Flow-controlled Ventilation (FCV) in Moderate Acute Respiratory Distress Syndrome (ARDS) Due to COVID-19

Study Overview
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Brief Summary
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Flow controlled ventilation (FCV) is a fairly new mode of mechanical ventilation, consisting of a constant inspiratory and expiratory flow. Inspiration is thus comparable to volume controlled ventilation (VCV). The actively controlled, constant flow during expiration is unique. FCV is known to minimize dissipated energy to the lung [ref] and is therefore supposed to aid in lung protective ventilation. The VICAR study is designed as a prospective single cohort crossover trial. The intervention consists of a sequence of respiratory modes: baseline pressure controlled ventilation (PCV) during 5 minutes, followed by 30 minutes of FCV with an evone respirator (Ventinova Medical B.V., Eindhoven, The Netherlands) and eventually 30 minutes of VCV. Every participant will receive the intervention. Respiratory rate (RR), positive end-expiratory pressure (PEEP) and inspiratory fraction of oxygen (FiO2) will be held constant. According to the manufacturers guidelines, an I:E ratio of 1:1 will be pursued during FCV. During FCV, the respirator will be set with the same PIP as during baseline PCV. For VCV, the same tidal volume as during baseline PCV will be set.

Official Title
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Flow-controlled Ventilation (FCV) in Moderate Acute Respiratory Distress Syndrome (ARDS) Due to COVID-19 - an Interventional Cross-over Study

Conditions
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COVID-19 Acute Respiratory Distress Syndrome, Respiration, Artificial

Intervention / Treatment
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* Diagnostic Test: Arterial blood gas (ABG)
* Other: Recording of hemodynamic monitoring
* Other: Recording of respiratory monitoring


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: P/F-ratio: 100-200 (moderate ARDS) SpO2 88-94% PaO2 60-80 mmHg COVID-19 positive on a PCR test Exclusion Criteria: BMI > 40 kg/m² Prone ventilation Already invasively mechanically ventilated for more than 10 days Refusal to participate

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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 |
| --- | --- |
| Sequential baseline PCV - FCV - VCV<br>Each participant will be subjected to baseline pressure controlled ventilation (PCV) during 5 minutes, followed by 30 minutes of FCV with an evone respirator (Ventinova Medical B.V., Eindhoven, The Netherlands) and eventually 30 minutes of VCV. Respiratory rate (RR), positive end-expiratory pressure (PEEP) and inspiratory fraction of oxygen (FiO2) will be held constant. According to the manufacturers guidelines, an I:E ratio of 1:1 will be pursued during FCV. During FCV, the respirator will be set with the same PIP as during baseline PCV. For VCV, the same tidal volume as during baseline PCV will be set. | Diagnostic Test: Arterial blood gas (ABG)<br>* Arterial blood gasses will be drawn during baseline PCV, and every 15 minutes during FCV and VCV respectively. pO2 (mmHg), pCO2 (mmHg) and pH will be recorded.<br>Other: Recording of hemodynamic monitoring<br>* Hemodynamic parameters (invasive arterial blood pressure (mmHg) and heart rate (beats per minute)) will be recorded every 5 minutes.<br>Other: Recording of respiratory monitoring<br>* Tidal volume (ml), respiratory rate (breaths per minute), minute volume (l/min), dynamic compliance (ml/cmH2O), resistance (cmH2O/l/min), plateau pressure (cmH2O), mean airway pressure (cmH2O), positive end-expiratory pressure (cmH2O), peak inspiratory pressure (cmH2O) and fraction of inspired oxygen will be recorded every 5 minutes.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Arterial oxygen tension, PaO2 (mmHg) | Arterial partial oxygen tension as measured on an arterial blood gas sample. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| P/F ratio or Horowitz index (mmHg) | Ratio of the arterial oxygen tension PaO2 (mmHg) divided by the inspiratory fraction of oxygen FiO2. | Post hoc calculation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SpO2 (%) | Oxygen saturation as measured by pulse oxymetry. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| FiO2 | Fraction of inspired oxygen as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| PEEP (cmH2O) | Positive end-expiratory pressure as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| Pmean | Mean airway pressure (cmH2O) as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| PaCO2 | Arterial partial tension of carbon dioxide (mmHg) as measured on an arterial blood gas sample. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| MV | Minute volume (l/min) as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| TV | Tidal volume (ml) as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| RR | Respiratory rate (breaths per minute) as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| Pplat | Plateau airway pressure (cmH2O) as measured by the respirator | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| PIP | Peak inspiratory airway pressure (cmH2O) as measured by the respirator. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| ABPsys | Systolic arterial blood pressure (mmHg) as measured by a pressure transducer on an arterial catheter. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| ABPmean | Mean arterial blood pressure (mmHg) as measured by a pressure transducer on an arterial catheter. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| ABPdia | Diastolic arterial blood pressure (mmHg) as measured by a pressure transducer on an arterial catheter. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 
| HR | Heart rate (beats per minute) as measured on a 5-lead continuous electrocardiogram. | Approximately 1 hour (5 min. PCV + 30min. FCV + 30 min. VCV) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Flow controlled ventilation (FCV)