Managing COPD: Oxygen therapy

Many people who have COPD need constant use of supplemental oxygen. Because damaged or blocked lungs do not properly absorb oxygen, they often cannot distribute enough oxygen to the rest of the body. Without sufficient oxygen, the rest of a person's organs are unable to work properly. Supplemental oxygen increases the amount of pure oxygen a person breathes in, so the lungs have more oxygen to absorb and distribute to the rest of the body. By getting the most oxygen possible, breathing is easier and a person is able to do more activities without becoming short of breath.

Measurement of oxygen levels

Health care providers determine whether a person needs supplemental oxygen by measuring blood oxygen levels, or how much oxygen the lungs deliver into the blood stream to deliver to other organs. Depending on blood oxygen levels, a person may be prescribed supplemental oxygen to make breathing easier.

There are two main ways to determine the amount of oxygen in a person's blood: an arterial blood gas test and an oximeter test.

Arterial blood gas (ABG) test

For an ABG test, a health care provider draws blood directly out of an artery and measures blood levels in a laboratory. This is the most accurate method of measuring blood oxygen levels. It can be done during an initial visit with a health care provider.


An oximeter is a small, non-invasive device that fits on a person's finger tip. The oximeter shines light through the finger and measures the amount of light absorbed by a person's hemoglobin, the part of red blood cells that carries oxygen. The amount of light absorbed tells a health care provider how much oxygen is absorbed.

A common test utilizing an oximeter is the six-minute walk test. This test may be done during a visit with a health care provider. A health care professional places the oximeter on a person's finger and asks the person to walk with the professional for up to six minutes. This test evaluates a person's need for supplemental oxygen during activity.

Depending on blood oxygen levels, a person may be prescribed supplemental oxygen to make breathing easier.

Oxygen systems

Supplemental oxygen is delivered through three types of devices: oxygen concentrators, compressed oxygen cylinders and liquid oxygen systems. Each of these devices pushes oxygen through tubing and into a person's nose.
  • Oxygen concentrators constantly take in room air and filter out other gasses to produce only oxygen. The oxygen is pushed through a small tube and delivered directly to a person's nose using nasal canals. Concentrators are most commonly used at home, but portable models are also available.
  • Compressed oxygen cylinders are small tanks filled with enough oxygen to last four to eight hours, depending on a person's oxygen requirements. These tanks can be refilled by a health care provider and reused for many years. Compressed oxygen cylinders weigh fewer than 8 pounds and are small enough to be carried in small side packs or on wheeled carts.
  • Liquid oxygen cylinders are small tanks filled with liquid oxygen, which is made by cooling oxygen gas.  Compared with other systems, liquid oxygen cylinders hold more oxygen in smaller containers. However, they cannot be kept for a long time because the oxygen will evaporate.

Precautions for all systems

Regardless of the system, it is very important to remember: oxygen is highly flammable. Smoking should not be allowed near oxygen equipment and oxygen should not be stored near furnaces, water heaters or other sources of heat or flame. It is also important to check for leaks and take adequate care of the equipment. Always read the instruction manual and have equipment checked regularly by a professional.


Delivery Devices

There are several devices used to deliver oxygen from an oxygen system into a person's body.
  • Nasal cannulae are small tubes that rest just inside a person's nose. A nasal cannula receives oxygen from an oxygen system, which pushes oxygen through small, thin tubing that runs under the chin, around the ears and under the nose. Nasal cannulae are the most popular oxygen delivery device because they are inexpensive and non-invasive. They are not as efficient as other methods, though, because they deliver oxygen constantly, regardless of whether a person is inhaling. 
  • Oxygen conserving devices work with a person's breathing pattern to deliver oxygen only during inhalation, while the person is taking in breath. The health care provider and the oxygen professional determine if a device can or should be used. There are different types of conserving devices available.
          Reservoir cannula is a device that is attached to the oxygen tubing between the nasal cannulae and the oxygen source. This device stores oxygen in a small reservoir during exhalation and releases that stored oxygen when a person inhales. 
          Intermittent flow devices are affixed to the oxygen tank and regulate the volume of oxygen delivered with inhalation. There is a variety of types of devices available.
  • Transtracheal oxygen devices deliver oxygen directly through a small catheter inserted into the trachea (the airway tube in the throat). This approach is very efficient but also invasive. Minor but costly surgery is needed to insert the catheter, and there is a risk of infection, frequent mucus plugging, and a need for constant cleaning.