This editorial was invited by the Editorial Board of the European Journal of Anaesthesia to accompany the consensus document.1

In the changing healthcare landscape, sustainability has evolved from buzzword to imperative, and so we welcome the release of the European consensus document for sustainable anaesthesia, a significant stride towards aligning healthcare with environmental stewardship.1 At the heart of this document lies a comprehensive framework encompassing reducing emissions, optimising energy use, managing waste and the supply chain and enhancing well being. This approach redefines how we administer anaesthesia, emphasising both patient care and the ecological impact of medical interventions.

Reducing emissions is an important goal, with the healthcare sector playing a significant role. This consensus document delineates different strategies to mitigate our emissions, promoting more environmentally friendly anaesthetic agents, optimising gas delivery systems, and embracing energy-efficient technologies and practices.

Prioritising impact for quantitative sustainability

The document offers numerous suggestions, but pinpointing the most effective ones is challenging, hindering readers from identifying urgent priorities. For example, it may not be immediately apparent that eliminating desflurane (1 minimal alveolar concentration administered with 2 l fresh gas flow (FGF) for 1 h equals approximately 350 kg CO2-Equivalent-Emissions (CO2EE)) or N2O (70% N2O administered with 2 l FGF for 1 h equals 42 kg CO2EE) carries a significantly greater impact than reducing the number of syringes in the regional anaesthesia set (one 10 ml syringe equals around 0.043 kg CO2EE). Likewise, decommissioning of central piping for nitrous oxide should be a top priority because it has an impact several orders of magnitude higher than most other interventions.2

Furthermore, certain measures, while laudable for their environmental benefits, may have limited impact from the standpoint of the average anaesthesiologist. The consensus document should highlight accessible ways for anaesthesiologists to reduce their ecological footprint.

Quantitative approach for rational policy

A quantitative approach is crucial for rational policy decisions. Quantifying the impact of each intervention allows us to first pick the low-hanging fruit. Some interventions can yield a literal 1000-fold greater impact with comparatively less effort than others, a crucial insight to emphasise.

Given that any intervention requires effort, attention and staff adaptation, simultaneously implementing all desired changes is impractical and impossible. Therefore, strategic prioritisation is crucial to optimise ecological benefits with acceptable costs. Life cycle assessments (LCA) provide essential data for accurately measuring intervention impacts. The cradle-to-grave approach enables quantitative comparisons of ecological benefits and comprehensive assessments by revealing emissions from production to disposal. One of the most exemplary illustrations pertains to volatile anaesthetics, where even in the consensus document, they are only referred to as ‘scope 1 emissions’, thereby neglecting their very significant production emissions. However, as with any other LCA of medical devices, production emissions should also be considered. This is crucial for substances like sevoflurane or desflurane, for which production emissions are notably significant, effectively doubling the overall climate impact in the case of sevoflurane.3

Every second counts

An anaesthesiologist using desflurane for 3 weeks (40 h × 3 = 120 h) at 2 l FGF emits 42 000 kg of CO2EE. This surpasses the cumulative emissions over a complete 40-year career using total intravenous anaesthesia (TIVA) (<40 000 kg CO2EE). Similarly, the annual leakage from centrally piped nitrous oxide easily exceeds 1 000 000 kg CO2EE, equivalent to the cumulative lifetime emissions of 25 anaesthesiologists employing TIVA. The disparity in the impact of certain practices is so pronounced that every day of unnecessary pollution exacerbates a profound environmental impact.

Conveying a sense of magnitude

Figure 1 provides a comparative example, illustrating the scale by comparing the annual carbon footprint of various anaesthesia techniques with the annual CO2 emissions of an average EU citizen.

Fig. 1:

Comparing an anaesthetist's annual carbon footprint resulting from the choices for a particular anaesthetic (technique) with an average citizen's emissions.

Avoiding dependence on ‘science fiction solutions’

A notable concern is the imperative to steer clear of pinning our hopes on speculative technologies, such as ultraviolet C (UVC) destruction of volatile anaesthetics, which has yet to find practical applications in clinical settings. Other technologies like zeolite or carbon-based scavenging systems still lack substantiated ecological benefits and may offer only modest improvements at best.

Concentrating on science fiction-like solutions may divert attention from interventions that have undeniably proven to be highly effective. We provide an evidence-based list of top priorities to emphasise the importance of implementing immediate, tangible measures with proven substantial effects. This ensures our efforts target important practices that can be readily adopted into clinical settings.

Priority list

Anaesthesiologists can immediately make great reductions in their carbon footprint by following five consecutive steps, without major effort and without any impact on patient care.4

(1) Inform yourself about N2O leaks in your hospital. If using central piping, ask the technical department about last year's consumption. In typical hospitals, these losses often surpass 1 000 000 kg of CO2EE per year. Eliminate central piping of N2O and, wherever necessary, consider transition to cylinders. (2) Stop using desflurane. (3) Stop using N2O whenever possible. (4) Adopt TIVA as the default maintenance anaesthesia, reserving sevoflurane for specific indications such as mask induction or when vascular access is compromised. (5) Implement minimal flow ventilation when still using volatile anaesthetics. (6) Include climate-friendly anaesthesia programs in anaesthesia residency training. Protecting the climate saves money

Implementing eco-friendly measures can often come with added costs. However, it is crucial to note that sustainable anaesthesia can bring economic benefits, easing its introduction into today's economic landscape. Below, we present two calculation examples.

Modern anaesthesia workstations

At flow rates of 6 l min−1, 2 l min−1 or minimal flow (∼0.3 l h−1), the consumption of sevoflurane amounts to approximately 39, 14, and 7 ml h−1, respectively.5 Two thousand hours of maintenance anaesthesia per year result in sevoflurane consumption of 78, 28 and 14 l, and CO2EE emissions of 167 000, 60 000 and 30 000 kg, respectively.3,6,7 The associated costs (at Belgian prices) for consumed sevoflurane of 32 100€, 11 500€, and 5800€ demonstrate more savings than the depreciation of automated minimal flow anaesthesia workstations.

Total intravenous anaesthesia pumps

Investing in syringe pumps can yield cost savings over sevoflurane within months, offering both environmental and financial benefits. Propofol tender prices may vary, but estimating 2€ per hour of anaesthesia generally overestimates actual costs. The savings, compared with sevoflurane anaesthesia typically far exceed the depreciation cost of modern TCI pumps.

The hidden environmental cost of anaesthetic freedom

Considerations of the ethical dimension of anaesthesia's environmental impact remain unaddressed in the consensus document.

At home, citizens make efforts to reduce their climate impact through choices like improving insulation or avoiding air travel. However, the discretionary decisions made by anaesthesiologists at work can significantly outweigh any individual effort at home. Our generation will need to confront the ethical question: is it justifiable to permit individual anaesthetists’ arbitrary choices, made in the name of therapeutic freedom, to lead to emissions exceeding those of a small village? As we weigh up our choices, we should note that our decisions will have no impact whatsoever on patient outcome.

In conclusion, the consensus document marks a pivotal step in aligning healthcare practices with environmental stewardship. Although the comprehensive framework addresses several meritorious goals, a critical concern arises about the abundance of recommendations. Deciphering the most important and effective measures becomes challenging for the reader, necessitating a quantitative approach for prioritisation. Sustainable practices not only contribute to ecological well being but also are often economically advantageous. As we navigate this transformative journey, acknowledging the ethical dimension and attending to proven, immediate measures will ensure a healthier, greener future for generations to come.

Acknowledgements relating to this article

Assistance with the study: none.

Conflicts of interest: none.

Financial support and sponsorship: none.

This article was handled by Anne-Claire Lukaszewicz

Comment from the Editor: this Editorial was checked by the editors but was not sent for external peer review.

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