Who needs oxygen therapy?

We all need to breathe and use oxygen from the air around us. Normal room air usually contains 21% oxygen.Oxygen levels around us can change for a variety of reasons: at altitude, for example, or in polluted areas. Oxygen is carried in the blood by Haemoglobin (Hb) in the red blood cells.

For some people with respiratory disease, the lung tissues become damaged or the muscles used for respiration become weakened and this will eventually lead to a change in the composition and quantities of the blood gases, oxygen (O2) and carbon dioxide (CO2).

It is important to know that O2 therapy is not indicated for every person who is breathless. Only small numbers of patients are prescribed oxygen therapy for breathlessness.

In some individuals the effect of increasing O2 can cause an increase in CO2. This retention of CO2 is known as Hypercapnia. This can be dangerous. Symptoms include headaches, drowsiness and reduced respiration. This condition can be fatal if unrecognised.

To determine who needs O2 therapy there are ways to measure the composition of the blood gases and assess the patients O2 with an pulse oximeter.