Treatment of hypoxemia in obstructive sleep apnea

Many patients suffering from obstructive sleep apnea (OSA) have intermitten t oxygen desaturation associated with periods of apnea or hypopnea. Oxygen saturation levels below 90% are considered harmful.(1) Usually, treatment i s directed at correcting the apnea, which will in turn prevent hypoxemia. U nfortunately, many patients fail or are not candidates for nasal continuous positive airway pressure (CPAP) or surgical correction of their OSA. Forty -three patients with persistent OSA and nocturnal hypoxemia below 90% who w ere not candidates for additional surgical or CPAP therapy were treated wit h nocturnal oxygen supplementation. Standard symptoms associated with OSA a nd the Epworth Sleepiness Scale (ESS) were recorded before treatment and 30 days after the start of the treatment. In 21 patients, polysomnography stu dies were performed to compare the Respiratory Disturbance Index (RDI) scor e and minimum oxygen saturation levels when the patients were breathing roo m air or breathing 4 L/minute of oxygen by nasal cannula. Subjective sympto ms of obstructive sleep apnea improved, and the ESS score significantly dec reased after a 30-night treatment with oxygen. Split-night polysomnography showed a significant increase in minimum oxygen saturation during oxygen ad ministration. The RDI did not significantly change with treatment. Oxygen a dministration for the correction of OSA-related nocturnal hypoxemia was bot h safe and effective in alleviation of OSA-related symptoms. It also appear ed to have a beneficial effect on minimum oxygen saturation levels. Thus, o xygen therapy may be considered a treatment option in patients who fail to comply with CPAP and are not candidates for a surgical procedure.