Apneic Oxygenation Via Nasal Cannulae: 15 L/Min vs High-Flow

Study Overview
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Brief Summary
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This is a randomized clinical trial investigating the utility of apneic oxygenation via nasal cannulae in the post-induction setting for the purpose of prolonging the safe apneic time. Three groups will be compared, a control group at 0 L/min, a 15 L/min and a 60 L/min group. The primary outcome will be the difference in the partial pressure of oxygen in arterial blood (PaO2) between groups throughout the nine-minute apneic period.

Detailed Description
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Airway management can be a life saving therapy. One major complication that may occur during airway management is a lack of oxygen in the blood. If severe or prolonged, this lack of oxygen can result in permanent brain damage, damage to other vital organs or even death. Strategies already exist to help prevent a lack of oxygen in the blood (hypoxemia), however research involving new ways to oxygenate patients may help to minimize the chance of hypoxemia during airway management. Apneic oxygenation is a novel method of delivering oxygen to a patient despite a lack of active respiration (i.e. the patient is not breathing on their own and the investigators are not providing the patient an artificial breath). The simplest and least invasive method to provide apneic oxygenation is the application of oxygen through nasal cannulae during airway management. Several different techniques to provide apneic oxygenation via nasal cannulae have been previously described(1-3), however randomized trials comparing these methods do not exist. This study will examine the change over time of the amount of oxygen dissolved in the blood (PaO2) in each of the three treatment groups: a control group (no apneic oxygenation), a 15 L/min group and a 60 L/min group. This data will help to determine the extent of benefit apneic oxygenation provides in this setting.

Official Title
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Apneic Oxygenation Via Nasal Cannulae: 15 L/Min vs High-Flow

Conditions
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Apneic Oxygenation

Intervention / Treatment
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* Drug: 0 L/min oxygen via conventional nasal cannulae
* Drug: 15 L/min oxygen via conventional nasal cannulae
* Drug: 60 L/min oxygen via high-flow nasal cannulae


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of Anesthesiologists Physical Status Classification 1 to 3 Body Mass Index 28 to 35 Elective surgery under general anesthesia Exclusion Criteria: Evidence of difficult airway management (from patient history or clinical examination) Features suggestive of difficult bag mask ventilation Significant uncontrolled gastroesophageal reflux disease Significant respiratory disease (including severe asthma or chronic obstructive pulmonary disease, oxygen dependency, pulmonary hypertension, identified by pulmonary function tests or inability to climb one flight of stairs) Significant cardiac disease (ischemic heart disease, severe valvular disease, severe arrhythmia, congestive heart failure, ejection fraction < 50%, inability to climb one flight of stairs) Inability to lie flat (skeletal deformities, orthopnea) Hemoglobin < 100 g/L Pregnancy Neuromuscular disorder Known or suspected cervical spine instability Patients undergoing neurosurgical procedures Any clinical or radiological evidence of increased intracranial pressure Any expected requirement for rapid sequence intubation Allergy to any of the agents used for induction of general anesthesia in the study Contraindication to insertion of radial artery cannula Uncorrected coagulopathy Significant nasal obstruction

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 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: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: 0 L/min<br>These participants will receive 0 L/min oxygen via conventional nasal cannulae during the apneic period. | Drug: 0 L/min oxygen via conventional nasal cannulae<br>* Patients will have conventional nasal cannulae placed under chin prior to induction of anesthesia. Immediately post-induction these will be placed into the nares. They will be removed from the nares at the end of the study when the airway has been secured. There will be no oxygen flowing through the cannulae in this group during the study.<br>* Other names: 0 L/min apneic oxygenation;|
| Experimental: 15 L/min<br>These participants will receive 15 L/min oxygen via conventional nasal cannulae during the apneic period. | Drug: 15 L/min oxygen via conventional nasal cannulae<br>* Patients will have conventional nasal cannulae placed under chin prior to induction of anesthesia. Immediately post-induction these will be placed into the nares. They will be removed from the nares at the end of the study when the airway has been secured. There will be 15 L/min of oxygen flowing through the cannulae in this group during the study.<br>* Other names: 15 L/min apneic oxygenation;|
| Experimental: 60 L/min<br>These participants will receive 60 L/min oxygen via high-flow nasal cannulae during the apneic period. | Drug: 60 L/min oxygen via high-flow nasal cannulae<br>* Patients will have high-flow nasal cannulae placed under chin prior to induction of anesthesia. Immediately post-induction these will be placed into the nares. They will be removed from the nares at the end of the study when the airway has been secured. There will be 60 L/min of oxygen flowing through the cannulae in this group during the study.<br>* Other names: 60 L/min apneic oxygenation;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PaO2: repeated measures every 90 seconds after induction | data collected from serial arterial blood gas measurements | 0-9 minutes after induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Partial pressure of carbon dioxide in arterial blood (PaCO2): repeated measures every 90 seconds after induction | data collected from serial arterial blood gas measurements | 0-9 minutes after induction | 
| Lowest oxygen saturation by pulse oximetry (SpO2) encountered during study | continuous monitoring: data collected from electronic charting software | 0-9 minutes after induction | 
| Time to desaturation below 95% SpO2 | continuous monitoring: data collected from electronic charting software | 0-9 minutes after induction | 
| Number of participants with SpO2 below 95% | continuous monitoring: data collected from electronic charting software | 0-9 minutes after induction | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Tracheal intubation, High flow nasal oxygen, Airway management, Apneic oxygenation