Horton General Hospital is set to greatly reduce its carbon emissions following a change to the way it delivers nitrous oxide.

More than 500 tonnes of carbon dioxide equivalent (CO2e) will be saved every year at the Banbury hospital due to the decommissioning of its nitrous oxide (N2O) manifold.

Since February, it has switched to a portable supply of N2O delivered in small cylinders when needed.

N2O, whilst used in healthcare for sedation and pain relief, is a harmful greenhouse gas.

In the past, it was distributed via a manifold, a system delivering it to pipelines throughout the hospital.

Audits across UK hospitals have found this to be wasteful.

The current approach delivers the gas on an individual basis, meaning significantly less is kept on-site.

The hospital previously used only about five per cent of N2O ordered - amounting to around 618 tonnes CO2e.

It is projected that roughly 95 per cent of this, or 587 tonnes CO2e, can now be saved annually.

This CO2e reduction equates to 261,586 return train journeys between Banbury and Oxford, 345 tonnes of plastic, or leaving a low-energy light bulb on for 39,133 years.

It is also expected to save approximately £8,000 annually from 2025 onwards.

Dr Marta Astraverkhava, a consultant anaesthetist at Oxford University Hospitals NHS Foundation Trust (OUH), said: "We as a team were determined to identify nitrous oxide wastage so we could reduce its environmental impact and support the trust and NHS-wide pledge to be net zero by 2040.

"We are proud to be able to change our approach at the Horton and vastly reduce the amount of nitrous oxide being wasted."

Shifting to N2O cylinders that attach directly to the anaesthetic machines, as opposed to being transported via long pipes, increases efficiency and eliminates risk of leaks.

Horton General Hospital accounts for nearly half of the total N2O footprint across the four OUH hospitals.

It is the first to transition from wall supply to portable gas provision with the Nuffield Orthopaedic Centre, Churchill Hospital and John Radcliffe Hospital, all in Oxford, planning to follow suit.

Mark Holloway, chief estates and facilities officer with responsibility for sustainability at OUH, said: "Exploring the disposal of nitrous oxide across the trust was an action included in the OUH Green Plan, so we are pleased to make such a big step forward in our efforts to reduce the trust’s carbon footprint in this way.

"While we still have work to do to reduce nitrous oxide across the wider organisation, I am thankful to my colleagues whose hard work and dedication to delivering sustainable improvement has delivered this important project."