lung and airway disorders
Oxygen Therapy
Introduction
Oxygen therapy is a treatment that delivers extra oxygen to the lungs when the level of oxygen in the blood is too low. Oxygen is a gas that makes up about 21% of the air we breathe. The lungs take oxygen from the air and transfer it to the bloodstream (see Exchanging Oxygen and Carbon Dioxide ). Oxygen is needed to burn fuel to release energy, such as in a car engine. Similarly, all living tissue needs oxygen to provide energy for the body. Without enough oxygen, cells function poorly and eventually die. Many diseases, particularly lung diseases, decrease the amount of oxygen in the bloodstream. In such cases, people may benefit from being given extra oxygen. Doctors used to give extra oxygen to many sick people. However, evidence has shown that oxygen is not helpful unless a person's oxygen level is actually low. Breathing too much oxygen can actually damage the lungs after a period of time. To ensure that oxygen is given only to people who need it, doctors check the level of oxygen in their bloodstream using a Arterial Blood Gas (ABG) Analysis and Pulse Oximetry (pulse oximetry). Once the level of oxygen is determined, oximetry may be used to adjust oxygen flow settings (how much oxygen the person gets per minute) over time. 