Focal reexpansion pulmonary edema after drainage of large pleural effusions: clinical evidence suggesting hypoxic injury to the lung as the cause of edema.

BACKGROUND: The purposes of this study were to review possible causes of reexpansion pulmonary edema (RPE) and to attempt to explain atypical distributions of RPE after drainage of large pleural effusions.

METHODS: Five patients had focal RPE after routine drainage of large pleural effusions. In these cases, pleural effusion did not completely fill the hemithorax, and part or all of the ipsilateral upper lobe remained aerated. Reexpansion was accomplished by chest tube drainage with -20 cm H2O suction in four cases and by percutaneous needle aspiration without application of negative intrapleural suction in one.

RESULTS: In all five cases, RPE developed in the portion of the lung that had been collapsed but did not develop in the portion of the lung that remained aerated.

CONCLUSIONS: This suggests that hypoxic injury to the atelectatic lung, rather than mechanical stress, is the most plausible explanation for RPE.