Turning off the anaesthetic gas scavenging equipment in the Royal United Hospital Bath (RUH), day surgery theatre suite when not in use.

Project completed as part of the 2024/25 RUH Bath Green Team Competition.

Team members: Thea Morgan Anaesthetist RUH, Lauren Brain (Anaesthetist RUH)

Setting / patent group: Anaesthetics, day surgery

Issue: Anaesthetics contribute to 2% of the NHS carbon footprint and 5% of acute hospitals carbon footprint. Operating theatres consume 3-6 times more energy than other hospital areas (NHS Scotland, 2023). A key contributor is Anaesthetic Gas Scavenging Systems (AGSS), designed to remove anaesthetic gases for staff safety.

Intervention: This work involved the Estates team and identifying which theatres are interlinked, and how easy it is to turn off various systems. There are three main areas which contain theatres in the RUH and it was felt that starting in day surgery theatres would be a good starting point as each scavenging system can be individually isolated. Day surgery theatres are used in daytime hours Monday to Friday, meaning there are 118 hours a week on average that scavenging is operating when the theatres are not in use. The project was highlighted to the Theatre Services Group and needs to go through further governance channels but has been warmly received. The challenge has

been identifying who will be responsible for turning the scavenging on and off around the theatre list. The project has not resulted in the system being turned off during the night and the weekends to date but has highlighted other areas that teams can look into to try and reduce energy consumption alongside the scavenging systems. Other projects are underway at present to turn off heating and ventilation in areas that are not in use. Previously theatre checklists were in use at the beginning and the end of the list. These lists were routinely used but over time they are not being undertaken regularly. As part of a wider project, the checklists are looking to be reintroduced. The beginning of the list would include a question to check that the scavenging was turned on and then the end of the list checklist would refer to turning off the scavenging system.

Potential Outcomes:

No results currently, once established we intend to monitor incident reporting.

Environmental: It is estimated that if each theatre in day surgery turned off the anaesthetic gas scavenging for 14 hours a day (Monday to Friday) and 48 hours on the weekend when unoccupied, there would be approximately 42,191.23kg of carbon dioxide emissions saved per annum. This is equivalent to driving 124,315km in an average car.

Financial: Each anaesthetic gas scavenging uses around 5kW per hour so if turned off for 14 hours a day (Monday to Friday) and for 48 hours on a weekend and if the cost of electricity is estimated at £0.20 per kW per hour then per theatre the savings to the hospital could be around £6,132 per year. This would have an annual saving over the 5 theatres of around £30,660.

Key learning point:

It was hoped that the project would have been implemented and tested by this point but it is important that we ensure it is safely introduced and the project receives the necessary approvals. The lasting change for the project will hopefully come from embedding this within a wider project to reduce energy consumption within theatres and to ensure the legacy continues.