Oxygen therapy for COPD

Overview

People with severe cases of chronic obstructive pulmonary disease (COPD) may develop hypoxia, or low levels of oxygen in the blood. Breathlessness is not necessarily a sign of hypoxia. Hypoxia can only be diagnosed by taking a blood sample from an artery, a test known as arterial blood gas. If you are diagnosed with hypoxia, you may benefit from supplemental oxygen through oxygen therapy. Oxygen therapy is only available by prescription.

Some people with hypoxia only require oxygen therapy when they are walking, eating, sleeping, or during airline flights. Others may have resting hypoxia, and need supplemental oxygen even when they are sitting still. When someone needs oxygen therapy 24 hours a day, this is known as long-term oxygen therapy (LTOT). Those who require LTOT must use it at least 15 hours a day to experience benefits. However, for maximum benefits, those who need LTOT should use oxygen therapy 24 hours a day.

What does it involve?
If your doctor prescribes oxygen therapy, discuss your needs with them and decide together which type of oxygen delivery system will work best for you. This decision should be based on your oxygen needs at home, during resting conditions, and also during activity and outside the home. If the doctor suspects that your oxygen is low during sleep, you may be asked to spend a night in a sleep laboratory so your oxygen can be monitored overnight. Where you live will also play a role in what type of device will work best for you.

Once you have made this decision, your doctor will give you a certificate of medical necessity that contains details about your prescription. Once the certificate has been issued, you will probably not be able to change your equipment for five years unless your oxygen requirements or condition change significantly.

There are three main types of oxygen delivery devices: Oxygen-gas cylinders, oxygen concentrators, and liquid-oxygen devices.

Oxygen-gas cylinders are steel containers filled with highly compressed oxygen. It is important to frequently check the pressure valves of your oxygen-gas cylinder for proper functioning. When one cylinder is emptied, the regulator must be removed from the empty canister and attached to a full one. There are large, heavy cylinders for use at home and small, portable ones for use when you go out. The small cylinders last about eight hours. Small oxygen-gas cylinders are often used for outings by people who use oxygen concentrators at home.

Oxygen concentrators collect oxygen from the air as it is needed. The machine can weigh up to 50 pounds, and must be plugged into an electrical outlet to function. The oxygen concentrator can be wheeled from room to room, but is not designed to be portable outside the home. The compressor inside the machine makes noise when it is running. Smaller, battery-operated oxygen concentrators are currently under development. Oxygen concentrators have filters that must be thoroughly washed and dried once a week. The machine must also be professionally serviced once a year or after 10,000 hours of use.

When oxygen is cooled to -297°F, it becomes liquid. Liquid oxygen is much more compact than gaseous oxygen, which allows for greater ease of storage. Liquid-oxygen devices are quiet and compact. There is a large reservoir of liquid oxygen that will remain at your home. It will be refilled by a delivery service once every week or two, depending on how much oxygen you use. You will need to be trained to refill your portable device from the larger reservoir.

No matter what type of oxygen delivery device you have, your movements will be limited by the length of the tubing attached to your device. The maximum recommended length for tubing is 50 feet, but it is best to use the minimum length of tubing necessary for your daily movements around the home. The tubing should be changed every six or 12 months.

You may also choose to incorporate an oxygen-sparing device. These pieces of equipment conserve oxygen when you breathe through your oxygen delivery device. Using an oxygen-sparing device reduces the amount of oxygen you use and makes the oxygen supply last longer. Types of oxygen-sparing devices include on-demand devices, reservoir cannulas and trans-tracheal oxygen.

Intended Outcomes
If you have low oxygen levels, oxygen therapy can help you live longer. It can increase your energy, improve kidney function and help correct problems with memory or confusion. Oxygen therapy can improve your health and help you have significantly better quality of life.

Results
Some studies have shown that LTOT can improve survival rates in people with severe COPD and severe resting hypoxia. There is evidence that LTOT may improve quality of life, cognitive function, and exercise capacity, and decrease heart disease, depression, and the number of times a person is hospitalized.

Constraints
While using oxygen therapy, your movements are limited by the length of the tubing attached to your device.

If you require LTOT, you will need to bring your portable oxygen device with you any time you leave the house.

It can be cumbersome and expensive to bring oxygen therapy equipment with you during travel, especially by air. Carefully check regulations before bringing oxygen equipment on airplanes, trains or boats.

Oxygen is a dangerous fire hazard. Do not smoke while using oxygen therapy. Do not use oxygen around lit cigarettes, open flames or anything with the potential to cause sparks. Always keep your oxygen equipment at least six feet away from any potential source of flame. Make sure that all types of oxygen tanks are stored on level, stable flooring, secured from tipping and located safely away from hazards.