A study has found that anesthetic gases used to prepare patients for surgery accumulate in the atmosphere, contributing to climate change. Anesthetic gases comprise just a small portion of gases in Earth's atmosphere, but they pose a big problem as they are dramatically more potent than greenhouse gases.
Consider desflurane — about 2.2 pounds of the anesthetic gas has the same warming potential as 5,512 pounds of carbon dioxide.
Martin Vollmer, an atmospheric chemist from the Swiss Federal Laboratories for Materials Science and Technology, and his colleagues reported their findings from the study in the journal Geophysical Research Letters.
Researchers used measurements from atmospheric concentrations of desflurane, sevoflurane, halothane and isoflurane in 2014 and compared it with carbon dioxide levels from the same year.
Hands down, carbon dioxide was more prevalent — a billion times more abundant than sevoflurane, the most prevalent of the anesthetic gases. Nitrous oxide, another common anesthetic gas, was not included in the study because it has uses beyond surgical anesthesia.
Measurements were taken from air samples obtained in the Northern Hemisphere since the year 2000. An expedition to the North Pacific aboard the icebreaker Araon also provided data, as well as research from the King Sejong station in the South Shetland Islands. Since 2013, anesthetic gases have been tracked from Switzerland, with measurements taken every two hours.
To come up with global emission estimates, researchers used a two-dimensional computer model for atmospheric chemistry and transport, combining that with air sample measurements. This resulted in top-down estimates (based on actual measurements from the atmosphere) of how much anesthetic gas entered the atmosphere in 2014.
The top-down estimates can be compared to bottom-up estimates that other researchers produced using information on the amount of anesthetic gas being sold every year, the amount of the gas not absorbed by patients and the amount that escapes from operating rooms.
Jodi Sherman, an anesthesiologist from the Yale University School of Medicine, reviewed the study, noting that its results could benefit the environment and must not be overlooked. Sherman suggested that desflurane be dropped as an anesthetic gas option.
Though some anesthesiologists disagree with her suggestion, pointing to desflurane's clinical advantages, Sherman doesn't think there's any substance to their argument.
"There's nothing unique about desflurane that we can't do with other drugs. Desflurane we could live without, and every little bit makes a difference," Sherman said.
Stefan Reimann, Fabian Schoenenberger, Matthias Hill, Doris Hofstetter, Matt Rigby and Tae Siek Rhee also contributed to the study.
Photo: Resolute Support Media | Flickr
