BELA
Research type
Research Study
Full title
Breathing patterns during Entonox Labour Analgesia
IRAS ID
364852
Contact name
Christopher J Mullington
Contact email
Sponsor organisation
Intersurgical Ltd
Duration of Study in the UK
1 years, 11 months, 29 days
Research summary
Nitrous oxide is a potent greenhouse gas and prolonged occupational exposure is harmful. Entonox, a 50:50 mix of nitrous oxide and oxygen, has not been decommissioned as a means of delivering pain relief in labour because there are no viable alternatives. Sevoflurane is more sustainable and less harmful alternative to Entonox. However, currently there are no suitable administration devices. Intersurgical Ltd are developing a device to deliver sevoflurane labour analgesia, but to ensure the device delivers the correct dose of sevoflurane a greater understanding of breathing patterns during labour is required.
The primary aim of this physiological study is to record the breathing patterns of women whilst they use Entonox for labour pain relief. A secondary aim is to examine how effective Entonox is in relieving labour pain.
30 women will be recruited, and their breathing patterns will be recorded with a flow sensor attached to the Entonox mouthpiece. Nitrous oxide concentrations will be recorded with a gas analyser and pain relief will be assessed with questionnaires.
This study constitutes a vital step in the development a novel method of delivering pain relief during labour which, if successful, could lead to the decommissioning of Entonox.
REC name
London - Surrey Borders Research Ethics Committee
REC reference
26/PR/0199
Date of REC Opinion
26 Mar 2026
REC opinion
Further Information Favourable Opinion