Inhaled anesthetics punch well above their weight when it comes to generating greenhouse gases, so the specialty of anesthesiology has been trying to reduce its reliance on the most egregious of these agents. The largest teaching hospital in Europe appears to have found a successful approach.
Anesthesiologists and intensive care staff at the Charité medical system in Berlin, Germany, reduced carbon emissions from anesthetic gases by more than 80% between 2018 and 2023. Education about greenhouse gases in anesthetic agents caused the institution to abandon use of the carbon-intensive anesthetic gas desflurane altogether, according to a new report in Anesthesia & Analgesia.
The authors of the article noted 2024 was the first year global warming exceeded 1.5° C above preindustrial levels, the benchmark set by the Intergovernmental Panel on Climate Change to reduce the worst impacts of climate change like extreme heat or flooding. The strategies in the report aim to encourage anesthesiologists to reduce their carbon footprint without harming patient care.
The greenhouse effect of desflurane — a halogenated organic compound — is more than 2500 times that of carbon dioxide, by one estimate. Ending the use of the substance required the commitment of hospital leadership and Anesthesia Department heads, and study leaders hope other anesthesiologists in Germany and beyond follow suit.
“There’s no argument anymore that desflurane is best for managing anesthesia,” said study leader Susanne Koch, MD, a lecturer and anesthesiologist at Charité. Anesthesiologists once used desflurane, thinking it was the easiest agent for patients to wake up from after surgery, Koch said. But today frontal electroencephalography can help ensure patients receive adequate anesthesia from injected agents like propofol, which have not been associated with climate change, Koch added.
Koch and colleagues found volatile gases linked to anesthesia practices at Charité produced more than 7500 metric tons of carbon dioxide every year from 2015 to 2017. In 2018, she began educational efforts throughout the institution to describe the environmental impact of anesthetic gases, particularly desflurane. These efforts, whether in lectures at department meetings, information sessions at anesthesia conferences, publications, or specialized training courses, discouraged the use of desflurane.
Charité produced an estimated 6792 tons of carbon dioxide from anesthesia in 2018, a figure that fell to 1454 tons in 2023, Koch’s group reported. In 2018, the head of the Anesthesiology Clinic at one Charité hospital halted use of the product, a policy that became effective throughout Charité in 2023. Instead, anesthesiologists use propofol.
Charité is just the start. Koch, who sits on the sustainability committee of the European Society of Anaesthesiology and Intensive Care, wants the body to issue guidelines that discourage use of desflurane across the continent.
“We put out position papers, but these are not guidelines,” Koch said, adding that society guidelines are important for changing behavior more than other kinds of documents.
Moving Desflurane Down the Hall
Desflurane was developed at the University of California, San Francisco (UCSF) in the late 1980s. “UCSF Health invented desflurane, and now we’ve eliminated it,” said Seema Gandhi, MD, an anesthesiologist and medical director of Sustainability at the institution. Similar to the experience at Charité, Gandhi said the decision required top-down leadership to stop using desflurane — one complicated by the fact researchers at UCSF had invented the substance.
Before abandoning desflurane altogether, UCSF took the interim step of moving it to a central supply cabinet to make it less accessible to clinicians. This simple change reduced the use of the product, Gandhi recalled, although senior leadership had to remove it from the hospital system entirely. In a 2023 interview, Gandhi estimated the move has saved the equivalent of 240 gas-powered cars worth of carbon emissions per year in San Francisco.
Other anesthetic agents, like sevoflurane, also have a high potential to exacerbate climate change. For sevoflurane in particular, anesthesiologists may be using more than is clinically necessary, Gandhi said, thanks in part to guidance from the US Food and Drug Administration for clinicians to administer at least 2 L/min of the agent for surgeries lasting 2 hours or longer.
That recommendation is based on animal models and is excessive for people, Gandhi said. In 2023, the American Society of Anesthesiologists (ASA) released a statement that 0.5 L/min of sevoflurane is sufficient in most cases.
“Sevoflurane is the most common gas used in the world right now,” Gandhi said, adding she hoped the ASA statement is encouraging health systems to save money on sevoflurane supplies by encouraging less use per procedure while lowering greenhouse gas emissions.
The sources in this story reported no relevant financial conflicts of interest.
Marcus A. Banks, MA, is a journalist based near New York City who covers health news with a focus on new cancer research. His work appears in Medscape Medical News, Cancer Today, The Scientist, Gastroenterology & Endoscopy News, Slate, TCTMD, and Spectrum.
