Environmental sustainability in anaesthesia and critical care

Abstract

The detrimental health effects of climate change continue to increase. Although health systems respond to this disease burden, healthcare itself pollutes the atmosphere, land, and waterways. We surveyed the 'state of the art' environmental sustainability research in anaesthesia and critical care, addressing why it matters, what is known, and ideas for future work. Focus is placed upon the atmospheric chemistry of the anaesthetic gases, recent work clarifying their relative global warming potentials, and progress in waste anaesthetic gas treatment. Life cycle assessment (LCA; i.e. 'cradle to grave' analysis) is introduced as the definitive method used to compare and contrast ecological footprints of products, processes, and systems. The number of LCAs within medicine has gone from rare to an established body of knowledge in the past decade that can inform doctors of the relative ecological merits of different techniques. LCAs with practical outcomes are explored, such as the carbon footprint of reusable vs single-use anaesthetic devices (e.g. drug trays, laryngoscope blades, and handles), and the carbon footprint of treating an ICU patient with septic shock. Avoid, reduce, reuse, recycle, and reprocess are then explored. Moving beyond routine clinical care, the vital influences that the source of energy (renewables vs fossil fuels) and energy efficiency have in healthcare's ecological footprint are highlighted. Discussion of the integral roles of research translation, education, and advocacy in driving the perioperative and critical care environmental sustainability agenda completes this review.

Seeing the wood for the trees: Insights into reducing inhalational agent consumption

“…The environmental cost of inhalational agents is being increasingly recognised. 2,3 Desflurane is both the most expensive agent in routine use and has far and away the greatest environmental footprint. McGain et al calculate that 1 MAC-hr of desflurane at a fresh gas flow of 1 L/min is equivalent to driving 300 km while for sevoflurane and isoflurane the distances are 6.5 and 13 km, respectively.…”

“…McGain et al calculate that 1 MAC-hr of desflurane at a fresh gas flow of 1 L/min is equivalent to driving 300 km while for sevoflurane and isoflurane the distances are 6.5 and 13 km, respectively. 3 Any steps to reduce desflurane consumption are a good thing. The decrease in desflurane consumption described in the study by Mostad et al 1 is the equivalent to 15-30 kg CO 2 for every case lasting an hour or more.…”

Sustainable veterinary anaesthesia: single centre audit of oxygen and inhaled anaesthetic consumption and comparisons to a hypothetical model

“…As well as avoiding the use of desflurane and nitrous oxide, one simple method of reducing oxygen and IAA consumption, and consequently the release of waste anaesthetic gases into the atmosphere, is to use low‐flow inhalational anaesthesia administered via a circle breathing system in preference to higher flow anaesthesia administered via a non‐rebreathing system (McGain et al . 2020). Although numerous definitions of low‐flow anaesthesia exist they all involve the use of rebreathing anaesthetic systems with fresh gas flows below a patient's minute volume (Meakin 1999).…”

“…Whatever the definition, literature suggests that most anaesthetists in human medicine fail to use efficient fresh gas flows during most anaesthetics (McGain et al . 2020).…”

Fresh gas flow during total intravenous anaesthesia and marginal gains in sustainable healthcare. Comment on Br J Anaesth 2020; 125: 773-8

“…3 Sustainability can be conceptualised using the 'triple bottom line' model, incorporating financial, social, and environmental considerations. 4,5 Zhong's work indicates clear potential for financial benefit, and patient care is unlikely to be affected by FGF rates within the range of 1-6 l.min -1 if a heat and moisture exchanging filter is used. 6 From an environmental standpoint, Zhong and colleagues state that the climate change impacts of different FGF rates within this range is 'minimal' (e.g.…”