Effect of Three Modalities of Spontaneous Breathing Tests on Respiratory Efforts in Tracheostomized Patients

Study Overview
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Brief Summary
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Datas are lacking concerning weaning from mechanical ventilation for tracheostomized patients. In particular, the effect of different modalities of spontaneous breathing trials on respiratory effort has not been extensively described. This crossover physiology study will include 18 tracheostomized patients ventilated for more than 72 hours. The objective of this study is to compare the effect of three different modalities of SBTs on respiratory effort in tracheostomized patients. The modalities tested are : Pressure Support Ventilation (PSV level 5 cmH2O, PEEP 5 cmH2O), T-piece test and high-flow Oxygen. Each modality is applied in a randomized order, during 30 minutes. During every modality tested, esophageal and gastric pressure, expired CO2, and comfort will be monitored, in addition to standard monitoring. Based on esophageal pressure monitoring, patient's respiratory efforts can be calculated either by esophageal pressure-time product and work of breathing. Pressure generated by inspiratory muscles will also be assessed.

Official Title
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Effect of Three Modalities of Spontaneous Breathing Tests on Respiratory Efforts in Tracheostomized Patients. Monocentric Crossover Interventionnal Study.

Conditions
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Mechanical Ventilation Complication

Intervention / Treatment
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* Procedure: Modality 1
* Procedure: Modality 2
* Procedure: Modality 3


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients for whom a tracheostomy is planned Patients on invasive ventilation for >72 hours Exclusion Criteria: Tracheostomy for upper airway obstruction or other disease Patients tracheostomized before current hospitalization Patients with Glasgow Coma Scale (GCS) < 8/10 after cardiac arrest Patients with GCS < 8/10 because of primary central neurologic disease Patients for whom therapeutic limitations have already been decided Patients for whom weaning from ventilation is not an objective Patients suffering from myasthenia gravis Patients with cardiac assistance device Patients with medullary lesion proximal to C5 Patients for whom nasogastric tube insertion is contraindicated

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: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Three different spontaneous breathing trials modalities will be tested in each patient in a randomized order. Washout periods will be performed between the tested modalities.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Modality 1 - Washout - Modality 2 - Washout - Modality 3<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|
| Other: Modality 1 - Washout - Modality 3 - Washout - Modality 2<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|
| Other: Modality 2 - Washout - Modality 1 - Washout - Modality 3<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|
| Other: Modality 2 - Washout - Modality 3 - Washout - Modality 1<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|
| Other: Modality 3 - Washout - Modality 2 - Washout - Modality 1<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|
| Other: Modality 3 - Washout - Modality 1 - Washout - Modality 2<br>Three different 30-minute modalities of deventilation will be performed in a randomized order in each patient. Washout periods of 30 minutes will occur between tested modalities. | Procedure: Modality 1<br>* Pressure support ventilation (PSV) modality<br>Procedure: Modality 2<br>* T-Piece modality<br>Procedure: Modality 3<br>* High-flow oxygen<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evolution of pressure-time product of esophageal pressure | Quantification of inspiratory effort of the patient | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evolution of work of breathing (WOB) | Total area of a Campbell diagram for esophageal pressure and volume during one respiratory cycle | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of esophageal pressure drop | Maximum variation of esophageal pressure during respiratory cycles | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of inspiratory muscle pressure (Pmus) | Pressure generated by patients' respiratory muscles | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of transdiaphragmatic pressure (Ptransdiaph) | Difference between gastric and esophageal pressure. Reflect of pressure generated by diaphragm during inspiration | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of tidal volume (VT) |  | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of respiratory rate (RR) |  | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of inspiratory airway flow |  | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of ratio of inspiratory time over total duration of a breathing cycle (ti/ttot) |  | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of Rapid Shallow Breathing Index (RSBI) | RR/VT - predictor during ventilation weaning of intolerance of SBT | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of respiratory system compliance (Crs) | Capacity of total respiratory system to gain volume for a given pressure | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of lungs compliance (CL) | Capacity of lungs to gain volume for a given pressure | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of chest wall compliance (Ccw) | Capacity of lungs to gain volume for a given pressure | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of transpulmonary pressure (Ptranspulm) | Alveolar pressure minus pleural pressure | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of ratio of total dead space volume over tidal volume | Calculated by means of expired CO2 and arterial blood gas CO2 | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of total dead space volume | Calculated by means of expired CO2 | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of total Positive End-Expiratory Pressure (PEEPtot) | Airway pressure during end-expiratory ventilator occlusion | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of heart rate | Standard monitoring | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of blood pressure | Standard monitoring | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of Plateau pressure (Pplat) | Airway pressure during end-inspiratory ventilator occlusion (corresponds to alveolar pressure) | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of intrinsic Positive End-Expiratory Pressure (PEEPi) | PEEPi minus PEEP set on ventilator | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Pulmonary strain | Measured as the ratio of tidal volume over functionnal residual capacity (FRV) | Recorded every 5 minutes during each sequence and washout period, 180 minutes | 
| Evolution of Diaphragmatic excursion (DE) | Ultrasound measurement of diaphragm movement during inspiration | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of Diaphragmatic thickening fraction (DTF) | Ultrasound measurement of diaphragm thickening during inspiration | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of hematocrits | Mesured by arterial blood | Recorded at minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of Richmond Agitation/Sedation scale (RASS) score | Used in ICU to monitor neurologic changes in patients. Scale from -5 (unarousable) to +4 (combative). 0 is a calm and responsive patient. | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of Borg dyspnea scale score | Numeric scale to quantify dyspnea from 0 to 10. 0 mean patient does not feel that breathing is difficult and 10 is a maximal dyspnea. Measured twice during each Spontaneous Breathing Trial | Recorded at minute 1 and minute 30 of each three spontaneous Breathing Trial, 90 minutes | 
| Evolution of Multidimensionnal dyspnea scale (MDP) score | Score to quantify comfort, dyspnea and assess respiratory effort as perceived by patient. This scale contains multiple items, divided in two dimensions : sensory and affective. Sensory dimension contains : intensity on a scale of 0 to 10 of five sensory qualities (physical breathing effort, air hunger, tightness, mental breathing effort, hyperpnoea) Affective dimension contains : a breathing discomfort scale (scale of 0 to 10) Measured once during each Spontaneous Breathing Trial | Recorded at minute 30 of each three spontaneous Breathing Trial, 90 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ventilation, Tracheotomy, Difficult weaning, Spontaneous Breathing Test, Esophageal pressure, Work of breathing, Esophageal pressure time-product, Difficult weaning from mechanical ventilation, Ventilation weaning