 Low-flow anesthesia has been shown to provide many benefits such as improved patient safety, cost savings, and environmental friendliness. However, one drawback is that the oxygen concentration of fresh gas flow and inspired gas can differ significantly when using low-flow anesthesia. To address this issue, researchers conducted a study to compare the effects of low-flow anesthesia on oxygen concentration. They found that the oxygen concentration decreases significantly in the first 15 minutes of use, but then stabilizes at around 30%. Additionally, they observed that the oxygen concentration remained stable throughout the duration of the procedure. These results suggest that low-flow anesthesia can be used safely and effectively without compromising oxygen levels. This article was authored by Jaewook Kim, Dong Heekong, Hoke Lee, and others.