Beyond the Basics: Thoracic Trauma

     Signs and symptoms are:

• Open wound to the thorax
• Decreased breath sounds on the affected hemithorax
• Tachypnea
• Tachycardia
• Dyspnea
• Subcutaneous emphysema
• Deteriorating SpO₂ reading
• Frothy blood at open wound
• Other signs of respiratory distress.

     The priority in managing an open pneumothorax is to occlude the open wound to the thorax immediately upon identification. Initially occlude it with a gloved hand as soon as it is found, and, as rapidly as possible, apply an occlusive dressing taped on three sides. Plastic wrap, Vaseline gauze, aluminum foil or a commercial device like the Asherman chest seal can be used. Once the wound is sealed, proceed with standard trauma care, including establishing and maintaining an airway and ventilation, maximizing oxygenation, maintaining circulation, rapid transport and initiating an intravenous line en route to the medical facility. Carefully reassess the patient, since the open pneumothorax can develop into a tension pneumothorax, especially if an injured visceral pleura allows air to escape internally into the pleural space from the injured lung.

Flail Chest
     A flail chest is defined differently by various sources. Most define it as two or three adjacent ribs fractured in two or more places, which creates a free-floating segment within the chest wall. The flail could be anterior, posterior, or involve the sternum with fractured ribs on both sides. It typically takes a significant blunt force applied to the thorax to produce a flail segment. In patients with some type of pathology that causes the ribs to weaken, such as osteoporosis, less force may be required to create a flail chest. When such significant force is applied to the chest, the lung has a tendency to become contused. Thus, a common second injury, which may be more lethal than the flail chest, is an underlying pulmonary contusion.

     A true flail segment has the ability to move independent of the remaining chest wall. Thus, when the chest wall is expanding, the negative intrathoracic pressure will draw the free-floating flail segment inward as the remainder of the chest moves outward. As the chest wall begins to reduce its size during exhalation, positive intrathoracic pressure causes the free-floating flail segment to move outward. This abnormal chest wall movement may interfere with effective generation of intrathoracic pressure and lung inflation.

     The pulmonary contusion allows blood to seep into the alveolar-capillary interface and within the alveoli. This interferes with the ability of oxygen and carbon dioxide to cross the alveolar membrane and alveolar-capillary interface and enter into the capillary, impeding effective gas exchange.

     The flail segment and pulmonary contusion will cause respiratory compromise. Both conditions may lead to severe hypoxia and hypercarbia.

     Pain associated with the rib fractures is typically a predominant complaint, along with signs and symptoms of respiratory distress. Severe pain may cause the patient to intentionally hypoventilate, leading to hypoxia and hypercarbia. Respiratory distress, hypoxia and hypercarbia may also be associated with a large pulmonary contusion. A poor SpO₂ reading; pale, cool and clammy skin; and cyanosis may be present.

     Paradoxical movement is often thought to be the predominant sign of a flail segment. However, when ribs fracture, the intercostal muscles may spasm, causing the flail segment to be initially stabilized. Thus, paradoxical movement may be initially missed upon inspection of the chest; however, palpation will reveal the unstable segment. This is one reason why palpation of the chest is necessary during the rapid trauma assessment. As intercostal muscles fatigue, the flail segment becomes more apparent upon inspection.