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Please use this identifier to cite or link to this item: http://hdl.handle.net/11055/755
Title: High-flow humidified nasal preoxygenation in pregnant women: a prospective observational study
Authors: Tan PCF
OJ Millay
Leeton L
Dennis AT
ANZCA/FPM Author: Dennis, AT
Millay, OJ
Tan, PCF
Keywords: pregnancy
cannula
anesthesia, obstetrical
airway management
oxygen
masks
Abstract: Background Obstetric airway guidelines recommend preoxygenation in preparation for general anaesthesia to achieve end-tidal oxygen concentrations (etO2) of ≥90%, and mention the potential use of high-flow humidified nasal oxygen (HFNO). We investigated the new HFNO technique (Optiflow™) in term pregnant women. Methods Seventy-three term participants underwent a 3 min HFNO protocol (30 L min−1 for 30 s, and then 50 L min−1 for 150 s). The etO2 was assessed for the first four breaths after simulated preoxygenation. The primary outcome was the proportion who achieved etO2 ≥90% for the first expired breath. The secondary outcomes were the proportion who achieved etO2 ≥80%; fetal heart rate before and after the test; the association of body mass index (BMI) to etO2 achieved with preoxygenation; and comfort levels of, and preference for, nasal and face mask preoxygenation. Results The proportion with first expired breath etO2 ≥90% was 60% [95% confidence interval (CI): 54–66%] and etO2 ≥80% was 84% (95% CI: 80–88%). There was no change in fetal heart rate from before to after the test (P=0.34). There was a negative association of BMI to etO2 achieved with preoxygenation (Pearson correlation: –0.26; P=0.027). There was no difference in comfort scores between nasal cannula and face mask (P=0.40). Forty-one (56%; 95% CI: 35–47%) women preferred the nasal cannula to the face mask. Conclusions HFNO using this protocol is inadequate to preoxygenate term pregnant women. Despite encouraging results in the literature reporting results in non-pregnant women, further work is required before justifying its use in pregnant women.
URI: http://hdl.handle.net/11055/755
DOI: https://doi.org/10.1016/j.bja.2018.08.015
Journal Title: British Journal of Anaesthesia
Type: Journal Article
Affiliates: The Royal Women's Hospital, Parkville, Australia
The University of Melbourne, Parkville, Australia
Study/Trial: Prospective Cohort Study
Appears in Collections:Scholarly and Clinical

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