O₂

Oxygen therapy — also known as supplemental oxygen — is the use of oxygen as a medical treatment, e.g. for low blood oxygen, carbon monoxide toxicity, cluster headaches, or to maintain enough oxygen while inhaled anaesthetics are given. Long term oxygen is often useful in people with chronically low oxygen, such as from severe COPD or cystic fibrosis. Medical oxygen can be given in a number of ways, e.g. via nasal cannula, face mask, or inside a hyperbaric chamber.

However, high concentrations of oxygen can cause oxygen toxicity such as lung damage or result in respiratory failure in those who are predisposed. It can also dry out the nose and increase the risk of fires in those who smoke.

Accordingly, the target medical oxygen saturation recommended depends on the condition being treated. In most conditions, a saturation of 94-98% is recommended, while in those at risk of carbon dioxide retention saturations of 88-92% are preferred, and in those with carbon monoxide toxicity or cardiac arrest, they should be as high as possible. Air is typically 21% oxygen by volume. Medical oxygen is also required by people for proper cell metabolism.

Commonly used in medicine since 1917, medical oxygen is on the World Health Organization’s Model List of Essential Medicines, the most effective and safe medicines needed in a health system. Healthcare professionals and organisations who use medical oxygen include doctors, dentists, nurses, veterinarians, anaesthetists, respiratory specialists, dermatologists, hospitals and day surgeries.