A 50-year-old woman with gradual deterioration of oxygenation after lung transplantation.

(CHEST 1999; 115:267–268) A 50-year-old woman develops a gradual deterioration in oxygenation shortly after single lung transplantation. This patient, with alpha-1-antitrypsin deficiency, undergoes right lung transplantation for emphysema. The surgery performed through a right thoracotomy is uncomplicated and the patient is transferred to the ICU for recovery. Shortly after arrival, the nurses notice a gradual but persistent deterioration in her oxygenation. Pulmonary artery balloon flotation catheter readings show a pulmonary artery balloon occlusion pressure of 10 mm Hg. The chest tubes are draining serosanguinous fluid without gross blood. A chest roentgenogram is obtained (Figure 1). The most likely cause of the patient’s problem is: