Explain Oxygen Therapyin respiratory support?

Oxygen is given to correct hypoxemia. An initial high concentration of oxygen (FiO2) is given while the underlying cause is identified and corrected. The dangers of supplemental oxygen in patients with hypercarbic COPD has been exaggerated - in general, hypoxia is far more dangerous than hypercarbia and should be corrected as priority. The adverse effects of high concentrations of oxygen (oxygen toxicity) is also unimportant in a hypoxic patient. The key is to give as much oxygen as is required to correct hypoxia.