High-flow Nasal Oxygenation in Obese Patients During Apnea

Study Overview
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Brief Summary
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Before going off to sleep patients are given oxygen to saturate blood with oxygen to extend time before a decrease in the level of oxygen in the blood occurs. During this period, obese patients have a faster decrease in the level of oxygen in their blood. This study uses a device called high-flow nasal cannula (HFNC), which delivers humidified high-flow oxygen through 2 small plastic tubes placed just inside nostrils. In the intensive care unit settings this device has been used extensively and has become a standard practice. Purpose of this study is to determine whether these high-flow nasal cannula increase the time safely when going to sleep during elective surgery.

Official Title
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Effectiveness of Apneic Oxygenation Using High-flow Nasal Cannula in Morbidly Obese Patients Undergoing General Anesthesia

Conditions
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Apneic Oxygenation, High-flow Nasal Cannulae, Bariatric Surgery, Anesthesia Induction

Intervention / Treatment
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* Device: HFNC
* Device: CON (control)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age more than18 years old ASA status I-III Elective surgery performed under general anesthesia requiring endotracheal intubation BMI more than 40 kg/m2 Exclusion Criteria: Chronic respiratory disease SpO2 <98% after supplementing oxygen Previous or anticipated difficult intubation Uncontrolled hypertension Ischemic heart disease Congestive heart failure Increased intracranial pressure Uncontrolled GERD Known allergy or contraindication to anesthesia drugs Nasal blockade contraindicating the use of HFNC

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: Parallel Assignment
Interventional Model Description: Consented patients will be randomly assigned either to the interventional group (High Flow Nasal Cannula- HFNC) or to the control group (CON). The Group HFNC will be preoxygenated using HFNC and the Group CON will receive standard preoxygenation.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: HFNC (High Flow Nasal Cannulae)<br>High Flow Nasal Cannulae providing humidified, high-flow oxygen during induction of anesthesia | Device: HFNC<br>* High flow nasal oxygen (60 l) under GA<br>|
| Active Comparator: CON (control)<br>Standard flow oxygen during induction of anesthesia | Device: CON (control)<br>* Standard oxygen (10-15 l) under GA<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurement of safe apnea time | Safe apnea time, defined by time to desaturation (SpO2 > 95%) or apnea maximum up to 6 minutes | Maximum up to 6 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Highest EtCO2 | Highest EtCO2 on commencing ventilation | Every minute up to 5 minutes on commencing ventilation | 
| Lowest SpO2 | Lowest SpO2 during intubation procedure | Every minute up to 5 minutes after intubation | 
| Time to regain baseline SpO2 | Time to regain baseline SpO2 after intubation | Up to 5 minutes after intubation |