Value Of Lung Ultrasound Combined With Diaphragmatic Ultrasound In Predicting Preoperative Pulmonary Function Of Patients

Objective:To explore the predictive value of lung ultrasound combined with diaphragmatic ultrasound in the evaluation of preoperative pulmonary function by analyzing the correlation between lung ultrasound combined with diaphragmatic ultrasound and preoperative pulmonary function test in patients.Methods:A total of 201 patients who met the inclusion criteria and exclusion criteria for elective surgery in the First Affiliated Hospital of Nanchang University from June 2021 to December 2021 were selected.One day before surgery,the patient was tested for lung function tests and recorded.In addition,the patient was subjected to lung ultrasound examination and diaphragmatic ultrasound examination,and the corresponding lung ultrasound images and diaphragmatic ultrasound images were obtained.According to the image results,the lung ultrasound score（LUSS）,diaphragmatic excursion（DE）,and diaphragmatic thickening fraction（DTF）were recorded.The patients were divided into normal lung function group（normal,mild obstructive ventilatory disorder）and abnormal lung function group（moderate to severe obstructive ventilatory disorder）according to the results of lung function test.The differences of ultrasonic indexes between the two groups were observed.The relationship between ultrasonic and lung function results was explored by Pearson correlation analysis and multi-factor regression analysis,to evaluate the accuracy of lung ultrasound combined with diaphragmatic ultrasound in predicting lung function.Results:（1）General data comparison between two groups:193 patients were finally included,including 144 cases with normal lung function and 49 cases with abnormal lung function.The comparison between the two groups showed that in the patients with abnormal pulmonary function,the amplitude of diaphragmatic movement was lower,the diaphragmatic thickness at the end of inspiration was thinner,the diaphragmatic thickening rate was lower,and the LUS score was higher,all of them have statistically significant differences（P<0.001）.（2）Analysis of influencing factors of lung function:multivariate logistic regression analysis showed that the quiet breathing diaphragm amplitude（OR=0.04[95%CI:0.00–0.35]P=0.004）,the thickening rate of quiet breathing diaphragm（OR=0.86[95%CI:0.80–0.94]P=0.001）,The rate of diaphragmatic thickening with forced breathing（OR=0.89[95%CI:0.84–0.95]P=0.001）,LUS score（OR=1.25[95%CI:1.14–1.65]P=0.027）,all independently affected lung function results,while the quiet breathing diaphragm amplitude and age did not.（3）Correlation analysis between influencing factors of pulmonary function and pulmonary function indexes:The amplitude of forced diaphragmatic muscle movement was positively correlated with airway obstruction（FEV₁）and ventilatory capacity（D_LCO and FVC）（r=0.340,0.263,0.412 P<0.01）,and negatively correlated with the degree of emphysema（RV/TLC%）（r=-0.394 P<0.01）;The thickening rate of forced diaphragm was positively correlated with FVC,FEV₁and D_LCO（r=0.388,0.471,0.295 P<0.01）.LUS score was negatively correlated with D_LCO,FVC,and FEV₁（r=-0.338,-0.309,-0.567 P<0.01）,and positively correlated with RV/TLC%（r=0.351 P<0.01）.Lung ultrasound combined with diaphragmatic ultrasound was negatively correlated with FVC、FEV₁and D_LCO（r=-0.320,-0.530,-0.260 P<0.01）,and positively correlated with RV/TLC%（r=0.316 P<0.01）。（4）ROC curve analysis of pulmonary ultrasound and diaphragmatic ultrasound in predicting abnormal lung function:The optimal cutoff value of deep breathing diaphragm amplitude in predicting abnormal lung function was 4.89cm,and the AUC was 0.87[95%CI:0.79,0.94],with specificity 83%and sensitivity 81%.The best cutoff value for predicting abnormal lung function by the rate of quiet breathing diaphragmatic thickening was 35.06%,and the AUC was 0.91[95%CI:0.86,0.97],with specificity 88%and sensitivity 85%.The best cutoff value for predicting abnormal lung function by using forced diaphragmatic thickening rate was 61.56%,and the AUC was 0.88[95%CI:0.83,0.94],with specificity 83%and sensitivity 86%.The optimal cutoff value of LUS score for predicting abnormal lung function was4.5 points,and AUC was 0.88[95%CI:0.80,0.96],with specificity 94%and sensitivity 80%.All the above single indicators could accurately predict abnormal lung function in patients.However,the combination of pulmonary ultrasound and diaphragmatic ultrasound had the highest accuracy in predicting abnormal lung function in patients,with AUC being 0.94[95%CI:0.89,0.98],specificity 83%and sensitivity 94%.Conclusion:Lung ultrasound and diaphragmatic ultrasound have high correlation with lung function and good prediction value for abnormal lung function,which can be used for rapid assessment of lung function in preoperative patients.