Pronation During Veno-venous Extra Corporeal Membrane Oxygenation

Study Overview
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Brief Summary
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The Acute Respiratory Distress Syndrome (ARDS) is defined by a recent (within 1 week) respiratory failure, not fully explained by cardiac failure or fluid overload. ARDS is also characterized by bilateral opacities at the chest imaging, with an alteration of the oxygenation while positive end-expiratory pressure equal or greater than 5 cmH2O is applied. Severe ARDS is characterized by a high mortality. In the most severe ARDS patients, venovenous extracorporeal membrane oxygenation (vv-ECMO) is increasingly accepted as a mean to support vital function, although not free from complications. In patients with severe ARDS, prone position has been used for many years to improve oxygenation. In these patients, early application of prolonged (16 hours) prone-positioning sessions significantly decreased 28-day and 90-day mortality. More recently, prone position and ECMO have been coupled as concurrent treatment. Indeed, the addition of prone positioning therapy concurrently with ECMO can aid in optimizing alveolar recruitment, and reducing ventilator-induced lung injury. Nowadays, few data exist on respiratory mechanics modifications before and after the application of prone position in patients with severe ARDS receiving vv-ECMO. The investigators have therefore designed this observational study to assess the modifications of mechanical properties of the respiratory system, ventilation and aeration distribution, and hemodynamics occurring during ECMO before and after prone position in patients with severe ARDS.

Official Title
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Effects of Pronation on Respiratory System Mechanical Properties and Ventilation in Patients With Acute Respiratory Distress Syndrome During Vv-ecmo

Conditions
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Acute Respiratory Distress Syndrome, Acute Respiratory Failure

Intervention / Treatment
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* Other: Prone Position during Extra Corporeal Membrane Oxygenation (ECMO)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all adult patients with a diagnosis of severe Acute Respiratory Distress Syndrome receiving veno-venous ECMO Exclusion Criteria: mechanical ventilation for 7 days or longer pregnancy body mass index (BMI) > 45 kg/m2 chronic respiratory failure with long-term oxygen therapy or domiciliary non-invasive ventilation cardiac failure resulting in veno-arterial ECMO history of heparin- induced thrombocytopenia cancer with a life expectancy of less than 5 years moribund condition or a Simplified Acute Physiology Score (SAPS-II) value of more than 90; current non drug- induced coma after cardiac arrest or presence of an irreversible neurologic injury decision to withhold or withdraw life--sustaining therapies presence of pneumothorax and/or pulmonary emphysema recent (1 week) thoracic surgery presence of chest burns inclusion in other research protocols refusal of consent.

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 |
| --- | --- |
| ECMO Prone Position<br>After baseline assessment in supine position, patients will be positioned in prone position to assess modification of lung mechanics, aeration and hemodynamics | Other: Prone Position during Extra Corporeal Membrane Oxygenation (ECMO)<br>* Pronation will be executed according to a predefined protocol: 4 caregivers will be required for the procedure, one of them being dedicated to the management of the head of the patient, the endotracheal tube and the ventilator lines. The others will stand at each side of the bed. In the first step, the direction of the rotation will be decided giving priority to the side of the central venous lines. The patient will be then moved along the horizontal plane to the opposite side of the bed selected for the direction of rotation. In the third step, the patient will be moved in the sagittal plane and maintained in that position for a short while to attach the cardiac electrodes to her/his back and to set a new bed sheet. In the last step, the patient will be turned to the complete prone position.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Driving Pressure | Difference between the airway plateau pressure and the total positive end-expiratory pressure after an inspiratory and expiratory hold maneuvers, respectively | 30 minutes after the prone positioning | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory system compliance | Driving pressure to the tidal volume ratio | 30 minutes after the prone positioning | 
| Cardiac output | Liters of blood flow ejected from the heart per minute, measured through a pulmonary artery catheter | 30 minutes after the prone positioning | 
| Pulmonary arterial pressure | pulmonary arterial pressure measured through a pulmonary artery catheter | 30 minutes after the prone positioning | 
| End-Expiratory Lung Impedance | Measurement of the end expiratory lung volume, as assessed by the electrical impedance tomography | 30 minutes after the prone positioning | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Extra Corporeal Membrane Oxygenation, Prone Position