Postoperative arterial hypoxaemia.

Postoperative arterial oxygen tension was measured in a group of patients. Unacceptably low levels were found in 32% of the patients and this hypoxaemia persisted in some cases for three days. The results enforce the principle that some patients whould be given prolonged oxygen therapy and this should cease only when blood gas analysis demonstrate the patients ability to maintain a safe PaO2 breathing air.