A trial comparing outcomes of two pre-oxygenation techniques in obstetric patients.

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.

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.

Adverse event data were collected during study procedures (i.e., from baseline measurements to end of pre-oxygenation at 3 minutes).