Prediction Of Bronchial Mucus Plug Formation In Patients With Mycoplasma Pneumoniae Pneumonia

Objectives: To find the risk factors associated with bronchial mucus plug formation and generate a predicted score using the clinical records of Mycoplasma pneumoniae pneumonia(MPP) patients.Methods: We retrospectively reviewed the clinical records of MPP patients treated with fiber optic bronchoscopy in Children’s Hospital of Soochow University between November 2011 and November 2015. Based on the airway mucosal lesions seen through the fiber bronchoscope,the patients were divided into the mucus plug group and the non—mucus plug group.Comparison was made between the above two groups in demographic, clinical, laboratory characteristics.Multivariate logistic regression was performed to identify the risk factors of mucus plug formation by the comparisons of single factor analysis showed P<0.05.Based on the OR value of significant risk factors, we create a predictied score. Draw the receiver operator characteristic curve and predicted score to assess the prediction ability of the logistic regression model.Results:1.Conforming to the selected standard was a total of 175 cases, 2 cases were excluded by the diagnosis of idiopathic pulmonary hemosiderosis, the remaining 173 cases were divided into 82 cases with mucus plug and 91 cases with non-mucus plug. In mucus plug group, there were 82 cases with pulmonary consolidation, 16 cases with pulmonary atelectasis, and 41 cases with pleural effusion.2.The average age of the mucus plug group was 2.52 ± 6.67 year-old, larger than that of the non-mucus plug group 5.42 ± 2.95 year-old,The difference between two groups was statistically significant(P<0.05), while there was no significant difference between the two groups in gender(P<0.05). The mucus plug patients had a longer fever duration, a higher peak body temperature and a higher possibility of pleural effusion. Besides, other laboratory parameters were also compared. Significant differences(P<0.05) were demonstrated in N%, PLT, CRP, LDH, CD3-CD19+, CD3+, CD3+CD4+ and CD3-(16+56)+ between the two groups.3. Multivariate logistic regression identified age, fever duration, CRP and LDH as independent risk factors for formation of mucus plug.The results of the logistic regression analysis showed that older than six year-old,fever duration more than 10 days,the level of CRP and serum LDH higher than 45mg/L and 450U/L respectively were the risk factors of airway mucus plug in children with Mycoplasma pneumoniae pneumonia. The area under the receiver operator characteristic curve of the regression model is 0.776,P<0.001, with 66.7% sensitivity and 76.7% specificity.Based on the OR value of significant risk factors, we assigned 1 point for age of older than six year-old, length of fever of more than 10 days and CRP of higher than 45mg/L and two points for LDH of higher than 450U/L. Using this predicted model, we identified the patients with mucus plug with 71.8% sensitivity and 78.9% specificity. The area under the ROC curve of this predicted model was 0.776.4.On the basis of the predicted score, 2 risk strata were identified: low risk, with scores of 0-3, encompassing 126 children with an incidence rate of mucus plug formation of 34.1% and high risk, with scores of 4-5, encompassing 47 children with an incidence rate of mucus plug formation of 80.9%.Conclusions:1.When the children with mycoplasma pneumoniae pneumonia are older than six year-old,fever duration more than 10 days,the level of CRP and serum LDH higher than 45mg/L and 450U/L respectively,it may indicate the formation of mucus plug,but its exact application value still needs to be further studied.2.Using predicted model, we assigned 1 point for age of older than six year-old, length of fever of more than 10 days and CRP of higher than 45mg/L and two points for LDH of higher than 450U/L. The higher the score, the greater the risk of airway mucus plugs formation in MPP.