Response to CPAP and UPPP in apnea.

Ninety-two consecutive patients with obstructive sleep apnea syndrome (OSAS) were studied before and six weeks after treatment with either nasal continuous positive airway pressure (CPAP) or uvulopalatopharyngoplasty (UPPP) (n = 46 per group). Assignment of patients to treatment was based on clinical considerations and patient preference. Patients were assessed by nocturnal polysomnography and performance on the Multiple Sleep Latency Test (MSLT) the following day. Before treatment, the CPAP and UPPP groups did not differ in sleep-related respiratory disturbance, oxygenation during sleep, fragmentation of sleep, or the level of excessive daytime sleepiness indicated by the MSLT. Both treatments produced significant improvement on all measures. However, improvement in UPPP patients was significantly less consistent than that of CPAP patients. To the extent that UPPP successfully reversed the respiratory disturbance (i.e., 50% reduction in respiratory events index), sleep continuity and daytime sleepiness were improved to a degree comparable to that of patients treated with CPAP.