lung and airway disorders
Oxygen Therapy
When oxygen is used
Some people with chronic lung disease need only a brief period of oxygen therapy during an acute flare up (exacerbation) of their lung disease. (See also Pulmonary Rehabilitation .) Others, in whom oxygen levels in the blood are consistently low (such as some people with severe COPD), may require oxygen therapy all the time. In people with severely low oxygen levels, long-term oxygen therapy increases survival time. The more hours a day the oxygen is used, the better the result. People survive longer when 12 hours of oxygen are used than when no oxygen is used. People survive even longer when oxygen is used continuously (24 hours per day). However, in people with moderate or slightly low oxygen levels due to chronic lung disease, long term-term oxygen use does not decrease risk of death. Regardless of the effects on mortality, long-term oxygen use may decrease shortness of breath and reduces the strain on the heart that lung disease causes. Both sleep quality and the ability to exercise tend to improve. Some people with chronic lung disease have low levels of oxygen only when they physically exert themselves. These people can limit their oxygen use to periods of exertion. Other people have low oxygen levels only when they are sleeping. These people can limit their oxygen use to overnight hours. 