Prone PositionSupine PositionPatient PositioningRespiratory Distress Syndrome, AdultNephrostomy, PercutaneousPostureAnoxiaPulmonary Gas ExchangeSudden Infant DeathBlood Gas AnalysisDisposable EquipmentVentilation-Perfusion RatioRespiration, ArtificialPositive-Pressure RespirationRespiratory MechanicsPulmonary CirculationOxygenNitrogen RadioisotopesOxygen Inhalation TherapyLaryngopharyngeal RefluxPronationBedsPulmonary VentilationIntraoperative ComplicationsSpineEquipment ReuseUreteral CalculiLaryngeal MasksSleepOrgans at RiskAirway ManagementIntubation, IntratrachealRespirationPressure UlcerLungFetal HypoxiaLung Volume MeasurementsOximetryGravitationProspective StudiesIntraoperative Care