AnalgesiaAnalgesia, EpiduralAnalgesia, ObstetricalAnalgesia, Patient-ControlledAnalgesics, OpioidPain, PostoperativeMorphinePain MeasurementBupivacaineAnesthetics, LocalAcupuncture AnalgesiaFentanylAnalgesicsAnesthesia, EpiduralMeperidinePainLabor PainSufentanilNerve BlockInjections, SpinalLabor, ObstetricAnesthesia, ObstetricalAmidesDouble-Blind MethodAnesthesia, SpinalTramadolAnalgesics, Non-NarcoticNaloxoneCesarean SectionPain ThresholdPostoperative Nausea and VomitingInterpleural AnalgesiaDrug ToleranceReceptors, Opioid, muAnesthesia, GeneralConscious SedationKetorolacProspective StudiesLidocaineLabor Stage, FirstHydromorphonePain ManagementPregnancyAnesthesia, CaudalClonidineAnesthesia and AnalgesiaKetamineFemoral NerveTreatment OutcomeReceptors, OpioidHypnotics and SedativesPirinitramideTime FactorsThoracotomyButorphanolAlfentanilNarcotic AntagonistsNalbuphineAnesthetics, CombinedAnesthesia, ConductionElectroacupunctureOpioid PeptidesPruritusMepivacaineDose-Response Relationship, DrugKetoprofenAnesthesia, LocalPlacebo EffectPostoperative CareAdjuvants, AnesthesiaMorphine DerivativesHyperalgesiaNitrous OxidePeriaqueductal GrayPentazocineAmbulatory Surgical ProceduresHysterectomyPiperidinesPain, IntractableBrachial PlexusDexmedetomidineDrug Administration SchedulePain PerceptionInjections, EpiduralAcetaminophenOxycodoneSensitivity and SpecificityInjections, IntravenousPatient SatisfactionAnesthesia, IntravenousAnti-Inflammatory Agents, Non-SteroidalDelivery, ObstetricObstetric Labor ComplicationsAnesthetics, DissociativeNociceptorsPrilocaineInfusions, IntravenousSpinal CordNeostigmineNociceptive Pain