A Clinical Study On The Application Of Quantitative CT In The Comprehensive Evaluation Of Home Noninvasive Positive Pressure Ventilation In The Treatment Of COPD

Objective:1.Observe and evaluate the efficacy of home noninvasive positive pressure ventilation in the treatment of COPD patients with GOLD 3 and GOLD 4combined with type?respiratory failure.2.Some parameters of quantitative CT were added,and longitudinal comparison was conducted before and after treatment,so as to provide more application basis for quantitative CT comprehensive evaluation of COPD patients with stable period.Method:Patients who were admitted to the department of respiratory and critical care medicine of yan'an university hospital from August 2018 to December 2019 due to acute exacerbation of COPD were selected.After hospitalization,the symptoms returned to the stable state,but still complicated with chronic respiratory failure.Patients with pulmonary function examination FEV₁/predicted value<50%,arterial blood gas analysis PaO₂<60mmHg,and PaCO₂>50mmHg were included in the study.There were two groups according to whether the patients were treated with long-term home non-invasive positive pressure ventilation:30 patients in the control group and 30 patients in the observation group.All patients with COPD plateau complicated with respiratory failure meet the diagnostic criteria of GOLD.After discharge,the control group was given conventional comprehensive treatment such as bronchodilator?home oxygen therapy.The observation group was treated with home non-invasive positive pressure ventilation under the premise of conventional comprehensive treatment.At 3 months,6 months,9months,and 1 year after discharge,regularly followed up on telephone and WeChat to inquire about the patient's stable treatment.Arterial blood gas analysis?PaO₂,PaCO₂?,pulmonary function?FEV₁%pred,FEV₁/FVC?,various scores include CAT,mMRC and6-minute walking distance at discharge and at 1-year follow-up.For patients with inspiratory phase,expiratory phase dual phase CT scan,and by using our"digital lung"tool to measure patient LAA%-950insp and LAA%-856exp,inspiratory phase average lung density MLDin,expiratory phase average lung density MLDex,MLDex and inspiratory expiratory phase average lung density is calculated in the ratio of average lung density MLDex/in,when the patients'discharge and follow-up of 1 year after chest imaging parameters,and on the above observation indexes obtained by the statistical analysis,comprehensive evaluation the efficacy of home noninvasive positive pressure ventilation in the treatment of COPD patients with GOLD 3 and GOLD 4 combined with type?respiratory failure.Results:1.The baseline data?patient's age,sex,BMI,PaO₂ and PaCO₂,pulmonary function parameters of FEV₁/FVC,FEV₁/FVC?CAT score,mMRC score,6-MWT and quantitative CT parameters LAA%-950insp?LAA%-856exp?MLDex/in?has no statistical significance?P>0.05?,the differences are comparable.2.The correlation analysis results:before treatment,observation group parameters of pulmonary function FEV₁%pred?FEV₁/FVC and quantitative CT parameters LAA%-950 insp,LAA%-856exp were positive correlation,MLDex/in there were negative correlation?P<0.01?;The control parameters of pulmonary function FEV₁%pred and FEV₁/FVC and quantitative CT parameters LAA%-950insp,LAA%-856exp there were negative correlation?P<0.01?,FEV1%pred?FEV1/FVC with MLDex/in there is negative correlation?P<0.05?.3.Statistical analysis was conducted on the collected observation indicators before and after treatment,and the following results were obtained:?1?The PaO₂ of the patients in the observation group and the control group both increased,the difference was statistically significant?P<0.01?,and the difference between the two groups was statistically significant?P<0.01?;The PaCO₂ of the patients in the observation group and the control group both declined,The difference was statistically significant?P<0.01?.Compared between the two groups,the difference was statistically significant?P<0.05?.?2?The mMRC score of the patients in the observation group decreased,and the difference was statistically significant?P<0.01?.The difference in the mMRC score of the control group before and after treatment was not statistically significant?P>0.05?.The difference between the two groups was statistically significant?P<0.01?;the CAT score of the patients in the observation group decreased,the difference was statistically significant?P<0.01?,the CAT score of the patients in the control group before and after treatment was not statistically significant?P>0.05?;the difference between the two groups was statistically significant Significance?P<0.01?;6-MWT increased in the observation group,the difference was statistically significant?P<0.01?,there was no significant difference between the control group before and after 6-MWT treatment?P>0.05?,between the two groups Comparison,the difference is statistically significant?P<0.01?.?3?The quantitative CT parameters LAA%-950insp,LAA%-856exp,MLDex/in of the observation group were lower than before treatment,the difference was statistically significant?P<0.01?;the quantitative CT parameters of the control group were LAA%-950insp,LAA%-856exp and MLDex/in showed no significant improvement after treatment,and the difference was not statistically significant?P>0.05?.Compared between the two groups,the difference in LAA%-950insp and LAA%-856exp after treatment was statistically significant?P<0.01?,and the difference in MLDex/in was statistically significant?P<0.05?.?4?After 1 year of treatment,there was no significant improvement in FEV1%pred and FEV₁/FVC between the observation group and the control group,and the difference was not statistically significant?P>0.05?.Conclusions:1.The application of home noninvasive positive pressure ventilation can increase the PaO₂ of patients with COPD GOLD 3 and GOLD 4 combined with type?respiratory failure,reduce the patient's PaCO2,reduce the degree of respiratory failure;reduce the patient's mMRC score and reduce the patient's breathing difficulties degree;reduce the patient's CAT score,delay the aggravation of the disease;increase 6-MWT,improve the patient's activity endurance;reduce the patient's quantitative CT parameters LAA%-950insp,LAA%-856exp and MLDex/in,to a certain extent can explain the improvement of COPD degree of emphysema and gas retention.However,after 1 year of application of home noninvasive positive pressure ventilation,the patient's pulmonary function did not improve significantly.2.Quantitative CT has correlations with lung function and various scores of COPD,which can comprehensively assess the severity of COPD.3.Quantitative CT can quantify and detect the tiny improvement in emphysema and gas retention before and after treatment in patients with undetected traditional lung function.