Sevoflurane, a volatile general anesthetic, and nitrous oxide, a gaseous anesthetic, produce different subjective, psychomotor, and analgesic effects at equal subanesthetic concentrations. In 12 healthy volunteers, sevoflurane caused greater amnesia, psychomotor impairment, and drowsiness than nitrous oxide, while only nitrous oxide provided analgesic effects. Recovery from both drugs was rapid. The distinct effect profiles align with their chemical and mechanistic differences.
Michael Faraday, best known for his work on electromagnetic induction, also contributed to the introduction of anesthesia. In 1818, he published an anonymous announcement that inhaling ether vapor produced effects on mentation and consciousness similar to those of nitrous oxide. Faraday likely learned about nitrous oxide's effects from his mentor Humphry Davy, an avid user. Ether was cheap and easily available, unlike nitrous oxide which required expensive apparatus. This announcement helped lead to student "ether frolics" and eventually the first surgical anesthetics. Notations in Faraday's handwriting confirm his authorship.