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According to a joint statement by the US National Academy of Sciences and the UK Royal Society, it is now more certain than ever that human activity is a leading cause of rapid, accelerated climate change. Our volatile anesthetics have up to 2,000 times more greenhouse gas contributing potential than the same amount of carbon dioxide, yet no emission regulations have been imposed. The carbon footprint of volatile agents exists in all anesthesia practices, indirectly affecting all humans. It manifests daily in the clinical practice of over 30,000 certified registered nurse anesthetists in the United States, as their anesthetic choices directly impact the environment. However, education about anesthetic choice and its impact has been overlooked, making many anesthesia providers unaware of meaningful ways to reduce ecological and economic costs. Decreasing the use of volatile agents by low-flow techniques and the use of a total intravenous anesthetic could dramatically reduce carbon footprint produced by anesthesia. The authors review other advantages of limiting or avoiding volatile agents beyond green anesthesia such as decreased costs, reduced postoperative nausea and vomiting, and lowering the risk of malignant hyperthermia.

Purpose\ud This work demonstrates specifically tailored microbubble‐based preparations and their suitability as MRI contrast agents for ingestion and measuring temporal and spatial pressure variation in the human stomach.\ud \ud Methods\ud Enhanced alginate spheres were prepared by incorporating gas‐filled microbubbles into sodium alginate solution followed by the polymerization of the mixture in an aqueous calcium lactate solution. The microbubbles were prepared with a phospholipid shell and perfluorocarbon gas filling, using a mechanical cavitational agitation regime. The NMR signal changes to externally applied pressure and coming from the enhanced alginate spheres were acquired and compared with that of alginate spheres without microbubbles. In vivo investigations were also carried out on healthy volunteers to measure the pressure variation in the stomach.\ud \ud Results\ud The MR signal changes in the contrast agent exhibits a linear sensitivity of approximately 40% per bar, as opposed to no measurable signal change seen in the control gas‐free spheres. This novel contrast agent also demonstrates an excellent stability in simulated gastric conditions, including at body temperature. In vivo studies showed that the signal change exhibited in the meal within the antrum region is between 5% and 10%, but appears to come from both pressure changes and partial volume artifacts.\ud \ud Conclusion\ud This study demonstrates that alginate spheres with microbubbles can be used as an MRI contrast agent to measure pressure changes. The peristaltic movement within the stomach is seen to substantially alter the overall signal intensity of the contrast agent meal. Future work must focus on improving the contrast agent's sensitivity to pressure changes.