Long-term oxygen therapy appears to be a safe means of treating hypoxemia. It can provide many physiologic improvements and prolongs life in persons with severe chronic arterial hypoxemia at rest. Recent studies suggest that arterial hypoxia is common during exercise and sleep, and it is likely that some patients with intermittent desaturation would benefit physiologically from supplemental oxygen. Oxygen is an expensive drug, and we do not know whether its benefits are greater than its costs in patients who are not hypoxic at rest. I believe that low-flow oxygen administered as continuously as possible should be strongly considered for all patients whose Pao2 is 55 mm Hg or less at rest, regardless of whether they have cor pulmonale, and for all patients with cor pulmonale, regardless of their Pao2.
John M Luce (1983) studied this question.