Nitrous OxideAnesthesia, InhalationAnesthetics, InhalationAnesthesia, GeneralAlfentanilPropofolIsofluraneHomocysteineAnesthesiaAnesthetics, CombinedEnfluraneAnesthesia Recovery PeriodMethyl EthersAnesthesia, LocalHalothaneAnesthetics, IntravenousPhenoperidineFentanylAnestheticsAnesthesia, IntratrachealAnesthesia, IntravenousAnesthesia, EpiduralAnesthesia, SpinalThiopentalAnesthesia, ConductionIntraoperative PeriodAnesthesia, DentalAnesthesia, ObstetricalIntubation, IntratrachealNitric Oxide SynthaseElectroencephalographyXenonCarbon DioxideDose-Response Relationship, DrugBlood PressureHemodynamicsAdjuvants, Anesthesia