The Effect of High Flow Oxygen Therapy Via Tracheostomy on Diaphragm Function

Study Overview
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Brief Summary
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While the high flow oxygen therapy (HFOT) respiratory support system, delivered through nasal cannulas, has demonstrated clinical benefits on respiratory function, limited data exist on whether such effects are also present in HFOT through tracheostomy. Therefore, the aim of the proposed study is to examine the short-term effects of HFOT as opposed to oxygen therapy via T-piece on diaphragmatic function in tracheostomized patients with prolonged weaning from mechanical ventilation.

Detailed Description
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Critically ill patients who experience difficulties in weaning from the ventilator often undergo tracheostomy. These patients usually undergo spontaneous breathing trials receiving oxygen via T-piece. While the high flow oxygen therapy (HFOT) respiratory support system, delivered through nasal cannulas, has demonstrated clinical benefits on respiratory function, limited data exist on whether such effects are also present in HFOT through tracheostomy. Therefore, we plan to perform a study to examine the short-term effects of HFOT on diaphragmatic function in tracheostomized patients with prolonged weaning from mechanical ventilation. After disconnection from the ventilator, patients will undergo a 30-minute spontaneous breathing trial receiving oxygen either conventionally via T-piece, or by HFOT delivered via tracheostomy, followed by a washout period of 15 min breathing through T-piece and 30 min receiving oxygen with the other modality in a randomized manner. At the start and end of each study period, patients will undergo an assessment through diaphragm ultrasonography, which includes excursion of diaphragmatic dome and thickness of diaphragmatic zone of apposition at end-inspiration and end-expiration. Subsequently, the diaphragmatic thickening fraction will be calculated as the difference between end-inspiratory and end-expiratory thickness divided by end-expiratory thickness. Also. arterial blood gases as well as respiratory rate (RR) and tidal volume (TV) (through a Wright's spirometer) will be measured.

Official Title
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The Effect of High Flow Oxygen Therapy Via Tracheostomy on Diaphragm Function in Patients With Prolonged Weaning From Mechanical Ventilation

Conditions
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Weaning Failure

Intervention / Treatment
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* Device: High Flow Oxygen Therapy
* Device: T-piece


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Mechanically ventilated patients with prolonged weaning and tracheostomy Exclusion Criteria: pregnancy

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: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants will receive two treatments : high flow oxygen therapy and T-piece.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: High Flow Oxygen Therapy<br>Tracheostomized patients will undergo a spontaneous breathing trial with high flow oxygen therapy. | Device: High Flow Oxygen Therapy<br>* A 30-minute spontaneous breathing trial using high flow oxygen therapy via tracheostomy.<br>|
| Active Comparator: T-piece<br>Tracheostomized patients will undergo a spontaneous breathing trial with T-piece as a standard of care. | Device: T-piece<br>* A 30-minute spontaneous breathing trial using T-piece via tracheostomy.<br>* Other names: Standard of care;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diaphragmatic function | Differences in diaphragmatic function between high flow oxygen therapy and T-piece will be assessed by diaphragm excursion measurement (in cm) using bedside ultrasound examination of the diaphragm. | 30 minutes | 
| Diaphragmatic thickening fraction | Differences in diaphragmatic thickening fraction between high flow oxygen therapy and T-piece will be assessed using bedside ultrasound examination of the diaphragm thickness of diaphragmatic zone of apposition at end-inspiration and end-expiration and subsequent calculation of the difference between end-inspiratory and end-expiratory thickness divided by end-expiratory thickness. | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Tidal volume | Differences in tidal volume between high flow oxygen therapy and T-piece will be assessed by tidal volume (in mL) measurement by a Wright's spirometer. | 30 minutes | 
| Respiratory frequence | Differences in respiratory frequency between high flow oxygen therapy and T-piece will be assessed by respiratory rate measurement (breaths per minute). | 30 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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prolonged weaning, tracheostomy, high flow oxygen therapy