CPAP via nasal mask: a treatment for occlusive sleep apnea.

A 38-year-old man had incapacitating hypersomnolence and severe occlusive sleep apnea. Baseline polysomnography revealed 92.9 apneic episodes per hour of sleep. Application of nasal continuous positive airway pressure through a modified nasal nitrous mask using a ball-valve resistor resulted in reduction of occlusive apnea to 1.17 episodes per hour of sleep and marked improvement in the quality of sleep.