Effects of long-term oxygen therapy in patients with chronic obstructive pulmonary disease.

Long-term oxygen therapy is largely used in the management of severe hypoxemia in patients with chronic obstructive pulmonary disease. It was demonstrated that long-term oxygen therapy prolongs life, prevents progression of hypoxic pulmonary hypertension, and controls polycythemia. Recent data suggest that in patients with moderate hypoxemia (Pao2 > 55 mm Hg), long-term oxygen therapy does not prolong life. Life expectancy in those patients seems to depend on the severity of airway obstruction. Long-term oxygen therapy improves cognitive functions and emotional status. There is some evidence suggesting that it also improves quality of life, but more data are needed. There are conflicting data concerning the rationale for nocturnal oxygen supplementation in patients with arterial blood desaturation during sleep.