Elevation of pulmonary artery pressure as a sign of pulmonary barotrauma (pneumothorax).

Pneumothorax occurs in approximately 25% of patients maintained on high levels of positive end-expiratory pressure. In several cases at our Institution, a sudden and rapid elevation in pulmonary artery pressure (PAP) monitored by use of the Swan-Ganz catheter accompanied the development of a pneumothorax. In the three cases described, the change in PAP was observed before a pneumothorax became otherwise clinically evident. Two of the three patients had marked restrictive lung disease associated with the adult respiratory distress syndrome and the third patient had large bilateral pleural effusions. It is postulated that the rise in PAP was related to a sudden decrease in the size of an already compromised pulmonary arterial vascular bed produced by hypoxic vasoconstriction and mechanical compression secondary to the pneumothorax. In the ICU, elevation of PAP may be a useful and early indicator of pulmonary barotrauma.