Improving Theatre Sustainability by rationalising the use of Anaesthetic Gas Scavenging Systems (AGSS) and Ventilation Systems

Improving Theatre Sustainability by rationalising the use of Anaesthetic Gas Scavenging Systems (AGSS) and Ventilation Systems

Project completed as part of Wrightington, Wigan and Leigh (WWL) Green Team Competition 2025.

Team members:  

• Dr Neelam Patel, Consultant Anaesthetist and Clinical Director, Wrightington, Wigan and Leigh Teaching Hospitals NHS FT.
• Mr Marcus Summers, Head of Operational Estates, Wrightington, Wigan and Leigh Teaching Hospitals NHS FT.
• Mr Josh Balmer, Environmental and Sustainability Manager, Wrightington, Wigan and Leigh Teaching Hospitals NHS FT.

Setting

Theatres at Wrightington, Wigan and Leigh Teaching Hospitals NHS FT, starting with Leigh Infirmary (4 day-case theatres) and with potential for wider rollout across 23 theatres trust-wide. 

Issue 

Anaesthetic Gas Scavenging Systems (AGSS) is a vital part of anaesthetic practice as it removes excess volatile anaesthetic gas away from the theatre environment to protect staff within the theatre environment. Theatre ventilation and laminar flow systems regulate environmental temperature and humidity, provide a level of infection control as well as a comfortable ambient temperature to operate in. These systems were running 24/7, despite the four day-case theatres having fixed weekday hours and no overnight activity. 

Intervention 

The team assessed feasibility to implement an automatic “theatre setback mode” at Leigh Infirmary, which would automate the shutdown of AGSS and ventilation systems outside of operational hours (7pm–7am weekdays and all weekend), reducing weekly runtime from 168 to 60 hours. The intervention requires works (e.g. replacing indicator lights, rewiring), automation with manual override for overruns, and staff training to ensure safe use and adoption. Approval for the works is pending. Staff were supportive, and the change encouraged sustainable practice within theatres. 

Outcomes 

Clinical: 

• No direct impact on patient outcomes; safety safeguards (e.g. manual override) maintained.

Environmental: 

• Projected annual carbon savings of 27,783.8 kgCO₂e, equivalent to driving over 81,000 miles in an average car.

Financial: 

• Initial enabling works cost £6,580.80. Net saving of £19,674.58 in year 1, rising to £26,255.39 annually from year 2. Potential for significantly greater savings if replicated across other sites. 

Social: 

• One-off training embedded into daily checks; minimal ongoing burden. 
• Staff engagement was strong, with enthusiasm for the change and its sustainability benefits.

Key learning point

Simple automation, backed by estates collaboration and staff engagement, can unlock substantial carbon and cost savings with minimal risk. Starting in day-case theatres with fixed hours provides a low-barrier, high-impact entry point for sustainable change