High Risk Factors And Prognosis Of The Respiratory Nervous System In Preterm Infants With Bronchopulmonary Dysplasia

Objective:By retrospective analysis and follow-up of clinical data,the research discussed the high risk factors of bronchopulmonary dysplasia(BPD)in premature infants,and predicted the influence factors of severity.Then the research evaluated the prognosis of respiratory system and nervous system in the near and long term in order to guide clinical prevention and early diagnosis and treatment and improve the quality of life of children.Methods:Part one: Clinical risk factors for bronchopulmonary dysplasia in preterm infantsHospitalized neonatal ward and neonatal intensive care unit(NICU)from Children’s Hospital of Soochow University from October 2013 to October 2017 and admitted to hospital within 7 days after birth,with a hospitalization time≥28 days data of preterm infants for retrospective analysis.(1)According to the corrected gestational age of 36 weeks whether oxygen inhalation(if the gestational age is over 32 weeks,whether oxygen time is at least 28 days),they were divided into two groups,BPD group and non-BPD group.To compare the incidence of BPD in preterm infants with preterm infants born every year for 4 years and hospitalization time ≥28 days,and analyze the changing trends.According to the birth weight(BW),gestational age(GA)to calculate the incidence of BPD in each group: less than 1000 g,1000~1499g,1500~1999g,2000~2499g,2500~3750g,less than 28weeks(wks),28 ~ 31+6wks,32 ~ 36+6wks;(2)The general conditions of pregnant mothers and preterm infants,laboratory examination on admission of premature infants,the occurrence of basic diseases and complications of premature infants,and the treatment measures were compared between BPD group and non-BPD group;(3)According to the children correct gestational age 36 weeks or whether the oxygen discharge(if GA≥32weeks,according to whether or not oxygen after 56 days),BPD were divided into mild BPD group(not oxygen)and moderate to severe BPD group(still need oxygen),to compare the clinical data between the two groups.(4)The ROC curves of BPD and the severity of the disease and its independent risk factors were drawn respectively by SPSS19.0 statistical software to reveal the predicted effect of the risk factors on the BPD and the severity of the disease.Part two:The study of respiratory system prognosis in premature infants with bronchopulmonary dysplasiaThe preterm infants who admitted in the neonatal ward and NICU in our hospital from October 2014 to October 2017 diagnosed as BPD,the non BPD premature infants who admitted at the same time and the full-term children aged 4 to 36 months whose lung function is normal.All follow-up infants were divided into four groups: full-term infants,non-BPD,mild BPD,and moderate-severe BPD(moderate BPD preterm infants+severe BPD preterm infants).Follow-up preterm infants completed pulmonary function tests and questionnaire surveys at 4 to 36 months of corrected gestational age and 4 to 36 months of age at term infants(including height,weight,respiratory infection,and number of rehospitalization).The patients in different groups(BPD group,non-BPD group,full-term children group,non-BPD group,mild BPD group,moderate-severe BPD group)and different ages(less than 6 months,6~12months,12~24months,24~36 months),and follow-up data(times of respiratory infections and rehospitalization,pulmonary function indicators,tidal breathing flow volume loop)were compared to assess the prognosis of children with respiratory system.Part three:Neuropsychological assessment of preterm infants with bronchopulmonary dysplasiaThe preterm infants diagnosed as BPD from October 2016 to October 2017 in the neonatal ward and NICU,the non BPD premature infants hospitalized in the same period and the normal full-term children aged 3 to 12 months in the outpatient clinic of our hospital were followed up.The preterm infants were divided into BPD group and non-BPD group,according to the presence or absence of BPD.All follow-up infants were divided into four groups: full-term infants,non-BPD,mild BPD,and moderate-severe BPD(moderate BPD preterm infants + severe BPD preterm infants).Follow-up preterm infants completed Gesell scale tests at 3 to 12 months of gestational age and 3 to 12 months of age at term infants.Comparative analysis on the general situation(weight,height,age,gender)and prenatal maternal general situation was done.Results:Part one: From October 2013 to October 2017,3759 preterm infants were hospitalized in neonatal department of our hospital were enrolled.A total of 550 patients met the inclusion criteria,including 66(12.0%)cases of BPD,24(36.4%)cases of mild BPD,32(48.5%)cases of moderate BPD,10(15.1%)cases of severe BPD.The incidences of BPD in preterm infants were 1.8%,1.1%,1.5%,2.5% and length of stay more than 28 days was 10.9%,8.0%,11.6% and 15.8% in 4 years,with the highest incidence of BPD from October 2016 to October 2017.Of 550 cases of premature infants,GA range was 25+6~36+6w,average GA was(31.50±2.20)w,BW range was 670~3750g,average BW was(1528±387)g.And the incidence of BPD subgroups with GA<28w,28~31+6w,32~36+6w were 20.0%,15.1% and 7.1%.The incidences of BPD subgroups with BW<1000g,1000~1499g,1500~1999g,2000~2499g and 2500~3750g were 42.1%,18.8%,7.9%,4.3% and 0.0%.The incidence of BPD decreased significantly with increased BW and GA.Univariate regression analysis showed that the following statistics were higher in BPD group than that in non-BPD group: GA<32w,BW<1500g,Pulmonary surfactant(PS),length of hospital stay,oxygen inhalation time,invasive ventilation time>5 days,Peak Inspiratory Pressure(PIP),Positive end expiratory pressure(PEEP),continuous positive airway pressure(CPAP)≥30 days,high frequency ventilation,Fi O2≥40%,Apgar(1min)<8 scores,transfusion≥3 times,Type II respiratory failure,neonatal respiratory distress syndrome(NRDS),patent ductus arteriosus(PDA),prenatal dexamethasone,antibiotic use time,enteral feeding start time,total enteral feeding time,average daily hospitalization costs.Multivariate logistic regression analysis showed that Fi O2≥40%(OR=6.40,95% CI 1.09~37.60),oxygen inhalation time(OR=1.20,95% CI :1.12~1.27),type II respiratory failure(OR=7.23,95% CI:2.62~19.98)(OR=3.69,95% CI: 1.23~11.10)were independent risk factors of BPD.The ROC curves of four risk factors and BPD were plotted as follows: Area under the curve(AUC)of ROC curve were 0.57,0.94,0.66,0.79 and 95% CI were 0.49~0.65,0.92~0.96,0.59~0.74,0.73~0.85 respectively.The AUC of predictive model was 0.95 and the 95% CI was 0.93~0.97.The results showed that 4 kinds of risk factors can predict the BPD early,and the predictive model can better predict the occurrence of BPD.There were 24 cases(36.4%)of mild BPD in 66 BPD cases,42 cases(63.6%)of moderate and severe BPD cases.Fi O2≥40% was risk factorof BPD severity(OR=9.77,95% CI:1.16~82.59).The severity of BPD was predicted early by Fi O2≥40%(AUC=0.634,95% CI: 0.50~0.77)with poor predictive power.Part two:90 patients completed the pulmonary function test,30 cases of BPD group,30 cases of non-BPD group,30 cases of full-term children group,including 15 cases of mild BPD group,15 cases of moderate-severe group.(1).General situation comparison: There was no significant difference between BPD group and non-BPD group in GA,BW,body length,weight and height at follow-up(P>0.05).(2).Respiratory infections and rehospitalization times:The number of respiratory infections,pneumonia,wheezing and rehospitalization in the BPD group were more than those in the non-BPD group(P<0.05).Respiratory tract infection,pneumonia,wheezing and rehospitalization were more frequently in moderate and severe BPD group than in non BPD group and mild BPD group and term infant group(P<0.05).With the increase of age,the time of respiratory tract infections and re-hospitalization decreased gradually.(3).Pulmonary function indicators : BPD group was lower than those in the non-BPD group in VT/Kg,TPTEF/Te,and VPTEF/Ve(P<0.05);RR in the BPD group was higher than that in the non-BPD group(P<0.05);With the degree of BPD gradually increases,VT/Kg,TPTEF/Te,and VPTEF/Ve gradually decreased.(P<0.05);TEF25 was higher in the full-term infant group than in the non-BPD group,mild BPD group and the moderate-to-severe BPD group(P<0.05).Pulmonary function parameters of different groups changed with age: VT/Kg,TPTEF/Te,and VPTEF/Ve in moderate-severe BPD group were lower than those in mild BPD group,non-BPD group,and full-term infant group when the child was less than 1 year old.RR in moderate-severe BPD group was higher than that in mild BPD group,non-BPD group,and full-term infant group(P<0.05);TEF75 and TEF50 in 12-24 months and 24-36 months were higher than <6 months and 6-12 months(P<0.05),there was no difference between 12-24 months and 24-36 months(P>0.05);With the age increasing,TEF25 gradually increased(P<0.05).(4).Comparison of different groups of TBFVL:TBFVL in patients was relatively smooth in inspiratory phase,approximately half an ellipse.With the increase of BPD,the expiratory peak moved forward,the expiratory curve was less smooth,the lower the expiratory branch was,the steeper the slope was.Part three: 57 cases infants completed Gesell scale test,including 22 cases of BPD,15 cases of non-BPD,11 cases of mild BPD,11 cases of moderate-severe BPD and 20 cases of full-term children.(1).Comparison of general situation: There were no significant difference between BPD group and non-BPD group in age,GA,BW and length,height and weight at follow-up(P>0.05).(2).Comparison of DQ in different energy regions of different groups: The DQ values of gross movement,fine exercise,physical performance,verbal ability,and energetic ability in BPD group was lower than non-BPD group(P<0.05).The DQ values of fine exercise,physical performance,verbal ability,and energetic ability in moderate-severe BPD group were lower than that in non-BPD group and mild BPD group(P<0.05).There was no significant difference in the gross exercise between the moderate and severe BPD group and the mild BPD group(P>0.05).(3)Comparison of developmental outcomes in different groups:There were no significant difference between BPD group and non-BPD group in the abnormal rates of developmental outcomes(P>0.05).The abnormal rate of development outcomes in moderate-severe BPD group was higher than that in non-BPD group,mild group and full-term infant group(P<0.05).Conclusion:Part one :The incidence of BPD in preterm infants with a hospital stay more than 28 days in our department was 12.0%.The incidence of BPD was significantly decreased with the increase of GA and BW in preterm infants.Fi O2≥40%,Type II respiratory failure,transfusion≥3 times and oxygen inhalation time were independent risk factors of BPD,the oxygen inhalation time is the best risk factor for predicting BPD.The prediction model constructed by factors can better predict the occurrence of BPD.Fi O2≥40% is a risk factor for the severity of BPD.It can predict the severity of BPD in the early stage and predict poor prognosis.Part two:The number of respiratory infections and rehospitalization in BPD preterm infants was significantly higher than that of non-BPD preterm infants,the more severe BPD,the more times of respiratory infection and rehospitalization.With increase of the age,the number of respiratory infection and rehospitalization gradually decreased.The obstruction of small airway was significantly worse than that in non-BPD preterm infants.The heavier the degree of BPD,the more severe the obstruction of small airways,especially within 1 year of age.with increase of the age,lung capacity gradually increased,small airway obstruction is better than the younger group.TBFVL can directly reflect the characteristics of tidal lung function in children with different degrees of bronchopulmonary dysplasia.Part three: Premature children’s neurodevelopmental behavior was worse than full-term children;The DQ values of gross movement,fine exercise,physical performance,verbal ability,and energetic ability in BPD group was lower than non-BPD group.The moderate-to-severe BPD was slower than mild BPD in fine motor,physical performance,verbal ability and response ability.The preterm infants with moderate to severe BPD have a higher rate of neurodevelopmental abnormalities than non-BPD and mild BPD preterm infants.