Preoxygenation with Optiflow – the effect of speech on oxygenation
Research type
Research Study
Full title
Preoxygenation with high flow nasal oxygen using Optiflow - does speech have an effect on end tidal oxygen achieved when compared to closed-mouth nasal breathing.
IRAS ID
231097
Contact name
Patrick Butler
Contact email
Sponsor organisation
R&D Southampton University Hospitals
Duration of Study in the UK
0 years, 4 months, 31 days
Research summary
Before anaesthetists commence anaesthetising patients it is common practice to ask the patient to breathe 100% oxygen for a few minutes (this is called preoxygenation). The reason for this is that the percentage of oxygen in the lungs can be raised from about 21% to 90% so that, when patients stop breathing, the extra oxygen in the lungs acts as a reservoir to keep them well oxygenated whilst the anaesthetist inserts a breathing tube into the airway. If the process of intubating the airway is difficult (eg due to anatomical problems) and prolonged the preoxygenation will give a larger reservoir of oxygen and the patient will be less likely to become poorly oxygenated and come to harm.
Preoxygenation can be done with a normal anaesthetic circuit or with other oxygen delivery equipment such as the Optiflow device. The latter it is most commonly used to treat awake patients with breathing difficulties but is increasingly used in anaesthesia to maintain a flow of oxygen via a patient's nasal airway and may be useful to prevent falls in oxygen levels during difficult intubation of the airway.
The amount of oxygen in the lungs after a period of preoxygenation can readily be measured with standard anaesthetic monitoring equipment.
Preoxygenation is commonly done with the patient breathing through their nose with a closed mouth. However, people often tend to talk to the anaesthetist and this may result in less efficient preoxygenation as they breathe in room air whilst doing so.
This study aims to investigate whether there is a measurable difference in the efficiency of Optiflow preoxygenation (as measured by expired oxygen content) when the patient either breaths only through their nose or when they talk during the process. Talking will be standardised by reading aloud a standardised text.REC name
North of Scotland Research Ethics Committee 2
REC reference
18/NS/0101
Date of REC Opinion
18 Sep 2018
REC opinion
Favourable Opinion