Fiberoptic Bronchoscopy and Bronchoalveolar Lavage in Critically Ill Ventilated Patients

Study Overview
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Brief Summary
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Fiberoptic bronchoscopy (FOB) is widely used as a diagnostic or therapeutic procedure in intensive care units. Patients with ARDS or COVID-19 disease often undergoes to these procedures. However, intensive care patients might suffer from serious side effects such as prolonged oxygen desaturation and adverse change in lung compliance and resistance. This study aims to evaluate these changes and determine their impact on patient stability.

Detailed Description
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Fiberoptic bronchoscopy (FOB) is widely used in intensive care units as a diagnostic or therapeutic procedure. FOB in respiratory failure patients supported by mechanical ventilation may worsen hypoxemia and hypercapnia, therefore FOB requires careful consideration in this patient population. The generally accepted indications for FOB in ventilated patients are removal of retained secretions, resolution of atelectasis and evaluation of hemoptysis. A diagnostic indication is the bronchoalveolar lavage (BAL), to sample the lower respiratory tract without contamination. Studies of FOB performed in mechanically ventilated patients suggest an acceptable safety profile, except for the occurrence of hypoxemia as the main adverse event. Bronchoalveolar Lavage (BAL) in normal volunteers is reported to be safe and does not lead to measurable changes in pulmonary function parameters. However, in intensive care patients may suffer from serious side effects such as prolonged oxygen desaturation. Moreover, reductions in arterial oxygen tension (PaO2) have been reported to persist in some patients for 4 h and more after the procedure. Authors reported the BAL procedure is associated to a worsening of PaO2/FiO2 ratio, in several ARDS patients the drop in PaO2 was higher than 30%. Moreover a physiological study in patients undergoing FOB and BAL showed adverse change in lung compliance and resistance. The purpose of this prospective study is to determine the alterations in respiratory mechanics (regional compliance and resistance) and gas exchange induced by FOB and BAL up to 6 hours after the procedure. The lung regional ventilation evaluation will be made by electrical impedance tomography (EIT).

Official Title
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Fiberoptic Bronchoscopy and Bronchoalveolar Lavage in Critically Ill Ventilated Patients: Impact on Respiratory Mechanics and Gas Exchange

Conditions
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Fiberoptic Bronchoscopy (FOB), Bronchoalveolar Lavage (BAL), Respiratory Disease

Intervention / Treatment
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* Procedure: Fiberoptic Bronchoscopy (FOB)
* Procedure: Bronchoalveolar Lavage (BAL)
* Diagnostic Test: Electrical Impedance Tomography (EIT)
* Diagnostic Test: Arterial Blood Gas test (ABG)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Mechanically ventilated ICU patients requiring a FOB or FOB + BAL Exclusion Criteria: PaO2/FiO2 ratio <100 Age < 18 years Pregnancy Unstable angina and recent (less than 1 week) myocardial infarction Uncontrolled cranial hypertension Major hemodynamic instability Any previous lung surgery (except for lung transplantation) Obesity (BMI > 50) Chest circumference > 150 cm Electronic implanted device (pacemaker, neurostimulator, etc.) Patients who had undergone several bronchoscopy procedures could not be included twice.

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

| Intervention/Treatment |
| --- |
|Procedure: Fiberoptic Bronchoscopy (FOB)|FOB under full sedation (RASS sedation scale -5) and full paralysis.|
|Procedure: Bronchoalveolar Lavage (BAL)|BAL under full sedation (RASS sedation scale -5) and full paralysis. Lavage: NaCl 0,9% 50ml x 3 in lung region targetted according to RX/CT scan.|
|Diagnostic Test: Electrical Impedance Tomography (EIT)|Realtime thoracic impedance coupled with ventilation parameters recording.|
|Diagnostic Test: Arterial Blood Gas test (ABG)|Multiples Arterial Blood Gas test (ABG) via arterial catheter.|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional Compliance Variation | The variation of regional compliance, calculated by electrical impedance | From FOB/BAL to 6 hours later | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional Resistance Variation | The variation of regional resistance, calculated by electrical impedance | From FOB/BAL to 6 hours later | 
| Regional Compliance and FOB duration | Relation between regional compliance variation and FOB duration | From FOB/BAL to 6 hours later | 
| Regional Compliance and PaO2 | Relation between regional compliance variation and PaO2 variation | From FOB/BAL to 6 hours later | 
| Atelectasis areas and BAL flooded areas | Relation between atelectasis impedance-detected areas and BAL flooded impedance-detected areas | From FOB/BAL to 6 hours later | 
| PaO2 and PaO2/FiO2 ratio | Variation of PaO2 and PaO2/FiO2 ratio post FOB/BAL | From FOB/BAL to 6 hours later | 
| PaCO2 | Variation of PaCO2 post FOB/BAL | From FOB/BAL to 6 hours later | 
| Endotracheal tube size and Fiberscope size | Relation between the endotracheal tube/fiberscope size ratio and gas exchanges | From FOB/BAL to 6 hours later | 
| Hemodynamic variations | Heart rate (HR), Blood Pressure (BP) | From FOB/BAL to 6 hours later | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Respiratory Insufficiency, Respiratory Distress Syndrome, Mechanical Ventilation, COVID-19, Fiberoptic Bronchoscopy (FOB), Bronchoalveolar Lavage (BAL)