Treatment of Obstructive Sleep Apnea (1)
Sleep-disordered breathing is a common disorder in the adult male population and is conservatively estimated to affect about 1 percent of that group. Although the precise definitions of sleep apnea and sleep hypopnea are still evolving, they are clinically identifiable entities which can cause significant sequelae, such as hypertension, nocturnal cardiac arrhythmias, daytime hypersomnolence, and cognitive impairment. Nasal CPAP has received widespread interest and acclaim as a treatment of OSA since its introduction in 1981,2 and is currently recommended as first-line treatment for OSA. It probably keeps the airway open by acting as a “pneumatic splint.” Nasal CPAP reliably abolishes nocturnal sleep-disordered breathing, is no more expensive than is nocturnal oxygen, and is associated with very few side effects. However, its efficacy has not been systematically compared to that of any other treatment modality for OSA, it is physically cumbersome, and 40 to 45 percent of patients are unable to comply with longterm CPAP use.
Nocturnal nasal oxygen is a logical treatment for sleep-disordered breathing, particularly for the hypoxemia-related sequelae. Nasal oxygen has been shown to abolish apnea-related hypoxemia and associated cardiac arrhythmias and to reduce apnea frequency. Its effect on cognitive function and daytime hypersomnolence is more controversial. However, there is an abundance of evidence from studies of patients with chronic obstructive lung disease indicating that long-term oxygen therapy is well tolerated and associated with improved survival in chronically hypoxemic patients. Despite initial fears, there have been no reports of morbidity due to respiratory acidosis in patients receiving nocturnal oxygen administration.