Pre-Oxygenation Techniques in Pregnancy

Study Overview
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Brief Summary
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A trial comparing outcomes of two pre-oxygenation techniques in obstetric patients.

Detailed Description
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Pre-oxygenation is performed prior to general anesthesia to prevent hypoxia during airway management. It is typically performed using a standard tight-fitting face mask; however, recent advances in oxygenation have occurred through the use of trans-nasal oxygen delivery devices, such as OptiFlow. There is limited evidence of the use of OptiFlow in the pregnant patient, and as such, this study aims to show that OptiFlow is as effective at pre-oxygenation as a standard tight-fitting face-mask technique in the pregnant population.

Official Title
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A Comparison of Pre-oxygenation Techniques in Pregnant Patients Prior to a Cesarean Delivery - A Randomized Clinical Trial

Conditions
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Preoxygenation

Intervention / Treatment
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* Device: Face Mask preoxygenation
* Device: OptiFlow preoxygenation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy (American Society of Anesthesiologists class 1 or 2), pregnant patients ≥36 weeks gestation scheduled for elective Cesarean delivery under neuraxial anesthesia. Exclusion Criteria: Comorbidities likely to alter outcome of respiration and gas exchange. Patients only able to breathe through their mouth. Patients who are in active labour. Patients unable to tolerate a face mask being held over their mouth and nose. Patients with a Body Mass Index ≥40kg/m2. Patients who are unable to give informed consent.

Ages Eligible for Study
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Minimum Age: 19 Years

Sexes Eligible for Study
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Female

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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Standard Face Mask Preoxygenation<br>Tidal volume breathing for via a face mask set at 100% oxygen and a rate of 15L/min. | Device: Face Mask preoxygenation<br>* Standard face mask preoxygenation.<br>|
| Experimental: Optiflow Preoxygenation<br>Tidal volume breathing with the OptiFlow system applied at 100% oxygen and a flow rate of 30-70L/min. | Device: OptiFlow preoxygenation<br>* Preoxygenation using transnasal humidified rapid insufflation ventilatory exchange (THRIVE).<br>* Other names: THRIVE;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| End Tidal Oxygen Concentration (ETO2) Following Tidal Volume Breathing Using Either Face Mask or OptiFlow | Concentration of oxygen at the end of a breath following 3 minutes of tidal volume breathing using either face mask or OptiFlow | From baseline ETO2 concentration to the end of 3 minutes of tidal volume breathing | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| End Tidal Oxygen Concentration (ETO2) Following Vital Capacity Breaths Using Either Face Mask or OptiFlow | Concentration of oxygen at the end of a breath following 8 deep breaths using either face mask or OptiFlow | From baseline ETO2 concentration to the end of 8 vital capacity breaths (approximately 3 minutes) |