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General Approach to Chest Trauma
 

  • examine the chest immediately after the airway is controlled

  • Inspect for open wounds, tenderness, crepitance, unequal respiratory motion

  • Listen to breath sounds

  • If a life-threatening injury is discovered during this examination, treat it before going on.

  • Following any intervention, reexamine the chest to determine the effects of treatment.

  • Obtain a chest x-ray on every patient who has suffered significant trauma.

  • Severe internal injury may be present without external tenderness.

  • Repeat the chest x-ray following any invasive intervention — for example, after intubation, CVP catheter placement, or chest tubes.

  • The presence of respiratory distress is ominous. About 50% of trauma patients presenting to the emergency department in respiratory distress will die. If both respiratory distress and shock are present, 75% will die.

  • Any patient with continued respiratory distress requires intubation. If tension pneumothorax has been ruled out, pulmonary contusion is the likeliest cause of respiratory impairment. If in doubt about whether intubation is truly required, intubate.

 

Myocardial Contusion

Fractures of the sternum are often associated with myocardial contusions, but cardiac injury can be seen without severe anterior chest injury. Myocardial contusion is a physical bruising of the cardiac muscle. The patient is prone to all the complications possible with acute myocardial infarction. Virtually all patients with chest pain following blunt trauma should have an ECG.

  • Clinical Findings: A high level of suspicion must be maintained. A tachycardia out of proportion to other injuries may be the only clue. A friction rub may be present.

  • Diagnosis: ECG may show ST elevation, or may be normal. Initial cardiac enzymes may be normal. If no other injuries requiring hospitalization are present, the decision to hospitalize the chest-injury patient to rule out myocardial contusion must be based on the clinical picture — for example, the presence of substernal pain or a bent steering column.

  • Treatment: These patients should be hospitalized for cardiac monitoring and serial enzyme determinations.

Flail Chest

Flail chest results when multiple rib fractures allow the chest wall to become unstable. As the patient breathes in, the negative pressure “sucks in” the unstable segment. This is usually not harmful until increased ventilatory pressures are required, as with partial airway obstruction or underlying pulmonary contusion. As the patient’s pulmonary condition worsens, the paradoxical rib motion becomes more severe, making respiration inefficient. The unconscious patient, who does not use the chest wall muscles to “splint” the injured area, will have a more pronounced flail effect.

  • Clinical Findings: Immediately after the injury, little paradoxical motion will be apparent. Crepitance of broken ribs is usually obvious on palpation. As the patient’s lungs stiffen, inward motion of the ribs will become more pronounced with inspiration. Hypoxia is usually not present unless there is underlying lung injury.

  • Diagnosis: Rib fractures will be seen on x-ray, but the diagnosis is made on clinical grounds by observing paradoxical motion of a segment of the chest wall.

  • Treatment: A large flail segment may be temporarily stabilized with towel rolls, tape, or sandbags placed against it. Intubation and ventilator support is required for all patients with large flail segments (bigger than 4-6 inches), and for any patient with underlying acute or chronic lung disease. When in doubt about whether intubation is needed, intubate.



Sucking Chest Wounds

An open wound allows air to be sucked into the chest with inspiration. If large enough, it may interfere with air motion in the lungs by decreasing the amount of negative pressure that can be generated during inspiration. Small wounds can form one-way valves, leading to tension pneumothorax.

  • Clinical Findings: An open chest wound will usually exhibit some unusual motion during respiration, such as retraction, shaking, or burping. Larger wounds will result in obvious air motion. This can usually be heard and felt, however the sound of air moving through the chest wound may not be obvious in a noisy emergency department.

  • Diagnosis: The diagnosis is made on clinical inspection of the wound. X-ray will show a pneumothorax, but action must be taken before the x-ray.

  • Treatment: The wound should be covered with an occlusive dressing such as Vaseline gauze covered by 4x4’s. Tape the dressing on three sides, so it can act as a one-valve — allowing air to exit the chest with expiration, but preventing sucking-in during inspiration. A chest tube should be placed at a second site. The wound itself is not used for the tube (even if its size is perfect) because of contamination.



Pulmonary Contusion

Bruising of the lung results from passage of a shock wave through the tissue. Microscopic disruption occurs at any air-tissue interface — of which the lungs have plenty. Injuries involving high velocity rather than slow crushing are more likely to cause pulmonary contusion.

  • Clinical Findings: Rales will often be heard. The chest x-ray shows opacity in the peripheral lung near to the injured chest wall. The chest x-ray may lag 12-24 hours behind the clinical extent of the contusion. Blood gases will tend to worsen for two or three days as edema increases in the lung. Stiffness of the lung causes dyspnea and elevated respiratory rate.

  • Diagnosis: The diagnosis is made when parenchymal infiltrate is seen adjacent to injured chest wall. Pulmonary contusion may exist, however, despite a normal x-ray.

  • Treatment: Treat milder cases with oxygen and observation. If respiratory distress is present, intubation and mechanical ventilation are beneficial while the lung recovers. Be aggressive in treating patients who have pulmonary contusion combined with severe abdominal injuries or COPD.



Hemothorax

Blood in the chest is most commonly due to lung injury. In these cases it will usually be mild. Massive hemothorax is most often due to bleeding from the major central chest vessels, but occasionally an intercostal artery can bleed sufficiently to cause a large accumulation of blood.      

  • Clinical Findings: Breath sounds will usually be decreased on the affected side. Hemothorax is distinguished from pneumothorax by dullness on percussion.


  • Diagnosis: Hemothorax should be suspected on finding unilateral decreased breath sounds and dullness to percussion. Chest x-ray may confirm the diagnosis, but an upright or decubitus film is often necessary. Up to a liter of blood may be present, and not seen, on a standard portable supine chest x-ray.


  • Treatment: Remove the blood of a moderate-sized hemothorax by chest tube, even if the blood accumulation is not enough to interfere with respiration. As thrombolytic substances are released by the old blood, bleeding often continues. Placement of a chest tube also serves to tamponade bleeding by bringing the lung surface up against the chest wall. The tube must be large (36-40), and should be aimed posteriorly. Most cases of hemothorax do not require operation unless bleeding continues.



Pneumothorax

Accumulation of air within the pleural space may compromise respiration by interfering with the expansion of the lung. Respiratory distress usually is not seen until the pneumothorax exceeds 40% of one lung’s volume, unless the patient has pre-existing lung disease or parenchymal lung injury. If pressure increases within the pleural space (tension pneumothorax), venous return to the chest slows, and shock develops. Pneumothorax is usually due to blunt rupture of the lung surface, rather than laceration by broken ribs.

  • Clinical Findings: Breath sounds will be decreased on the affected side. Pleuritic pain may not develop for hours. If the pneumothorax is large, hyperresonance to percussion may be present. Respiratory distress, shock, unilateral absence of breath sounds, and hyperresonance to percussion indicate tension pneumothorax.

  • Diagnosis: Diagnose pneumothorax from chest x-ray by observing a pleural stripe that has fallen away from the chest wall, with absence of lung markings beyond the stripe. A very small pneumothorax may not be visible on x-ray. Tension pneumothorax must be diagnosed on clinical grounds, as the physician must intervene before an x-ray can be taken. On finding the triad of respiratory distress, shock, and unilateral absence of breath sounds, a needle should be inserted in the second intercostal space anteriorly. The hiss of escaping air establishes the diagnosis.

  • Treatment: A very small (less than 1-2 cm) pneumothorax in an otherwise healthy individual can be observed without treatment if it remains stable on subsequent x-rays (6-8 hours later). Otherwise, evacuate the pneumothorax by chest tube insertion.




Cardiac Tamponade

Pericardial blood is usually due to penetrating injuries of the heart. In those cases that are not rapidly fatal, the pericardium may seal. The increasing pressure in the pericardial space prevents further bleeding from the cardiac wound. This pressure prevents the heart from filling completely, and obstructive shock can occur.

  • Clinical Findings: All patients in shock with a penetrating wound of the chest have cardiac injury until proven otherwise. Abdominal stab or gunshot wounds also may reach the heart. The classic triad of distended neck veins, low blood pressure, and muffled heart tones is present in less than a third of patients. Neck veins may not be distended if hypovolemia is present, and muffled heart tones are often not present. Pulsus paradoxus (a 10-15 mm drop in systolic blood pressure with inspiration) may be present.

  • Diagnosis: Suspect the diagnosis with penetrating injury and shock, or with blunt trauma and shock that does not respond to fluid resuscitation (and in which tension pneumothorax is ruled out). X-rays are usually normal. The diagnosis is established by aspirating non-clotting blood via pericardiocentesis.

  • Treatment: Pericardiocentesis may improve blood pressure with removal of as little as 5-10 mL of blood. Leave the catheter in place until the cardiac wound can be repaired.




Aortic Rupture

About 90 percent of patients with aortic rupture die within minutes, and of those who arrive at the hospital alive, another 90% will die. Most ruptures are due to auto accidents, with the site of rupture just beyond the left subclavian artery near the ligamentum arteriosum. The mechanism of injury is sudden motion of the heart and great vessels within the thorax, rather than direct crushing. Many patients will therefore have little external evidence of serious chest trauma.

  • Clinical Findings: Physical exam findings are rarely helpful. Weak leg pulses with hypertension in the arms, or a new murmur may suggest the diagnosis. Aortic rupture is more likely in patients with 1st or 2nd rib fractures.

  • Diagnosis: Order aortography when you suspect the diagnosis based on chest x-ray or physical exam findings. Chest x-ray may show deviation of the NG tube 1-2 cm to the right or blurring of the aortic knob. A widened upper mediastinum, deviation of the trachea to the right, a “pleural cap,” or loss of the clear space between the aorta and pulmonary artery may also suggest the diagnosis.

  • Treatment: Rapid fluid resuscitation while awaiting surgical repair.

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