Systemic air embolism is a rare but potentially catastrophic complication of percutaneous transthoracic needle lung biopsy.1 Systemic air embolism can occur as a result of placement of the biopsy needle tip into a pulmonary vein, thus entraining atmospheric air, or by the formation of bronchial-venous or alveolar-venous fistulous tracks. When pressure in the air containing spaces exceeds venous pressure (e.g., during coughing or positive pressure ventilation), embolization and entry of air into the left heart chambers can occur.2 Coronary and cerebral embolization can lead to cardiac and neurologic ischemia. A computed tomography scan in a 58-yr-old male who underwent a transthoracic needle lung biopsy in the prone position revealed air in the left atrium (arrow, panel A). Imaging in the right lateral decubitus position demonstrated air in the left ventricle and ascending aorta (arrow, panels B and C, respectively). Acute neurologic deterioration, bradycardia, and diffuse ST changes ensued.
Risk factors for systemic air embolism include biopsy of a central lung or cavitary lesions and coughing or positive pressure ventilation and use of hollow needles. Treatment of systemic air embolism includes supplying 100% oxygen and maintaining the patient in a right lateral decubitus and Trendelenburg position. In the right lateral decubitus position buoyant forces are hypothesized to keep air bubbles in a nondependent position away from the left ventricle outflow tract.3 Although controversy exists about the ability of buoyancy to counteract forward flow, appropriate positioning should be maintained until definitive treatment in the form of hyperbaric oxygen can be instituted. Despite aggressive resuscitative efforts, the abovementioned patient died.