Clinical analysis of pulmonary embolism in a child with Mycoplasma pneumoniae pneumonia

Abstract

To explore the essential points for diagnosis of pulmonary embolism in children with mycoplasma pneumonia. Retrospective analysis of the clinical and laboratory data of a pediatric case who developed pulmonary embolism after mycoplasma pneumonia was performed for the key points for diagnosis. A-six-year old boy was admitted with chief complaint of fever and cough for half a month, combined with chest pain and mild labored breath. Vital signs were stable. Breathing movement of the left side weakened and there was left lower lobe percussion dullness. Breath sound was found weakened in the left lung, and a few fine crackles were audible. The results of laboratory tests were as follows: mycoplasma antibody (IgM) 1:128, cold agglutinin test 1:1024, blood D dimer 14.81 mg/L; anticardiolipin antibody was positive; plasma protein C activity was 60% (normal range 70% - 130%). Pulmonary artery computed tomographic angiography revealed a mass opaque shadow in left lower lobe, the branch of left lower bronchial artery was partially obstructed. Echocardiography showed tricuspid valve mild regurgitation, estimated pulmonary pressure was 5.1 kPa. Single-photon emission computed tomography indicated that radioactivity distribution was apparently sparse in the dorsal segment, anterior basal segment, outer basal segment and inferior lingular segment of the left lung. The preliminary diagnosis on admission was mycoplasma pneumonia with pleural effusion, pulmonary embolism. Intravenous erythromycin combined with meropenem were administered. Anticoagulation therapy was initiated with low molecular weight heparin and then oral warfarin tablets. Pleural effusion disappeared soon, D dimer descended to 0.38 mg/L, and pulmonary artery pressure declined. After 3-month follow-up, anti-cardiolipin antibody was negative, plasma protein C activity recovered, and lung lesions were absorbed. When mycoplasma pneumonia is accompanied by chest pain or dyspnea and there are bloody pleural effusion, pulmonary hypertension, positive antiphospholipid antibody and elevated D dimer, pulmonary embolism should be considered. Diagnosis could be clarified by the result of pulmonary artery computed tomographic angiography.