DexmedetomidineAnesthesia, SpinalHypnotics and SedativesNasal Surgical ProceduresAdrenergic alpha-2 Receptor AgonistsDeep SedationAdrenergic alpha-AgonistsSpinal CordMedetomidineAnesthesia, ObstetricalAnesthesia, GeneralBupivacaineInfusions, IntravenousAnesthetics, LocalSpinal Cord InjuriesAnesthesiaAnesthesia, EpiduralCesarean SectionAdjuvants, AnesthesiaInjections, SpinalAnesthesia, LocalEphedrineAnesthesia Recovery PeriodAnesthesia, ConductionInfusions, ParenteralAnesthesia, IntravenousAnesthesia, InhalationHypotensionLidocaineConscious SedationTetracainePropofolFentanylInfusion PumpsNerve BlockAnesthetics, IntravenousShiveringDouble-Blind MethodAnesthetics, CombinedSpinal NervesSpecific GravitySpinal Nerve RootsPain, PostoperativeAmbulatory Surgical ProceduresMepivacaineAnalgesics, Non-NarcoticHemodynamicsSpinal Cord DiseasesImidazolesPreanesthetic MedicationMidazolamMonitoring, IntraoperativeAnalgesics, OpioidDose-Response Relationship, DrugAnesthetics, InhalationSpinal Cord NeoplasmsSpinal CanalSensationPrilocaineInfusions, Intra-ArterialAnesthesia, DentalReceptors, Adrenergic, alpha-2Pain MeasurementSpinal DiseasesSpinal Cord CompressionBlood PressureSurgical Procedures, MinorHeart RateAnestheticsSpinal PunctureIntraoperative ComplicationsSpinal NeoplasmsProspective StudiesIsofluraneClonidinePost-Dural Puncture HeadacheCarticaineKetamineIsotonic SolutionsTime FactorsRats, Sprague-DawleySpinal StenosisPostoperative Nausea and VomitingSpinal FusionSufentanilMorphinePregnancyAmidesAnalgesicsPlasma SubstitutesAnalgesia