The Efficacy Of Bronchoalveolar Lavage And Its Influence Factors In The Treatment Of Mycoplasma Pneumoniae Pneumonia With Atelectasis

Background and Objectives:Mycoplasma pneumoniae(MP)is one of the most important pathogens of community-acquired pneumonia(CAP)in children.Traditionally,Mycoplasma pneumoniae pneumonia(MPP)was thought to be a self-limited disease.However,the incidence of severe Mycoplasma pneumoniae pneumonia(SMPP)or refractory Mycoplasma pneumoniae pneumonia(RMPP)increased significantly recent years.The effect of conventional anti-mycoplasmal therapy becomes poor,often resulting in a lot of complications,of them atelectasis is one of the most common intrapulmonary complications.Although most atelectasis will recover after infections controlled,but they tend to have a longer duration of disease,and some even have sequelae due to their extensive or persistent presence of atelectasis.Bronchoalveolar lavage(BAL)can improve airway drainage,therefore promoting infection control and lung recovery.However,not all children with atelectasis can achieve therapeutic effect through BAL.This study aimed to investigate the efficacy of BAL and its influence factors in the treatment of MPP with atelectasis.Methods:A retrospective case-control study was performed on MPP patients with atelectasis once received BAL during hospitalization in the department of Pulmonology,Children’s Hospital Zhejiang University School of Medicine from January 1,2015 to July 31,2017.Fever relieved in 48 hours and chest imaging improved in 1 week after BAL were considered to be effective.Clinical data were collected,including age,sex,blood routine,lactate dehydrogenase(LDH),cytokines,complications,fever duration before BAL,course of disease before BAL,sputum plug,atelectasis scope and its CT values of atelectasis site.Student’s t test,Mann-Whitney U-test,or chi square test were used.Results:1.General information:A total of 163 patients were enrolled,including 69 boys and 94 girls,with the ratio of 1:1.36.Their ages ranged from 6 months to 12.6 years,and the average was 6.1 years.41(25.2%)patients had extrapulmonary complications and 98(60.1%)cases had pleural effusion.148 cases(90.8%)had atelectasis within one lobe,8 cases(4.9%)in more than one lobe but on the same side,and 7(4.3%)cases located in bilateral pulmonary lobes.2.Bronchoscopic findings:All patients had mucosal congestion,edema,and a lot of secretions under bronchoscopy.Of them,57 cases had sputum plug.3.Therapeutic effect of BAL on fever:113 patients still had fever at BAL.According to whether fever was relieved in 48 hours after BAL,they were divided into effective group(66 cases)and ineffective group(47 cases).The effective group were found less sputum plug when compared with the ineffective group(33%vs57%,χ2=6.499 p=0.011).The other indices such as age,sex,fever duration before BAL,course of disease before BAL,C reactive protein(CRP),LDH,IL-2,IL-4,IL-6,IL-10,TNF-a,IFN-γ,atelectasis scope and CT value showed no significant difference between the two groups(all p>0.05).4.Therapeutic effect of BAL on atelectasis:122 cases re-checked chest imaging one week after BAL.According to whether chest imaging improved,they were divided into effective group(81 cases)and ineffective group(41 cases).The effective group showed lower CT value,IL-6 and IL-10[58±9 vs 63±8HU,21.0(1.9,48.4)vs 36.4(21.8,93.6)ng/L,4.9(3.7,9.6)vs 7.7(4.4,12.0)ng/L],with statistically significant differences(t=-2.436,p=0.017;z=-2.387,p=0.017;z=-2.009,p=0.045).However,other indices such as sex,age,fever duration before BAL,course of disease before BAL,CRP,LDH,IL-2,IL-4,TNF-a,IFN-y levels,atelectasis scope showed no significant differences between the two groups(all p>0.05).5.Comparison of related factors of sputum plug:163 patients were divided into sputum plug group(57 cases)and non sputum plug group(106 cases)according to bronchoscopic findings.The sputum plug group showed higher LDH,CRP,IL-6,IFN-y,incidence of pleural effusion and extrapulmonary complications[585(433,833)vs 369(312,588)U/L,42(19,103)vs 25(12,45)mg/L,38.8(22.1,71.3)vs 20.7(9.2,48.3)ng/L,33.1(13.5,89.3)vs 12.7(6.5,33.6)ng/L,73.7%(42/57)vs 52.8%(56/106),40.4%(23/57)vs 17.0%(18/106)],with statistically significant differences(z=-4.865,p<0.001;z=-3.435,p=0.001;z=-3.098,p=0.002;z=-3.704,p<0.001;χ2=0.010,p=0.007;χ2=0.001,p=0.001).6.Therapeutic effect of BAL in sputum plug group and non sputum plug group:Fewer patients showed fever relief within 48 hours after BAL in the cases with sputum plug cases when compared with those without sputum plug[44.9%(22/49)vs 68.8%(44/64),χ2=0.011,p=0.009].Fewer patients showed chest imaging improvement within 1 week after BAL in the cases with sputum plug when compared with those without sputum plug,but did not reach significant difference[56.5%(26/46)vs 72.4%(55/76),χ2=0.073,p=0.056].7.Safety of BAL:In all cases,no serious complications occurred during and after BAL.Conclusion:1.BAL has some therapeutic effect on fever or atelectasis in MPP children complicated with atelectasis.2.The formation of the sputum plug in the large airway may hamper the fever relief within 48 hours after BAL.3.The chest imaging improvement was negatively correlated with the CT value of the atelectasis lesion,and serum levels of IL-6 or IL-10.