Study on the correlation between breath sound audio frequency spectrum analysis and lung function in patients with chronic obstructive pulmonary disease / 中国综合临床

ABSTRACT

Objective:To study the characteristics of breath sound spectroscopy in chronic obstructive pulmonary disease(COPD) patients with different lung function grades, to preliminarily determine the characteristic parameters and indicators of breath sound spectrograms with different lung function grades of COPD, and to explore the visualization and measurability of the differences in respiratory auscultation in patients with different lung function grades.Methods:Patients diagnosed and treated in Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine Chongming Branch from October 2018 to December 2020 were selected. Fifty-two patients with COPD (22 patients with moderate to moderate obstructive ventilation dysfunction (mild to moderate group), 30 patients with severe obstructive ventilation dysfunction (severe group)) and 36 normal controls (control group) were selected. The respiratory sounds were sampled with an electronic stethoscope and transmitted to the audit audio software to calculate the relevant data of respiratory sound pressure level (SPL) and the ratio to minute ventilation (VE) of samples with different lung function grades. A retrospective case-control study was used. The data with normal distribution were analyzed by one-way ANOVA, and the pairwise comparison was performed by SNK- q test. Results:The breathing audio frequency of mild-moderate, severe COPD patients and the control group has a sound pressure difference of (-0.5±2.2) dB and (-1.6±6.1) dB, (0.7±4.0) dB, and there was significant difference between each group ( F=2.64, P=0.038). The sound pressure level per minute ventilation (SPL 50-200/VE) of respiratory sound inspiratory phase in COPD patients with mild to moderate and severe obstructive ventilation dysfunction and the control group were (5.7±1.8) dB/L, (6.1±2.3) dB/L and (5.4±0.9) dB/L, respectively. The expiratory SPL 50-200/VE were (5.8±1.7), (6.3±2.2) and (5.3±1.2) respectively. There was significant difference among the three groups ( Finhalation=3.26, P=0.048; Frespiration=2.44, P=0.045). ROC curve results showed that SPL 50-200/VE in the inspiratory phase, SPL 50-200/VE in the expiratory phase, and sound pressure difference to assess different grades of obstructive ventilatory dysfunction had diagnostic value (AUC values were 0.697, 0.725 and 0.686, respectively; and P values were 0.015, 0.005 and 0.022, respectively). In some patients with COPD, abnormally high energy levels may appear in the time-frequency diagram of breath sounds. Conclusion:There are significant differences in respiratory audio spectrum analysis between patients with different degrees of obstructive ventilation dysfunction and those with normal ventilation function, which can provide a basis for auxiliary judgment of obstructive ventilation dysfunction.