Middle Ear VentilationFentanylAdministration, IntranasalAnalgesics, OpioidAnesthetics, IntravenousAnalgesia, EpiduralSufentanilNasal MucosaPreanesthetic MedicationAdministration, CutaneousAdjuvants, AnesthesiaAnesthesia, IntravenousPain, PostoperativeMidazolamAlfentanilBupivacaineAnesthetics, CombinedAnalgesia, ObstetricalAnesthesia, GeneralPropofolMorphineDouble-Blind MethodAnesthesia Recovery PeriodMice, Inbred BALB CAnalgesia, Patient-ControlledBreakthrough PainImmunity, MucosalPain MeasurementLungAnesthetics, LocalNitrous OxideNarcoticsReceptors, Opioid, mu