Anaesthesiologists and the Climate Crisis: Driving Change Through Green OT Initiatives

Let Us Do Our Bit to Protect Environment

Climate change crisis has become an existential danger of our time. As Secretary-General of United Nations António Guterres pointed out “The climate emergency is a race we are losing, but it is a race we can win”. Urgent action is required to halt its progression.

The greenhouse effect is a natural process where greenhouse gases (GHG) in Earth’s atmosphere trap heat, warming the planet and making it suitable for life. While essential, human activities that increase greenhouse gas emission intensify this effect, leading to global warming and climate change. The primary gases contributing to climate change, in order of their impact are Carbon dioxide (CO₂), Methane (CH₄) and Nitrous oxide (N₂O) and few others.

Global temperature changes are measured against the average temperature over a pre-industrial baseline of 1850–1900. This baseline is the earliest period for which high-quality observations of surface temperatures over the land and ocean are available. The average surface temperature currently is about 1.2°C above the 1850-1900 average. Even at current levels of global warming, we are already seeing devastating climate impacts, with widespread harms to people, economies, and nature.

The United Nations Intergovernmental Panel on Climate Change (IPCC) has made increasingly strident calls for humanity to reduce anthropogenic greenhouse gases. The latest IPCC report states that “strong, rapid, and sustained” greenhouse gas reductions are needed to limit global heating to 1.5°C.

Why is it important to not exceed 1.5°C?

Exceeding 1.5°C could trigger multiple climate tipping points with abrupt, irreversible impacts on humanity. The scientific evidence is unequivocal. Any further delay in combined global action will miss the rapidly closing window to secure a livable future.

Contribution of healthcare sector to climate change and how can it be mitigated?

Healthcare is responsible for 5% of global greenhouse gas emissions. Majority of greenhouse gas emissions is through extensive energy consumption, medical equipment purchases, and inappropriate management waste. Healthcare is expected to increasingly contribute to climate change, with increasing demand for healthcare worldwide. Although our understanding of the links between the environmental and economic sustainability of the healthcare system and the climate change is still in its infancy, healthcare facilities have a significant role to play in fighting climate change by implementing “green interventions” and sustainability strategies.

The Health and Environment Leadership Platform (H.E.L.P.) is an Indian network established by the Public Health Foundation of India (PHFI) in partnership with Health Care Without Harm (HCWH) in 2017 to promote environmental sustainability and climate resilience in the Indian healthcare sector. National Programme on Climate Change and Human Health (NPCCHH) is a flagship programme of the Ministry of Health and Family Welfare (MoHFW). Comprehensive Green and Climate Resilient Healthcare guidelines have been prepared (2023) to support the strengthening of the healthcare system in India.

Green Interventions, Targeting Healthcare Providers

• Improving energy use: On-site generation of renewable, energy monitoring, eco-friendly building design for green hospitals are identified as key operational measures. Simple measures to reduce consumption like switch off policy with regular walk rounds, purchasing energy efficient equipment and its maintenance, use of LEDs appear to have a significant potential to combat climate change.
• Reducing material and medical waste: Single-use plastics from consumables is important sources of GHG emissions. Promotion of reusable material and sustainable strategies for management of biomedical and general waste is an important crucial area.
• Circular economy paradigms in the healthcare industry: Reduce, Retain/Reuse, Reprocess, Repair/Refurbish, Repurpose, Recycle. Recycling is the lowest-impact circular economy strategy since it requires additional energy and material inputs to recover value from materials.
• Water conservation via low-flow fixtures and rainwater harvesting.
• Reducing food waste: The environmental footprint of food waste in the healthcare sector is higher than in the business sector. Interventions like reducing portion sizes or letting patients select their meals and using reusable service ware will help reduce carbon foot print.
• Sustainable Procurement: Choosing to purchase medical supplies, cleaning products, and equipment from vendors with environmental considerations in mind.
• Replacing polluting medical gases: In addition to inhalational anaesthetics, metered dose inhalers (MDI) are identified as one of the main drivers of GHG emissions in medicine, especially with increasing prevalence of respiratory diseases. Replacement of chlorofluorocarbon with hydrofluorocarbon inhalers and dry-powder inhalers, which have significantly lower environmental impact has been a major improvement reported in literature.
• Policies for reducing Low-Value Care: Examples of Low-Value Care are unnecessary diagnostic tests, ineffective treatments (e.g. treatments having little evidence of benefit).
• Innovating medical practice: New care protocols using telehealth solutions where appropriate.

Importantly, a few studies have shown financial benefits with climate mitigation efforts at facility level.

Environmental Sustainability in Operating Room and Perioperative Settings

Operating Rooms and related activities are the most resource intensive, generating 20-30% of total hospital waste. Anaesthesiologists being closely associated with operating room can lead in mitigating the negative environmental effects of operating room activities. Additionally, adopting some anaesthesia practice changes we can definitely contribute in reducing our carbon foot print as anaesthesiologist without compromising patient care.

Anaesthesia Equipment Choice and Practices

Anaesthesia is an equipment-intensive and waste-intensive specialty. The usual trend is toward increasing use of disposable equipment. Disposable equipment appears to be a very wasteful option. Although this is true in many cases, assumption alone may not be enough. Sustainability must be examined carefully. There must be a quantifiable analysis of sustainability along with cost and safety. Life cycle assessment (LCA) is an internationally accepted scientific method of such quantification. A Life Cycle Assessment, “cradle-to-grave” analysis, evaluates the entire environmental impact of a product/service, from raw material extraction (“cradle”) through manufacturing, distribution, use, and ultimate disposal (“grave”). A systematic review of perioperative product life cycle assessments found that reusable products were environmentally preferable to disposables.

Anaesthesia Management and Choice of Anaesthetics

Environmental Impact of Inhaled Anaesthetics

Inhaled Anaesthetics (volatile halogenated organic compounds and nitrous oxide) are recognised greenhouse gases and are significant contributor to healthcare-related greenhouse gas emissions with global warming potentials (GWP) ranging from 144 to 2540 times that of carbon dioxide. Nitrous oxide, additionally, has ozone layer destructive property. Inhaled anaesthetics account for 5% of total hospital’s carbon dioxide equivalent (CO2e) emission and responsible for 0.01% to 0.10% of total CO2e emissions that contribute to global warming.

The impact of inhaled anaesthetic agents on the environment will depend on the total amount used and released to the atmosphere and its GWP. The total amount released to atmosphere depends on the fresh gas flow rate, and the potency (MAC) of the agent. A higher MAC (lower potency) means greater quantities of gas must be used relative to other gases at similar fresh gas flows.

Table: Comparative Greenhouse Gas Emission of Common Inhaled Anaesthetics

MAC: Mean alveolar concentration; Based on EPA 2022 emission factor of 4.03×10^-4 metric tonnes of CO₂ equivalent per mile for average passenger vehicle; *MAC equivalent used for comparison, however use is typically 50-60%. (adapted from- Ryan et al; Global warming potential of inhaled anesthetics: application to clinical use. Anesth Analg. 2010;111(1):92-98.)

Choice of Agent

While the interventions required to mitigate environmental impacts of all inhalational agents are important, desflurane and nitrous oxide should receive more attention considering its impact on climate change.

Desflurane
Desflurane has a high GWP and due to its high MAC value (6%) compared to sevoflurane and isoflurane requires more quantity. Thus, the global warming potential of desflurane, scaled by clinical potency, becomes approximately 40-50 times that of sevoflurane and isoflurane over a 100-year period. There are no indispensable qualities of desflurane that cannot be achieved using other means having less environmental impact. Thus, desflurane should be avoided whenever possible. Desflurane is also significantly more expensive. Some health systems have started to eliminate desflurane from their pharmacy formularies. Scotland has become the first country to ban desflurane and in 2023 stopped its purchase. European Union and England have plans to do same in near future.

Nitrous oxide
Nitrous oxide is less potent (MAC 105) and is used in high concentrations (50-60%). Additionally, it has a very long atmospheric lifetime (114 yrs) and, therefore, in clinically relevant doses, its global warming impacts are similar to desflurane. Use of nitrous oxide decreases the requirement of volatile agent, but this positive impact is offset by its long atmospheric half-life and its effect on ozone layer. Another important consideration is that vast amount of N2O is lost at the point of central piping manifolds connections. This has led to calls for decommissioning nitrous oxide central piping and avoiding new construction. Substituting portable tanks (E-cylinder), and closing them between each use, reduces losses dramatically. Even, removing nitrous oxide from hospital formularies is being suggested by many, including paediatric specialists, who are beginning to suggest that its use is unnecessary.

At the least desflurane and N2O should be reserved only for cases where these agents are clearly preferred for clinical reasons.

Moving From Knowledge to Action Without Compromising Patient Care: Recommendations (Summary)

• Avoid inhalational anaesthetics with disproportionately high climate impacts (Desflurane, N2O).
• Substituting N2O central piping by portable canisters.
• Lowest possible FGF rates selected (e.g. <1/min during maintenance).
• Consider regional anaesthesia and total intravenous anaesthesia (TIVA). Avoid unnecessary high flow rates of oxygen.

Inhaled Anaesthetic Alternatives

The environmental impact of TIVA and/or regional anaesthesia can be significantly less than inhalational based anaesthesia, even after manufacturing, packaging, transport, administration and disposal of consumables are considered. Use of TIVA may possibly be associated with increased cost of procurement, limiting its utility in low and middle income countries.

Environmental Impact of Intravenous Anaesthetics and Other Pharmaceuticals

Considering GWP of inhalational anaesthetics; is it the simple answer to switch to TIVA and stop polluting the atmosphere? Unfortunately, it may not be that simple. Concerns with intravenous pharmaceuticals are that the drugs can end up in drinking water, although, concentrations measured are often below acutely toxic levels.

Measures to reduce drug waste is obviously a good idea. It is routine for many of us to draw up emergency (?) drugs at the beginning of each day, most of which are wasted. Prefilled syringes may be an answer or reducing the number of drugs routinely drawn up. The same is true with consumables. Keep ‘just in case’ thing ready but un-opened, unless time to prepare them would threaten patient safety.

Postoperative Management

Procedures on ambulatory basis and Enhanced Recovery After Surgery (ERAS) protocol help in obviating the resource impacts of hospital stay. As in the preoperative setting, postoperative communication between patients and providers can be conducted virtually, where appropriate.

Success Stories

• In 2013, the Yale New Haven Health System eliminated the anaesthetic gas desflurane from its formulary in favor of sevoflurane. This resulted in a reduction of carbon dioxide from the system’s largest hospital alone that was equivalent to taking 360 passenger vehicles off the road each year. The health system also saved about $1.2 million that year.
• The UK’s National Health Service (NHS) Lothian system in Scotland decommissioned leaky nitrous oxide central piping systems in two hospital sites. The resulting carbon dioxide reductions were comparable to 7600 flights from Paris to New York in a single year.

Conclusion

“First, there has to be a very simple recognition that climate change is a problem, and second, that healthcare is part of the problem and third, that there are very simple things that we can and ought to do to minimize our impact.” – Sherman.

Medical professionals can play a big role in mitigating climate change in their personal life and in professional life. Every healthcare facility should get associated with organizations working to promote environmental sustainability and climate resilience in the Indian healthcare sector, follow the recommendations and guidelines and incorporate green care protocols. As an anaesthesiologist should not only bring changes in operating room but can take a lead in making the healthcare facility more sustainable to the environment and also strive to get Green OT (Operation Theatre) Certification which is an accreditation by Bureau Veritas in India. Every little action at individual and organizational level does matter. Making small adjustments can lead to big results.

References

1. MacNeill AJ, Rizan C, Sherman JD. Improving sustainability and mitigating the environmental impact of anaesthesia and surgery along the perioperative journey: a narrative review. Br J Anaesth. 2024;133(6):1397-1409. doi:10.1016/j.bja.2024.05.042
2. Devlin-Hegedus JA, McGain F, Harris RD, Sherman JD. Action guidance for addressing pollution from inhalational anaesthetics. Anaesthesia. 2022;77(9):1023-1029. doi:10.1111/anae.15785
3. White SM, Shelton CL, Gelb AW, et al. Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists. Anaesthesia. 2022;77(2):201-212. doi:10.1111/anae.15598
4. Sondekoppam RV, Narsingani KH, Schimmel TA, McConnell BM, Buro K, Özelsel TJ. The impact of sevoflurane anesthesia on postoperative renal function: a systematic review and meta-analysis of randomized-controlled trials. Can J Anaesth. 2020;67(11):1595-1623. doi:10.1007/s12630-020-01791-5
5. Ryan SM, Nielsen CJ. Global warming potential of inhaled anesthetics: application to clinical use. Anesth Analg. 2010;111(1):92-98. doi:10.1213/ANE.0b013e3181e058d7
6. Greening the Operating Room and Perioperative Arena: Environmental Sustainability for Anesthesia Practice: Produced by the Task Force on Environmental Sustainability Committee on Equipment and Facilities – ASA Committee on Environmental Health in 2023