The effect of chronic nocturnal oxygen administration upon sleep apnea

Administration of nocturnal oxygen for 1 night to patients with obstructive sleep apnea(OSA) causes a moderate reduction in apneafrequency without improving hypersomnolence. Therefore, we administered oxygen chronically to patients with OSA to determine: ( 1) whether apneafrequency would be further reduced, ( 2) whether the effect of oxygen upon apneafrequency is correlated with an increased ventilatory response to hypoxia and hypercapnia, and ( 3) whether hypersomnolence improves with more prolonged oxygen administration. In a single-blinded, nonrandomized trial, we compared the effects of 1 month of oxygen (4 L/min by nasal cannula) with room air (4 L/min by nasal cannula) placebo during sleep in 7 men and 1 woman with obstructive sleep apnea. During non-REM sleep, acute oxygen administration elevated the average low oxyhemoglobin saturation during apneic events and decreased apneafrequency. These acute effects persisted during chronic oxygen administration but reverted to the preoxygen effects imm...