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Faculty of Health Sciences

Department of Anesthesia

Greener Gases

It’s time to choose Greener Gases.

Check out the new Greener Gases website!

Greener Gases Website

As Anesthesiologists, What If You Could Cut Your Greenhouse Gas Emissions By Up To 1/50th By Doing More Of What You Already Do?

Expandable List

  • Canada has the 3rd highest per-capita GHG emissions from healthcare in the world,emitting 33 million tonnes of CO2 equivalents (=4.6% of national total CO2 emissions),not including >200 000 tonnes of other pollutants
  • Impacts of climate change on health – named the greatest risk to global health by TheLancet, 2018
    • Heatwaves: Deaths due to heatwave tripled this year in BC – 719 total in one week
    • Extreme weather events more frequent and lethal: wildfires (incidence increased by 58% globally from 2016-19), tsunamis, tropical storms, floods, drought
    • Increased transmission of infectious diseases (e.g. transmission of malaria increased by almost 40% from 1950s to 2015-19)
    • Food security and malnutrition: crop yield potential of major staples (maize, wheat, soybean, rice has been consistently trending downward from 1981 to2019)
    • Displacement of coastal communities: 145-565 million people living in coastal areas. Climate change-exacerbated drought and famine was one factor in the Syrian refugee crisis
    • Increased respiratory diseases (e.g. asthma)
    • Mental health: anxiety, ptsd

Sources:

  1. Eckelman et al.,PloS ONE. https://doi.org/10.1371/journal.pmed.10026232. 
  2. https://globalnews.ca/news/7998945/b-c-heat-wave-saw-719-people-die-in-one-week-says-b-c-coroner/
  3. Everything else – Watts et al.,The Lancet. https://doi.org/10.1016/S0140-6736(20)32290-X

Sevoflurane vs Desflurane: Two anesthetic gases, vastly different environmental impacts.

  • ?95% of anesthetic gases used in the OR are released into the environment where they are hundreds to thousands of times more potent than CO2 as greenhouse gases [1]
  • Globally, anesthetic gases contributed to 3.1 million tonnes of CO2equivalents in 2014,and this is expected to increase as the number of surgeries worldwide increases. [1]
  • Sevoflurane and desflurane have very different environmental impacts [3]. What does this mean for me, an anesthesiologist?
    • For 1 hour of use, at a fresh gas flow of 1 L/min at a MAC of 1:
      • Using sevoflurane would be equivalent to the greenhouse gases produced by driving 6.5 km†
      • Using desflurane would be equivalent to the emissions produced by driving 320 km†
      • Using sevoflurane results in around 1/50th the amount of greenhouse gas emissions!
    • †Assumes average car emissions of 200g CO2/km. Calculated Based on methods used by Ryan and Nielsen [4]
  • What about money/cost?
    • A bottle of sevoflurane actually costs less than desflurane, so you would besaving your hospital money in the long run.
      • $90–$120 for a 250mL bottle of sevoflurane vs $140–170 for a 240mL ofdesflurane (Hamilton Health Sciences, exact prices not released due to negotiation contracts)
  • What about time to emergence/OR turnover rate?
    • While desflurane does generally result in faster wake-up times due to its lower solubility, studies show that on average, for the vast majority of surgical cases,desflurane only allowed patients to wake up 1–4 minutes faster*.
      • * Based on 2 meta-analyses of 37 RCTs total [5,6]. Emergence: time until patients followed commands, opened their eyes, were extubated, answer oriented.?
    • OR turnover depends on many factors, including type of surgery, patient comorbidities, support staff, the surgery team, and tapering of anesthetic.
      • In fact, most of the research studies measured the time to emergence from the abrupt discontinuation of anesthetic gases, which most would consider an amateur emergence strategy.
    • The bottom line: is 4 min faster wake-up worth 63kg more CO2 equivalent emissions per MAC-hour? We don’t think so. (flashback to the negative health effects of climate change)

References

  1. Vollmer MK et al, 2015.
  2. Özelsel TJP et al, 2019.
  3. Sulbaek Andersen MP et al, 2012.
  4. Ryan SM et al, 2010.
  5. Macario A et al, 2005.
  6. Chen WS et al, 2020.

ASA recommendations:The American Society of Anesthesiologists (ASA) recommends anesthesia providers reduce inhaled anesthetic atmospheric waste through the following strategies:

  • Utilize low fresh gas flows
  • Avoid high impact inhaled anesthetics: Desflurane, Nitrous Oxide
  • Consider intravenous and regional techniques
  • Invest in Waste Anesthetic Gas (WAG) trapping or destroying technology

Reference: 

American Society of Anesthesiologists. Greening the Operating Room andPerioperative Arena: Environmental Sustainability for Anesthesia Practice.;2014.https://www.asahq.org/about-asa/governance-and-committees/asacommittees/committee-on-equipment-and-facilities/environmentalsustainability/greening-the-operating-room-complete

A similar provider education and machine labelling initiative at Wisconsin led to a 64%decrease in carbon dioxide equivalent emissions per case

  • Reference: Zuegge KL, Bunsen SK, Volz LM, et al. Provider Education and VaporizerLabeling Lead to Reduced Anesthetic Agent Purchasing with Cost Savings and ReducedGreenhouse Gas Emissions. Anesth Analg.2019;128(6):E97-E99.doi:10.1213/ANE.0000000000003771

UWisconsin, Health Sciences North, and Yale New-Havenhave eachremoved desfluranefromtheir volatile anesthetic formulary.

  • Reference: Caycedo-Marulanda A, Caswell J, Mathur S. Comparing the environmentalimpact of anesthetic gases during transanal total mesorectal excision surgery at atertiary healthcare centre. Can J Anesth.2020;67(5):607-608.doi:10.1007/s12630-019-01527-0

Specifically at the HHS:

  • Attend our sustainability committee, email ____ to be added to the mailing list for future meetings.
  • Read our evidence-based anesthetic machine labels before choosing a volatile agent.
  • Read out white paper: [link]
  • Read our starter pack
  • Fill out our surveys
  • Engage in discussions and ask us questions

What you do makes a difference, and you have to decide what kind of difference you want to make. — Dr. Jane Goodall

“It’s time to make the switch to Greener Gases”

Further reading:

  • American Society of Anesthesiologists – Greening the Operating Room sustainability checklist
  • Yale Gassing Greener mobile app
    • features intuitive calculators to help clinicians determine their carbon emission equivalents from the amounts and flow rates of inhaled anesthetics used and to help facilities determine their carbon emissions from amounts of purchased inhaled anesthetics
  • University of Wisconsin provider education and label study
    • Reference: Zuegge KL, Bunsen SK, Volz LM, et al. Provider Education and VaporizerLabeling Lead to Reduced Anesthetic Agent Purchasing with Cost Savings and ReducedGreenhouse Gas Emissions. Anesth Analg. 2019;128(6):E97-E99.doi:10.1213/ANE.0000000000003771