A pulmonary laceration is a chest injury in which lung tissue is torn or cut. An injury that is potentially more serious than pulmonary contusion, pulmonary laceration involves disruption of the architecture of the lung, while pulmonary contusion does not. Pulmonary laceration is commonly caused by penetrating trauma but may also result from forces involved in blunt trauma such as shear stress. A cavity filled with blood, air, or both can form. The injury is diagnosed when collections of air or fluid are found on a CT scan of the chest. Surgery may be required to stitch the laceration, to drain blood, or even to remove injured parts of the lung. The injury commonly heals quickly with few problems if it is given proper treatment; however it may be associated with scarring of the lung or other complications. Presentation Complications Complications are not common but include infection, lung abscess, and bronchopleural fistula (a fistula between the pleural space and the bronchial tree). A bronchopleural fistula results when there is a communication between the laceration, a bronchiole, and the pleura; it can cause air to leak into the pleural space despite the placement of a chest tube. The laceration can also enlarge, as may occur when the injury creates a valve that allows air to enter the laceration, progressively expanding it. One complication, air embolism, in which air enters the bloodstream, is potentially fatal, especially when it occurs on the left side of the heart. Air can enter the circulatory system through a damaged vein in the injured chest and can travel to any organ; it is especially deadly in the heart or brain. Positive pressure ventilation can cause pulmonary embolism by forcing air out of injured lungs and into blood vessels. Causes Pulmonary laceration is a common result of penetrating trauma but may also be caused by blunt trauma; broken ribs may perforate the lung, or the tissue may be torn due to shearing forces that result from different rates of acceleration or deceleration of different tissues of the lung. Violent compression of the chest can cause lacerations by rupturing or shearing the lung tissue. Pulmonary laceration may result from blunt and penetrating forces that occur in the same injury and may be associated with pulmonary contusion. Lacerations of the lung tissue can also occur by compression of the alveoli against the ribs or spine. As with contusions, pulmonary lacerations