Identify clinical factors related to Mycoplasma pneumoniae pneumonia with hypoxia in children.

Background: To analyze the clinical characteristics of Mycoplasma pneumoniae pneumonia with hypoxia in children, and identify the associated risk factors of hypoxia in MPP.
Methods: A retrospective case-control study was performed on 345 children with Mycoplasma pneumoniae pneumonia (MPP) admitted to our hospital wards from January 2017 to June 2019. They were divided into three groups, namely MPP with hypoxia, refractory Mycoplasma pneumoniae pneumonia (RMPP), and general Mycoplasma pneumoniae pneumonia (GMPP). The clinical features, laboratory findings, imaging, and management were collected and compared in the three groups.
Results: The MPP with hypoxia patients (n = 69) had longer disease duration, a higher extra-pulmonary complications rate, and more severe radiological abnormalities (P < 0.05). They also needed more complicated treatments (P < 0.05). Meanwhile, the levels of white blood cell count (WBC), C-reactive protein (CRP), lactic dehydrogenase (LDH), interleukin (IL)-6, ferritin, D-dimer, fibrinogen (FG), alanine aminotransferase (ALT) and the percentage of neutrophils in the MPP with hypoxia group were significantly higher than those in the RMPP group and the GMPP group (P < 0.05). In ROC curve analysis, the percentage of neutrophils, WBC, CRP, LDH, IL-6, ferritin, D-dimer, and ALT were contributed to identify the MPP with hypoxia patients. Multivariate logistic regression analysis revealed that ferritin> 174.15 ng/mL, IL-6 > 25.475 pg/ml, and pleural effusion were significantly associated with the incidence of hypoxia in MPP (P < 0.01).
Conclusion: MPP with hypoxia patients presented more serious clinical manifestations. Ferritin> 174.15 ng/mL, IL-6 > 25.475 pg/ml and pleural effusion were related risk factors for hypoxia in MPP.