Unilateral pulmonary oedema following re-expansion of pneumothorax.

Unilateral pulmonary oedema is a rare complication in the routine management of spontaneous pneumothorax. Previous reports have emphasized excessive negative intrapleural pressure, rapid re-expansion of the lungs and bronchial obstruction as major factors in the pathogenesis. We have encountered four cases, and at least one of these factors have been absent in each case. Review of the literature, and our own experience suggests that the major factor is chronic and total lung collapse resulting in hypoxia and increased alveolar-capillary membrane permeability. Other factors which may be contributory are discussed.