Application Of Pulmonary Ultrasound In Children With Community-acquired Pneumonia

Objective:To study the application of lung ultrasound（LUS）in the diagnosis and condition assessment of community acquired pneumonia（CAP）in children.Content and Methods:133 children with community acquired pneumonia who were hospitalized in department of pediatrics of Fujian Provincial Hospital from January 2019 to January2021 were selected,75 cases were male（56.4%）and 58 cases were female（43.6%）.The age of children ranged from 1 month to 13 years old,and the median（P25,P75）was 4.00 years old（2.00,6.00）.133 children were taken by chest X-ray（CXR）and LUS within 24 hours before and after admission.21 cases with severe pneumonia were further evaluated by computed tomography（CT）scans.The result of CT scan was considered as a gold standard,compared with LUS and CXR,we studied the clinical value in diagnosis rate of lung consolidation.Correlation between LUS score and clinical indicators was analyzed by the LUS results.All of the children were divided into mild and severe group.The differences of LUS score and lung consolidation area were compared between two groups.According to the characteristic（ROC）curve,we determined cut-off point of the LUS score and the consolidation area to evaluate the mild and severe pneumonia,as well as determined the sensitivity and specificity of the cut-off point for the diagnosis of severe pneumonia of children.There were 22 children diagnosed as mycoplasma pneumoniae pneumonia,25 children diagnosed as bacterial pneumonia and 25 children diagnosed as viral pneumonia by the result of pathogens.The LUS score and lung consolidation area were compared among the three groups,the differences of LUS features were analyzed among the three group.Results:1.119 children were diagnosed as pneumonia by CXR,the positive diagnosis rate was 89.4%;108 children were diagnosed with pneumonia by LUS,the positive diagnosis rate was 80.9%;There was no difference in the diagnostic rate of CAP by the LUS and the CXR（P>0.05）.2.For the diagnosis of lung consolidation,74 of total 133 cases were diagnosed as lung consolidation by LUS（55.6%）,39 cases were diagnosed as lung consolidation by CXR（29.3%）,there were statistical differences in the diagnosis of lung consolidation by the LUS and CXR（P<0.05）.7 cases were diagnosed pleural effusion by LUS（6.6%）,8 cases were diagnosed pleural effusion by CXR（7.5%）.There was statistical difference between them（P<0.05）.107 cases were diagnosed exudative lesions by LUS（80.4%）,and 133 cases were diagnosed exudative lesions by CXR（100%）,CXR is better than LUS in the diagnosis of pulmonary exudative lesions.3.CT scan was used as a gold standard,the sensitivity of LUS to diagnose lung consolidation was 92.9%,the specificity was 28.6%,positive predictive value was72.2%,negative predictive value was 66.6%.Diagnostic coincidence rate was 71.4%in identifying lung consolidation.The sensitivity and specificity of CXR for diagnosing lung consolidation was 42.9%and 57.1%,positive predictive value was66.6%,negative predictive value was 33.3%,and diagnostic coincidence was 47.6%.LUS was better than CXR in the diagnosis of lung consolidation in children with CAP（P<0.05）.4.According to analyse the related factors affecting LUS score.The fever duration admitted was correlated with LUS score（P<0.05）with a correlation coefficient of 0.362.Blood C-reactive protein（CRP）at admission was correlated with LUS score（P<0.05）with a correlation coefficient of 0.243.The hospitalized days was correlated with LUS score（P<0.05）with a correlation coefficient of 0.313.There was no correlation between pulse oxygen saturation（Sp O₂）,white blood cell count（WBC）,lactate dehydrogenase（LDH）and LUS score（P>0.05）.5.Median（P25,P75）of LUS score in the severe pneumonia group was 8.000（4.000,9.000）and it was 4.000（1.000,8.000）in the mild pneumonia group.LUS scores of pneumonia in the two groups were different（P<0.05）.By drawing receiver operating characteristic（ROC）curve,LUS score of 6.5 was used as the cut-off point,the sensitivity for diagnosing severe pneumonia was 57.9%,the specificity was 71.1%.Area under curve（AUC）was 0.654（0.518,0.790）.Median（P25,P75）of pulmonary consolidation area in severe pneumonia group was 5.110（0.000,9.285）cm²,and that of mild pneumonia group was 0.085（0.000,3.125）cm².The difference was significant（P<0.05）.The lung consolidation area of 4.555cm² was used as the cut-off point,the sensitivity was 57.9%,specificity was 80.7%and AUC was 0.678（0.541,0.815）for diagnosing severe pneumonia by drawing ROC.6.Median（P25,P75）of LUS score of mycoplasma pneumoniae pneumonia group was 5.50（2.50,8.00）,4.00（1.00,8.00）in bacterial pneumonia group and 2.00（0.00,5.00）in viral pneumonia group.There was no statistical difference among three groups（P>0.05）.In the mycoplasma pneumonia group,there were 15 children（68.1%）had lung consolidation by LUS;12 children（48.0%）in the bacterial pneumonia group;6cases（24%）in the viral pneumonia group.There was no significant difference between the mycoplasma pneumonia group and the bacterial pneumonia group（P>0.0167）.The pulmonary consolidation rate of the mycoplasma pneumoniae pneumonia group was higher than that of the viral pneumonia group,there was statistical difference（P<0.0167）.There was no significant difference between bacterial pneumonia group and viral pneumonia group（P>0.0167）.Median（P25,P75）of pulmonary consolidation area was 1.4700（0.0000,10.4175）cm² in the mycoplasmal pneumonia group,2.6650（0.4225,12.0500）cm² in the bacterial pneumonia group,and 0.0000（0.0000,2.6650）cm² in the viral pneumonia group.There was no significant difference between the mycoplasma pneumoniae pneumonia group and the bacterial pneumoniae group（P>0.0167）.The pulmonary consolidation of the mycoplasma pneumoniae pneumonia group was higher than that of the viral pneumonia group（P<0.0167）.There was no statistical difference between the bacterial pneumonia group and the viral pneumonia group（P>0.0167）.Conclusion:1.There was no difference between LUS and CXR for diagnostic rate of CAP,but LUS reduced radiation side effects in children compared with radiological examination.There was clinical significance for diagnosis of CAP in children.2.The diagnostic rate of LUS for lung consolidation was higher than that of CXR,and we can calculate the consolidation area by LUS,there was great clinical significance for the assessment and follow-up of CAP.3.There was a certain correlation between LUS score and fever days admited,blood C-reactive protein and hospitalized days,and there was clinical significance for the assessment of the condition and prognosis of children with CAP.4.LUS score and lung consolidation area were helpful for the screening of children with severe CAP.5.The incidence of lung consolidation in mycoplasma pneumoniae pneumonia group were higher than that of viral pneumonia group.