Unilateral pulmonary edema following spontaneous pneumothorax.

Two patients who developed the rare phenomenon of unilateral pulmonary edema after expansion of their spontaneous pneumothoraces are described. The edema occurs mostly in patients who have had symptoms of pneumothorax for at least 3 days and its pathophysiology may be due to decrease in surfactant activity and changes in the alveolar-capillary basement membrane. Precautions to minimize the severity of this potentially lethal complication are stressed.