Annotation for Point H
Treatment for bronchovenous air embolism demands immediate pulmonary hilar cross-clamping to prevent further propagation of pulmonary venous air.37,38 air in the apex of the left ventricle; then with an open pericardium, needle aspiration is performed to remove intracardiac air. In addition, aspiration of the aortic root may be required to alleviate any accumulated air. Vigorous cardiac massage may promote dissolution of air already present in the coronary arteries,39 and direct needle aspiration of the right coronary artery with a tuberculin syringe may be lifesaving. The production of air emboli is enhanced by the underlying physiology —there is relatively low intrinsic pulmonary venous pressure caused by associated hypovolemia and relatively high bronchoalveolar pressure from assisted positive-pressure ventilation. This combination increases the gradient for air transfer across bronchovenous channels.40 Although more often observed in penetrating trauma, a similar process may occur in patients with blunt lacerations of the lung parenchyma.