Prone PositionSupine PositionPatient PositioningNephrostomy, PercutaneousRespiratory Distress Syndrome, AdultPosturePulmonary Gas ExchangeSudden Infant DeathDisposable EquipmentRespiration, ArtificialPositive-Pressure RespirationRespiratory MechanicsNitrogen RadioisotopesVentilation-Perfusion RatioLaryngopharyngeal RefluxPronationPulmonary CirculationBedsIntraoperative ComplicationsSpinePostoperative ComplicationsProspective StudiesIntraoperative CareEquipment ReuseLaryngeal MasksUreteral CalculiAirway ManagementOrgans at RiskTreatment OutcomePulmonary VentilationBlood Gas AnalysisPressure UlcerSleepTomography, X-Ray ComputedIntubation, IntratrachealGravitationOxygen