Validation of a Semi-automatized Method to Detect Cyclic Hyperinflation on CT-scan in ARDS

Study Overview
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Brief Summary
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This study aims to validate a semi-automatized method to quantify cyclic hyperinflation on CT-scan of ARDS patients. The gold standard will be cyclic hyperinflation assessed on the same CT scan, using manual segmentation of the lung.

Official Title
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Validation of a Semi-automatized Method to Detect Cyclic Hyperinflation on CT-scan in ARDS

Conditions
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Acute Respiratory Distress Syndrome (ARDS)

Intervention / Treatment
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* Other: ARDS patients


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ARDS patients defined by the Berlin definition invasive mechanical ventilation with an arterial oxygen pressure (PaO2)/inspired fraction of oxygen (FiO2) ratio ≤ 200 mm Hg Indication of CT scan identified by the clinician in charge oesophageal catheter already inserted Exclusion Criteria: requirement of contrast agent for a chest CT-scan ARDS criteria present for more than 72 hours Chronic Obstructive Pulmonary Disease (COPD) on a previous lung function test pneumothorax or bronchopleural fistula patient without both sedation and neuromuscular blocking agents contra-indication to transport to the imaging facility treatment with extracorporeal membrane oxygenation or extracorporeal carbon dioxide (CO2) removal Latex or curare allergy patient previously included in the study pregnancy patient under limitation of care patient under an exclusion period following inclusion in another clinical trial patient under a legal protective measure patient unaffiliated with social security inform consent not obtained by next of kin

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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: ARDS patients<br>All the patients will be evaluated with the same procedure, as the study relates to evaluation of the diagnostic performance of a semi-automated method to detect cyclic hyperinflation on CT scan | Other: ARDS patients<br>* The patient will be installed on the scanner bed. Two series of tomographic sections will be acquired: one during an expiratory break, the other during an inspiratory pause. cyclic hyperinflation measured by semi-automatic segmentation and by manual segmentation<br>* Other names: CT measurements;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| cyclic hyperinflation measured by manual segmentation | Bias and precision of semi-automated measure will be assessed with the Bland and Altman Technique, using cyclic hyperinflation by manual segmentation as a reference | 2 hours after inclusion | 
| cyclic hyperinflation measured by semi-automated segmentation | Bias and precision of semi-automated measure will be assessed with the Bland and Altman Technique, using cyclic hyperinflation by manual segmentation as a reference | 2 hours after inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| prevalence of cyclic hyperinflation on CT scan | cyclic hyperinflation assessed by manual segmentation on CT scan | 2 hours after inclusion | 
| area under receiver operating characteristic (ROC) curve of respiratory system driving pressure to detect cyclic hyperinflation assessed by manual segmentation |  | 2 hours after inclusion | 
| area under ROC curve of transpulmonary driving pressure to detect cyclic hyperinflation assessed by manual segmentation |  | 2 hours after inclusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ARDS, computed tomography, cyclic hyperinflation, mechanical ventilation