High Flow Nasal Oxygen at Extubation for Adults Requiring a Breathing Tube for Treating Severe Breathing Difficulties

Study Overview
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Brief Summary
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The goal of this feasibility study is to learn whether a new approach to breathing tube removal within the Intensive Care Unit is safe and acceptable to participants who require a breathing tube for the management of severe breathing difficulties. The main questions it aims to answer are: What is the recruitment rate to the study over 12 months? Is the study design acceptable and safe to participants? Participants will receive high flow nasal oxygen before their breathing tube is removed. The investigators will compare this with standard practice of applying conventional, low-flow oxygen after the breathing tube removed to see if this effects the rate of repeat breathing tube insertion. The investigators hypothesise that they will recruit 30 participants to the study protocol (15 participants in each group) over 12 months and that our study protocol will be tolerable and acceptable to participants.

Official Title
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A Randomised, Feasibility Trial of Simultaneous Application of Flow at Extubation (SAFEx) in Patients Requiring Intubation and Ventilation for the Management of Acute Respiratory Failure

Conditions
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Respiratory Insufficiency

Intervention / Treatment
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* Device: Fisher and Paykel HealthCare Airvo™ 3 high flow system
* Device: Conventional Oxygen Therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant aged 18 to 80 years old at time of recruitment to study) Ventilated for greater than or equal to 48 hours with respiratory failure Treating clinician agrees ready for a planned extubation (but pressure support ventilation, fraction of inspired oxygen less than or equal to 40 , positive end expiratory pressure less than or equal to 10 centimetres of water, Respiratory rate less than 20 breaths per minute) Minimal secretions Neurologically intact (In the opinion of the treating clinician, the participant is unlikely to fail extubation due to their neurological status) Cardiovascularly stable (systolic blood pressure greater than or equal to 70 millimetres of mercury, heart rate less than or equal to 150 beats per minute) Written informed consent Exclusion Criteria: Cardiac Implant Device Internal Neurostimulator Unstable Spinal Fracture or Spinal Cord Injury Body Mass Index >50kg/m^2 Skin lesions or dressings over electrode belt site Pregnancy or Lactating Intercostal Chest Drain (at treating clinician's discretion) Severe type II respiratory failure (arterial partial pressure of carbon dioxide greater than or equal to 12 kilopascals) Severe acidosis (Hydrogen ion concentration greater than or equal to 80 nanomoles per litre) Chronic respiratory disease limiting functional capacity (MRC breathlessness grade IV or V) Severe heart failure (New York Heart Association Grade III or IV) Decreased GCS Cardiovascular instability (systolic blood pressure less than or equal to 69 millimetres of mercury or heart rate greater than or equal to 151 millimetres of mercury ) Pulmonary embolism Nasal obstruction Previous bleomycin administration Base of skull fracture Life expectancy less than or equal to 3 months

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 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
Interventional Model Description: Participants will be randomised in a 1:1 manner between two treatments at time of extubation: SAFEx treatment or standard care.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: SAFEx<br>Electrical Impedance Tomography recording is commenced 15 minutes prior to planned extubation. High Flow Nasal Therapy (HFNT) is commenced at least 10 minutes prior to planned extubation. At 5 minutes before extubation, the flow rate of HFNT should be established at 60 litres per min (or as high as can be tolerated by the participant) and the fraction of inspired oxygen (FiO2) set at 40 percent. Prior to extubation, endotracheal, infraglottic and supraglottic suctioning are performed. Then, the cuff is let down followed by immediate extubation with simultaneous application of HFNT. 10 minutes after extubation, the FiO2 is weaned in a protocolised manner to 21 percent - or as close to 21 percent as possible over 25 minutes. If the participant is safely weaned onto room air, the flow rate of HFNT is then reduced in a protocolised manner over 120 minutes: 60 minutes at 60 litres per minute (or the highest flow rate tolerated) and then 60 minutes at 30 Litres per minute. | Device: Fisher and Paykel HealthCare Airvo™ 3 high flow system<br>* High Flow Nasal Oxygen Delivery Device<br>|
| Active Comparator: Standard Care<br>Electrical Impedance Tomography recording commenced 15 minutes prior to planned extubation. Prior to extubation, endotracheal, infraglottic and supraglottic suctioning are performed. Then, the cuff is let down followed by immediate extubation on to low flow conventional oxygen with a fraction of inspired oxygen of up to 40 percent. Then, the participant is weaned at the discretion of their clinician over the next 2 hours and 35 minutes. | Device: Conventional Oxygen Therapy<br>* Low flow oxygen delivery device (Flow rate between 2 litres per minute and 15 litres per minute)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The recruitment rate to the study over 12 months with 1:1 randomisation of participants between SAFEx treatment and standard care. | The associated end point will be the average rate of recruitment per month over 12 months of participants who complete the full study protocol (with a set upper limit of 30 participants recruited to the protocol over 12 months corresponding to a recruitment rate of 2.5 participants per month). | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The incidence of Adverse Events and Serious Adverse Events associated with trial procedures. | This will focus primarily on aspects of SAFEx and Electrical Impedance Tomography Measurement. | 72 hours | 
| Patient Visual Analogue Scale scores for questions exploring the tolerability of SAFEx treatment compared with that of standard care. | Questions will ask participants to rate their experience on a 1 to 10 scale for: Overall comfort Perceived dyspnoea Ability to speak Ability to hear Ability to clear secretions Sensation of bloating Sensation of dry mouth Sensation of nasal dryness Fear | 72 hours | 
| Withdrawal rate from the study. | The number of participants requesting to withdraw from the study due to inability to tolerate the trial procedures. | 72 hours | 
| The rate of completion of the SAFEx weaning protocol. | The percentage of participants who completed the weaning protocol without breaching any of the physiological participant safety criteria. | 2 hours 50 minutes | 
| The duration of weaning tolerated before desaturation occurred. | The average fraction of inspired oxygen and oxygen flow rate administered in each group before desaturation occurred. | 2 hours 50 minutes | 
| The failure rate of Electrical Impedance Tomography measurement. | Defined as the proportion of participants in whom impedance data cannot be computed. | 2 hours 50 minutes | 
| The participant self-rated Visual Analogue Scale score for questions exploring the tolerability of Electrical Impedance Tomography Measurement. | Questions will ask participants to rate their experience on a 1 to 10 scale for: Overall comfort whilst wearing EIT Overall comfort on removal of EIT Overall ease of breathing with EIT | 72 hours | 
| The change in global electrical impedance between each group. | The change in end expiratory lung impedance and delta impedance between each group. | 2 hours 50 minutes | 
| The reintubation rate in each group. | The rate of repeat intubation will be measured in each group at 24, 48 and 72 hours post-extubation. | 72 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Extubation Failure, Airway Extubation, Oxygen Inhalation Therapy, Electric Impedance