Oxygen Therapy in Chronic Obstructive Lung Disease

Excerpt

To the editor, The information obtained from the Nocturnal Oxygen Therapy Trial (1) does indeed seem to indicate that continuous oxygen therapy is associated with a lower mortality than nocturnal oxygen therapy in hypoxemic chronic obstructive lung disease. As stated by the authors, however, the reason for this difference is not clear. Further analysis of the data on pulmonary hemodynamics is needed, particularly pulmonary vascular resistance. The 11% decline in pulmonary vascular resistance in patients in continuous oxygen therapy is consistent with animal studies showing that continuous but not intermittent normoxemia may reverse anatomic evidence of pulmonary hypertension (1, 2).