More and more people are using oxygen therapy outside the hospital, permitting them to lead active, productive lives. People with asthma, emphysema, chronic bronchitis, occupational lung disease, lung cancer, cystic fibrosis, or congestive heart failure may use oxygen therapy at home.

The Prescription
A physician must write a prescription for oxygen therapy. The prescription will spell out the flow rate, how much oxygen you need per minute—referred to as liters per minute (LPM or L/min)—and when you need to use oxygen. Some people use oxygen therapy only while exercising, others only while sleeping, and still others need oxygen continuously. Your physician will order a blood test that will indicate what your oxygen level is and help determine what your needs are.

The Equipment
There are three common ways of providing home oxygen therapy:

• A liquid oxygen system;
• A standard oxygen concentrator, and
• A portable oxygen concentrator

Home oxygen is rarely delivered in the older large, steel gas cylinders any longer since frequent and costly home deliveries are necessary every few days to replace empty tanks.  Each of the three current methods of providing home oxygen is examined in more detail below.

Liquid Oxygen – Oxygen is stored as a very cold liquid in a large, barrel-like vessel (called a dewar) that acts like a large thermos.  When released, the liquid oxygen immediately converts to a gas and you breathe it in, just like the compressed oxygen in the older steel cylinders.

An important advantage of liquid oxygen is you can transfer some of the liquid oxygen into a smaller, portable vessel that can be carried when you have to leave your home.  The time you can spend away from the dewar can be extended if there is an oxygen-conserving device built into the portable vessel.  Oxygen-conserving devices will be explained below. 

A liquid oxygen dewar must be periodically refilled by the home care company but not as frequently as with the older steel tanks.  This is because 1 unit of liquid oxygen expands to 860 units of gaseous oxygen.  However, liquid oxygen is expensive and will evaporate from the dewar when not being used.   When used as directed, a full dewar can last up to 2 weeks.

Standard Oxygen Concentrator – This is an electrically powered device, weighing about 50 pounds, that separates oxygen from the air by removing nitrogen.  Since air is a mixture of 78% nitrogen and 21% oxygen, removing the nitrogen allows the oxygen to concentrate to over 90%.  This system has a number of advantages.  Since a concentrator essentially makes its own oxygen, there is no need for resupplies by the home care company.  However, you must have a small cylinder as a backup in the event of a power failure.  You should also advise your local electric utility company that you use oxygen in order to get priority services when there is a power failure.

Your home care company can also provide you with small, lightweight, portable cylinders to use when you must leave your home, for example when you visit your doctor, or go grocery shopping.  Empty cylinders will need to be replaced by your home care company.  However, one way to make these smaller cylinders last longer is to use an oxygen-conserving regulator.  These regulators deliver a short burst of oxygen, but only when you inhale.  Since no oxygen is flowing when you exhale, oxygen is conserved.  Cylinders with an oxygen-conserving regulator can last 3–4 times longer than when oxygen is flowing all the time, as is the case with older regulators.

Some home care companies now offer a special pressure booster that can take some of the oxygen produced by your concentrator to refill the small portable cylinders.  This is a great advantage since you can refill your own cylinders when you get back home.  By refilling your own portable cylinders, you don't have to worry about calling your home care company to replace empty cylinders.

Portable Oxygen Concentrator – Advances in technology have significantly reduced the size and weight of the standard oxygen concentrator.  There are various models of lightweight portable oxygen concentrators.  Some weigh as little as 5 pounds where others weigh closer to 17 pounds, but all are easily transportable. So, not only can a portable concentrator be used in your home, but you can also take it with you whenever you need to leave your home. 

Portable concentrators can be powered from a standard household electrical outlet, from the power outlet in any motor vehicle, or from a rechargeable battery.  This feature makes portable concentrators very convenient, and eliminates the need for small portable cylinders.  Since they are battery operated, portable concentrators can also be used when taking a trip on an airplane.  However, you might have to take along additional batteries depending on how many hours the flight will take.

Since there are many different models of portable concentrators, there are also differences in how much concentrated oxygen each model can produce. As a rule of thumb, the smaller the portable concentrator, the lower the amount of oxygen it can concentrate each minute.  For some patients, the smaller portable concentrators may not be able to produce enough oxygen to meet their needs.  It is therefore very important to have a respiratory therapist confirm that a particular model will work for you.  Otherwise you might not get enough oxygen when you need it.

Oxygen Administration Devices
The most common way to administer home oxygen is with a nasal cannula.  This is a two-pronged piece of soft vinyl at one end of plastic tubing that is placed about ¼ inch into your nostrils. The tubing rests over your ears, or can be attached to the frame of specially designed eyeglasses.  The other end of the tubing is connected to the oxygen equipment, where the oxygen flow is set.

Another way to administer oxygen is with a transtracheal catheter, but this is not for everyone.   It requires insertion by a physician of a small flexible plastic catheter in the neck, just below the Adam’s Apple.  The catheter is held in place with a necklace and the oxygen supply tube is connected to the catheter.  The oxygen is then delivered directly into your lower windpipe.

Transtracheal oxygen delivery has several advantages.  When you button the collar of your shirt or wear a scarf, no one can tell that you are using oxygen.  Also, since oxygen is delivered directly into the airway (bypassing the mouth, nose and upper throat), much lower oxygen flow rates are required.   Some people using transtracheal can get by with oxygen flow rates of ¼ to ½ liters per minute instead of the more common 2 liters per minute.

There are a few disadvantages associated with transtracheal oxygen.  One is that you might need to attach a humidifier bottle to your oxygen equipment to add some moisture to the oxygen.  This is usually needed when the oxygen flow rate is 1 liter per minute or greater.  You must also take special daily care of the small opening in your neck (called a stoma) to prevent infection.  The catheter will also need to be replaced every so often. 

Safety
You should never smoke while using oxygen. Warn visitors not to smoke near you when you are using oxygen. Put up no-smoking signs in your home where you most often use the oxygen. When you go to a restaurant with your portable oxygen source, ask to be seated in the nonsmoking section. Stay at least five feet away from gas stoves, candles, lighted fireplaces, or other heat sources. Don't use any flammable products like cleaning fluid, paint thinner, or aerosol sprays while using your oxygen.

If you use an oxygen cylinder, make sure it is secured to some fixed object or in a stand. If you use liquid oxygen, make sure the vessel is kept upright to keep the oxygen from pouring out; the liquid oxygen is so cold it can hurt your skin. Keep a fire extinguisher close by, and let your fire department know that you have oxygen in your home. If you use an oxygen concentrator, notify your electric company so you will be given priority if there is a power failure. Also, avoid using extension cords if possible.

Care of Equipment
The home care company that provides the oxygen therapy equipment you use should provide you with instructions on user care and maintenance of your particular equipment. Here are some general guidelines for your cleaning procedures. You should wash your nasal prongs with a liquid soap and thoroughly rinse them once or twice a week. Replace them every two to four weeks. If you have a cold, change them when your cold symptoms have passed.

Check with your health care provider to learn how to clean your transtracheal catheter. The humidifier bottle should be washed with soap and warm water and rinsed thoroughly between each refill. Air dry the bottle before filling with sterile or distilled water. The bottle and its top should be disinfected after they are cleaned.

If you use an oxygen concentrator, unplug the unit, then wipe down the cabinet with a damp cloth and dry it daily. The air filter should be cleaned at least twice a week. Follow your home medical equipment and services company's directions for cleaning the compressor filter.

Do’s and Don’ts

• Don't ever change the flow of oxygen unless directed by your physician.
• Don't use alcohol or take any other sedating drugs because they will slow your breathing rate.
• Make sure you order more oxygen from your dealer in a timely manner.
• Use water-based lubricants on your lips or nostrils. Don't use an oil-based product like petroleum jelly.
• To prevent your cheeks or the skin behind your ears from becoming irritated, tuck some gauze under the tubing. If you have persistent redness under your nose, call your physician.

Trouble
Call your physician if you experience frequent headaches, anxiety, blue lips or fingernails, drowsiness, confusion, restlessness, anxiety, or slow, shallow, difficult, or irregular breathing. Also, call your physician if you feel any symptoms of illness.

Medicare, Medicaid, and Commercial Insurance
Certain insurance policies may pay for all your oxygen, but payment is based on laboratory results, diagnosis, and other information. Your physician or home care company may be able to answer your questions about coverage.

Reviewed: April 12, 2012
Revised: