Obstructive sleep apnea: Part I. Pathophysiology, diagnosis, and medical management.

Obstructive sleep disordered breathing (OSDB) is a spectrum of disease resulting from changes in the upper airway. It affects a large proportion of the adult population, and in its most severe form, obstructive sleep apnea syndrome (OSAS), patients suffer the adverse effects of sleep disturbance and oxygen desaturation. Daytime somnolence leads to a significantly higher incidence of automobile and work-related accidents, while nocturnal hypoxia is associated with multiple physiological derangements. Patients with OSAS have higher incidences of hypertension, coronary artery disease, congestive heart failure, and arrhythmias. Noninvasive testing is used to confirm the diagnosis, and treatment may be conservative, medical, or surgical. Treatment is designed to improve daytime somnolence and has been shown to improve morbidity and mortality among patients with OSDB.