The appropriate use of oxygen.

The scientific evidence for the efficacy of oxygen therapy in acute hypoxemia is limited. In chronic hypoxemia continuous oxygen therapy appears to decrease mortality. Current indications for oxygen treatment are PaO(2) less than 60 in acute hypoxemia and less than 55 in chronic hypoxemia. Physical and physiological hazards of oxygen are reviewed. Three syndromes of pulmonary oxygen toxicity are described: tracheobronchitis, adult respiratory distress syndrome, and bronchopulmonary dysplasia.