Prone Positioning and Spontaneous Breathing

Study Overview
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Brief Summary
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Spontaneous breathing during mechanical ventilation has been recommended in patients with ARDS and is currently used. in part because oxygenation is better and there is a lower risk of diaphragm dysfunction due to disuse. The other approach to minimizing lung injury from spontaneous effort is the use of neuromuscular blockade; an early and short term (48 hours) of neuromuscular blockade in patients with severe ARDS has been shown to decrease inflammation and to improve survival. The investigators propose a pilot study to test the feasibility and the physiological effects of allowing spontaneous breathing in the prone position in patients with ARDS.

Detailed Description
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The multi-center feasibility study will enroll 12 adult ARDS patients from the Intensive Care Units (ICUs) in Japan and Peru. Informed consent will be obtained from the patient or legally authorized substitute decision maker. Moderate-to-severe ARDS patients who are planned to turn to prone positioning, based on the attending physician's decisions will be included. Prior to initiating the protocol, patients will be sedated deeply with sedatives and/or opioids. Ventilator settings, physiological data, esophageal pressure and diaphragm activity will be recorded and physiological measurements will be collected for 5 minutes in supine (Measurement 1: Supine + spontaneous effort) . Patients will be paralyzed with a continuous infusion of rocuronium, and Measurement 2 (Supine + paralysis) will be recorded. The critical care team in the ICU change the position from supine to prone. After waiting for at least 1 hour in prone positioning, Measurement 3 (Prone + paralysis) will be recorded. Continuous infusion of rocuronium will be gradually decreased (and can be terminated) until spontaneous breathing will be observed without reaching an excessive level. The presence of spontaneous breathing will be evaluated by the negative swing of esophageal pressure, and Measurement 5 (Prone + spontaneous breathing) will be recorded.

Official Title
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Prone Positioning and Spontaneous Breathing: a Feasibility Study

Conditions
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Critical Illness, ARDS

Intervention / Treatment
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* Procedure: Supine + spontaneous effort
* Procedure: Supine + paralysis
* Procedure: Prone + paralysis
* Procedure: Prone + spontaneous breathing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients ≧ 18 years old Patients with moderate-to-severe ARDS as per the Berlin definition Patients with esophageal balloon manometry Patients planned to turn to prone positioning, based on the attending physician's decisions Exclusion Criteria: Contraindication for prone positioning, referring to a previous randomized clinical trial Intracranial pressure >30 mm Hg or cerebral perfusion pressure <60 mmHg Massive hemoptysis requiring an immediate surgical or interventional radiology procedure Tracheal surgery or sternotomy during the previous 15 days Serious facial trauma or facial surgery during the previous 15 days Cardiac pacemaker inserted in the last 2 days Unstable spine, femur, or pelvic fractures Major hemodynamic instability: Mean arterial pressure lower than 60 mm Hg despite adequate fluid resuscitation and two vasopressors or increase of vasopressor dose by 30% in the previous 6 hours. Contraindication to EIT electrode placement Burns, chest wall bandaging limiting electrode placement, pacemaker Clinical judgement of the attending physician against proning and/or spontaneous breathing

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
Intervention Model: Sequential Assignment
Interventional Model Description: Measurement 1 (Supine + spontaneous effort) , Measurement 2 (Supine + paralysis) , Measurement 3 (Prone + paralysis) , Measurement 4 (Prone + spontaneous breathing)
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: study arm<br>all patients will receive all four intervention in the same sequential method | Procedure: Supine + spontaneous effort<br>* without muscle paralysis in supine position<br>Procedure: Supine + paralysis<br>* administer muscle paralysis in supine position<br>Procedure: Prone + paralysis<br>* change the patient position from supine to prone with muscle paralysis<br>Procedure: Prone + spontaneous breathing<br>* cease the paralysis in supine position<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| spontaneous breathing | The intensity of spontaneous breathing during supine vs. prone estimated by an esophageal manometry | Through study completion (up to 24 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| inflammatory cytokines | IL-6 levels | Through study completion (up to 24 hours) | 
| Trans-pulmonary pressure | Trans-pulmonary pressure | Through study completion (up to 24 hours) | 
| electrical activity of diaphragm | electrical activity of diaphragm | Through study completion (up to 24 hours) | 
| gas exchange | gas exchange | Through study completion (up to 24 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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spontaneous breathing, prone position, muscle paralysis