In anaesthesia, medicinal oxygen is used:
During surgery to maintain tissue oxygenation.
Before and after surgery: Most patients undergoing anaesthesia receive a few minutes of oxygen therapy before surgery in the anaesthetic room and after surgery in the recovery room until they are fully conscious. However, some patients need a longer period of oxygenation before surgery, including those with pre-existing respiratory dysfunction, smokers, and patients undergoing certain procedures such as abdominal or thoracic surgery. These patients, together with elderly patients and those receiving drugs that depress breathing, may also benefit from a longer duration of oxygen therapy in the recovery room and on their return to the ward in order to reduce the risk of hypoxia and its complications.