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A 25-year-old man is brought the emergency room by emergency medical services (EMS) directly from the scene of a shooting. On arrival in the trauma bay he is awake and confused, but protecting his airway. He has decreased breath sounds on the right side, and a palpable femoral pulse. His vital signs are significant for tachycardia to 140, a blood pressure of 90/40, tachypnea, and an oxygen saturation of 88% on 4-L nasal cannula. A chest film shows a right-sided hemopneumothorax. A tube thoracostomy is performed with return of air and 500 cc of blood, and improvement in his mental status and vital signs.
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A complete secondary survey reveals a laceration to his right lateral neck, and gunshot wounds to the right axilla and right thigh. He has right anterior chest crepitus, and a large non-pulsatile hematoma in his right thigh.
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Trauma is a major leading cause of death in the United States and the world. Worldwide, injuries are the fifth leading cause of death overall, and the leading cause of death in those under 35 years of age.1 In 2011, nearly 5 million people worldwide died from traumatic injuries, compared with 6.8 million from all infectious diseases.2 In the United States, trauma is the fifth leading cause of death,3 and is the leading cause of death among individuals aged 1 to 44 years.
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While penetrating trauma usually constitutes only 15% of injuries incurred in the civilian sector, in some urban centers in the United States, this fraction approaches 20% to 45%.1,4 Although the incidence of stabbings and gunshots has decreased in the United States,4 higher rates of gun ownership have been associated with higher rates of suicide by firearm.5 The injury pattern of penetrating trauma tends toward more severe thoracoabdominal injuries than in blunt trauma, and about 90% of injuries to the great vessels of the thorax are caused by penetrating trauma.1 In addition, while less than 20% of deaths in blunt trauma are due to bleeding, nearly half of patients with lethal penetrating injuries bleed to death.4
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The pathophysiology of penetrating trauma depends on the energy of the injury and the type of projectile. In a study of injuries from the 1991 Gulf War, shrapnel injuries all affected soft tissue, one third caused bony injury, and only 10% caused abdominal or thoracic visceral injury.6 A stab wound imparts relatively little energy, and injury depends on the size of the weapon used. The wounding potential of bullets depends on velocity, caliber, and whether the bullet expands or not (i.e., whether or not it is jacketed). The bullet mass determines the penetration depth of the bullet, and bullet shape determines trajectory through tissues. Tissue factors, including elasticity and density, determine how the tissue will respond ...