Evaluation of Airway Pressure Release Ventilation in COVID-19 ARDS

Study Overview
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Brief Summary
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The 2020 pandemic of the coronavirus (SARS-CoV2) has lead to an increase in ARDS cases requiring invasive mechanical ventilation in the ICU (Intensive Care Unit). The investigators hypothesize that airway pressure release ventilation (APRV) could be beneficial in patients with ARDS secondary to SARS-COV2 viral pneumonia.

Detailed Description
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Lung protective mechanical ventilation is the cornerstone of ARDS management, reducing the work of respiratory muscles and optimizing gas exchange. However, it can be the source of deleterious effects, grouped under the terms of ventilator induced lung injury (VILI) and ventilator induced diaphragm dysfunction. The protective ventilatory strategy has led to a significant improvement in the prognosis of ARDS patients, by reducing the volume of the air and oxygen mixture (lower tidal volume) delivered to the lungs and thus reducing the pulmonary stress and strain. However, this protective ventilation usually requires deep sedation and neuromuscular blockade to avoid deleterious patient-ventilator asynchrony. Airway Pressure Release Ventilation (APRV) has been proposed to reduce patient-ventilator asynchrony and reduce the VILI. The operating principles of APRV are based on the presence of two pressure levels that are kept constant. Spontaneous breathing is possible at any time at both pressure levels if the patient is not deeply sedated or under neuromuscular blockade. The investigators hypothesize that APRV mode could be beneficial on oxygenation and respiratory work in patients with ARDS secondary to SARS-COV2 viral pneumonia.

Official Title
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Evaluation of Airway Pressure Release Ventilation on Oxygenation in Acute Respiratory Distress Syndrome in Adult Patients With COVID-19 Pneumonia

Conditions
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ARDS, COVID19

Intervention / Treatment
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* Other: Airway pressure release ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients treated in Nancy University Hospital between 01/04/2020 and 31/06/2020 for COVID-19 ARDS, requiring invasive ventilation Trial of airway pressure release ventilation during the ICU stay Exclusion Criteria: Patients requiring veno-venous ECMO Patients unable to complete the 6-hour APRV trial due to poor tolerance : SpO2 decrease < 90% on FiO2 70%, haemodynamic instability (MAP < 65mmhg without vasopressors, or 0.5 mg/h increase in norepinephrine, ventilator asynchrony (respiratory rate >35), hypercapnia (pH < 7,25 or PaCO2 >60mmHg)

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 |
| --- | --- |
| Airway Pressure Release Ventilation<br>Patients with COVID-19 ARDS requiring invasive mechanical ventilation in ICU, on Volume Assist Control ventilation (VAC) or Pressure Assist Control (PAC), are switched to airway pressure ventilation (APRV). If APRV doesn't lead to improvement in oxygenation the ventilatory mode is switched back to VAC or PAC ventilatory mode. | Other: Airway pressure release ventilation<br>* Ventilator management strategy<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of patients improving PaO2/FiO2 ratio at 6 hours of APRV | Increase of at least 20% of the PaO2/FiO2 ratio | 6 hours after starting APRV | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of interventions on ventilator settings | Number of interventions by the physician on APRV settings | 6 hours after starting APRV | 
| Change in mean blood pressure | Variations of blood pressure in millimeters of mercury | 6 hours after starting APRV | 
| Change in heart rate | Variations of heart rate in beats per minute | 6 hours after starting APRV | 
| Changes in catecholamine doses | Variations of catecholamine doses in milligrams per hours | 6 hours after starting APRV | 
| Changes in static compliance at the end of 6 hours of APRV | Static compliance (Cstat) defined as : Cstat = (VT/(Pplat-PEPtot)) Tidal Volume (VT), Plateau pressure (Pplat) and Total Positive End-expiratory Pressure (PEEPtot) | 6 hours after starting APRV | 
| Variations of minute ventilation | Minute ventilation in liters per minute | 6 hours after starting APRV | 
| Changes in static compliance 4 hours after stopping APRV | Static compliance (Cstat) defined as : Cstat = (VT/(Pplat-PEPtot)) Tidal Volume (VT), Plateau pressure (Pplat) and Total Positive End-expiratory Pressure (PEEPtot) | 4 hours after starting APRV | 
| Proportion of patients with a decrease of the PaO2/FiO2 ratio | Percentage of patients with a decrease of the PaO2/FiO2 ratio | 4 hours after stopping APRV | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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SARS-CoV-2, Airway Pressure Release Ventilation, Intensive Care Unit, APRV, Acute respiratory failure