Home Oxygen is an essential part of life. Normal healthy people usually have a blood oxygen level above 85 units (mmHg). In people with lung problems, the level may fall to low levels even though the body can continue to perform normally. When oxygen levels fall below 55-60 units, added oxygen may be helpful. Chronic obstructive pulmonary disease (COPD) is the term used most commonly to describe smoke-related conditions such as emphysema and chronic bronchitis. Patients with these problems may have severe shortness of breath with a normal oxygen level. In the later stages of COPD, low oxygen levels become more common. Supplemental oxygen in patients with severe COPD and low oxygen levels of 55-60 units or below, prolongs life and in some cases also improves the quality of their life. Patients who use their added oxygen for 24 hours a day show a longer life span than those who use it for 15 hours; and these people in turn do better than those who use it only during sleeping hours.
The same criteria are used for giving oxygen to people with other diseases such as cystic fibrosis and pulmonary fibrosis. Oxygen may also be used for relief of breathlessness in patients who have lung cancer when the blood oxygen is low. Oxygen is supplied for emergency use to patients who have had severe acute life-threatening attacks of asthma, or for severe angina heart disease when these patients have a low oxygen level, when maximal medical treatment has been given and heart surgery is not possible.