Charing Cross Hospital overhauls anaesthetic supply to reduce carbon footprint

We have taken a big step forward in our efforts to reduce greenhouse gas emissions at Imperial College Healthcare NHS Trust, by switching off the wall supply for nitrous oxide (an anaesthetic gas) at Charing Cross Hospital and introducing a less wasteful alternative supply.

Charing Cross is believed to be one of just a handful of major hospitals in England to decommission its entire nitrous oxide manifold (the system that delivers the gas to the pipelines around the hospital) in one go. This will reduce greenhouse gas emissions by at least 460 tonnes of C02e (carbon dioxide equivalent) a year, which is around one per cent of the Trust’s carbon footprint. The carbon saved is estimated to be the equivalent of driving a petrol car around the earth 57 times. 
Nitrous oxide has been used for over 175 years as part of anaesthesia within healthcare but it is a potent greenhouse gas, estimated to be nearly 300 times worse than carbon dioxide for the environment. Recent research highlighted how a significant proportion of nitrous oxide emissions at older NHS hospitals like Charing Cross is due to waste from manifolds and the associated old pipe structure.
The staff-led project is a big contribution to delivering on the Trust’s Green Plan, specifically the goal of becoming more sustainable in the use of medicines, equipment and anaesthetic gases. It is a result of many months of work to find a solution and test its feasibility and involved teams across the Trust, particularly pharmacy, sustainability, estates, and anaesthetics.
While nitrous oxide is no longer available from wall mounted sockets at Charing Cross, the team has made sure that an alternative supply is accessible for all clinicians who need it. The original switch off took place in May and the manifold has now been decommissioned permanently, following a planned pause to make sure there were no issues.
Dr Tom Dolphin, consultant anaesthetist at Imperial College Healthcare NHS Trust said: “This is a big step forward in our efforts to reduce the Trust’s carbon footprint.
“It’s been a real team effort over many months, with enthusiastic input from our pharmacy, sustainability, estates and anaesthetics teams. I’m delighted we’ve now made the switch permanent, following a pause to ensure there were no issues. We’re now aiming to do the same at other sites in the Trust where nitrous oxide is used.”
Dr Bob Klaber, director of strategy, research & innovation at Imperial College Healthcare NHS Trust, said: “This is a really innovative and impactful project and I’m grateful to the many teams who worked so hard over the past six months to make it possible.
“We are one of the biggest NHS Trusts in the country, with an ageing estate, and are absolutely committed to reducing our impact on the environment and reaching carbon net zero before 2045.”
The Trust also recently installed 'volatile capture technology' (VCT) canisters designed to capture anaesthetic gases at Charing Cross, Hammersmith and St Mary’s hospitals, in a large scale feasibility trial funded by Imperial Health Charity to reduce carbon emissions in surgery. 

Anaesthetic gases are potent greenhouse gases and when patients receive a general anaesthetic, the gases they exhale are normally released via pipes into the atmosphere from the hospital roof. 

The new VCT canisters will capture significant volumes of the exhaled anaesthetic gases, which can then be purified and reused. The team will use the findings from the feasibility trial to make a case to roll this out permanently across the Trust.

Find out more about Imperial College Healthcare’s Green Plan