Pharyngeal AIrway Obstruction in Obstructive Sleep Apnea

It is well recognized that airflow obstruction in obstructive sleep apnea is caused by collapse of the pharynx. Although the precise anatomic and structural factors leading to pharyngeal collapse are not known, it is generally appreciated that collapse is caused by a complex interaction of structural and neuromuscular factors. The pharynx is comprised of numerous anatomic structures. Its properties are modulated dynamically by neural activation of its musculature. This neuromuscular control is required to integrate the normal functions of the pharynx in respiration, alimentation, and speech. In obstructive sleep apnea, however, such control goes awry as pharyngeal collapse interferes with its normal respiratory function during sleep. This article examines the underlying mechanisms for pharyngeal collapse in apneic patients and their therapeutic implications.