以往认为，分泌性中耳炎是由于咽鼓管机能不良（狭窄或阻塞），不能平衡中耳气压，导致中耳渗出所致。近来报告，中耳气体在中耳腔与粘膜血管之间的弥散在造成中耳负压中所起的作用比咽鼓管机能不良的作用更为突出。乳突腔在中耳有效的气体交换中起压力缓冲腔的作用。当乳突气 In the past that secretory otitis media is due to dysfunctional eustachian tube (stenosis or obstruction), can not balance the pressure in the middle ear, resulting in exudation due to the middle ear. Recently, it has been reported that the dispersion of middle-air gas between the middle ear cavity and mucosal blood vessels plays a more prominent role in causing negative pressure in the middle ear than the dysfunctional eustachian tube. The mastoid cavity acts as a pressure buffer cavity in the effective gas exchange in the middle ear. When Babysit’s breath