The benefits of long-term oxygen therapy (LTOT) in patients with chronic obstructive pulmonary disease (COPD) and hypoxemia have been demonstrated in multicenter trials in both North America and Europe. A significant increase in survival was observed in the NIH-sponsored Nocturnal Oxygen Therapy Trial (NOTT) after one year of nearly continuous oxygen therapy, along with improvements in neuropsychologic function. Home oxygen therapy is expensive, however, and requires a substantial patient and family commitment that usually lasts for the lifetime of the patient. Many patients begin home oxygen therapy at a time when they are clinically unstable, often on discharge from a hospital following an acute exacerbation of respiratory disease. Other patients may have been observed for years as outpatients and have demonstrated a progressive reduction in arterial oxygen tension. In all patients, it is important that they be clinically stable and receive optimal therapy for their pulmonary disease before LTOT is prescribed.
Several studies have demonstrated reductions in pulmonary artery pressure or pulmonary vascular resistance associated with oxygen therapy in patients with COPD.