Anesthesia and Analgesia: General AnesthesiaHigh-flow Nasal Oxygen Versus Standard Flow Facemask Preoxygenation in Pregnant Patients: A Randomized Physiological StudyShippam, W.; Preston, R.; Douglas, J.; Taylor, J.; Albert, A.; Chau, A.Author Information British Columbia Women’s Hospital; Vancouver, BC, Canada; University of British Columbia, Vancouver, BC, Canada; Women’s Health Research Institute, Vancouver, BC, Canada Obstetric Anesthesia Digest: March 2020 - Volume 40 - Issue 1 - p 46-47 doi: 10.1097/01.aoa.0000652956.31658.b6 Buy Metrics Abstract (Anaesthesia. 2019;75:450–456) While preoxygenation is an important component of safe general anesthesia, it is often suboptimal for obstetric patients. This is due to several factors including air entrainment even with a tight-fitting mask, the need for rapid delivery of the fetus in many situations, and human factor issues. For obstetric patients, an end-tidal oxygen concentration (EtO2) ≥90% is recommended before initiating rapid sequence induction and tracheal intubation. The standard practice for preoxygenation in this population is usually either 3 minutes of tidal volume breathing or 8 vital capacity breaths with facemask administration of 100% oxygen at 15 L/min. Growing in popularity for nonobstetric patients, including children, is high-flow nasal oxygen (HFNO) to increase the time to desaturation during induction of general anesthesia; however, literature on HFNO for obstetric patients is sparse. This study aimed to determine whether preoxygenation with HFNO (30 to 70 L/min oxygen flow) via nasal prongs is as effective as the recommended preoxygenation using standard 15 L/min oxygen administered via a tight-fitting facemask in obstetric patients. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.