上气道阻塞(UAO)对机体的影响取决于阻塞的部位,阻塞处气道的大小,损害的性质和呼吸时期,能否引起症状则取决于阻塞的严重程度。如上气道直径降为8mm时运动时可产生症状,阻塞处为5mm时休息时即可产生吸气性阻塞并引起哮鸣音。 胸腔外的上气道为大气压所包围,胸腔内的上气道为胸腔压力所围绕。气管内,外的压力差称为经壁压(Transmural Pressure)。若气管外压力>气管内,即正性经壁压时则气道隔闭。反之,负性经壁压时则气道开放。 The effects of upper airway obstruction (UAO) on the body depend on the site of the obstruction, the size of the airway at the obstruction, the nature of the lesion, and the duration of the breath. Whether it can cause symptoms depends on the severity of the obstruction. When the diameter of the upper airway is reduced to 8mm, it can produce symptoms when exercising, and when the obstruction is 5mm, it can produce aspiration block and cause wheeze. The extrathoracic external airway is surrounded by atmospheric pressure, and the upper airway in the chest is surrounded by chest pressure. The pressure difference between the inside and outside of the trachea is called Transmural Pressure. If the tracheal pressure> trachea, that is positive when the wall pressure is the airway barrier. Conversely, the negative pressure when the airway is open.