Sleep Apnea: Is Your Patient at Risk.

摘要

Sleep apnea is a serious, potentially life-threatening condition. It is a breathing disorder characterized by repeated collapse of the upper airway during sleep, with consequent cessation of breathing. Virtually all sleep apnea patients have a history of loud snoring. They may also unknowingly experience frequent arousals during the night, resulting in chronic daytime sleepiness or fatigue. There are two discrete types of sleep apnea: central and obstructive. Central sleep apnea, characterized by a lack of airflow in the absence of ventilatory effort, is rare. Obstructive sleep apnea is much more common and is referred to as sleep apnea hereafter. It is characterized by closure of the upper airway, resulting in the cessation of airflow despite persistent ventilatory effort. Apnea is defined as cessation of airflow for more than 10 seconds. A related event, hypopnea, is characterized by a reduction in airflow associated with a decrease in oxygen saturation. The average number of apnea hypopnea events per hour of sleep is called the apnea-hypopnea index (AHI). Adults may experience up to five events per hour without symptoms. In general, as AHI increases, so does the severity of symptoms. An AHI of five or greater in combination with self-reported hypersomnolence is indicative of the sleep apnea syndrome.