The following steps are necessary in the successful management of hypoxia: 1. Establish the presence of hypoxemia with measurements of arterial blood gases. 2. Search for signs of tissue hypoxia. 3. Assign a physiologic cause for hypoxemia. 4. Begin oxygen therapy by a method appropriate to underlying pathophysiologic mechanism, as outlined in Table 2. 5. Repeat arterial blood gas measurements to assure adequate reversal of hypoxemia. 6. Treat any underlying disease(s).