Post-extubation High-flow Nasal Oxygen for Preventing Extubation Failure

Study Overview
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Brief Summary
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Patients intubated due to acute respiratory failure have a high risk of infectious complications, airway injuries and multiple organic failure, so performing a successful extubation from mechanical ventilation is key. Between 10 and 20% of patients develop extubation failure, which is related to an increased in-hospital death rate, infections, higher costs and longer hospital stays. High-flow nasal oxygen therapy delivers heated, humidified air at flows up to 60L/min, and an oxygen concentration close to 100%, providing a fresh air reservoir at the naseo-pharyngeal level, evening out the peak inspiratory flow rate of the patient, improving air conductance, promoting secretion management, increasing end-expiratory lung volume, and applying a positive end-expiratory pressure. Such effects result in decreased breathing work, dyspnea relief, improved use tolerance, increased oxygenation, and lower fraction of inspired oxygen in patients with hypoxemic respiratory failure. High-flow oxygen therapy has recently been described to decrease extubation failure in a group of patients classified with low failure risk, in comparison to Venturi mask, and it was not inferior to non-invasive mechanical ventilation in high risk patients. However, it is worth pointing out that a large percentage of the patients included in such studies did not develop acute respiratory failure primarily. Given the beneficial effects described above, the investigators hypothesize that high-flow nasal oxygen therapy decreases the risk of extubation failure in a group of patients that required invasive mechanical ventilation due to primary acute hypoxemic respiratory failure.

Detailed Description
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Intubated patients recovering from primary acute hypoxemic respiratory failure who have passed a spontaneous breathing trial will be included in the study. Following extubation, patients will be randomized assigned to one of two study groups. Heart rate, breathing rate, median arterial pressure, FiO2, SpO2, and dyspnea and comfort levels will be measured at defined intervals after extubation (basal, 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours). An arterial blood gas test will be performed 60 minutes and 24 hours after extubation. The number of patients fulfilling certain preset criteria regarding extubation failure will be determined. Extubation failure shall be defined as the need for using invasive mechanical ventilation again within two days following extubation based on the criteria below: Breathing rate over 25 breaths per minute for more than two hours. Heart rate above 140 beats per minute or with a sustained increase or decrease greater than 20%. Clinical data showing fatigue of the respiratory muscles or an increase in breathing work. SaO2 <90%; PaO2 <80 mmHg with a FiO2 > 50%. Hypercapnia (PaCO2 >45 mmHg or >20% compared to the value before extubation) with a pH below 7.33. Patients who do not fulfill the extubation failure criteria after the first 48 hours of admission may receive extra supplementary oxygen through any device (e.g., nasal cannula, face mask, reservoir mask, etc.). Every day, SpO2 will be measured and the moment when the patient reaches SpO2 >94% with no need for oxygen will be determined.

Official Title
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Post-extubation High-flow Nasal Oxygen vs. Conventional Oxygen in Patients Recovered From Acute Hypoxemic Respiratory Failure for Preventing Extubation Failure

Conditions
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Extubation Failure

Intervention / Treatment
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* Device: High-flow nasal oxygen
* Device: Venturi mask


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Hypoxemic primary acute respiratory failure Invasive mechanical ventilation for at least 48 hours Successful Spontaneous Breathing Trial Exclusion Criteria: Immediate indication for invasive mechanical ventilation Immediate indication for non-invasive mechanical ventilation Self-extubation One or more failed Spontaneous Breathing Trial Chronic respiratory failure Neuromuscular diseases Tracheostomy. Nasal cavity pathology Facial surgery Failure to authorize the informed consent

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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High-flow nasal oxygen<br>Randomized patients will receive oxygen through a high flow nasal device capable of delivering humidified, heated air at an output rate of 40 L/min | Device: High-flow nasal oxygen<br>* Randomized patients will receive oxygen through a high nasal flow device capable of delivering humidified, heated air at an output rate of 40 L/min<br>|
| Active Comparator: Conventional oxygen<br>Randomized patients will receive oxygen through a Venturi mask at an air flow of 15 L/min | Device: Venturi mask<br>* Randomized patients will receive oxygen through a Venturi mask at an air flow of 15 L/min<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Post-extubation failure | Number of patients with extubation failure criteria in each group | First 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2/FiO2 Ratio Record. | An arterial blood gas test will be performed once the high-flow oxygen or Venturi mask is placed. | Post-extubation period and up to 48 hours later. | 
| Determination of FiO2 Requirements. | Assessment of FiO2 requirements at the time of extubation (when high-flow oxygen or Venturi mask is placed) and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours. The aim is to maintain SpO2 levels > 94% with the minimal FiO2 possible. | Post-extubation period and up to 48 hours later. | 
| Respiratory Rate Record at Defined Intervals. | Quantification of respiratory rate at the time of placement high-flow oxygen or Venturi mask and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours and 48 hours. | Post-extubation period and up to 48 hours later. | 
| Heart Rate Record at Defined Intervals. | Quantification of heart rate at the time of placement high-flow oxygen or Venturi mask and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours and 48 hours. | Post-extubation period and up to 48 hours later. | 
| Mean Arterial Pressure Record at Defined Intervals. | Quantification of mean arterial pressure at the time of placement high-flow oxygen or Venturi mask and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours and 48 hours. | Post-extubation period and up to 48 hours later. | 
| Treatment Comfort Assessment by means of a Visual Analogue Scale at Defined Intervals. | To record patient comfort by means of a Visual Analogue Scale tool at the time of placement high-flow oxygen or Venturi mask and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours and 48 hours. Visual Analogue Scale range (0 = better to 10 = worse). | Post-extubation period and up to 48 hours later. | 
| Dyspnea Assessment by means of a Visual Analog Scale at Defined Intervals. | To measure the level of dyspnea by means of a Visual Analogue Scale tool at the time of placement high-flow oxygen or Venturi mask and then at 60 minutes, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours and 48 hours. Visual Analogue Scale range (0 = better to 10 = worse). | Post-extubation period and up to 48 hours later. | 
| Number of Days Requiring Oxygen after Successful Extubation | After successful extubation, the level of SpO2 will be measured on a daily basis, recording the time when a level of SpO2> 94% is reached by the patient without the use of supplemental oxygen. | Post-extubation period and up to 14 days later. | 
| Number of Days Spent in the ICU after Extubation. | There will be quantified the total length of stay in the ICU after extubation. | Post-extubation period and up to 28 days later. | 
| Days Spent in the Hospital After Extubation. | There will be quantified the total length of stay in the hospital after extubation. | Post-extubation period and up to 28 days later | 
| Number of Deaths in the ICU after Extubation. | There will be quantified the number of patients deceased in each group | Post-extubation period and up to 28 days later | 
| Number of Deaths in the Hospital after Extubation. | There will be quantified the number of patients deceased in each group | Post extubation period and up to 28 days later. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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High-Flow nasal oxygen