45 min per step) are tested in the following order: Peep titration strategy according to Express method (A) - Peep titration strategy according to overdistension and collapse estimation (B) - Peep titration strategy according to Express method (A) - Peep titration strategy according to estimation of lung inhomogeneity (C) | Other: Ventilation strategy<br>* Patients are ventilated in randomized order with three different ventilation strategies (A,B and C)<br>|
| Experimental: A-C-A-B<br>Four consecutive steps (45 min per step) are tested in the following order: Peep titration strategy according to Express method (A) - Peep titration strategy according to estimation of lung inhomogeneity (C) - Peep titration strategy according to Express method (A) - Peep titration strategy according to overdistension and collapse estimation (B) | Other: Ventilation strategy<br>* Patients are ventilated in randomized order with three different ventilation strategies (A,B and C)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in PaO2 (mmHg) | As it is a physiological study, all the outcomes will be analyzed with the same importance! | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in PaCO2 (mmHg) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Plateau pressure (cmH2O) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Positive end expiratory pressure (cmH2O) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Expiratory and inspiratory transpulmonary pressure (cmH2O) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Regional ventilation distribution (%) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Center of ventilation (%) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Overdistension and collapsus (%) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Global and regional end expiratory lung impedance changes (IU) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| End expiratory lung volume (mL) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Blood pressure (mmHg) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Heart rate (bpm) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 
| Cardiac output (L/min) | As it is a physiological study, all the outcomes will be analyzed with the same importance | Time : 0 ; 45 minutes ; 90 minutes ; 135 minutes ; 180 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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EIT, ARDS, PEEP titration, Mechanical Ventilation