Can one lung ventilation prevent air embolism in the lung injury victim?

The current literature indicates that patients with hilar lung injury who are receiving positive pressure ventilation are at risk for systemic air embolism, but no studies have yet tested an alternative to the current management: immediate thoracotomy and hilar clamping. We wanted to demonstrate that one lung ventilation of the uninjured lung protects against the formation of arterial air embolism in the presence of contralateral hilar lung injury. In 6 juvenile swine, the right bronchus was selectively ventilated, and ultrasound of the abdominal aorta was used to detect air emboli. The hilum of the left lung was stabbed with a scalpel; after a brief period of monitoring to detect air emboli, the tip of the endotracheal tube was withdrawn into the trachea and the left lung ventilated. Air emboli were detected in 2 animals. The air emboli did not form while the lung was isolated, but they did appear immediately when the endotracheal tube was withdrawn into the trachea. Air was also noted in the chambers of the heart and coronary arteries, and led to fibrillation and death. One lung ventilation appears to protect against arterial air embolism in unilateral hilar lung injury. (Curr Surg 57:349–353)