气道近端部分(如咽下部、喉、气管等处)受阻或外周气道广泛狭窄,都能使气流严重受阻。近端梗阻时,主要的病理生理改变是通气不足。一旦梗阻解除或被避开,气体交换就能正常进行。同样,弥漫性气道阻塞(即哮喘、慢性支气管炎和肺气肿)伴随的呼吸衰竭,即以通气不足为特征,而后者又都伴有血氧减少,主要是由于通气和灌血失调所致。 The proximal part of the airway (such as pharynx, larynx, trachea, etc.) blocked or extensive narrowing of the peripheral airway, can make the air flow severely blocked. In proximal obstruction, the major pathophysiological change is hypoventilation. Once the obstruction is relieved or avoided, gas exchange can proceed normally. Similarly, respiratory failure associated with diffuse airway obstruction (ie, asthma, chronic bronchitis, and emphysema), characterized by hypoventilation, which in turn is associated with hypoxemia, is primarily due to ventilatory and hematogenous disorders To