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Sustainability of Entonox in obstetrics: a qualitative study

02 February 2023
Volume 31 · Issue 2



Nitrous oxide is a potent greenhouse gas widely used in childbirth in the form of Entonox. In this study, its use was investigated because of its negative climate effect. The study aimed to identify and investigate midwives' use of Entonox in the labour ward of a tertiary Scottish hospital.


This qualitative service evaluation was conducted using semi-structured interviews with 10 midwives and an environmental sustainability manager. Thematic analysis using combined deductive and inductive approaches were used to analyse the data.


Deductive analysis revealed all six work systems factors from the system engineering initiative for patient safety framework to be pertinent to Entonox use in the labour ward, with specific influences and perceived outcomes of Entonox use found through inductive analysis.


A reduction in Entonox use would be difficult, but changes have been recommended to raise awareness among healthcare staff of Entonox risks and create a more environmentally sustainable work system.

Environmental sustainability in healthcare has become an NHS priority. Climate change is now acting as a serious threat to human health globally (Kotcher et al, 2021) and given that the provision of healthcare is a known pollutant (Lenzen et al, 2020), it is imperative that health services lead by example in combating such effects. As an organisation, the NHS has stated that more must be done to meet the targets set out by the 2008 Climate Change Act and that development of current practice is required (Winter, 2019). NHS England set targets in line with the NHS net zero commitment for the NHS carbon footprint to be net zero by 2040, aiming for an 80% reduction in this area by 2028–2032 (NHS England, 2020).

Anaesthetic gases make up 5% of the carbon footprint for acute organisations, with nitrous oxide and desflurane being the greatest culprits for negative climate effect (Charlesworth and Swinton, 2017). A 2020 paper suggested that a vital measure anaesthetists can take is to avoid these anaesthetic gases to limit their carbon footprint (McGain et al, 2020). Nitrous oxide is widely used in childbirth as Entonox, a 50:50 mix of nitrous oxide and oxygen. Improving sustainability in the context of nitrous oxide use requires identifying all relevant factors that influence its use in healthcare settings, specifically in labour wards where Entonox is widely used (Care Quality Commission, 2021).

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