Related Experiment Video
Updated: Jun 14, 2025
Retinal Vascular Reactivity as Assessed by Optical Coherence Tomography Angiography
Published on: March 26, 2020
Pre-oxygenation using high flow humidified nasal oxygen or face mask oxygen in pregnant people - a prospective
P C F Tan1, P J Peyton2, A Deane3
1Department of Critical Care, The University of Melbourne, Parkville, Victoria 3052, Australia; The Royal Women's Hospital, 20 Flemington Road, Parkville 3052, Australia.
Background:
Airway guidelines recommend pre-oxygenation of obstetric patients to an end tidal oxygen concentration (etO2) ≥90%. High flow nasal oxygen (HFNO) achieves this in 60% of pregnant people. However face mask (FM) pre-oxygenation also may not achieve this target in all patients. In this study we determined whether HFNO pre-oxygenation is non-inferior to FM pre-oxygenation.
Methods:
This randomised controlled crossover non-inferiority trial was conducted on healthy participants of gestational age ≥37 weeks in a simulated environment. Participants underwent pre-oxygenation for three minutes with HFNO and FM oxygen in randomised order. HFNO was delivered at a maximal flow of 70 l.min-1 and FM oxygen at 10 l.min-1. The primary outcome was etO2 on first expired breath after pre-oxygenation. Non-inferiority was defined as a mean difference in first etO2 between groups of ≤5%.
Results:
Seventy participants were randomised with 62 analysed. Age (mean (SD)), gestation (median (IQR)), and body mass index (median (IQR)), were 34.7 (4.6) years, 39 (38.4, 39.4) weeks, 29 (26.6, 32.4) kg.m-2 respectively. First etO2 after HFNO pre-oxygenation was greater than after FM pre-oxygenation (HFNO pre-oxygenation mean (SD) 90.2 (3.9)% versus FM pre-oxygenation 88.7 (3.0)%; mean difference = 1.45%, 95% CI 0.19 to 2.72%; p = 0.025. Forty-four (71%) participants achieved ≥90% first etO2 concentration after HFNO pre-oxygenation versus 27 (44%) after FM pre-oxygenation (p = 0.002).
Conclusions:
In this cohort of pregnant people at term in a simulated environment, pre-oxygenation with HFNO was not inferior to FM pre-oxygenation. FM pre-oxygenation did not achieve pre-oxygenation targets in over 50% of participants.
Related Concept Videos
01:30Administering Oxygen by Mask
Administering oxygen by mask is a common nursing intervention that provides supplemental oxygen to patients with respiratory distress or chronic lung conditions. This procedure involves delivering oxygen at a specified rate through a face mask connected to an oxygen source.
Equipment
The equipment necessary for this procedure includes:
01:26Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
01:29Administering Oxygen by Nasal Cannula
Nasal Cannulas
A nasal cannula is a lightweight tube split into two prongs placed in the nostrils,...
01:16Oxygen Delivering System II: Venturi Mask and Transtracheal Oxygen
Venturi Mask
The Venturi mask, named after the Venturi effect, is designed to deliver precise oxygen concentrations. It consists of a large tube with an oxygen inlet that narrows down, causing a pressure drop that pulls air in through adjustable side ports. The mask is a lightweight,...
01:16Treatment for Pulmonary Arterial Hypertension: Oxygen Therapy for Respiratory Failure
Oxygen therapy is vital in increasing and maintaining blood oxygen levels in PAH patients. As a result, it aids in reducing fatigue,...
01:19Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...