HFN Versus NIV in Cystic Fibrosis. The HIFEN Study

Study Overview
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Brief Summary
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Many patients with cystic fibrosis (CF) require hospitalization and/or Intensive Care Unit (ICU) admission because of acute exacerbation of chronic respiratory failure or for any acute deterioration of clinical status. Non-invasive ventilation (NIV) is the first option for the clinical management of CF patients with moderate-to-severe respiratory distress and NIV has been shown to improve gas exchange, reduce respiratory muscle work and improve pulmonary function in patients with obstructive lung disease in general and those with acute CF exacerbation. High-flow nasal oxygen cannula (HFN) is a relatively new system providing heated and humidified, high-flow (50L/min) oxygen through the nostrils. This device provides a small positive pressure, probably washes-out the pharyngeal dead space, reduces inspiratory resistance, and possibly facilitates secretion clearance. The technique is very well tolerated. From a physiologic standpoint, this device could help CF patients by improving gas exchange, reducing respiratory workload, and facilitating mucus clearance. Non-interrupted delivery may be possible given better clinical tolerance in contrast with bi-level positive pressure NIV. Whether the short-term physiological efficacy of HFN is comparable to NIV is unknown and there is no study on the benefit of HFN in CF patients. The aim of this study is to compare the physiological effects of HFN and NIV in CF patients requiring ventilatory support. Our hypothesis is that HFN will not be inferior to NIV, as evaluated by breathing pattern, gas exchange, and respiratory workload and will decrease dead space. In addition, comfort and preference between the two techniques will be evaluated.

Official Title
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Randomized Cross-over Physiologic Study of High Flow Nasal Oxygen Cannula Versus Non-invasive Ventilation in Cystic Fibrosis. The HIFEN Study

Conditions
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Cystic Fibrosis

Intervention / Treatment
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* Device: High flow nasal oxygen cannula
* Device: Noninvasive ventilation


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: Age ≥ 18 years Cystic fibrosis as defined by clinical features in conjunction with 2 CF causing mutations and/or 2 sweat tests with sweat chloride > 60 mmol/l Clinical indication for NIV based on at least one of the following criteria: Signs of clinical respiratory distress - RR > 24/min, accessory muscle use, or increased dyspnea Progressive increase in arterial PCO2 Nocturnal hypoventilation treated by NIV but requiring daytime NIV because of clinical worsening Exclusion criteria: Active massive hemoptysis Pneumothorax with pleural drainage and persistent air leak Hemodynamic instability requiring vasopressors Uncooperative Recent upper airway or esophageal surgery Patients with skin or chest wall or abdominal trauma

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
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: CF patients HFN<br>CF patients who meet the eligibility criteria will be randomized to receive HFN and then crossover to other device. | Device: High flow nasal oxygen cannula<br>* HFN will be set with an inspiratory flow rate at 45-55 L/min (maximal tolerated flow), temperature at 37°C or 34°C if perceived as too warm, and fraction on inspired oxygen (FiO2) will be adjusted to achieve an oxygen saturation (SpO2) of at least 92%.<br>|
| Experimental: CF patients NIV<br>CF patients who meet the eligibility criteria will be randomized to receive NIV and then crossover to other device. | Device: Noninvasive ventilation<br>* The setting of NIV will be appropriately adjusted, based on the clinical assessment of the respiratory therapist in charge and will not be modified during the test.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The decrease of diaphragmatic workload (thickening fraction of the diaphragm) |  | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Respiratory parameters | respiratory rate (RR), minute ventilation | 30 minutes | 
| Gas exchange | pulse oximetry, transcutaneous carbon dioxide partial pressure (PCO2) | 30 minutes | 
| Electromyographic activity of the diaphragm |  | 30 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Cystic fibrosis, High-flow nasal oxygen cannula, Non-invasive ventilation, Respiratory distress, Oxygen therapy