Ultrasound Evaluation Of Diaphragm Function And Its Correlation With Pulmonary Function In Patients With Chronic Obstructive Pulmonary Disease

Objective Ultrasound was used to evaluate the changes of diaphragm function in patients with chronic obstructive pulmonary disease(COPD),and to clarify the relationship between the changes of diaphragm and the level of pulmonary function.Methods Eighty-one COPD patients who were hospitalized in Angang general hospital from March 2018 to January 2019 were divided into mild group,moderate group and severe group according to the lung function level and the2017 edition of global strategy for diagnosis and prevention of COPD.At the same time,30 cases of healthy control group were selected.All the participants were examined as follows:(1)pulmonary function test;(2)Ultrasound was used to measure the diaphragm thickness at the end of quiet expiration and forced expiration,and the ratio of the end of forced expiration to the end of quiet expiration was calculated;(3)Ultrasound was used to measure the diaphragm mobility during quiet breathing and forced breathing,and the difference between them was calculated;(4)Modified Medical Research Council Dyspnea Scale(m MRC)was used to assess dyspnea.(5)The correlation between diaphragm mobility and pulmonary function and m MRC was analyzed.Results Measurement of diaphragmatic mobility by ultrasonography:The diaphragm mobility in quiet breathing phase(P< 0.05),forced breathing phase(P < 0.05)and the difference of diaphragm mobility in different breathing phase(P < 0.05)were different in each group.In the diaphragm movement during quiet breathing,there was no significant difference between the control group and the mild group(P> 0.05),but there was no significant difference between the mild group and the moderate group(P> 0.05),and there was significant difference between the severe group and other groups(P< 0.05).There was no significant difference in diaphragm mobility between the control group and the mild group(P> 0.05),but there was significant difference between the moderate group and the severe group and other groups(P< 0.05).Comparing the difference of lower diaphragm mobility in different breathing phases of each group,there was significant difference among the groups(P< 0.05).As the degree of pulmonary function impairment increases,the diaphragm mobility increases gradually in the quiet breathing phase,decreases gradually in the forced breathing phase,and decreases gradually in the difference of diaphragm mobility in different breathing phases.Measurement of diaphragm thickness by ultrasonography:The diaphragm thickness at the end of quiet expiration(P< 0.05)and the ratio of the diaphragm thickness at the end of forced inspiration to that at the end of quiet expiration(P< 0.05)were different in each group.There was no significant difference in end-inspiratory diaphragm thickness between groups(P> 0.05).In the calm end-expiratory diaphragm thickness,there was no significant difference between the control group and the mild group(P> 0.05),but there was no significant difference between the mild group and the moderate group(P> 0.05),and there was significant difference between the severe group and other groups(P< 0.05).The ratio of the diaphragm thickness at the end of forced inspiration to that at the end of quiet expiration was compared among the groups,and the difference was statistically significant(P< 0.05).The diaphragm thickness at the end of quiet expiration gradually increased with the aggravation of pulmonary function damage,and the ratio of the diaphragm thickness at the end of forced inspiration to that at the end of quiet expiration gradually decreased.The correlation analysis between diaphragm mobility and pulmonary function and dyspnea score: In COPD group,diaphragm mobility was positively correlated with body weight(BMI),airway obstruction(FEV1% pred,FEV1 /FVC%),ventilation ability(FVC%pred,IC%pred,MVV%pred),and negatively correlated with emphysema(RV / TLC%pred),dyspnea(m MRC).Multivariate linear regression analysis showed that FEV1% pred [β = 0.728,95% CI(0.027,0.042)] was the influencing factor of diaphragm mobility.Conclusions1.With the aggravation of lung function damage,the thickness of diaphragms at the end of calm exhalation increased gradually,but there was no change at the end of forced inspiration.2.The degree of diaphragm movement decreased with the aggravation of lung function damage in COPD patients.3.The phrenic mobility of COPD patients was related to pulmonary function index and degree of dyspnea(m MRC).