[Clinical features and treatment of refractory Mycoplasma pneumoniae pneumonia unresponded to conventional dose methylprednisolone in children].

Objective: To analyze the clinical manifestations of refractory Mycoplasma pneumoniae pneumonia (RMPP) which unresponded to methylprednisolone in the dosage of 2 mg/(kg·d) for 3 days.

Method: Retrospective analysis was performed on the clinical data of 110 children (64 boys and 46 girls) with RMPP. The patients were divided into "effective group" and "ineffective group" according to initial effect of 2 mg/(kg·d) methylprednisolone. The clinical manifestations, laboratory examination, radiological features and bronchofibroscopic findings of the children were compared. In order to seek the reference indexes which indicate nonresponsive to 2 mg/(kg·d) methylprednisolone, an ROC curve was made, of which the diagnostic cut-off was five independent correlation factors while grouping was made according to patients' different response to glucocorticosteroid.

Result: The effective group had 86 (86/110, 78.2%) children while ineffective group had 24 (24/110, 21.8%). The ineffective group children had the following performance: 16 children (16/24, 66.7%) in ineffective group had ultrahyperpyrexia (T ≥ 40 °C), which was significantly more severe compared to those in effective group (32/86, 37.3%, P < 0.01); the levels of white blood cell (WBC) count, percentage of neutrophils count (N), C-reactive protein (CRP), serum ferritin (SF), alanine transaminase (ALT), lactic dehydrogenase (LDH), creatine kinase isoenzyme (CK-MB) and fibrinogen (Fib) in ineffective group were significantly higher than those in effective group(P < 0.01); while percentage of lymphocyte count (L) was lower than that in effective group(P < 0.01). Proportion of mixed infection in ineffective group was higher than that in effective group (33.3% vs. 4.7%). Radiological manifestations: It was more frequently seen in ineffective group that chest CT scan indicated high density consolidation in no less than a whole pulmonary lobe and pulmonary necrosis (41.7% vs. 0%). Abundant secretions blockage (45.0% vs. 16.9%) and mucosal necrosis (37.5% vs. 8.1%) on bronchofibroscopy were more frequently seen in ineffective group. The critical values of the five independent correlation factors were CRP 110 mg/L, SF 328 mg/L, LDH 478 IU/L, N 0.78, L 0.13.

Conclusion: Treatment with 2 mg/(kg·d) methylprednisolone can improve clinical symptoms and radiological manifestations of most children with RMPP quickly, but it may be ineffective in some situations such as lasting high fever or ultrahyperpyrexia for more than 7 days, CRP ≥ 110 mg/L, N ≥ 0.78, L ≤ 0.13, serum LDH ≥ 478 IU/L, SF ≥ 328 µg/L, chest CT scan indicating high density consolidation in more than a whole pulmonary lobe involved and moderate-abundant pleural effusion.