Life SciencesPhysiologyPsychophysiologySleep MedicineSleep NeurologyAltitude PhysiologyHypoxia PhysiologySleep AssessmentSleep DisturbanceSleep PhysiologySleep-wake DisordersHypoxiaNeurophysiological Responses To HypoxiaNocturnal HypoxemiaSleepSleep At AltitudeSleep Hypoventilation SyndromeSleep-related HypoventilationSleep-related Hypoxemia
The effects of hypobaric hypoxia upon the electrophysiologically assessed sleep of four male and four female subjects--18-29 years old--were measured during two successive nights at 493 torr (3500 m) in a hypobaric chamber. Five subjects experienced varied levels of acute mountain sickness (AMS). Sleep disturbance was primarily manifested as "insomnia" in two subjects experiencing higher levels of AMS. Relatively normal amounts of synchronized sleep were observed at 493 torr, implying the occurrence of sleep hypoventilation.