Study On Application Value Of Expiratory Time In Quality Control Of Routine Ventilation Lung Function In Asthmatic Children

Objective: The quality control of lung function is very important for children’s lung function examination.Forced expiratory time(FET)is the standard of expiratory end in the quality control of lung function.Currently,it is considered that the expiratory time of children aged 6-10 years old is ≥3s or children over 10 years old is ≥6s.However,obstructive ventilation dysfunction can lead to prolonged expiratory time,and restrictive ventilation dysfunction can lead to shortened expiratory time,thus affecting the application of FET in quality control of ventilation function.In the past,the reference range of FET was based on healthy children and defined by age,without considering the influence of ventilation dysfunction.Therefore,by analyzing the results of routine ventilation lung function test in children with asthma of different ages and types of ventilation disorders,this study explored the application value of expiratory time in the quality control of routine ventilation lung function in asthmatic children,optimized the quality control evaluation index of children’s lung ventilation function test,so as to improve the quality control of end criteria of children’s lung function test.Methods: The lung function data of children with asthma who underwent pulmonary ventilation function examination in Shengjing Hospital Affiliated to China Medical University from January 2015 to February 2023 were retrospectively collected.(1)General data and lung function test data should be collected by electronic medical records.According to quality control standards and physician experience and examination process,children’s lung function test data which are qualified for final check quality control should be selected.The time-flow curve can be detected by Engauge Digitizer software.Expiratory time(FET)was divided into effective expiratory time(ETe)and platform expiratory time(ETp).(2)According to medical records and pulmonary function test results,the children were divided into four groups: normal pulmonary ventilation function group,restricted ventilation dysfunction group,obstructive ventilation dysfunction group,mixed ventilation dysfunction group.SPSS26.0 software was used for statistical analysis to analyze the differences of FET,ETe and ETP among different types of ventilation dysfunction,different genders and different ages,and to study the application value of expiratory time in the quality control of routine ventilation lung function in children with asthma.Results:1.Different types of ventilation function had significant differences on the FET and ETe(P<0.05).The FET and ETe in the obstructive ventilation dysfunction group and the mixed ventilation dysfunction group were longer than those in the normal group,the FET and ETe in the obstructive ventilation dysfunction group were the longest,and those in the restrictive ventilation dysfunction group were the shortest,while there was no significant difference in the ETp among different types of ventilation dysfunction(P>0.05),suggesting that the ETp was not affected by the type of ventilation dysfunction.2.In the normal ventilation group,there were no significant difference in FET,ETe and ETp among different ages(P>0.05).In the ventilation dysfunction group,ETp of different age groups had no significant difference(P>0.05),but significant differences in ETe among different age groups(P>0.05),except for the group with moderate obstructive ventilation dysfunction.There were significant differences in FET between the moderate restrictive ventilation dysfunction group and the mild obstructive ventilation dysfunction group at different ages(P>0.05),but no significant differences in other groups with abnormal ventilation function(P>0.05).3.The severity of ventilation dysfunction had effects on ETp,FET and ETe(P<0.05),but the affected expiratory duration is different in different types of ventilation dysfunction.In obstructive ventilation dysfunction,the degree of ventilation dysfunction had no significant effect on FET(P>0.05),but had an effect on ETe and ETp(P<0.05).ETe in moderate group was longer than that in mild group,while ETp was shorter than that in mild group.Among the restricted ventilation dysfunction,the degree of ventilation dysfunction had no significant effect on the FET and ETe(P>0.05),but had an effect on the ETp(P<0.05),and the ETp in the severe restricted group was the longest.In the mixed ventilation dysfunction,the degree of ventilation dysfunction had no significant effect on ETe and ETp(P>0.05),but had an effect on FET(P<0.05).The FET in the severe mixed group was longer than that in the moderate mixed group.4.There was no significant difference between different genders in FET and ETp(P>0.05),but there were significant differences in ETe(P<0.05),among which,the ETe of boys was significantly longer than that of girls,suggesting FET and ETp were not affected by gender.5.Correlation analysis of common indicators showed that height was correlated with FET in the normal ventilation function group(P<0.05),but the strength of the correlation was very weak(r=0.195),and there was no significant correlation with ETe and ETp(P>0.05).There was a correlation between weight and ETe(P<0.05),and the correlation intensity was weak(r=0.279),but there was no significant correlation between weight and FET and ETp(P>0.05).In the abnormal ventilation function groups,there was a correlation between FVC and ETe(P<0.05),but the correlation strength was very weak(r=0.181),and there was no significant correlation between FVC and ETe(P>0.05).There was no significant correlation between FEV1 and FET,ETe and ETp(P>0.05).FEV1/FVC was correlated with FET and ETe(P<0.05),and had a weak negative correlation with FET(r=-0.115),whlie a strong negative correlation with ETe(r=-0.664),but no significant correlation with ETp(P>0.05).Conclusions:1.FET and ETe were affected by the types of ventilation dysfunction,in which obstructive and mixed ventilation dysfunction were longer than normal,and restrictive ventilation dysfunction was shorter than normal.ETp were not affected by the types of ventilation dysfunction.2.FET,ETe and ETp were all affected by age,but ETp was only affected by age in the moderate obstructive ventilation dysfunction group.3.Gender has an impact on ETe,with boys growing longer than girls;There was no significant effect on ETp and FET.4.The severity of ventilation dysfunction has influence on ETp,FET and ETe,but the affected expiratory duration is different in different types of ventilation dysfunction.In conclusion,compared with FET,ETp is less affected and is more suitable as the end of expiratory standard.