摘要
哮鸣是连续的肺异位音。美国胸科协会肺术语委员会将喘息定义为主频为400hz或以上的高频连续声音。Rhonchi的特点是低音连续的声音,其主频约为200赫兹或更少。喘鸣主要频率的大变异性是自动分析和定量喘鸣遇到的困难之一。在自动喘息表征中观察到的巨大变化强调了呼吸声分析标准化的必要性。这种标准化将有助于确定哮鸣识别的诊断标准。喘息产生的机制首先被比作玩具喇叭,它的声音是由振动簧片产生的。喘息的音调取决于气道壁面的质量和弹性以及流速。最近,提出了一种基于通过湿陷管气流稳定性的数学分析的喘鸣生产模型。根据这个模型,喘息是由气道壁和流体一起产生的,由一个临界气流速度引起。 Many circumstances are suitable for the production of continuous adventitious lung sounds. Thus, wheezes can be heard in several diseases, not only asthma. Wheezes are usual clinical signs in patients with obstructive airway diseases and particularly during acute episodes of asthma. A relationship between the degree of bronchial obstruction and the presence and characteristics of wheezes has been demonstrated in several studies. The best result is observed when the degree of bronchial obstruction is compared to the proportion of the respiratory cycle occupied by wheeze (tw/ttot). However, the relationship is too scattered to predict forced expiratory volume in one second (FEV1) from wheeze duration. There is no relationship between the intensity or the pitch of wheezes and the pulmonary function. The presence or quantification of wheezes have also been evaluated for the assessment of bronchial hyperresponsiveness. Wheeze detection cannot fully replace spirometry during bronchial provocation testing but may add some interesting information. Continuous monitoring of wheezes might be a useful tool for evaluation of nocturnal asthma and its treatment.