The major purpose of breathing is gas exchange: trading carbon dioxide for oxygen. While there is another way for the body to excrete some of its waste carbon dioxide, breathing is the only way to get oxygen. Therefore in patients that exchange gases poorly, such people with severe COPD, oxygen therapy becomes a desirable treatment. Oxygen therapy are either tanks or machines that supplement oxygen to the air patients are breathing. This increases the concentration of oxygen in the patients' lungs, and thus increases the rate oxygen is delivered to the blood.
The major symptom of COPD is dyspnea, the feeling of breathlessness. In milder cases of COPD, this feeling of breathlessness only occurs after significant physical exertion. In more severe cases, dyspnea can also occur at rest. This feeling is correlated to the level of oxygen in the blood. By supplementing their oxygen, patients with COPD often do not feel breathless, or at least, feel less breathless. Studies have shown that even though there are many medications that treat the symptoms of COPD, oxygen is the only one that actually prolongs the life of the patients with COPD.
The specific cutoff for needing oxygen therapy is a pulse oximeter reading of ≤ 88%, while at rest or during exertion. An oxygen saturation of 88% corresponds to a PaO2 of about 56 mmHg on arterial blood gas laboratory results. Due to the design of blood, an oxygen saturation of below 88% can fall very quickly, which could be life-threatening. Patients with COPD that have a reading of 88% or below tend to benefit from oxygen therapy. Patients pulse oximeter readings that are higher that 88% generally do not benefit from oxygen supplementation.
After a pulmonologist determines that the pulse oximeter reading is ≤ 88%, the physician will contact an oxygen supplier of the patient's choice, who will then do a home sleep study. This will help the oxygen supplier tailor the treatment to the patient's specific needs.
The most familiar one is the simple tank. This a continuous flow device that provides an adjustable amount of oxygen. The problem with this device is that it wastes a lot of oxygen, since it releases oxygen even when the patient is exhaling. This inefficiency necessitates that the tanks have a high capacity, result in large tanks. To conserve oxygen, there is a device that provides a adjustable amount of oxygen only when the patient is inhaling called a demand oxygen pulsing device. The advantage of these devices are that the patient does not need to carry as a large tank when the oxygen is conserved, making it especially useful when the patient is on the go.
The final kind of oxygen supplementation is an oxygen concentrator. These devices that take the room air, and manipulate it so there is more oxygen. Their major advantage is that they do not use oxygen tanks that need to be refilled.
If used as directed, none.
Be aware that while oxygen by itself is not flammable, it does accelerate the rate of combustion. Do not smoke near oxygen. Stay away from any possibly sources of ignition when using oxygen.
The oxygen in the tanks are kept under high pressure. The tanks should not be punctured or excessively heated, or they may explode causing severe injury or death.