Effects of the COVID-19 pandemic on environmental sustainability in anaesthesia. Response to Br J Anaesth 2021;126:e118-e119

The environmental impacts of anesthesia

PURPOSE OF REVIEW

The healthcare sector has a substantial environmental footprint, and the delivery of anesthesia contributes significantly. Inhaled anesthetics themselves are potent greenhouse gases, unused intravenous medication exert toxic effects on the environment, and the increasing reliance on single-use devices has led to an ever-growing amount of solid waste produced in operating rooms. This review discusses many of these environmental impacts and suggests practices to mitigate the environmental footprint of anesthetic practice.

RECENT FINDINGS

The choice of anesthesia maintenance has significant environmental implications, with nitrous oxide and desflurane having the highest carbon footprint of all anesthetic agents. Using low fresh gas flows and supplementing or replacing inhalational agents with propofol leads to a significant reduction in emissions. Many intravenous anesthetic agents pose a risk of environmental toxicity, and efforts should be made to decrease medication waste and ensure appropriate disposal of unused medications to minimize their environmental impacts. Additionally, consideration should be given to replacing single-use devices in the operating rooms with reusable alternatives that are often both environmentally and economically superior. And solid waste generated in the operating room should be segregated thoughtfully, as processing regulated medical waste is a highly energy-intensive process.

SUMMARY

Significant opportunities exist to improve the environmental footprint of anesthesia practice, and with the rapidly worsening climate crisis, the importance of implementing changes is greater than ever.

How much do we throw away in the intensive care unit? An observational point prevalence study of Australian and New Zealand ICUs

Objective

During the current COVID pandemic, waste generation has been more evident with increased use of single use masks, gowns and other personal protective equipment. We aimed to understand the scale of waste generation, recycling rates and participation in Australian and New Zealand (ANZ) ICUs.

Design

This is a prospective cross-sectional point prevalence study, as part of the 2021 ANZICS Point Prevalence Program. Specific questions related to waste and sustainability practices were asked at the site and patient level.

Setting and participants

ANZ adult ICUs and their patients on the day of the study.

Main outcome measures

Amount of single use items disposed of per shift, as well as the engagement of the site with sustainability and recycling practices.

Results

In total, 712 patients (median number of patients per ICU = 17, IQR 11-30) from 51 ICUs across ANZ were included in our study; 55% of hospitals had a sustainability officer, and recycling paper (86%) and plastics (65%) were frequent, but metal recycling was limited (27%). Per patient bed space per 12-h shift there was recycling of less than 40% paper, glass, intravenous fluid bags, medication cups and metal instruments. A median of 10 gowns (IQR 3-19.5), 10 syringes (4.5-18) and gloves 30 (18-49) were disposed of per bed space, per 12-h shift. These numbers increased significantly when comparing patients with and without infection control precautions in place.

Conclusions

In ANZ ICUs, we found utilisation of common ICU consumables to be high and associated with low recycling rates. Interventions to abate resource utilisation and augment recycling are required to improve environmental sustainability in intensive care units.

A 24-Hour Waste Audit of the Neuro ICU during the COVID-19 Pandemic and Opportunities for Diversion

We conducted a series of 24-hour waste audits in a 20-bed pod of a Neurosciences Intensive Care Unit (Neuro ICU) during the COVID-19 pandemic to 1) determine the unit's waste generation practices, 2) calculate associated downstream greenhouse gas emissions, and 3) identify opportunities to reduce landfill waste and emissions. We collected and weighed municipal solid waste, regulated medical waste, and mechanical recycling. We then compared the current, "as-is" practices to an ideal, "should-be" model which adds the alternative waste and reprocessing streams of industrial composting, advanced recycling, and sterilization followed by reuse. We found that the unit produced a total of 97.3 kg of waste over 24 hours, or 4.9 kg of waste per patient per day. 96.8% of this waste is currently landfilled. Emissions generated by processing landfill waste totaled 119.7 metric tons per year of CO₂ equivalents. With the should-be sorting model, 24.7% of total waste produced by the unit could be diverted from landfills. Of this potentially divertible waste, 47.9% could undergo post-consumer industrial composting, 28.0% could undergo mechanical recycling, 22.2% could undergo advanced recycling, and 1.9% could undergo sterilization followed by reuse. Emissions from processing landfill waste in the should-be model totaled 110.6 metric tons per year of CO₂ equivalents, representing a 7.7% decrease. These findings highlight the potential utility of alternate waste streams in this setting as well as the urgent need for complementary upstream waste reduction strategies to meaningfully reduce the Neuro ICU's landfill reliance and greenhouse gas emissions.

Potential Life-Cycle Environmental Impacts of the COVID-19 Nucleic Acid Test

Massive diagnostic testing has been performed for appropriate screening and identification of COVID-19 cases in the ongoing global pandemic. However, the environmental impacts of COVID-19 diagnostics have been least considered. In this paper, the environmental impacts of the COVID-19 nucleic acid diagnostics were assessed by following a full cradle-to-grave life-cycle approach. The corresponding life-cycle anthology was established to provide quantitative analysis. Moreover, three alternative scenarios, i.e., material substitution, improved waste treatment, and electric vehicle (EV)-based transportation, were further proposed to discuss the potential environmental mitigation and conservation strategies. It was estimated that the life cycle of a single COVID-19 nucleic acid diagnostic test in China would lead to the emission of 612.9 g CO2 equiv global warming potential. Waste treatment, as a step of life cycle, worsen the environmental impacts such as global warming potential, eutrophication, and ecotoxicity. Meanwhile, diesel-driven transportation was considered as the major contributor to particulate air. Even though COVID-19 diagnostics are of the greatest importance to end the pandemic, their environmental impacts should not be ignored. It is suggested that improved approaches for waste treatment, low-carbon transportation, and a reliable pool sampling strategy are critical for the achievement of sustainable and green diagnostics.

Ecoresponsible actions in operating rooms: A health ecological and economic evaluation

BACKGROUND

In the current context of climate change, actions must be taken to improve the hospital's ecological footprint, particularly in the operating room, which is a major consumer of medical devices.

METHODS

This prospective pilot study assessed the ecological and economic impacts of sustainable actions targeting medical devices designed by a multidisciplinary working group and implemented in the 24 operating rooms of a University Hospital over one year. The ecological analysis was based on the life cycle assessment method and categorized in seven impacts. The economic impact was assessed by a micro-costing analysis and divided in four main expense items: human and material resources, logistics, and waste management.

RESULTS

In total, 13 actions were implemented with the aim of reducing waste volume, improving waste sorting, and increasing eco-responsible purchases. In one year, these 13 actions allowed avoiding the emission of 203 tons eq CO₂. The environmental and human toxicity benefits were 707.8 and 156.2 tons of 1.4 dichlorobenzene, respectively. Concerning non-renewable resources, these actions avoided the extraction of 9 tons of oil (petroleum) and 610 kg of copper per year. These actions led to a land occupation reduction of 1071.3 m²year and to water saving of 552 m³. From the economic side, the implementation of these actions brought a gain of €3747.9 for the first year and of €5188.2 for the following years.

CONCLUSION

The integration of sustainable measures in operating rooms leads to important ecological benefits and also generating savings. This more eco-responsible approach should be considered in all healthcare establishments that generate a significant annual volume of waste.

Principles of environmentally-sustainable anaesthesia: a global consensus statement from the World Federation of Societies of Anaesthesiologists

The Earth's mean surface temperature is already approximately 1.1°C higher than pre-industrial levels. Exceeding a mean 1.5°C rise by 2050 will make global adaptation to the consequences of climate change less possible. To protect public health, anaesthesia providers need to reduce the contribution their practice makes to global warming. We convened a Working Group of 45 anaesthesia providers with a recognised interest in sustainability, and used a three-stage modified Delphi consensus process to agree on principles of environmentally sustainable anaesthesia that are achievable worldwide. The Working Group agreed on the following three important underlying statements: patient safety should not be compromised by sustainable anaesthetic practices; high-, middle- and low-income countries should support each other appropriately in delivering sustainable healthcare (including anaesthesia); and healthcare systems should be mandated to reduce their contribution to global warming. We set out seven fundamental principles to guide anaesthesia providers in the move to environmentally sustainable practice, including: choice of medications and equipment; minimising waste and overuse of resources; and addressing environmental sustainability in anaesthetists' education, research, quality improvement and local healthcare leadership activities. These changes are achievable with minimal material resource and financial investment, and should undergo re-evaluation and updates as better evidence is published. This paper discusses each principle individually, and directs readers towards further important references.

Global climate change and the role of anesthesiologist

Background: Environmental issues and health problems related to global climate change are becoming increasingly serious. An effective eco-friendly strategy is required to reduce medical waste and greenhouse gas emissions caused by anesthesia in hospitals.Current Concepts: Inhalation anesthetics are very strong greenhouse gases in the order of desflurane, isoflurane, nitrous oxide, and sevoflurane. Anesthetics with high global warming potential and long atmospheric lifetimes should be used with caution. Only the minimum required dose of an anesthetic drug with a low persistence bioaccumulation toxicity index is recommended for use. Disposable anesthesia products are known to have a low purchase price and low risk of cross-contamination; however, this may not be the case. By using eco-friendly anesthetic supplies, recycling and reuse, we can avoid wasting money and resources.Discussion and Conclusion: Greenhouse gas emissions from the use of anesthetics are excluded from United Nations regulations due to their necessity. However, while guaranteeing patient safety, anesthesiologists must fulfill their professional ethical obligations by striving to reduce medical waste and greenhouse gas emissions.

Interactions of SARS-CoV-2 with inanimate surfaces in built and transportation environments

Understanding the interactions and transmission of pathogens with/via inanimate surfaces common in the built environment and public transport vehicles is critical to promoting sustainable and resilient urban development. Here, molecular dynamics (MD) simulations are used to study the adhesion of SARS-CoV-2 (the causative agent of COVID-19) to some of these surfaces at different temperatures (same for surfaces and ambiance) ranging from -23 to 60 °C. Surfaces simulated are aluminum, copper, copper oxide, polyethylene (PE), and silicon dioxide (SiO₂). Steered MD (SMD) simulations are also used to investigate the transfer of the virus from PE and SiO₂ when a contaminated surface is touched. The virus shows the lowest and highest adhesions to PE and SiO₂, respectively (20 vs 534 eV). Influence of temperature is not found to be noticeable. Using simulated water molecules to represent moisture on the skin, SMD simulations show that water molecules can lift the virus from the PE surface but damage the virus when lifting it from the the SiO₂ surface. The results suggest that the PE surface is a more favorable surface to transmit the virus than the other surfaces simulated in this study. The results are compared with those reported in a few experimental studies.

Moving towards green anaesthesia: Are patient safety and environmentally friendly practices compatible? A focus on single-use devices

OBJECTIVE

Discuss if the use of disposable or reusable medical devices leads to a difference in terms of hospital-acquired infection or bacterial contamination. Determine which solution is less expensive and has less environmental impact in terms of carbon footprint, energy and water consumption and amount of waste.

METHODS

We carried out a narrative review. Articles published in English and French from January 2000 to April 2020 were identified from PubMed.

RESULTS

We retrieved 81 articles, including 12 randomised controlled trial, 21 literature reviews, 13 descriptive studies, 6 experimental studies, 9 life-cycle studies, 6 cohort studies, 2 meta-analysis, 4 case reports and 8 other studies. It appears that pathogen transmission in the anaesthesia work area is mainly due to the lack of hand hygiene among the anaesthesia team. The benefit of single-use devices on infectious risk is based on weak scientific arguments, while reusable devices have benefits in terms of costs, water consumption, energy consumption, waste, and reducing greenhouse gas emissions.

CONCLUSION

Disposable medical devices and attire in the operating theatre do not mitigate the infectious risk to the patients but have a greater environmental, financial and social impact than the reusable ones. This study is the first step towards recommendations for more environmental-friendly practices in the operating theatre.