Usually, a standard oxygen source can deliver up to a half liter of oxygen per minute (LPM) to a patient, but higher flow rates may be required. A high flow concentrator can provide more than 6 liters of oxygen per minute. In addition, a large, non-portable gas tank can also be used.

Many patients with advanced chronic lung disease have low blood oxygen levels. In these situations, it can be very dangerous for the patient. Depending on the severity, they may need aggressive medical attention. Even mildly low blood O2 can have negative effects on the body’s function. These problems can range from suboptimal performance to organ damage. Having too little oxygen can affect the heart, kidneys, and blood filtering.

A common way of delivering O2 is by using a nasal cannula. The flow can either be a continual stream or an intermittent one. A continual flow refers to the rate of O2 gas that is continuously delivered to the nasal cannula. If the patient is exercising, they may use a higher rate of O2 than if they are not.

The oxygen is drawn into the blood stream by the haemoglobin in the red blood cells. The oxygen then binds to the haemoglobin and is carried to the various organs. The alveoli are the tiny sacs in the lungs that help pull the oxygen into the blood stream. When the alveoli are destroyed, they cannot do their job and some of the O2 gas goes into the surrounding air.