To our knowledge, nocturnal oxygen and nasal CPAP have not been compared as treatments of obstructive sleep apnea in a controlled trial. Because of our clinical impression that patients with mild obstructive sleep apnea are least likely to tolerate nasal CPAP, and because nasal CPAP is well established as first line treatment for severe obstructive sleep apnea, we undertook our study to evaluate the relative efficacy of nasal oxygen and nasal CPAP in treating patients with mild OSA. flovent inhaler
Methods
Subjects were recruited from patients studied in the Sleep Apnea Laboratory at the University of Kentucky College of Medicine, either through routine clinical referral or as part of an ongoing study of sleep disordered breathing in the elderly.
We defined an apnea as total cessation of airflow at the nose and mouth lasting for at least 10 seconds as indicated by both a thermistor and a COa meter. We defined hypopnea as a reduction in the amplitude of the thermistor signal by at least 50 percent for 10 seconds or longer, accompanied by a 4 percent or greater fall in arterial oxygen saturation. Apnea plus hypopnea indices were calculated by dividing the sum of apneas and hypopneas per night of study by the total sleep time measured in hours. For every minute of nocturnal monitoring, the highest SaOa and lowest SaO, were identified and recorded. In addition, the number of falls ^4 percent in SaOs were recorded.