Sleep apnea.

Obstructive sleep apnea is a common disorder characterized by repetitive collapse of the pharyngeal airway during sleep. The disorder results primarily from an anatomically small upper airway in conjunction with pharyngeal dilator muscles that can compensate for the anatomic deficiency awake, but not asleep. Ventilatory control instability and a low arousal threshold may contribute to the disorder as well. The consequences of sleep apnea fall into two domains: (1) neurocognitive dysfunction (sleepiness and decreased quality of life) resulting from sleep fragmentation and (2) cardiovascular disease (hypertension, stroke, myocardial infarction, and heart failure) likely resulting from the intermittent hypoxia. The disorder is generally diagnosed in the sleep laboratory over the course of a night, although alternative approaches in the home are also utilized. A number of treatment options are available. Continuous positive airway pressure remains the most consistently effective approach, although oral appliances (generally mandibular-advancing devices) and a number of surgical procedures have some demonstrated efficacy. Thus, therapy must be individualized to the patient's desires and the severity of the apnea.