Evaluation, quantifying and minimising the carbon footprint of inhalational anaesthesia in operation theatres at the Children’s Hospital at Westmead.


  • Reza Kahlaee The Children’s Hospital at Westmead
  • Justin Skowno The Children’s Hospital at Westmead
  • Andrew Weatherall The Children’s Hospital at Westmead


Background: Inhalational anaesthetic agents, particularly Nitrous, have significant global warming effects. We are uniquely positioned to minimise our carbon footprint through the change of conduct of practice. To quantify the local significance, we undertook an audit of CHW’s inhalational anaesthetic usage over the past 12 months to quantify both the carbon footprint (in equivalent tonnes of CO2) and the monetary cost of our inhalational anaesthetics. The Nitrous carbon footprint was significantly greater than that of the volatile agents, and the financial cost was not insignificant. This data highlights the potential for significantly reducing our department’s carbon footprint by minimising Nitrous use and limiting fresh gas flows. A significant portion of this consumption likely occurs at the point of gas induction which creates a point of practice change that could have significant reductions in overall gas usage.

Aims: Minimising the carbon footprint of inhalational anaesthesia at the Children’s Hospital at Westmead (CHW), Creating a database (DB) for ongoing access to anaesthesia/surgical data for future research purposes.

Methods: Physiological data, anaesthetic volatiles, Nitrous, and medical air used in all anaesthesia-induced operations were captured, anonymised and restored in a DB using anaesthetic machines and electronic monitors in surgical wards at CHW from 15.10.2021-15.10.2022.

Results: Recent rationalisation in volatile anaesthetic consumption at Royal North Shore Hospital (RNS) achieved a 12-month change of 66% reduction in eCO2 and $82000 reduction in the direct cost of volatiles (39.3). For comparison, RNS does ~20000 cases per year (baseline ~1200 tonnes eCO2 footprint), and CHW does ~15000 cases per year (baseline ~2300 tonne eCO2 footprint).

Conclusions: Similar changes implemented at CHW would be equivalent to an over 1,500-tonne reduction in eCO2 and over $165,000 in direct cost savings each year.





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