Epidural SpaceAnesthesia, EpiduralAnesthesia, GeneralAnesthesiaAnesthesia, LocalNeedlesInjections, EpiduralAnesthesia, ObstetricalAnesthesia, SpinalDura MaterAnesthesia, InhalationAnesthesia, ConductionSpinal CanalLigamentum FlavumAnalgesia, EpiduralAnesthesia, IntravenousLumbosacral RegionAnesthetics, LocalEpidural NeoplasmsAnesthesia Recovery PeriodAnesthesia, DentalAnesthesia, CaudalLipomatosisSpinal Nerve RootsFentanylRadiculopathyAnalgesia, ObstetricalCoccyxLumbar VertebraeLidocaineBupivacaineFiber Optic TechnologyThoracic VertebraeAnesthetics, InhalationAnesthetics, IntravenousSpinal DiseasesMyelographyTissue AdhesionsAdjuvants, AnesthesiaNerve BlockPropofolSpinal CordLaminectomyInjections, SpinalMathematical ConceptsIntracranial HypotensionIsofluraneIntervertebral Disc DisplacementFluoroscopyMethyl EthersAnesthesiologySpinal Cord CompressionBlood Patch, EpiduralEpidural AbscessAnesthetics, CombinedSpinal NeoplasmsCatheterizationAnatomy, Cross-SectionalMonitoring, IntraoperativeAnestheticsNitrous OxideHalothaneCervical VertebraeTomography, X-Ray ComputedEndoscopySpinal Cord DiseasesMagnetic Resonance ImagingAnesthesia, Closed-CircuitSpinal StenosisLow Back PainAnesthetics, GeneralPreanesthetic MedicationSteroidsKetamineAmbulatory Surgical ProceduresThiopentalProspective StudiesPregnancy Trimester, ThirdPentobarbitalAnesthetics, Dissociative