Breakthrough PainAdministration, BuccalFentanylAnalgesics, OpioidLabor PainPainDouble-Blind MethodAnalgesia, EpiduralPain MeasurementDose-Response Relationship, DrugEthanolNasal SpraysTime FactorsNeoplasmsChronic DiseasePain, PostoperativeChronic PainPain ManagementPain ThresholdPain, IntractableRadionuclide GeneratorsLow Back PainBack PainAnesthetics, IntravenousAbdominal PainNeck PainTreatment OutcomeMorphineEpisode of CareAdministration, CutaneousAerosolsPelvic PainFacial PainPain PerceptionBupivacaine