[The 513th case: acute respiratory failure after bilateral lung transplantation]

A 67-year-old male had undergone bilateral lung transplantation for chronic obstructive pulmonary disease 11 months before the current presentation. He was admitted with a 5-day history of cough with sputum, and a 2-day history of fever. Computed tomography (CT) of the chest revealed rapidly progressive bilateral diffuse "ground glass" opacities. Despite anti-infective therapy and methylprednisolone pulse therapy, his condition deteriorated, necessitating endotracheal intubation with mechanical ventilation and veno-venous extracorporeal membrane oxygenation (V-V ECMO) for life support. A bedside cryobiopsy was undertaken, with pathology confirming the organizing pneumonia diagnosis. Comprehensive treatment was continued: methylprednisolone, tacrolimus for immunosuppression, and prophylactic anti-infectives. His partial pressure of oxygen in the blood by the fraction of inspired oxygen ratio and imaging findings improved gradually. ECMO support was discontinued after 2 weeks, and he was discharged 1-month later, resuming normal daily activities. At 2-month follow-up, he exhibited improved exercise tolerance. Chest CT showed bilateral upper-lobe emphysema (predominantly upper-lobe reticular shadows) and significant bilateral upper-lobe pleural thickening. After 12 months of fllow-up, a diagnosis of chronic lung allograft dysfunction was made based on imaging findings and the trajectory of pulmonary function.