Fig. 19:  This Figure shows the effects of oxygen therapy in COPD in patients who have nocturnal desaturation alone.^[1]  Again, the Table summarizes several small studies – six in aggregate, three randomized controlled trials, the others not – looking at survival, pulmonary hemodynamics, and sleep efficiency, and it can be seen that in aggregate, there was no survival benefit of supplementary oxygen in these studies.  Only one study, of 16 subjects by Fletcher, showed a reduction in pulmonary hemodynamics or improvement in secondary pulmonary hypertension that also showed an improvement in sleep; the only other study that showed improvement in sleep was the study by Calverley in only six subjects. 

So overall, while the data show significant benefits for supplemental oxygen on mortality in patients with COPD and with mild-to-moderate hypoxemia, the data fail to demonstrate improvement in exercise tolerance or on pulmonary hemodynamic survival or sleep quality in nocturnal desaturation.