Bronchial asthma is the most common chronic airway disease in childhood characterized by chronic airway inflammation and airway hyperresponsiveness.The assessment of small airway function plays an important role in the diagnosis and management of asthma.This article will describe the definition of small airways, pulmonary function testing and their application in the clinical diagnosis and management of asthma.

Refractory mycoplasma pneumoniae pneumonia(RMPP) is a common type of community-acquired pneumonia in children which seriously influence children′s physical and mental health.There is no uniform diagnostic criteria.The clinical manifestations were fever, cough and other clinical symptoms 7 days after regular application of macrolides.Lung imaging showed progressive exaceration.Some patients are not treated timely because of lack of specific diagnostic criteria and left pulmonary sequelae eventually, which affect the quality of life seriously.Related researches of RMPP are emerging in recent years.This paper reviews the laboratory diagnosis, pathogenesis, clinical features and treatment of RMPP.

Objective To improve the pediatrician's understanding of severe combined immunodefi-ciency disease (SCID),so as to strengthen the early diagnosis and treatment of SCID. Methods The clinical manifestations,related immunological findings,imaging findings and outcomes of 10 SCID children admitted to our hospital from 2007 to 2018 were retrospectively analyzed. Results The clinical manifestations of primary SCID were frequent infections shortly after birth. There were 8 males and 2 females in this study. The average age of onset was 4. 2 months,and the average age of diagnosis was 6 months. Eight cases of thymus shadow were absent,9 cases of pulmonary CT showed severe pneumonia,and 3 cases of pulmonary fungal infection. Six of 7 children died of infection and the age of death was less than 1 year old. Laboratory exami-nation showed that 10 patients had abnormal cell and humoral immune function;10 cases of CD3 +T cells were <20%,3 cases of CD16 +CD56 +( NK%) >85%,7 cases ≤ 2%. There was an increase in B cell reactivity of 7 cases,but the secretion of immunoglobulin in 5 cases was significantly reduced. Seven cases of IgG<2. 0 g/L,3 cases>2. 0 g/L. Eight cases were confirmed of the primary SCID by genetic testing. Con-clusion The clinical manifestations of SCID are frequent bacterial,viral and fungal infections in a short time after birth. In clinical work,when small infants are repeatedly infected after birth,or multiple sites are serious-ly infected and prolonged,we must think of the possibility of SCID and timely related immune function tests, strive to achieve early diagnosis,timely treatment,and early bone marrow stem cell transplantation.

The chest tightness variant asthma (CTVA)is a new clinical variant of asthma,with chest tightness or sighing respiration as the main or only clinical manifestations,without wheezing,shortness of breath and other typical symptoms of asthma. And the patients with CTVA are likely to be misdiagnosed in clinical work. The clinical features are chest tightness existed persistently or repeatedly,symptoms lasting more than 8 weeks,the presence of airway hype-rresponsiveness or reversible airflow limitation confirmed by lung function examination,effective to the treatment of β agonists or inhaled corticosteroids,and other diseases should be excluded.

Objective To analyze the characteristics of airway hyperresponsiveness and fractional exhaled ni-tric oxide (FeNO)in children with chest tightness variant asthma (CTVA)in comparison with cough variant asthma (CVA)and the typical asthma. Methods From January 2012 to June 2015,37 atypical asthma children with chest tightness as the sole presenting manifestation were selected as subjects (CTVA group). Meanwhile,100 children who were newly diagnosed as CVA and 100 children who were newly diagnosed as typical asthma were selected as control group. All of the children in 3 groups had completed FeNO measurement,spirometry and with either positive result of bronchial provocation test or positive result of bronchial dilation test. The differences in FeNO and spirometry data among 3 groups were analyzed. Results FeNO was 11. 0(6. 0,33. 0)ppb in CTVA group,but 28. 0(16. 0,52. 0) ppb in typical asthma group,which indicated that FeNO was significantly lower in CTVA group than that in typical asth-ma group (P < 0. 05). The accumulated provocative dose of methacholine resulted in a 20％ (PD20-FEV 1 )drop in forced expiratory volume in 1 second (FEV 1 ),which was 0. 480(0. 145,0. 663)mg in CTVA group and 0. 180 (0. 097, 0. 463)mg in typical asthma group. PD20-FEV 1 was significantly higher in CTVA group than that in typical asthma group,and the difference was statistically significant(P < 0. 05). FeNO was 18. 5(8. 0,34. 0)ppb and PD20-FEV 1 was 0. 330(0. 120,0. 730)mg in CVA group,which had no statistically significant differences between CTVA group and CVA group(all P > 0. 05). Conclusion CTVA children have lower airway hyperresponsiveness and lower FeNO than typical asthma children. CTVA children may have similar airway hyperresponsiveness as CVA children.

Objective To investigate the effects of mycoplasma pneumoniae(MP)infection on the exhaled nitric oxide level and lung function in asthmatic children,analyze the correlation between exhaled nitric oxide level and lung function and to provide reference for the treatment and monitoring of asthmatic children.Methods Sixty-eight children aged from 5 to 13 years old with mild or moderate asthma during June 2011 to January 2013 were collected.MP-IgG antibody,MP-IgM antibody,MP-DNA,total serum IgE,FeNO measurement and spirometry were examined on the next day morning.They were divided into two groups according to the pathogen:ashtma with MP group and ashtma without MP group.Then the levels of nitric oxide level and lung function indicators between the two groups were analyzed.Results The FeNO level in ashtma with MP group was significantly higher(P<0.05).There were no differences between two groups in lung function parameters such as FVC,FEV1,FEV1 / Vcmax,MEF25 and MEF50(P>0.05),but differnces were found in MEF75 and PEF(P<0.05).No correlation was found between FeNO levels and lung function parameters(FVC,FEV1,FEV1/Vcmax,MEF50,MEF25,MEF75 and PEF).Conclusion In asthma children with MP infection,the FeNO level was significantly increased and no correlation was found between FeNO levels and lung function.

Objective To study the characteristics of pulmonary function in atypical asthmatic children with chest tightness or sighing breath as the sole presenting manifestation,and explore the diagnostic values of fractional exhaled nitric oxide (FeNO) for the atypical asthma.Methods Seventy-nine atypical asthmatic children with chest tightness as the sole presenting manifestation during January 2012 to June 2015 were selected as subjects.All of the subjects performed spirometry,FeNO measurement,total serum IgE and specific IgE determination on their first visit,and with either positive bronchial provocation test or positive bronchial dilation test.As well as 100 healthy children who perfomred FeNO measurement were selected as control group during the same period.The pulmonary function data and FeNO values were analyzed in children who were finally confirmed as atypical asthma.Results In atypical asthma children,the abnormal rate of forced expiratory flow 50％,75％ (FEF50,FEF75) and maximum mid-expiratory flow (MMEF) were 27％,43％ and 33％.Methacholine provocation dose causing a 20％ fall in FEV1 (PD20-FEV1) were 0.41 (0.19 ～0.67)mg and were positively related with MMEF(r =0.301,P =0.007).FeNO concentration in atypical asthma patients were 13.0 × 10-9 (7.0 ×10-9 ～24.0 × 10-9),higher than that in control group(P ＜0.05).Significant correlations were found between FeNO and total serum IgE (r =0.672,P =0.001).No correlations were found between FeNO and FEV1 (P ＞0.05),between FeNO and FEV1/FVC％ (P ＞0.05) or between FeNO and PD20-FEV1 (P ＞0.05).The diagnostic values of FeNO for the atypical asthma were analyzed using the receiver operating characteristic curve,the area under the curve was 0.600.Conclusion The characteristics of pulmonary function in atypical asthma are hypofunction mainly in small airway and patients with lower MMEF had higher airway hyperresponsiveness.The diagnostic values of FeNO in atypical asthma are limited.

Objective To observe the clinical efficacy and safety of GINA regimen and GINA regimen combined with oral Huaiqihuang granule in the treatment of children with bronchial asthma.Methods A ran-domized,single blind,multicenter,parallel controlled clinical trial wascarried out.A total of 1 128 patients with bronchial asthma in children were randomized into two groups.The observation group were treated with GINA regimen combined with oral Huaiqihuang granule.The GINA regimen treatment group was treated by GINA reg-imen.Clinical assessment and C-ACT scores was observed in first month,third month,sixth month after treat-ment.Clinical assessment included the times of upper respiratory tract infection occurrence,bronchitis and pneu-monia,asthmatic attacks,application of emergency medicine,hospitalizations due to asthmatic.Drug adverse effect in the two groups was compared.Results The times of upper respiratory tract infection,bronchitis and pneumonia,asthmatic was significantly decreased(P <0.05 ),and C-ACTscores were significantly higher(P <0.05)in the first month,the third month,and the sixth month after treatment.There were 16 cases of drug relat-ed adverse reactions.Seven cases were in observation group(n ﹦7)(1.15%)and 9 cases in the GINA regimen treatment group(n ﹦9)(1.73%).There was no significant difference of adverse effect between the two groups (P >0.05).Conclusion The treatment of bronchial asthma in children with GINA regimen combined with oral Huaiqihuang granule can significantly reduce the incidence of respiratory infections and the number of asthmatic attacks dramatically and safely improve clinical curative effect,asthma control.

Objective This retrospective study was based on 1 415 cases that had been done the flex-ible bronchoscopy examination.The data were analysed to investigate the value of flexible bronchoscope in the children's respiratory system diseases diagnosis,treatment and etiological study.Methods A total of 1 415 cases who admitted from June 2012 to December 2013 were included in the study and they were all met the inclusion criteria,had complete clinical data,done bronchoscope examinations,abnormal in the broncho-scope and diagnosed definitely.The endoscopic manifestation,clinical symptoms,X-ray film,laboratory data were analysed.Results In 1 415 cases,55.4% were boy,and 55.5% were younger than 5 years.Two cases (0.14%)were laryngeal cartilage soften,one case(0.07%)was epiglottic cyst,3 cases(0.21 %)were tra-cheomalacia,25 cases(1.8%)were bronchial foreign bodies,20 cases(1.4%)were tracheal bronchus de-formity,8 cases(5.7%)were tracheal stenosis,two cases(0.14%)were bronchial bridge,5 cases(0.35%) were bronchiolitis obliterans,6 cases (0.42%)were bronchiectasis,one case(0.07%)was immotile cilia syndrome,10 cases (0.71%)were bronchial tuberculosis,one case (0.07%)was aspergillosis,one case (0.07%)was pulmonary hemosiderosis,2 cases (0.14%)were pulmonary arteriovenous fistula,9 cases (0.63%)were plastic bronchitis,1 316 cases(93%)were founded tracheal intima inflammation,including the 350 cases(24.7%)of edema,mucosal folds form,279 cases(19.7%)of mucus plug obstruction,176 cases(12.4%)of suppurative obstruction,355 cases(25.1 %)of tracheal mucosal erosion necrosis,156 ca-ses(1 1.1 %)of wall fibrosis,stenosis,occlusion.Mycoplasma pneumoniae was the most common pathogen dectected in alveolar lavage.We also found that mycoplasma pneumonia easily combined the infection of bac-teria.A total of 1 19(22.7%)cases were no pathogens detected.In 1 415 cases,the main adverse reaction in the operations was hypoxemia caused by airway obstruction.Conclusion Flexible bronchoscopy examination is a very safe and reliable operation in diagnosis and treatment of respiratory diseases in pediat-rics,and plays an important role in the diagnosis of congenital developmental airway diseases,detection of pneumonia patho-gens and the treatment of lobe pneumonia.

Objective To investigate the advantages of pediatric electronic fiber bronchoscope ( FBO) in the infant bronchial foreign body,discuss the clinical features of infant bronchial foreign body,lung imaging characteristics and the kinds of microscopically position,the change of airway mucosa after stimulation by for-eign body under local anesthesia in 30 cases of infant bronchial foreign body. Methods Thirty cases,aged 0 to 3 years,were collected from September to December,2014. All of them were with foreign bodies examined by FBO in pediatric bronchoscopy room in Shengjing Hospital of China Medical University. Results In all infants, 6 cases (20. 0%) without history of inhaled foreign bodies and 24 cases (80. 0%) with a record history of in-haled. In the aspects of signs:normal breath sounds with a history of no choking cough in children were 2 cases (6. 7%) ,wheezing sounds were 3 patients (10. 0%) and weakened side breath sound was 1 case (3. 3%);with a history of choking cough in children,6 cases(20. 0%) with normal breath sounds,12 cases(40. 0%) with wheez-ing,6 cases(20. 0%) with lateral breath sounds less. Lung imaging characteristics was lack of specific perform-ance:only a case of all(n=30)show foreign body directly. Otherwise,other 29 cases had no specificity. Lung em-physema in 13 cases (43. 3%) is the main characteristic,while normal imaging findings in 2 cases (6. 7%). For-eign bodies in 19 cases were in the left lung (63. 4%) and 21 cases(70. 0%) of foreign body stimulated granula-tion inside airway,necrosis sputum bolt in distal obstruction of airway occured in 5 cases (16. 7%). Inhalled time of foreign body in airway was 4. 5 [2. 8,12. 5] day and inhalled time of foreign body in airway correlation coefficient with granulation hyperplasia(r=0. 688,P=0. 000),there was a significant correlation. Main adverse reaction was low oxygen in 6 cases (16. 7%). Conclusion The diagnostic accuracy of FBO under local anesthesia on children is high-er than other methods,and the FBO bronchial foreign bodies under local anesthesia is a safe and effective method.