Pre-oxygenation With High-flow Nasal Cannula in Caesarian Section Under General Anesthesia

Study Overview
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Brief Summary
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The investigators and other groups have demonstrated that high-flow nasal oxygen used during preoxygenation for emergency surgery is at least equally effective as preoxygenation compared to standard tight fitting mask. The investigators also have data from a recent study that indicates that high-flow nasal oxygen might decrease the risk of clinically relevant desaturation below 93% of arterial oxygen saturation. The studies investigating the concept of high-flow nasal oxygen has up to this date excluded pregnant women. Pregnant woman is a patient group with known difficulties to maintain adequate saturation levels during apnoea. Due to smaller functional residual capacity their oxygen stores after preoxygenation are smaller compared to patients with a normal body mass index. The pregnant woman also have a higher oxygen demand and metabolism due to the growing placenta and the fetus. Pregnant women are therefore a patient group where a method that could prolong time until desaturation would be even more valuable and potentially could save lives. Based on the above, the investigators now aim to conduct a clinical pilot study, where pregnant women undergoing caesarian section under general anesthesia are pre and perioxygenated with high-flow nasal oxygen. Data from that group will be compared with patients preoxygenated in a traditional manner with tight facemask. This study is done to evaluate an established technique on a patient category that in theory could gain a lot from it.

Official Title
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Pre-oxygenation With High-flow Nasal Cannula in Pregnant Women Undergoing Caesarian Section Under General Anesthesia - a Pilot Study

Conditions
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Pregnancy Related, Anesthesia, Oxygen Deficiency, Cesarean Section Complications

Intervention / Treatment
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* Device: Nasal high flow oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult, >18 years old Caesarian section under general anesthesia. Pregnant in week 30 or later Capable of understanding the study information and signing the written consent. Exclusion Criteria: BMI >45 Dependency on non-invasive ventilation to maintain oxygen saturation

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

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: Non-Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: One intervention group that is compared to a control group that is standard treatment.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Preoxygenation with nasal high flow oxygen<br>Preoxygenation with nasal high flow oxygen | Device: Nasal high flow oxygen<br>* Pregnant women scheduled for cesarian section in general anaesthesia will be preoxygenated using nasal high flow oxygen<br>|
| No Intervention: Control group<br>Standard preoxygenation according to hospital protocol with tight fitting facemask | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of patients with peripheral arterial oxygen saturation below 93% from start of pre-oxygenation until one minute after tracheal intubation and comparison between intervention and control | arterial peripheral oxygen saturation | Up to 1 minute after intubation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of Endtidal concentration of oxygen after intubation between intervention and control |  | The first breaths after intubation eg. within 20 seconds of intubation | 
| Comparison of Endtidal carbondioxide concentration after intubation between intervention and control |  | The first breaths after intubation eg. within 20 seconds of intubation | 
| Comparison of Number of patients with regurgitation of gastric contents between intervention and control |  | During intubation eg up to 0 seconds after intubation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Preoxygenation, Perioxygenation, Nasal high flow oxygen, Cesarian sectio