Postural Recruitment Maneuver in Patients With Acute Respiratory Distress Syndrome Due to COVID-19 Infection

Study Overview
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Brief Summary
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The purpose of this study is to evaluate if a postural recruitment maneuver (PRM) improves the aeration and distribution of lung ventilation in patients with Acute Respiratory Distress Syndrome (ARDS) caused by COVID-19 infection; without the need to reach high airway pressures as in the standard lung recruitment maneuver and / or place the patient in prone position. This strategy could be particularly useful in the context of a major health emergency in centers with limited resources.

Detailed Description
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The PRM is based on the known effect of gravity on transpulmonary pressure (PL). Two principles explain its mechanism of action: 1) the first indicates that atelectasis and poorly ventilated areas of the lung can improve their aeration by putting the lung in the highest position. Opposite lateral decubitus causes that upper lung to have a higher PL and allow a recruiting effect at moderate airway pressures. 2) The second principle is based on Laplace's Law and postulates that once the upper lung is recruited, it remains without lung collapse if a sufficient level of positive end-expiratory pressure (PEEP) is applied. Based on these two precepts, PRM consists of sequentially moving the patient from the supine to the left lateral decubitus to recover the aeration of the right lung. After that, the patient is placed in the right lateral position to recruit the left lung; keeping the right lung without collapse by continuous use of PEEP. Finally, the patient returns to the supine position looking for an improvement in the distribution of ventilation and global pulmonary aeration, with a subsequent improvement in gas exchange and pulmonary mechanics.

Official Title
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Feasibility and Physiological Effects of a Postural Recruitment Maneuver in Patients With Acute Respiratory Distress Syndrome Due to COVID-19 Infection

Conditions
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Sars-CoV2, ARDS

Intervention / Treatment
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* Procedure: Lateral Position (left and right lateral decubitus)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients > 18 years of age Patients with moderate-to-severe ARDS as per the Berlin definition Infection due to COVID-19 Body mass index (BMI) ≤ 35 kg /m^2. Exclusion Criteria: Contraindication for EIT monitoring Unstable spine or pelvic fractures Pacemaker, automatic implantable cardioverter defibrillator Skin lesions between the 4th and 5th ribs where the EIT belt is worn Pregnancy Major hemodynamic instability:: Mean arterial pressure lower than 60 mm Hg despite adequate fluid resuscitation and use of vasopressors. FC> 120 or <60 per minute Presence of uncontrolled arrhythmias. More than 1 week of mechanical ventilation Failure of more than 2 extrapulmonary organs.

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Moderate to severe ARDS patients due to COVID-19 infection<br>Mechanically ventilated patients with moderate to severe ARDS due to COVID-19 infection admitted to the COVID Intensive Care Unit of Rebagliati Hospital. | Procedure: Lateral Position (left and right lateral decubitus)<br>* Prior to initiating the protocol, patients will be sedated deeply with sedatives and opioids and paralyzed. Patients will be evaluated in 5 positions sequentially: 1) Supine 2) Left lateral 3) Supine 4) Right lateral 5) Supine. The side with the least ventilation evaluated by EIT will define which side will start the sequence. Each step will last 30 minutes. Aeration measured by Electric Impedance Tomography (EIT) and lung ultrasound, distribution of the lung ventilation and perfusion measured by EIT, ventilator and hemodynamic parameters, esophageal pressure, and blood gas analysis will be recorded at the end of each step. Continuous monitoring of blood pressure, heart rate and saturation of arterial blood (SpO2) will be carried out during all steps of the protocol to assess the tolerance to the procedure.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effects of a postural recruitment maneuver in lung aeration | Lung aeration measured by ultrasound reaeration score, ranges from 0 (all regions are well aerated) to 36 (all regions are consolidated). | Through study completion (up to 24 hours) | 
| Effects of a postural recruitment maneuver in distribution of ventilation | Distribution of ventilation measured by EIT (distribution and changes in the impedance in AU, arbitray units) | Through study completion (up to 24 hours) | 
| Effects of a postural recruitment maneuver in gas exchange | Gas exchange measured by blood gas analysis (PaO2, PaCO2, in mmHg) and capnography (end-tidal CO2, in mmHg) | Through study completion (up to 24 hours) | 
| Effects of a postural recruitment maneuver in respiratory mechanics | Respiratory mechanics measured by esophageal balloon (esophageal pressure, transpulmonary pressure, in cmH2O) | Through study completion (up to 24 hours) | 
| Effects of a postural recruitment maneuver in hemodynamic | Hemodynamic data measured by invasive arterial monitoring (mean arterial pressure, in mmHg) | Through study completion (up to 24 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Feasibility of a postural recruitment maneuver | Oxigenatory tolerance evaluated with pulse oximeter (arterial oxygen saturation, in percentage) | Through study completion (up to 24 hours) |