Risk Factors And Prognosis Of Airway Mucous Plug In Children With Mycoplasma Pneumoniae Pneumonia Of Pulmonary Consolidation Or Atelectasis

Objective: To analyze the risk factors of airway mucous plug in children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis and guide clinical therapy to decrease the incidence of sequela caused by airway obstruction. To discuss the clinical characteristics and treatment of children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis who present formation of mucous plug and low rate of recovery to provide the basis for treatment and prognosis judgment.Methods:1 We conducted a retrospective study of the clinical data of 373 children with Mycoplasma pneumoniae pneumonia who received fiber bronchoscope covering the period between May 2012 and January 2014 admitted to the respiratory department of Hebei Children’s Hospital. Some cases who did not meet the inclusion criteria were removed. Based on the airway mucosal lesions seen through the fiber bronchoscope, the remaining 116 subjects were divided into the mucous plug group(n=67) and the non-mucous plug group(n=49). There was mucous plug forming that mucous secretion obstructed more than one segmental bronchi in mucous plug group, while mucosa rough, hyperemia, reductus and little secretion. Comparison was made between the above two groups in gender, age of onset, febrile course, pleural effusion, white blood cell counts, neutrophil ratio, C reactive protein, serum lactate dehydrogenase level, initial time of received macrolides and fiber bronchoscope. The indicators were analyzed by the logistic regression analysis if their results of single factor analysis showed P<0.05. Draw the receiver operator characteristic curve to assess the prediction ability of the logistic regression model.2 We conducted a retrospective study of the clinical data of 116 children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis who showed formation of mucous plug in fiber bronchoscope examinations covering the period between May 2012 and May 2014 admitted to the respiratory department of Hebei Children’s Hospital. Among of them, 67 cases were followed up 2 months. Based on the review of imaging, the selected cases were divided into two groups: the low rate of recovery group(n=30) and the control group(n=37). Comparison was made between the above two groups in gender, age of onset, febrile course, white blood cell counts, neutrophil ratio, lymphocyte ratio, blood platelet counts, C reactive protein, glutamic-pyruvic transaminase, glutamic oxalacetic transaminase, serum lactate dehydrogenase, fibrinogen, Ig A, Ig G, Ig M, mixed infection, pleural effusion, initial time of received macrolides, glucocorticoids and fiber bronchoscope. Subsequently, we drawed the receiver operator characteristic curve of the significant differences of indicators to obtain the cut-off and diagnostic accuracy.Results:1 The results of single factor analysis showed that between the mucous plug group and the non-mucous plug group, there was no statistically significant difference in gender(P=0.581). The average age of the mucus plug group was larger than the non-mucous plug group, P<0.05. In regard to the febrile course(d)(the median and interquartile range) [11.0(10.0, 12.0) vs 8.0(7.0, 11.0), P<0.001), serum level of C reactive protein(mg/L) [54.0(30.8, 88.0) vs 20.8(10.0, 33.3), P<0.001), serum lactate dehydrogenase levels(U/L) [402.0(316.0, 593.0) vs 299.0(250.0, 362.5), P<0.001), the proportion of the merger pleural effusion [43(64.2%) vs 14(28.6%), P<0.001], the mucus plug group were higher than the non-mucous plug group. The peripheral blood neutrophils ratio of the mucus plug group had a tendency to rise compared with the non-mucous plug group, but no statistical difference(P=0.051). But there were no significant difference in routine blood leukocyte count, the initial time of received macrolide antibiotics and fiber bronchoscope between the two groups, P values were 0.513, 0.587 and 0.951 respectively.2 The results of the logistic regression analysis showed that older than three years(P=0.013, OR=7.468), febrile course more than 10 days(P=0.004, OR=4.008), the level of C reactive protein and serum lactate dehydrogenase higher than 40mg/L(P=0.002, OR=5.408) and 350U/L(P=0.010, OR=3.633) respectively were the risk factors of airway mucous plug in children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis.3 The area under the receiver operator characteristic curve of the regression model is 0.846, P<0.846, and the regression model has above average diagnostic accuracy.4 In regard to the febrile course(d)(the median and interquartile range) [13(12, 18) vs 11(9, 12), P<0.001], neutrophil ratio(%) [(75.3±7.6) vs(62.1±10.4), P<0.001], serum level of C reactive protein(mg/L) [101.0(59.0, 137.4) vs 34.1(22.4, 56.9), P<0.001], serum lactate dehydrogenase levels(U/L) [(480.1±170.0) vs(387±104.8), P<0.05], fibrinogen(g/L) [5.1(4.7, 5.5) vs 4.4(3.9, 4.6), P<0.001], Ig M(g/L) [2.4(1.3, 3.7) vs 1.3(0.9, 1.7), P<0.01] and the proportion of the merger pleural effusion[30(100%) vs 20(54.1%), P<0.001], the low rate of recovery group were higher than the control group; while lymphocyte ratio was lower than that in control group(P<0.001).5 The initial time of received macrolides(d) [6(4, 8) vs 5(3, 6), P<0.05] and fiber bronchoscope(d) [(16.5±5.5) vs(10.9±2.5), P<0.001] in low rate of recovery group were later than those in control group.6 The critical values of five correlation factors were fever durations 11.5d, neutrophil ratio 70.7%, C reactive protein 57.2mg/L, fibrinogen 4.7g/L, initial time of received fiber bronchoscope 13.5d and the area under curve respectively were 0.828, 0.889, 0.851, 0.785 and 0.788.Conclusions:1 When the children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis are older than three years, febrile course more than 10 days, the level of C reactive protein and serum lactate dehydrogenase higher than 40mg/L and 350U/L, it may indicate the formation of mucous plug. We should give fiber bronchoscope alveolar lavage promptly, use hairbrushes or biopsy forceps to remove mucus plug and give corticosteroids to reduce immune inflammatory response, in order to reduce the sequela such as pulmonary atelectasis and bronchiolitis obliterans.2 When children with Mycoplasma pneumoniae pneumonia of pulmonary consolidation or atelectasis show formation of mucous plug, they may take two months to completely recover in some situations such as fever duration more than 11.5 days, C reactive protein≥57.2mg/L, fibrinogen≥4.7 g/L, initial time of received fiber bronchoscope later than 13.5 days and mergering pleural effusion.