Some people with chronic lung disease need only a brief period of oxygen therapy during an acute exacerbation of their lung disease. Others, in whom oxygen levels in the blood are consistently low, may require oxygen therapy on a daily basis. In these people, oxygen use improves survival. The more hours a day the oxygen is used, the better the result. Survival is better when 12 hours of oxygen are used than when no oxygen is used. Survival is even better when oxygen is used continuously (24 hours per day). Long-term oxygen use decreases shortness of breath and reduces the strain on the heart that lung disease causes. Both sleep 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.
Once the critical level of oxygen is determined, oximetry may be used to adjust oxygen flow settings over time. Oximetry is painless and uses a simple device that is attached to a finger or ear to measure the concentration of oxygen in the blood.
Oxygen for long-term home use is available from three different delivery systems: electrically driven oxygen concentrators, liquid systems, and compressed gas. Inside the home, liquid and compressed gas systems use large tanks to store oxygen. Small, portable tanks of compressed oxygen also may be needed for brief periods—a few hours—outside the home. Each system has advantages and disadvantages.
Oxygen is typically administered with continuous flow through a two-pronged nasal tube (cannula), even though this system is highly wasteful of oxygen. To improve efficiency and increase the person's mobility, several devices, including reservoir cannulas, demand-type systems, and transtracheal catheters, can be used. When a person exhales, a reservoir cannula stores oxygen in a small chamber, and then returns the oxygen when the person inhales. Demand-type systems deliver oxygen only when triggered by the machine's user (such as when a person inhales or presses on the device). They do not deliver oxygen continuously. Some have small reservoirs. A transtracheal catheter is a small tube that is inserted through the skin directly into the windpipe. Oxygen is then delivered directly to the windpipe. Usually, a respiratory therapist or physician instructs the person about proper oxygen use.
While using oxygen therapy at home, it is important to stabilize the source (if a tank, possibly using a stand) and store it in an area that is out of the way so it will not fall. Oxygen sources should be closed tightly when not in use. Because oxygen is flammable and can cause an explosion, it is also important to keep tanks away from any sources of ignition, such as matches, heaters, or hair dryers. No one in the house should smoke when oxygen is in use.