Respiratory Mechanics and Gas Exchange in Patients With COVID-19 and Hypoxemic Acute Respiratory Failure

Study Overview
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Brief Summary
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Data on respiratory mechanics and gas exchange in acute respiratory failure in COVID-19 patients is limited. Knowledge of respiratory mechanics and gas exchange in COVID-19 can lead to different selection of mechanical ventilation strategy, reduce ventilator-associated lung injury and improve outcomes. The objective of the study is to evaluate the respiratory mechanics, lung recruitability and gas exchange in COVID-19 -associated acute respiratory failure during the whole course of mechanical ventilation - invasive or non-invasive.

Detailed Description
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In December 2019, an outbreak of a novel coronavirus (SARS-CoV-2) emerged in Wuhan, China and rapidly spread worldwide. The World Health Organization (WHO) declared the outbreak a pandemic on March 11th, 2020. The clinical disease (COVID-19) results in critical illness in about 5% of patients with predominant acute respiratory failure. The goal of the study is the evaluation of the respiratory mechanics (peak inspiratory pressure (PIP), plateau pressure (Pplat), static compliance (Cstat), driving pressure (DP) at different positive end-expiratory pressure (PEEP) levels and different tidal volumes (Vt) (6-8 ml/kg ideal body weight), lung recruitability (by change of DP and oxygenation) and gas exchange (PaO2/FiO2 ratio and alveolar dead space) in COVID-19 -associated acute respiratory failure during the whole course of mechanical ventilation - invasive or non-invasive for selection of safe and effective PEEP level, Vt, respiratory rate (RR) and inspiratory oxygen fraction (FiO2) during the whole course of mechanical ventilation - invasive or non-invasive. This study is multicentral observational trial in 3 University clinics.

Official Title
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Respiratory Mechanics and Gas Exchange in Patients With COVID-19 and Hypoxemic Acute Respiratory Failure: Multicentral Observational Study

Conditions
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SARS Pneumonia

Intervention / Treatment
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* Diagnostic Test: Respiratory mechanics measurement
* Diagnostic Test: Gas exchange measurement


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all patients with COVID-19 and acute respiratory failure on invasive and noninvasive ventilation Exclusion Criteria: Patients who reached the following goals at conventional oxygen therapy (oxygen flow < 15 l/min): peripheral capillary oxygen saturation(SpO2) > 93%, no visible work of auxiliary respiratory muscles, no fatigue, stable hemodynamics (no need in any catecholamines and/or life-threatening heart rhythm abnormalities), less than 24 ours in intensive care unit (ICU) by any reason, lung emphysema, primary lung diseases (chronic obstructive lung disease-COPD, interstitial lung diseases, etc) or tumour metastases in lungs, chronic decompensated diseases with extrapulmonary organ dysfunction (tumour progression, liver cirrhosis, congestive heart failure), atonic coma.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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

| Intervention/Treatment |
| --- |
|Diagnostic Test: Respiratory mechanics measurement|Measurement of peak inspiratory pressure, plateau pressure, calculation of static compliance and driving pressure|
|Diagnostic Test: Gas exchange measurement|Measurement of arterial oxygen and tension and arterial dioxide tension, calculation of arterial partial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2) ratio and alveolar dead space|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Optimum positive end-expiratory pressure (PEEP) level | Positive end-expiratory pressure (PEEP) selection at minimum level with maximum static compliance and the highest peripheral capillary oxygen saturation over fraction of inspired oxygen (SpO2/FiO2) | On day 1 during mechanical ventilation | 
| Optimum positive end-expiratory pressure (PEEP) level | Positive end-expiratory pressure (PEEP) selection at minimum level with maximum static compliance and the highest peripheral capillary oxygen saturation over fraction of inspired oxygen (SpO2/FiO2) | On day 7 during mechanical ventilation | 
| Number of patients with recruitable lung | Peripheral capillary oxygen saturation (SpO2) change from 90% after recruitment maneuver (doubled tidal volume for 15 respiratory cycles) - if peripheral capillary oxygen saturation (SpO2) after recruitment maneuver more than 95%-recruitable | On day 1 during mechanical ventilation | 
| Number of patients with recruitable lung | Peripheral capillary oxygen saturation (SpO2) change from 90% after recruitment maneuver (doubled tidal volume for 15 respiratory cycles) - if peripheral capillary oxygen saturation (SpO2) after recruitment maneuver more than 95%-recruitable | On day 7 during mechanical ventilation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in alveolar dead space | Calculation of the alveolar dead space using end-tidal carbon dioxide measurement and arterial carbon dioxide tension measurement | On day 1, 3, 5, 7, 10, 14, 21 during mechanical ventilation | 
| Change in plethysmogram variability during recruitment maneuver | Measurement of plethysmogram variability before and during recruitment maneuver | On day 1, 3, 5, 7, 10, 14, 21 during mechanical ventilation | 
| Change in arterial partial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2) ratio | Calculation of the arterial partial oxygen tension to inspiratory oxygen fraction (PaO2/FiO2) ratio using arterial oxygen tension measurement | On day 1, 3, 5, 7, 10, 14, 21 during mechanical ventilation | 
| Optimum positive end-expiratory pressure (PEEP) level | Positive end-expiratory pressure (PEEP) selection at minimum level with maximum static compliance and the highest peripheral capillary oxygen saturation over fraction of inspired oxygen (SpO2/FiO2) | On day 3, 5, 10, 14, 21 during mechanical ventilation | 
| Change in driving pressure with different positive end-expiratory pressure (PEEP) levels | Driving pressure calculation at different positive end-expiratory pressure (PEEP) levels (8, 10, 12, 14) | On day 1, 3, 5, 7, 10, 14, 21 during mechanical ventilation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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SARS Pneumonia, ARDS, COVID-19, compliance, recruitability