Comparison of Oxygen Delivery Devices for Reversal of Altitude-Induced Hypoxemia in Normal Subjects

Subjects will be monitored non-invasively with pulse oximetry, end-tidal carbon dioxide, tissue oxygenation and ECG. The mean seal level oxygen saturation will be recorded.Subjects exposed to an altitude of 14,000 feet will experience moderate hypobaric hypoxia. The mean oxygen saturation at this altitude is 83%. Subjects will receive oxygen from both an oxygen concentrator or a cylinder of oxygen following exposure to hypobarism. Oxygen from each source will be increased in 1 liter per minute increments until the oxygen saturation returns to the baseline sea level oxygen saturation. The oxygen requirement to return oxygen saturation to baseline values will be recorded. The flow from the concentrator and the cylinder will be compared.