Current status and research on chronic respiratory failure in Japan.

Chronic respiratory failure is defined on the basis of gas exchange in the lung. Recent studies have suggested serious clinical problems in patients with disabling dyspnea not necessarily related to gas exchange. Home oxygen therapy not only prolongs life expectancy but also improves the quality of daily life. In Japan, pulmonary emphysema, sequelae of pulmonary tuberculosis, and interstitial pneumonia/pulmonary fibrosis are the 3 major diseases currently treated by home oxygen therapy. Respiratory failure caused by interstitial pneumonia/pulmonary fibrosis and lung cancer is on the increase and is also treated by home oxygen therapy. Clinical problems on mechanisms and treatment of chronic respiratory failure are reviewed from recent data.