A 22-year-old man complains of shortness of breath and chest pain after a motorcycle crash. He is breathing spontaneously but has decreased breath sounds on the left side. His respiratory rate is 40; his heart rate is 115 beats per minute (bpm); and he has an oxygen saturation of 82% on a non-rebreather mask.
Motor vehicle crash is the most common etiology of thoracic trauma. Rib fractures occur in about 10% of blunt trauma patients and can indicate injuries to the underlying lung parenchyma, pleura, or abdominal viscera. Among patients with rib fractures, flail chest occurs in about 5% of all trauma patients and confers significant morbidity secondary to the underlying pulmonary contusions. Rib fractures can also be seen after episodes of severe coughing, in repetitive sports (most commonly in rowing and golf), and in the setting of metastatic malignancy. Most mortality in rib fracture patients is actually related to extra-thoracic injuries, including head, craniofacial, and intra-abdominal injuries.1
Pneumothorax is a common problem in acute care surgery, occurring in up to 40% of blunt trauma patients.2 In primary pneumothorax, air can gain entry into the pleural space spontaneously from subpleural blebs, or as a result of diffuse pulmonary disease. Secondary causes of pneumothorax are numerous and include penetrating or blunt trauma, barotrauma from mechanical ventilation, thoracic procedures or instrumentation, and central venous catheter placement. Rare causes include esophageal perforation and catamenial pneumothorax secondary to pleural endometriosis.
Hemothorax occurs in up to 50% of blunt trauma cases,2 but can also result from malignancy, be iatrogenically induced, or develop spontaneously. A list of causes and examples of hemothorax is given in Table 21–1.
TABLE 21–1Underlying Causes of Hemothorax |Favorite Table|Download (.pdf) TABLE 21–1Underlying Causes of Hemothorax
|Cause ||Example |
|Iatrogenic || |
Central line placement
After thoracotomy or thoracostomy
Complication of anticoagulant therapy
|Neoplasia ||Metastatic or primary |
|Dyscrasia ||Hereditary hemorrhagic telengiectasia |
|Mechanical || |
Torn pleural adhesion
Aneurysmal disease of major or minor vessels
|Abdominal source || |
|Infectious || |
|Congenital || |
|Other || |
Rib fractures are usually uncomplicated and require no specific treatment, but they can also be associated with significant injuries, including pneumothorax, hemothorax, and pulmonary contusion. Fractures of the lower ribs can signal intra-abdominal injuries, notably of the liver and spleen. Despite traditional teaching, there is no evidence of an association between aortic injuries and first and second rib fractures.3
Flail chest refers to a free-floating segment of the chest wall secondary to consecutive rib fractures. The mobile segment moves paradoxically during respiration (e.g., inward during spontaneous inspiration) and is associated with contusions of the underlying pulmonary parenchyma that confer significant morbidity and mortality. Pulmonary contusions are essentially a bruise of the ...