呼吸音分析技术用于心源性和非心源性呼吸困难的鉴别诊断

Respiration sound patterns used to distinguish the cardiogenic dyspnea from dyspnea all pulmonary own

目的 临床上心力衰竭，慢性阻塞性怖病和哮喘急性加重时均可以通过听诊器发现异常呼吸音，目前为止尚不能对以上呼吸音进行定量分析。对于就诊于急诊科的呼吸困难患者，鉴别诊断其发生原因对于临床治疗措施和预后关系密切。本研究的目的就是应用计算机辅助的呼吸音分析技术对心源性和非心源行呼吸困难时的呼吸音进行定量分析，同时评价其临床应用价值。方法本实验为前瞻性临床研究，应用呼吸音分析记录装置记录患者呼吸过程中所产生的呼吸音，通过计算机辅助技术将呼吸音转化成图像。收集因急性呼吸困难来北京大学第三医院急诊就诊的患者59人，根据患者最终出院诊断分为3组：急性心力衰竭患者22人，慢性阻塞性肺病急性加重期患者19人，哮喘急性发作患者18人。选择同期健康志愿者20人作为对照组。对三组患者的呼吸音图像进行定量分析，分析指标为吸气相最大呼吸音能量图面积和最大吸气相／最大呼气相能量比值。组间比较采用t检验。结果健康对照组、心力衰竭组、慢性阻塞性肺病急性加重期患者和哮喘急性发作患者的吸气相最大呼吸音能量图面积分别为：（76．2±4．5），（67．6±6．7），（72．2±7．6）和（52±11．7）千像素（P〈0．01）。健康对照组、心力衰竭组、慢性阻塞性肺病急性加重期患者和哮喘急性发作患者的吸气相最大呼吸音能量图左右侧面积之比分别为1：1、1：1、1：1和1：0．4。健康对照组、心力衰竭组、慢性阻塞性肺病急性加晕期患者和哮喘急性发作患者的最大吸气相／呼气相能量峰值比值分别为：（6．3±5．2），（5．6±4．0），（2．0±2．2）和（0．3±0．3），P〈0．01：结论与健康对照相比较，心力衰竭患者组的吸气相最大呼吸音能量图面积明显缩小，吸气相最大呼吸音能量图左右面积之比及最大吸气相／最大呼气相能量比值尢差别；与健康对照相比较，慢性阻塞性肺病患者的吸气相最大呼吸音能量图面积无差别，吸气相最大呼吸音能量图左右面积之比无差别，最大吸气相／最大呼气相能量比值明显缩小；与健康对照相比较，哮喘患者的吸气相最大呼吸音能量图面积明显缩小，吸气相最大呼吸音能量图左右面积不对称，最大吸气相／最大呼气相能量比值明显缩小。以上图像特点对鉴别心力衰竭、阻塞性肺病和哮喘所引起的呼吸困难有帮助。

Objective To evaluate the distribution of respiratory sound intensity in patients with congestive heart failure （CHF） or chronic obstructive pulmonary disease （COPD） or asthma during acute exacerbation because those patients present with characteristically anscultatory findinge on lung examination which can be used for differential diagnosis. Method Respiratory. sounds throughout each cycle were recorded and displayed by using an acoustic-based imaging technique. Breath sound distribution was mapped to create a gray-scale of two-dimensional images based on intensity of sound （vibration）. Consecutive patients with CHF （n = 22）, COPD （n = 19）and asthma （ n = 18） were imaged at the time of presentation to the emergency department. Geographical area of the images and the volume of respiratory sound were quantitatively analyzed. Results The mean geographical areas of the vibration energy image in inspiratory maximal energy frame in healthy volunteers, CHF, COPD and asthma patients were （76.2± 4.5）, （67.6± 6.7）, （72.2 ± 7.6） and （52 ±11.7） kilo-pixels, respectively （ P 〈 0.01 ）. The ratios of left geographical area of the vibration energy image in inspiratory maximal energy frame in healthy volunteers, CHF, COPD and asthma patients were 1 ： 1,1 ： 1,1 ： 1 and 1 ： 0.4, respectively （ P 〈 0.01）. The ratios of vibration energy values at peak inspiration and expiration （peak I/E ratio） in healthy volunteers, CHF, COPD and asthina patients were （6.3 -± 5.2）, （5.6 ± 4.0）, （2.8± 2.2） and （0.3± 0.3）, respectively （ P 〈 0.01 ）. Conclusions Compare with healthy volunteers, the geographic area of the image in patents with CHF is smaller, and there is no difference in peak L/E vibration ratio between two lungs. In patients with COPD, there is no difference in geographic area of the image in comparison with volunteers, and there is significant decrease in peak I/E ratio. In patients with asthma, the geographic area of the image is much smaller than that of volunteers, and the peak I/E ratio is even still decreased between two lungs. These characteristics may be helpful in distinguishing acute dyspnea due CHF from that due to COPD or asthma.