FIG. 19:  Supplemental oxygen can improve arterial oxygen saturation, but it may not correct the underlying CSA or hypoventilation, and there is a theoretical concern that it may actually worsen CSA or hypoventilation.^[13]  Patients using opioids may have a reduced arousal and ventilatory response to hypercapnia.  Therefore oxygen therapy can potentiate hypoventilation or prolong central apneas by essentially knocking out the hypoxemic respiratory drive. 

Conversely, if the arousal threshold is low and respiratory controller gain is high due to pain, oxygen therapy may actually stabilize breathing when taken with chronic opioids.  To date there have been no systematic studies of supplemental oxygen and its effects on Op-CSA.