Analgesia, Patient-ControlledAnalgesiaAnalgesia, EpiduralAnalgesia, ObstetricalAnalgesics, OpioidPain, PostoperativeMorphinePain MeasurementBupivacaineAnesthetics, LocalAcupuncture AnalgesiaFentanylAnalgesicsAnesthesia, EpiduralMeperidineLabor PainPainSufentanilProton Pump InhibitorsInfusion PumpsInjections, SpinalNerve BlockLabor, ObstetricAnesthesia, ObstetricalAmidesIon PumpsAnesthesia, SpinalTramadolDouble-Blind MethodAnalgesics, Non-NarcoticNaloxoneCesarean SectionPostoperative Nausea and VomitingPain ThresholdInterpleural AnalgesiaDrug ToleranceReceptors, Opioid, muInfusion Pumps, ImplantableAnesthesia, GeneralConscious SedationKetorolacLabor Stage, FirstLidocaineHydromorphonePain ManagementAnesthesia, CaudalClonidineAnesthesia and AnalgesiaSodium-Potassium-Exchanging ATPaseKetamineFemoral NervePregnancyReceptors, OpioidPirinitramideHypnotics and Sedatives