Nitrous oxide is a potent greenhouse gas with 300 times the warming potential of carbon dioxide and is an ozone-depleting substance. It makes up at least 80% of NHS medical gas emissions. Evidence shows that between 75-99% of procured gas never reaches clinical use.
To support NHS Trusts to reduce nitrous oxide waste safely and efficiently, we’ve published the Nitrous Oxide Toolkit: Reducing waste in NHS trusts. This interactive tool has been developed using the learnings and experiences of trusts across the country and provides practical guidance for others doing this work.
How can we reduce nitrous oxide waste in NHS trusts, and why should we?
Nitrous oxide and nitrous oxide/oxygen mixture are used in many clinical settings across the NHS, delivered through vast stretches of piping hidden inside hospital walls. Alifia Chakera, a pharmacist in Scotland, was the first person to realise that a large majority of gas is wasted through these pipeline systems before reaching patients. Evidence from many hospitals has since revealed that through pipeline leaks, oversupply and inefficient stock management, up to 75-99% of procured gas never reaches clinical use.
Trusts can reduce this waste by using supply systems that are simpler, require smaller volumes of gas and are often portable. This allows clinicians to use small cylinders of the gas where they are needed, without relying on vast piped systems.
Why this matters
In addition to reducing greenhouse gas emissions from waste gas leaking out of the system, multiple trusts that have done this work have also reported cost savings. Complex medical gas pipeline systems are costly to maintain, especially when oversized. Trusts have reported savings of thousands of pounds when gas supply systems are down-sized. This is because trusts no longer need to maintain and invest in complex systems and can reduce the amount of gas they buy.
As maintaining and supplying these complex systems also takes up staff time and resources, some trusts have found that using a smaller, simpler system frees up staff time, enabling them to do other critical tasks.
Solutions across different clinical settings
From our work developing a toolkit to share learnings and provide practical guidance to help teams in the NHS reduce nitrous oxide, it’s clear that all trusts with a medical gas pipeline supply system for anaesthesia can move to a portable cylinder supply system, aligned to clinical need. This is supported by the consensus statement from the Royal College of Anaesthetists and, based on evidence from early adopters, could lead to significant reductions in both emissions and gas consumption.
For nitrous oxide/oxygen mixture (known as gas and air or Entonox), trusts with a medical gas pipeline system in areas of low clinical use (such as endoscopy and emergency departments) can move these clinical areas to a portable cylinder system and decommission parts of the pipeline system that deliver to these areas. This can significantly reduce the volume of gas procured and the associated emissions, again by up to 99%.
For high clinical use areas like maternity, removing a medical gas pipeline supply requires careful consideration of clinical workflows and patient care needs. We have seen some examples, like King’s College Hospital NHS Foundation Trust and Hull University Teaching Hospitals NHS Trust, working to ensure that nitrous oxide/oxygen mixture delivery to maternity is effective for patients and staff, whilst also reducing waste and environmental impact. With more trusts working to identify waste levels in maternity and innovate towards more efficient delivery models, there’s significant potential for reducing both emissions and costs.
For all clinical areas, trusts can make improvements to systems. These include enhancing stock control of gas cylinders to match clinical need and avoiding waste due to overstocking or expiry and monitoring cylinder use to identify system inefficiencies, ensuring equipment is regularly checked and maintained. It also involves encouraging clinical best practices like disconnecting demand valves and depleting cylinders fully before replacement. Small changes can add up to significant waste reduction over time.
Our collaborative approach
We have delved into the experience of clinicians, sustainability leaders and staff in the NHS who have been involved in nitrous oxide waste reduction work. Through interviews, focus groups and site visits across trusts from all seven regions in England, we found that many learned similar lessons and faced similar challenges. Our toolkit brings together those experiences, sharing them widely to benefit all NHS trusts.
We found there wasn’t a one-size-fits-all approach to reducing nitrous oxide waste. The toolkit has been designed to be flexible to maintain relevance in different settings and contexts, whilst being clear on the key actions required to reduce waste. Each section has been tailored specifically for different stakeholders and equal focus has been given to different clinical areas, that require different solutions.
Through creating the toolkit we have built a community of practice, a culture of sharing, and ultimately a blueprint for overcoming the barriers.
Looking ahead
Looking ahead, the collaborative approach that shaped this guidance must continue to evolve to address the challenging issue of waste from nitrous oxide/oxygen mixture. To do so, trusts must embrace innovative, multidisciplinary collaboration – drawing on the expertise of engineers, clinicians, pharmacists and others, as shown in successful examples of this work. Exploring and testing new strategies, across the system, is the best way to tackle this ongoing challenge.
Thank you to the NHS staff who have contributed their time and efforts to create the toolkit and help ensure that it provides useful and enduring advice for all those working to reduce nitrous oxide emissions in healthcare.