Preoxygenation With High Flow Nasal Cannula Prolongs Normoxia Time During Induction of Anaesthesia of Bariatric Patients and is Superior to Conventional Preoxygenation With Face Mask.

Study Overview
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Brief Summary
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To compare preoxygenation for induction of general anaesthesia with High Flow Nasal Cannula vs preoxygenation with face mask in patients undergoing bariatric surgery. The hypothesis is that preoxygenation with High Flow Nasal Cannula prolongs normoxia time during induction of anaeshesia and is superior to conventional preoxygenation with face mask. Primary endpoint will be the time during which spO2 > 92 %. Secondary endpoint will be paCO2.

Official Title
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Preoxygenation With High Flow Nasal Cannula Prolongs Normoxia Time During Induction of Anaesthesia of Bariatric Patients and is Superior to Conventional Preoxygenation With Face Mask.

Conditions
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Compare Preoxygenation Methods in Bariatric Patients

Intervention / Treatment
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* Other: Preoxygenation with High Flow Nasal Cannula
* Other: Preoxygenation via face mask


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age over 18 elective bariatric surgery written consent Exclusion Criteria: preexisting lung diseases, congenital heart diseases known difficult airway SpO2 < 92% under ambient air conditions known diaphragmal hernia clinically relevant reflux

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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Accepts Healthy Volunteers

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: Two groups of patients. One receiving preoxygenation via High Flow Nasal Cannula and one group receiving preoxygenation via face mask
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Preoxygenation via THRIVE/High Flow Nasal Cannula<br>Patients receive preoxygenation for induction of general anaesthesia via High Flow Nasal Cannula for the duration of 5 minutes. After that the induction agents will be given. Now arterial blood gases will be drawn every 2 minutes and the SpO2 will be measured until the 6th apnoeic ABG or if the SpO2 decreases to 92%. After that normal intubation follows. | Other: Preoxygenation with High Flow Nasal Cannula<br>* Preoxygenation for 5 minutes via High Flow Nasal Cannula. After induction of anaesthesia apnoeic oxygenation with HFNC<br>|
| Active Comparator: Preoxygenation via face mask (PROX)<br>Patients receive preoxygenation for induction of general anaesthesia via tight fitting face mask for the duration of 5 minutes. After that the induction agents will be given. Now arterial blood gases will be drawn every 2 minutes and the SpO2 will be measured until the 6th apnoeic ABG or if the SpO2 decreases to 92%. After that normal intubation follows. | Other: Preoxygenation via face mask<br>* Preoxygenation for 5 minutes via face mask. After induction of anaesthesia apnoeic oxygenation with tight fitting face mask<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Normoxia time SpO2 > 92% | Time in which the SpO2 remains > 92% while patient is apnoeic | 10 Minutes after induction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| paCO2 | Increase in arterial CO2 during Apnoea | 10 Minutes after induction |