Dead Sea: natural oxygen enrichment at low altitude.

Patients with advanced chronic obstructive lung disease often require oxygen supplementation, which has been shown to increase survival but requires a device such as an oxygen tank and tubing. The inspired partial pressure of oxygen depends on barometric pressure, which is related directly to altitude. At the Dead Sea, located 402 m below sea level, the barometric pressure reaches 800 mm Hg, thus resulting in high inspired oxygen levels. We have taken this topographic advantage to study oxygen-dependent patients with advanced lung disease. We found significant increases in arterial oxygen tension, exercise capacity, sleep oxygen saturation, and an improvement in quality of life while staying at the Dead Sea. This was found during both a short stay (1 week) as well as a longer stay (3 weeks). The improvement in exercise capacity persisted 2-3 weeks after leaving the area. We conclude that the low altitude at the Dead Sea can be of benefit to patients with advanced lung disease who are hypoxemic. The higher the altitude of the normal residence of the patient, the greater is the expected benefit of a sojourn at the Dead Sea.