Switching Anesthetic Gases to Go Green

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Photo by Jack Carey

In conversations with people in health care about climate change, I hear a frequent refrain—

What can I do? How can my health system or hospital or practice make a difference?

Our emissions in health care are unnecessarily high—the health damage from pollutants that come out of health care itself are commensurate with the 44,000 - 98,000 deaths in hospitals resulting from medical errors (according to Matthew Eckelman and Jodi Sherman in their PLOS ONE article)

Let's start there: let's lower our own carbon footprint.

Today I’ll share one opportunity that many systems are pursuing, and that is lowering the significant emissions associated with anesthetic gases. Most inhaled anesthetic gases are unmetabolized and end up vented straight into the atmosphere. Many are greenhouse gases (like hydrofluorocarbons) that are even worse than carbon dioxide in terms of their ability to trap heat in our atmosphere, much much worse.

A quick review CO2 equivalents from our publication in NEJM Catalyst.

"Measurements of carbon footprint or emissions are most commonly reported in terms of CO2 and carbon dioxide equivalents (CO2e). CO2e is calculated by using the global warming potential of 1 ton of a gas relative to 1 ton of CO2 over a given period of time (typically 100 years). For example, 1 ton of the general anesthetic desflurane is equivalent to 2,540 tons of CO2; 1 ton of
a similar anesthetic, sevoflurane, corresponds to 130 tons of CO2.6 As a point of reference, on average, a gasoline-powered car emits 1 ton of CO2 per 2,500 miles driven — about the distance from Boston to Salt Lake City."

(Want a quick primer on #decarbonizinghealthcare? Check out this LinkedIn article)

Desflurane and sevoflurane are commonly used anesthetics that are released into the atmosphere. Anesthesiologists tell me that they are virtually interchangeable in clinical practice. Moving from desflurane to sevoflurane can save a hospital money AND significantly reduce the carbon emissions. Leana Wen M.D. M.Sc. Wen wrote an informative editorial in The Washington Post and talked with several systems, including Ascension and Virginia Mason Hospital and Seattle Medical Center about their successes switching off desflurane, and experts like Emily (Emmie) Mediate at Health Care Without Harm.

Besides switching to sevoflurane, we can do even better, we can use LESS sevoflurane, because even it has a very high environmental impact. Just out is an article published in the American Society of Anesthesiologists Monitor that points out that instead of pumping out higher than necessary flows of these gases, lower “fresh gas flow (FGF)” rates of less than 1 L/min provide effective anesthesia and lower pollution. They blame the waste on the outdated sevoflurane FDA package insert (that suggests higher FGF rates, despite the literature to the contrary).

The authors, Seema Gandhi (University of California, San Francisco), Jeffrey Feldman, Lauren Berkow, and Jodi Sherman, also point out that lowering FGF saves health system and our health care system. The two research studies they cite show that University of Washington Medical Center and UCSF saved over $100,000 per year by alerting their anesthesiologists when FGFs exceed a set threshold. (This research was sponsored, in part, by The Commonwealth Fund.)

In the UK, where the National Health Service announced in 2020 that their entire country’s health system would be net zero by 2040-2045, the entire nation will have stopped the use of desflurane outright by 2024. The Royal College of Anaesthetists and the Association of Anaesthetists fully support this.They figured that anesthetic gases contributed 2% to the overall carbon footprint of their health system. Here’s what their Chief Sustainability Officer, Nick Watts, says will be the effect:

“Stopping the use of desflurane across the NHS, with use allowed only in exceptional clinical circumstances, will further reduce harmful emissions by around 40 kilotonnes of carbon a year – the same as powering 11,000 homes every year.”

Already the use has dropped from 20% of all anesthetic gases to 3%. The NHS is well on their way. Read more of what Watts has to say here.

So the next time you wonder what we can do to combat climate change--think about the operating room.

Ask your teams what they are doing to use lower emissions (and lower cost) anesthetic gases? Have they switched away from desflurane? And for all their inhaled anesthetics, are they using the lowest flow rates necessary for effective anesthesia?

And if so, GREAT JOB!

#climatechange, #netzero, #healthcaresafety, #healthcare, #anesthesiology