Climate change and human health: Last call to arms for us

Climate change, now the foremost global health hazard, poses multifaceted challenges to human health. This editorial elucidates the extensive impact of climate change on health, emphasising the increasing burden of diseases and the exacerbation of health disparities. It highlights the critical role of the healthcare sector, particularly anaesthesia, in both contributing to and mitigating climate change. It is a call to action for the medical community to recognise and respond to the health challenges posed by climate change.

Similarity and dissimilarity in alterations of the gene expression profile associated with inhalational anesthesia between sevoflurane and desflurane

Although sevoflurane is one of the most commonly used inhalational anesthetic agents, the popularity of desflurane is increasing to a level similar to that of sevoflurane. Inhalational anesthesia generally activates and represses the expression of genes related to xenobiotic metabolism and immune response, respectively. However, there has been no comprehensive comparison of the effects of sevoflurane and desflurane on the expression of these genes. Thus, we used a next-generation sequencing method to compare alterations in the global gene expression profiles in the livers of rats subjected to inhalational anesthesia by sevoflurane or desflurane. Our bioinformatics analyses revealed that sevoflurane and, to a greater extent, desflurane significantly activated genes related to xenobiotic metabolism. Our analyses also revealed that both anesthetic agents, especially sevoflurane, downregulated many genes related to immune response.

Exploring anaesthetists' views on the carbon footprint of anaesthesia and identifying opportunities and challenges for reducing its impact on the environment

A shift in practice by anaesthetists away from anaesthetic gases with high global warming potential towards lower emission techniques (e.g. total intravenous anaesthesia) could result in significant carbon savings for the health system. The purpose of this qualitative interview study was to understand anaesthetists' perspectives on the carbon footprint of anaesthesia, and views on shifting practice towards more environmentally sustainable options. Anaesthetists were recruited from four hospitals in Western Sydney, Australia. Data were organised according to the capability-opportunity-motivation model of behaviour change. Twenty-eight anaesthetists were interviewed (July-September 2021). Participants' age ranged from 29 to 62 years (mean 43 years), 39% were female, and half had completed their anaesthesia training between 2010 and 2019. Challenges to the wider use of greener anaesthetic agents were identified across all components of the capability-opportunity-motivation model: capability (gaps in clinician skills and experience, uncertainty regarding research evidence); opportunity (norms, time, and resource pressures); and motivation (beliefs, habits, responsibility and guilt). Suggestions for encouraging a shift to more environmentally friendly anaesthesia included access to education and training, implementing guidelines and audit/feedback models, environmental restructuring, improving resource availability, reducing low value care, and building the research evidence base on the safety of alternative agents and their impacts on patient outcomes. We identified opportunities and challenges to reducing the carbon footprint of anaesthesia in Australian hospitals by way of system-level and individual behavioural change. Our findings will be used to inform the development of communication and behavioural interventions aiming to mitigate carbon emissions of healthcare.

Does gender still matter in the pursuit of a career in anaesthesia?

A survey sent to fellows of the Australian and New Zealand College of Anaesthetists (ANZCA) aimed to document issues affecting gender equity in the anaesthesia workplace. A response rate of 38% was achieved, with women representing a greater proportion of respondents (64.2%). On average women worked fewer hours than men and spent a larger percentage of time in public practice; however, satisfaction rates were similar between genders. There was a gender pay gap which could not be explained by the number of hours worked or years since achieving fellowship. The rates of bullying and harassment were high among all genders and have not changed in 20 years since the first gender equity survey by Strange Khursandi in 1998. Women perceived that they were more likely to be discriminated against particularly in the presence of other sources of discrimination, and highlighted the importance of the need for diversity and inclusion in anaesthetic workplaces. Furthermore, women reported higher rates of caregiving and unpaid domestic responsibilities, confirming that anaesthetists are not immune to the factors affecting broader society despite our professional status. The overall effect was summarised by half of female respondents reporting that they felt their gender was a barrier to a career in anaesthesia. While unable to be included in statistics due to low numbers, non-binary gendered anaesthetists responded and must be included in all future work. The inequities documented here are evidence that ANZCA's gender equity subcommittee must continue promoting and implementing policies in workplaces across Australia and New Zealand.

Nitrous Oxide Use in Australian Health Care: Strategies to Reduce the Climate Impact

Nitrous oxide is a useful inhaled analgesic. Due to its high global warming potential and ozone-depleting properties, the nitrous oxide emissions related to health care are being increasingly scrutinized. In this narrative review, we will discuss the clinical uses of nitrous oxide relevant to anesthetists, in addition to its contribution as a greenhouse gas. Using available data from Australia, we will explore potential strategies for reducing the impact of those emissions, which are likely to be applicable in other countries. These include destruction of captured nitrous oxide, minimizing nitrous oxide waste and reducing clinical use. Anesthesia clinicians are well placed to raise awareness with colleagues and consumers regarding the environmental impact of nitrous oxide and to promote cleaner alternatives. Reducing use is likely to be the most promising reduction strategy without large-scale changes to infrastructure and subsequent delay in action.

The financial and environmental impact of purchased anaesthetic agents in an Australian tertiary hospital

Anaesthetic agents have various financial and environmental impacts. Climate change is one of the biggest threats to human health, and anaesthetic gases contribute to global heating by acting as greenhouse gases. The primary aim of this study was to quantify the financial and environmental impacts of anaesthesia maintenance agents used during surgery in an Australian university teaching hospital. The volume of desflurane, sevoflurane, isoflurane and propofol purchased by a university teaching hospital between 2010 and 2020 was analysed and described in terms of financial and environmental impact. Estimated carbon emissions and financial costs of each agent per annum were calculated using the volumes purchased for each agent. A model of ideal anaesthetic agent usage was used to hypothesise the financial and environmental impact of replacing desflurane (the most environmentally damaging and expensive agent) with alternative agents. Using 2019 as an example year at our health service, replacing desflurane with low flow sevoflurane would save greenhouse gas emissions equivalent to driving over 1.4 million kilometres in an average petrol car. Removing desflurane from machines at our institution could save an estimated A$14,630 per annum through reduced machine testing alone. Our findings and calculations indicate that reducing the use of desflurane would have both financial and environmental benefits for healthcare.

An Accessible Clinical Decision Support System to Curtail Anesthetic Greenhouse Gases in a Large Health Network: Implementation Study

BACKGROUND

Inhaled anesthetics in the operating room are potent greenhouse gases and are a key contributor to carbon emissions from health care facilities. Real-time clinical decision support (CDS) systems lower anesthetic gas waste by prompting anesthesia professionals to reduce fresh gas flow (FGF) when a set threshold is exceeded. However, previous CDS systems have relied on proprietary or highly customized anesthesia information management systems, significantly reducing other institutions' accessibility to the technology and thus limiting overall environmental benefit.

OBJECTIVE

In 2018, a CDS system that lowers anesthetic gas waste using methods that can be easily adopted by other institutions was developed at the University of California San Francisco (UCSF). This study aims to facilitate wider uptake of our CDS system and further reduce gas waste by describing the implementation of the FGF CDS toolkit at UCSF and the subsequent implementation at other medical campuses within the University of California Health network.

METHODS

We developed a noninterruptive active CDS system to alert anesthesia professionals when FGF rates exceeded 0.7 L per minute for common volatile anesthetics. The implementation process at UCSF was documented and assembled into an informational toolkit to aid in the integration of the CDS system at other health care institutions. Before implementation, presentation-based education initiatives were used to disseminate information regarding the safety of low FGF use and its relationship to environmental sustainability. Our FGF CDS toolkit consisted of 4 main components for implementation: sustainability-focused education of anesthesia professionals, hardware integration of the CDS technology, software build of the CDS system, and data reporting of measured outcomes.

RESULTS

The FGF CDS system was successfully deployed at 5 University of California Health network campuses. Four of the institutions are independent from the institution that created the CDS system. The CDS system was deployed at each facility using the FGF CDS toolkit, which describes the main components of the technology and implementation. Each campus made modifications to the CDS tool to best suit their institution, emphasizing the versatility and adoptability of the technology and implementation framework.

CONCLUSIONS

It has previously been shown that the FGF CDS system reduces anesthetic gas waste, leading to environmental and fiscal benefits. Here, we demonstrate that the CDS system can be transferred to other medical facilities using our toolkit for implementation, making the technology and associated benefits globally accessible to advance mitigation of health care-related emissions.

Anesthesia and the renal sympathetic nervous system in perioperative AKI

Approximately 7% of patients undergoing non-cardiac surgery with general anesthesia develop postoperative acute kidney injury (AKI). It is well-known that general anesthesia may have an impact on renal function and water balance regulation, but the mechanisms and potential differences between anesthetics are not yet completely clear. Recently published large animal studies have demonstrated that volatile (gas) anesthesia stimulates the renal sympathetic nervous system more than intravenous propofol anesthesia, resulting in decreased water and sodium excretion and reduced renal perfusion and oxygenation. Whether this is the case also in humans remains to be clarified. Increased renal sympathetic nerve activity may impair renal excretory function and oxygenation and induce structural injury in ischemic AKI models and could therefore be a contributing factor to AKI in the perioperative setting. This review summarizes anesthetic agents' effects on the renal sympathetic nervous system that may be important in the pathogenesis of perioperative AKI.

Carbon Footprint of General, Regional, and Combined Anesthesia for Total Knee Replacements

BACKGROUND

Health care itself contributes to climate change. Anesthesia is a "carbon hotspot," yet few data exist to compare anesthetic choices. The authors examined the carbon dioxide equivalent emissions associated with general anesthesia, spinal anesthesia, and combined (general and spinal anesthesia) during a total knee replacement.

METHODS

A prospective life cycle assessment of 10 patients in each of three groups undergoing knee replacements was conducted in Melbourne, Australia. The authors collected input data for anesthetic items, gases, and drugs, and electricity for patient warming and anesthetic machine. Sevoflurane or propofol was used for general anesthesia. Life cycle assessment software was used to convert inputs to their carbon footprint (in kilogram carbon dioxide equivalent emissions), with modeled international comparisons.

RESULTS

Twenty-nine patients were studied. The carbon dioxide equivalent emissions for general anesthesia were an average 14.9 (95% CI, 9.7 to 22.5) kg carbon dioxide equivalent emissions; spinal anesthesia, 16.9 (95% CI, 13.2 to 20.5) kg carbon dioxide equivalent; and for combined anesthesia, 18.5 (95% CI, 12.5 to 27.3) kg carbon dioxide equivalent. Major sources of carbon dioxide equivalent emissions across all approaches were as follows: electricity for the patient air warmer (average at least 2.5 kg carbon dioxide equivalent [20% total]), single-use items, 3.6 (general anesthesia), 3.4 (spinal), and 4.3 (combined) kg carbon dioxide equivalent emissions, respectively (approximately 25% total). For the general anesthesia and combined groups, sevoflurane contributed an average 4.7 kg carbon dioxide equivalent (35% total) and 3.1 kg carbon dioxide equivalent (19%), respectively. For spinal and combined, washing and sterilizing reusable items contributed 4.5 kg carbon dioxide equivalent (29% total) and 4.1 kg carbon dioxide equivalent (24%) emissions, respectively. Oxygen use was important to the spinal anesthetic carbon footprint (2.8 kg carbon dioxide equivalent, 18%). Modeling showed that intercountry carbon dioxide equivalent emission variability was less than intragroup variability (minimum/maximum).

CONCLUSIONS

All anesthetic approaches had similar carbon footprints (desflurane and nitrous oxide were not used for general anesthesia). Rather than spinal being a default low carbon approach, several choices determine the final carbon footprint: using low-flow anesthesia/total intravenous anesthesia, reducing single-use plastics, reducing oxygen flows, and collaborating with engineers to augment energy efficiency/renewable electricity.

EDITOR’S PERSPECTIVE

[New challenges for anesthesia due to the climate change]

BACKGROUND

The climate crisis is the most serious threat to global health in the twenty-first century. In western countries 5-10% of all greenhouse gas emissions originate from the healthcare sector and the main contributing factors are energy-intense departments (intensive care units, operating suits and prehospital emergency services).

OBJECTIVE

The aim of this review is to provide background knowledge and practical ideas to achieve climate-neutral hospitals.

MATERIAL AND METHODS

Narrative review with information on the topics of (I) volatile anesthetics as greenhouse gases, (II) energy supply in hospitals and (III) solid waste management.

RESULTS AND CONCLUSION

(I) Volatile anesthetics are highly potent greenhouse gases, especially desflurane has a major global warming potential. Total intravenous anesthesia (TIVA) with propofol or regional anesthetic techniques have a much lower impact on the climate. (II) Using sustainable energy sources as well as initiating energy sparing techniques, such as light-emitting diodes (LED) and motion sensors, can reduce CO₂ emissions. (III) Waste can be managed by the reduce, reuse, recycle, rethink and research concept. Doctors should actively contribute to reach the climate goals.

Inhalational anaesthetics, ozone depletion, and greenhouse warming: the basics and status of our efforts in environmental mitigation

PURPOSE OF REVIEW

Following their use for medicinal purposes, volatile inhalational anaesthetic agents are expelled into the atmosphere where they contribute to anthropogenic climate change. We describe recent evidence examining the benefits and harms associated with their use.

RECENT FINDINGS

The environmental harms associated with desflurane and nitrous oxide likely outweigh any purported clinical benefits. Life cycle analyses are beginning to address the many gaps in our understanding, and informing choices made on all aspects of anaesthetic care. There is, however, an urgent need to move beyond the debate about anaesthetic technique A vs. B and focus also on areas such as sustainable procurement, waste management, pharmacological stewardship and joined-up solutions.

SUMMARY

There is now compelling evidence that anaesthetists, departments and hospitals should avoid desflurane completely, and limit nitrous oxide use to settings where there is no viable alternative, as their environmental harms outweigh any perceived clinical benefit. Life cycle analyses seem supportive of total intravenous and/or regional anaesthesia. There are many other areas where choices can be made by individual anaesthetists that contribute towards reducing the environmental burden of healthcare, such as prioritising the reduction of inappropriate resource use and over-treatment. However, this all requires joined up solutions where all parts of an organisation engage.

Environmental sustainability in anaesthesia and critical care

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.