While doctors have significantly refined their techniques over the subsequent 150 years—ether made patients throw up and was flammable enough to cause mid-surgery explosions—there are still outstanding questions about how anesthesia works. Now, he adds, researchers have identified the specific brain molecules that anesthesia tweaks to alter our consciousness. Low doses of most anesthetics, says Franks, work by affecting our brain cells’ receptors. Why we need better anestheticsGeneral anesthesia is now very safe, with deaths linked to anesthesia occurring less than one in every 100,000 uses. If we can better understand anesthesia and create drugs that mimic natural rest more effectively, there could be huge benefits for patients.