Low-Flow vs. High-Flow Nasal Cannula for Hypoxemic Immunocompromised Patients During Diagnostic Bronchoscopy

Study Overview
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Brief Summary
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Pneumonia is a lung infection. Fiberoptic bronchoscopy is a test to diagnose the type of lung infection. While this procedure is being performed, a small amount of oxygen is delivered into the nose (low flow nasal cannula). Occasionally during this procedure, the blood oxygen of the patient may drop and an intervention such as increasing the oxygen flow, or placing the patient on a breathing machine is required. An alternative device called 'Optiflow' can provide high flow oxygen through nasal cannula, and is comfortable for patients. If Optiflow is used during bronchoscopy, it may prevent the blood oxygen from dropping.

Detailed Description
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Pneumonia is a lung infection that is a common complication in people with cancer, because of a weak immune system. Fiberoptic bronchoscopy is a test that is commonly used to help doctors diagnose the type of lung infection and treat it appropriately. It involves passing a thin tube with a camera at the end inside the lungs, and taking some fluid samples which are sent for analysis. While this procedure is being performed, a small amount of oxygen is delivered into the nose (low flow nasal cannula). Occasionally during this procedure, the blood oxygen of the patient may drop (even if the patient is receiving oxygen, and especially if the patient has severe pneumonia), and the procedure may have to be interrupted or prematurely stopped. If the oxygen level drops significantly, an intervention such as increasing the oxygen flow, or in the worst-case scenario temporarily placing the patient on a breathing machine is required. An alternative device called 'Optiflow' can provide high flow oxygen through nasal cannula, and is comfortable for patients. Optiflow was approved by Health Canada in 2006, and is commonly used in hospitals in Ontario and around the world to support patients whose blood oxygen is low. If Optiflow is used during bronchoscopy, it may prevent the blood oxygen from dropping.

Official Title
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Low-Flow vs. High-Flow Nasal Cannula for Hypoxemic Immunocompromised Patients During Diagnostic Bronchoscopy: A Randomized Controlled Trial

Conditions
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Hypoxia, Immunocompromised, Hematologic Malignancy, Post Hematopoietic Stem Cell Transplant, Pulmonary Infiltrates

Intervention / Treatment
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* Device: High Flow Nasal Cannula or Low Flow Nasal Cannula


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult patients ≥18 years scheduled to undergo FOB (as determined by their medical care team) who are immunocompromised (active hematologic malignancy or post hematopoietic stem cell transplant), and are hypoxic with pulmonary infiltrates. Hypoxia will be defined as requiring supplemental low flow oxygen ≥ 2L/min by nasal cannula to maintain SpO2 >90%. Exclusion Criteria: requiring supplemental oxygen > 8L/min by nasal cannula; receiving HFNC before randomization; nasal deformity or packing precluding HFNC use; hypercapnia (PaCO2 > 60) or respiratory acidosis (pH <7.25); requiring NIV for over 1 hour or intubated.

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
Interventional Model Description: Patients will be randomized to either HFNC delivered at 50 L/min with FiO2 50% delivered for at least 5 min prior to FOB and throughout the procedure; or to conventional supplemental LFNC delivered at 6L/min applied for at least 5 minutes prior to FOB and throughout the procedure.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Flow Nasal Cannula (HFNC)<br>Oxygen is delivered at 50 L/min with FiO2 50% delivered for at least 5 min prior to FOB and throughout the procedure. | Device: High Flow Nasal Cannula or Low Flow Nasal Cannula<br>* HFNC vs LFNC<br>|
| Active Comparator: Low Flow Nasal Cannula (LFNC)<br>Oxygen is delivered at 6L/min applied for at least 5 minutes prior to FOB and throughout the procedure. | Device: High Flow Nasal Cannula or Low Flow Nasal Cannula<br>* HFNC vs LFNC<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Desaturation during FOB | Any desaturation during FOB or during the 1 hour post-FOB defined as a drop in SpO2 of 4% or more for more than 1 minute or any drop in O2 less than 90%, and necessitating an increase in FiO2 to maintain a saturation ≥92% for at least 1 minute. | The SpO2 will be measured using a bedside SpO2 measuring device during or 1 hour post-FOB defined as a drop in SpO2 of 4% or more for > 1 minute or any drop in O2 <90% necessitating an increase in FiO2 to maintain a saturation ≥92% for at least 1 minute. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Hypoxia, HFNC, Bronchoscopy, Immunocompromised, Hematological malignancy